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  • 301.
    Boström, Fanny
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Experimental testing of adsorbents for H2S removal in industrial applications: A comparative study on lifetime and cost effectiveness of different materials2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Harmful emissions are a global issue and cause trouble for human health and for the environment. There is a wide variety of pollutants and one pollutant is hydrogen sulfide, H2S, that is a member of the group Volatile Sulfur Compounds. H2S is a compound that is known for its smell of rotten eggs and is detectable by the human nose at very low concentrations. At higher concentrations, H2S is highly toxic and even deadly for humans. It is also a corrosive gas, and can, therefore, cause problems for materials that are being exposed to it. This can be an issue when H2S is present in biogas since it can damage engines or pipes. It can also poison catalysts that are used for methane upgrading.

    There are different methods of removing H2S from air and common ones are to use adsorption media or catalytic oxidation for gas-solid reactions. The catalytic oxidation is oxidizing the H2S and converts it into elemental sulfur. A problem with these techniques is that they need replacement after some time when they have been saturated.

    The aim and objectives for this project are to find appropriate materials to test in a test rig that was finalized at the beginning of the project, to compare their lifetime. This was done to find the most cost effective material for H2S removal. The effect of humidity in the air was also examined.

    Eight different samples were tested. Two of these were activated carbonwithout impregnations and the other six were partial catalytic materials (impregnated carbons or metal oxide based materials). The partial catalytic materials were significantly better than the activated carbons. The lifetimes varied among the partial catalytic materials as well, andare believed to be due to different active compounds on the surfacesand the structure. When running the experiments with 70 % relative humidity, the lifetimes were significantly longer than when the same materials were run for 30 %. A lower concentration of H2S in low relative humidity showed lower or the same loading capacity than higher concentrations. Regeneration was tested for one of the metal based materials with a satisfactory result.

  • 302.
    Boujemaoui, Assya
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. 831220-7585.
    Polycaprolactone  Nanocomposites Reinforced  with   Cellulose Nanocrystals  Surface - modified  via  Covalent  Grafting  or  Physical Adsorption - a Comparative studyManuscript (preprint) (Other academic)
  • 303.
    Boujemaoui, Assya
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. 831220-7585.
    RAFT/MADIX Polymerization of Vinyl Acetate on Cellulose Nanocrystals for Nanocomposite ApplicationsManuscript (preprint) (Other academic)
  • 304.
    Boujemaoui, Assya
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. 831220-7585.
    Surface Modification of Nanocellulose towards Composite Applications2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nanocelluloses have attracted great interest during recent decades owing to their renewability, abundancy and remarkable physical and mechanical properties. The aim of this work was to investigate new strategies for surface modification and functionalization of nanocelluloses and their subsequent incorporation in polymer-host matrices.

    Nanocomposites of cellulose nanofibrils (CNF) and polycaprolactone (PCL) were produced by employing CNF nanopaper (NP) as a template and surface-initiated ring-opening polymerization (SI-ROP) of ε-caprolactone (ε-CL). SI-ROP of ε-CL from filter paper (FP) was also carried out for comparison. A larger amount of PCL was grafted from NP than from FP. The grafted NP had stronger mechanical properties than neat PCL.

    Cellulose nanocrystal (CNC)-reinforced polyvinyl acetate (PVAc) nanocomposites were also investigated. CNC were modified via “SI-reversible addition-fragmentation chain transfer and macromolecular design via the interchange of xanthate” (SI-RAFT/MADIX) polymerization of vinyl acetate (VAc). The resulting nanocomposites exhibited improved mechanical performance than the unmodified CNC.

    It is generally agreed that covalent grafting is superior to physical adsorption for the modification of a reinforcing agent. However, this hypothesis has never been thoroughly investigated. CNC was modified either through covalent grafting or through physical adsorption of poly(butyl methacrylate) (PBMA). Both methods resulted in improved mechanical performance than that of pure PCL or PCL containing unmodified CNC. However, covalent grafting gave the best mechanical performance even at high relative humidity.

    Functionalized CNC (F-CNC) were obtained through a versatile methodology employing organic acids bearing a functional group were employed for the simultaneous acid hydrolysis and esterification of cellulose fibers. This provided a facile route for the preparation of F-CNC.

  • 305.
    Boujemaoui, Assya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Mazieres, Stephane
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Destarac, Mathias
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    SI-RAFT/MADIX polymerization of vinyl acetate on cellulose nanocrystals for nanocomposite applications2016In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 99, p. 240-249Article in journal (Refereed)
    Abstract [en]

    In the present work, poly(vinyl acetate) grafted cellulose nanocrystals (CNC-g-PVAc) were prepared via surface initiated reversible addition-fragmentation chain transfer and macromolecular design via the interchange of xanthates (SI-RAFT/MADIX) polymerization. Successful grafting of PVAc from CNC was confirmed by FT-IR and TGA analysis. PVAc nanocomposites reinforced with CNC-g-PVAc, as well as pristine CNC for comparison, of different weight percentages (0.5, 1, 3 and 5 wt%) of CNC were prepared via solvent casting. The PVAc reinforced with CNC-g-PVAc resulted in higher transparency and improved mechanical properties compared with unmodified CNC nanocomposites. The addition of 5 wt% CNC-g-PVAc increased the modulus of neat PVAc with as much as 154%. The proposed SI-RAFT/MADIX on CNC could be applied to wide range of monomers, and it is believed to be an efficient and robust method for CNC functionalization, thus expanding the potential applicability of CNC.

  • 306.
    Boujemaoui, Assya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Mongkhontreerat, Surinthra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Preparation and characterization of functionalized cellulose nanocrystals2015In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 115, p. 457-464Article in journal (Refereed)
    Abstract [en]

    In this work, a series of functional nanocrystals (F-CNCs) was successfully produced by an efficient preparation method, combining acid hydrolysis and Fischer esterification with various organic acids. Functionalities such as ATRP initiators, double bonds, triple bonds, and thiols could be incorporated on CNCs. Surface modification was confirmed by FT-IR, XPS, and elemental analysis. Physical properties of FC-NCs were assessed by AFM, XRD and TGA. Moreover, ATRP initiator functionalized CNCs were utilized to graft poly(methyl methacrylate) via ATRP, thiol functionalized CNCs were reacted with Ellman's reagent to determine the thiol content and dye disperse red 13 was attached to alkyne functionalized CNCs to estimate the propiolate content. The herein presented method is a highly versatile and straightforward procedure for the preparation of F-CNCs which is believed to be a better alternative for the commonly utilized, extensive, multistep, and time consuming post functionalization methods.

  • 307.
    Boutonnet, Magali
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Lögdberg, Sara
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Elm Svensson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Recent developments in the application of nanoparticles prepared from w/o microemulsions in heterogeneous catalysis2008In: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 13, no 4, p. 270-286Article in journal (Refereed)
    Abstract [en]

    This paper reviews the use of microemulsions, especially the water-in-oil (w/o) microemulsions, for preparation of nanoparticles that are employed as catalyst components in heterogeneous catalytic reactions. The objective is to show the growing interest of using microemulsions in the preparation of different types of materials such as metals, single metal oxides or mixed metal oxides with a broad range of application in heterogeneous catalysis and also in electrocatalysis. In most cases, the catalytic material showed improved catalytic properties as a result of the special synthesis environment created by the microemulsions. Still, research is needed for a better understanding of such beneficial effects. In addition, this method needs improvements in order to produce, in an environmentally friendly way, a suitable amount of material for use in industrial-scale catalytic processes.

  • 308.
    Boutonnet, Magali
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Sanchez-Dominguez, Margarita
    Microemulsion droplets to catalytically active nanoparticles: How the application of colloidal tools in catalysis aims to well designed and efficient catalysts2017In: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 285, p. 89-103Article in journal (Refereed)
    Abstract [en]

    In this review, we report the successful application of a colloidal tool, namely microemulsions (ME) in the design of catalysts for various applications. First, a brief introduction to MEs and the water-in-oil (w/o) ME reaction method is given. The first ME formulations used for catalyst synthesis are discussed. Catalytic activity of the materials obtained from those initial studies, both as particles deposited onto a support as well as directly as nanoparticles in ME suspension is described. Then various application examples which highlight several important properties of the catalysts obtained from w/o ME are given. For example, particle size control achieved with ME is very relevant to surface sensitive reactions, whose selectivity depends greatly on metal particle size. Another important aspect is related to the unique microenvironment of MEs which results in specific interactions within the formed materials; this is particularly important for certain catalysts such as mixed oxide particles, conferring them with special properties and enhanced performance. Comparison of activity and selectivity of impregnation-prepared versus ME-prepared materials is given for several catalytic reactions. Finally, the more recently developed oil-in-water (o/w) ME method is described, along with examples of materials obtained by this method as catalysts, including photocatalysis. The different aspects discussed in this review demonstrate the importance of the ME reaction method for the design of nanocatalysts with enhanced activity and selectivity.

  • 309.
    Brandin, Jan
    et al.
    Linnaeus University.
    Hulteberg, Christian
    LTH, Lund University.
    Kusar, Henrik
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    A review of thermo-chemical conversion of biomass into biofuels-focusing on gas cleaning and up-grading process steps2017Report (Other academic)
    Abstract [en]

    It is not easy to replace fossil-based fuels in the transport sector, however, an appealing solution is to use biomass and waste for the production of renewable alternatives. Thermochemical conversion of biomass for production of synthetic transport fuels by the use of gasification is a promising way to meet these goals.

    One of the key challenges in using gasification systems with biomass and waste as feedstock is the upgrading of the raw gas produced in the gasifier. These materials replacing oil and coal contain large amounts of demanding impurities, such as alkali, inorganic compounds, sulphur and chlorine compounds. Therefore, as for all multi-step processes, the heat management and hence the total efficiency depend on the different clean-up units. Unfortunately, the available conventional gas filtering units for removing particulates and impurities, and also subsequent catalytic conversion steps have lower optimum working temperatures than the operating temperature in the gasification units.

    This report focuses on on-going research and development to find new technology solutions and on the key critical technology challenges concerning the purification and upgrading of the raw gas to synthesis gas and the subsequent different fuel synthesis processes, such as hot gas filtration, clever heating solutions and a higher degree of process integration as well as catalysts more resistant towards deactivation. This means that the temperature should be as high as possible for any particular upgrading unit in the refining system. Nevertheless, the temperature and pressure of the cleaned synthesis gas must meet the requirements of the downstream application, i.e. Fischer-Tropsch diesel or methanol.

    Before using the gas produced in the gasifier a number of impurities needs to be removed. These include particles, tars, sulphur and ammonia. Particles are formed in gasification, irrespective of the type of gasifier design used. A first, coarse separation is performed in one or several cyclone filters at high temperature. Thereafter bag-house filters (e.g. ceramic or textile) maybe used to separate the finer particles. A problem is, however, tar condensation in the filters and there is much work performed on trying to achieve filtration at as high a temperature as possible.

    The far most stressed technical barriers regarding cleaning of the gases are tars. To remove the tar from the product gas there is a number of alternatives, but most important is that the gasifier is operated at optimal conditions for minimising initial tar formation. In fluid bed and entrained flow gasification a first step may be catalytic tar cracking after particle removal. In fluid bed gasification a catalyst, active in tar cracking, may be added to the fluidising bed to further remove any tar formed in the bed. In this kind of tar removal, natural minerals such as dolomite and olivine, are normally used, or catalysts normally used in hydrocarbon reforming or cracking. The tar can be reformed to CO and hydrogen by thermal reforming as well, when the temperature is increased to 1300ºC and the tar decomposes. Another method for removing tar from the gas is to scrub it by using hot oil (200-300ºC). The tar dissolves in the hot oil, which can be partly regenerated and the remaining tar-containing part is either burned or sent back to the gasifier for regasification.

    Other important aspects are that the sulphur content of the gas depends on the type of biomass used, the gasification agent used etc., but a level at or above 100 ppm is not unusual. Sulphur levels this high are not acceptable if there are catalytic processes down-stream, or if the emissions of e.g. SO2 are to be kept down. The sulphur may be separated by adsorbing it in ZnO, an irreversible process, or a commercially available reversible adsorbent can be used. There is also the possibility of scrubbing the gas with an amine solution. If a reversible alternative is chosen, elementary sulphur may be produced using the Claus process.

    Furthermore, the levels of ammonia formed in gasification (3,000 ppm is not uncommon) are normally not considered a problem. When combusting the gas, nitrogen or in the worst case NOx (so-called fuel NOx) is formed; there are, however, indications that there could be problems. Especially when the gasification is followed by down-stream catalytic processes, steam reforming in particular, where the catalyst might suffer from deactivation by long-term exposure to ammonia.

    The composition of the product gas depends very much on the gasification technology, the gasifying agent and the biomass feedstock. Of particular significance is the choice of gasifying agent, i.e. air, oxygen, water, since it has a huge impact on the composition and quality of the gas, The gasifying agent also affects the choice of cleaning and upgrading processes to syngas and its suitability for different end-use applications as fuels or green chemicals.

    The ideal upgraded syngas consists of H2 and CO at a correct ratio with very low water and CO2 content allowed. This means that the tars, particulates, alkali salts and inorganic compounds mentioned earlier have to be removed for most of the applications. By using oxygen as the gasifying agent, instead of air, the content of nitrogen may be minimised without expensive nitrogen separation.

    In summary, there are a number of uses with respect to produced synthesis gas. The major applications will be discussed, starting with the production of hydrogen and then followed by the synthesis of synthetic natural gas, methanol, dimethyl ether, Fischer-Tropsch diesel and higher alcohol synthesis, and describing alternatives combining these methods. The SNG and methanol synthesis are equilibrium constrained, while the synthesis of DME (one-step route), FT diesel and alcohols are not. All of the reactions are exothermal (with the exception of steam reforming of methane and tars) and therefore handling the temperature increase in the reactors is essential. In addition, the synthesis of methanol has to be performed at high pressure (50-100 bar) to be industrially viable.

    There will be a compromise between the capital cost of the whole cleaning unit and the system efficiency, since solid waste, e.g. ash, sorbents, bed material and waste water all involve handling costs. Consequently, installing very effective catalysts, results in unnecessary costs because of expensive gas cleaning; however the synthesis units further down-stream, especially for Fischer-Tropsch diesel, and DME/methanol will profit from an effective gas cleaning which extends the catalysts life-time. The catalyst materials in the upgrading processes essentially need to be more stable and resistant to different kinds of deactivation.

    Finally, process intensification is an important development throughout chemical industries, which includes simultaneous integration of both synthesis steps and separation, other examples are advanced heat exchangers with heat integration in order to increase the heat transfer rates. Another example is to combine exothermic and endothermic reactions to support reforming reactions by using the intrinsic energy content. For cost-effective solutions and efficient application, new solutions for cleaning and up-grading of the gases are necessary.

  • 310.
    Brattsell Bukowski, Emma
    KTH, School of Chemical Science and Engineering (CHE).
    Undersökning av koldioxidlagring för Plantagons vertikala växthus: med avseende på aminbaserade Sorbenter och växters koldioxidförbrukning2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report focuses on whether it is possible to effectively store carbon dioxide from ambient air using amine-based mesoporous support sorbents in a closed system. The closed system is a building designed by Plantagon, which includes both an office and a greenhouse section. In the office sections people are producing carbon dioxide through the respiration and the plants in the greenhouse needs carbon dioxide to grow. Therefore, the supply of carbon dioxide to the greenhouse section could be obtained by the produced amount of carbon dioxide from the people in the office section.

    Why Plantagon construct this type of building depends on the challenge of producing food in the cities in order to reduce climate impact. The prevailing disturbances of the climate, which is largely due to emissions of greenhouse gases such as carbon dioxide, carbon dioxide storage has become an important issue in the climate debate. Because the amine-based sorbent material demonstrated good results in the adsorption of carbon dioxide, these materials is the focus of this report although other techniques also have shown good results in storing carbon dioxide.

    The best way to increase the photosynthetic rate and to get the plants in the greenhouse to grow faster, a supply of carbon dioxide is required, which is estimated to be 1000 ppm during the hours when the photosynthesis takes place. The carbon dioxide consumption in the Plantagon greenhouse is based on studies on conventional greenhouses. The needed amount of carbon dioxide varies between 288-720 kg per day, depending on plant, as well as the plants specific parameters of growth. The maximal amount of carbon dioxide that people produce in the office space of the building is 126 kg per day.

    The calculated values of carbon dioxide consumption showed that quantities of 288 to720 kg carbon dioxide must be supplied to the greenhouse each day to maintain a constant level of 1000 ppm in the greenhouse. Even if the produced amounts of carbon dioxide, 126 kg per day, from the office space are transported into the greenhouse, large quantities of carbon dioxide are still required to keep a constant carbon dioxide level. Therefore carbon dioxide must be supplied to the greenhouse from elsewhere. Due to the high volumes of carbon dioxide that are required in the greenhouse daily, it is likely that the purchase and installation of an adsorption system for the storage of carbon dioxide in the building is not the perfect solution until further investigations are done based up on experimental analyses.

  • 311.
    Brett, Calvin
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. DESY, Photon Sci, Hamburg, Germany.
    Mittal, Nitesh
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Ohm, Wiebke
    DESY, Photon Sci, Hamburg, Germany..
    Söderberg, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Roth, Stephan V.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. DESY, Photon Sci, Hamburg, Germany..
    In situ self-assembly study in bio-based thin films2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 312.
    Brown, Shelley
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Georén, Peter
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Behm, Mårten
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Lindbergh, Göran
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Characterisation and modelling of a high-power density lithium-ion positive electrode for HEV application2004Conference paper (Refereed)
    Abstract [en]

    In this study, the impedance response of a porous electrode based on LiNi0.8Co0.15Al0.05O2 was investigated using an impedance model including the following features: Butler-Volmer kinetics; double layer capacitance; solid phase concentration and potential gradients; electrolyte phase concentration and potential according to the concentrated electrolyte theory; particle size distribution; and an empirical relation between equilibrium potential and state of charge. The model was evaluated by fitting it to experimental results using different electrolytes and states of charge. In addition, the characteristic parameters for the electrode were obtained from the fitting results.

  • 313.
    Bruce, Carl
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Surface Modification of Cellulose by Covalent Grafting and Physical Adsorption for Biocomposite Applications2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is an increasing interest to replace fossil-based materials with renewable alternatives. Cellulose fibers/nanofibrils (CNF) are sustainable options since they are biobased and biodegradable. In addition, they combine low weight with high strength; making them suitable to, for example, reinforce composites. However, to be able to use them as such, modifications are often necessary. This study therefore aimed at modifying cellulose fibers, model surfaces of cellulose and CNF. Cellulose fibers and CNF were thereafter incorporated into composite materials and evaluated.

    Surface-initiated ring-opening polymerization (SI-ROP) was performed to graft ε-caprolactone (ε-CL) from cellulose fibers. From these fibers, paper-sheet biocomposites were produced that could form laminate structures without the need for any addition of matrix polymer.

    By combining ROP and atom transfer radical polymerization (ATRP), diblock copolymers of poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) and PCL were prepared. Quaternized (cationic) PDMAEMA, allowed physical adsorption of block copolymers onto anionic surfaces, and, thereby, alteration of surface energy and adhesion to a potential matrix. Furthermore, the architecture of block copolymers of PCL and PDMAEMA was varied to investigate effects on morphology/crystallinity and adsorption behavior. In addition, poly(butadiene) was also evaluated as the hydrophobic block in the form of cationic and anionic triblock copolymers.

    Polystyrene (PS) was covalently grafted from CNF and used as reinforcement in PS-based composites. In an attempt to determine stress transfer from matrix to CNF, a method based on Raman spectroscopy was utilized.

    Covalent grafting and physical adsorption of PCL from/onto CNF were compared by incorporating modified CNF in PCL matrices. Both approaches resulted in improved mechanical properties compared to unmodified CNF, but even at low amounts of modified CNF, covalent grafting gave tougher materials and indicated higher interfacial adhesion.

  • 314.
    Bryngelsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Grönkvist, Stefan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Möllersten, Kenneth
    CDM from Jevons’ perspective: Do emission reductions go together with increasing supply of energy, efficiency improvement and rapid development?2005Article in journal (Other academic)
  • 315.
    Bryngelsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Hansson, Anders
    Energy policy on shaky ground?: A study of CCS-scenarios2009In: Energy Procedia, ISSN 1876-6102, no 1, p. 4673-4680Article in journal (Refereed)
    Abstract [en]

    Scenarios play an important role for the societal acceptance of CCS. This paper looks into influential reports containing CCS scenarios and analyses results, key assumptions and drivers for CCS' deployment. Significant uncertainties regarding CCS' development were in several cases excluded or marginalized. Despite these shortcomings, scenarios support a massive deployment of CCS and reflect an undivided optimism. If CCS would fail to meet the high expectations a backlash could follow. Indications were found that new scenarios including uncertainties are needed to balance this over-optimism. So-called unpleasant scenarios are often valuable in helping decision makers develop flexible strategies and policies.

  • 316.
    Bryngelsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Lindfeldt, Erik G.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Heller, Jan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    The modelling of a hybrid combined cycle with pressurised fluidised bed combustion and CO2 capture2009In: International journal of greenhouse gas control, ISSN 1750-5836, Vol. 3, no 3, p. 255-262Article in journal (Refereed)
    Abstract [en]

    This study investigates the possibility of capturing CO2 from flue gas under pressurised conditions, which could prove to be beneficial in comparison to working under atmospheric conditions. Simulations of two hybrid combined cycles with pressurised fluidised bed combustion and CO2 capture are presented. CO2 is captured from pressurised flue gas by means of chemical absorption after the boiler but before expansion. The results show a CO2 capture penalty of approximately 8 percentage points (including 90% CO2 capture rate and compression to 110 bar), which makes the efficiency for the best performing cycle 43.9%. It is 5.2 percentage points higher than the most probable alternative, i.e. using a natural gas fired combined cycle and a pulverised coal fired condensing plant separately with the same fuel split ratio. The largest part of the penalty is associated with the lower mass flow of flue gas after CO2 capture, which leads to a decrease in work output in the expander and potential for feed water heating. The penalty caused by the regeneration of absorbent is quite low, since the high pressure permits the use of potassium carbonate, which requires less regeneration heat than for example the more commonly proposed monoethanolamine. Although the efficiencies of the cycles look promising it will be important to perform a cost estimate to be able to make a fair comparison with other systems. Such a cost estimate has not been done in this study. A significant drawback of these hybrid cycles in that respect is the complex nature of the systems that will have a negative effect on the economy.

  • 317.
    Bryngelsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Westermark, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    CO2 capture pilot test at a pressurized coal fired CHP plant2009In: Energy Procedia, ISSN 1876-6102, Vol. 1, no 1, p. 1403-1410Article in journal (Refereed)
    Abstract [en]

    CO2 capture from pressurized flue gas using a variation of the hot potassium carbonate process has been demonstrated at a pilot plant with authentic flue gas from the Vartan combined heat and power plant in Stockholm. The plant has served as a proof of concept installation, and has confirmed that: i) the pre-treatment of the flue gas is adequate for protecting the absorbent from degradation, ii) the CO2 capture efficiency is high (> 98 %), iii) no harmful components are fed to the gas turbine, and iv) absorbent degradation is low (0.85 mole percent/month).

  • 318.
    Bryngelsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Westermark, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Feasibility study of CO2 removal from pressurized flue gas in a fully fired combined cycle: the Sargas project2005In: Proceedings of the 18th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS, 2005, p. 703-710Conference paper (Refereed)
    Abstract [en]

    In this article a novel concept for CO2 removal from power plants is discussed from a systems perspective. The main advantage of the process is that the investment cost and the power penalty for CO2 removal can be substantially reduced compared to conventional combined cycles. The proposed technical solution comprises fully fired combined cycle, which minimizes the amount of flue gas. Furthermore, the CO2 absorption is performed at pressurized conditions prior to the expansion, which further enhances the CO2 removal. The modification of the power cycle and integration of absorption stages makes CO2 removal equipment much more compact and allows the use Of CO2 absorbents with lower heat demand for the regeneration. The partial pressure of CO2 is above atmospheric pressure and removal efficiencies above 95% can be obtained with potassium carbonate absorption (the Benfield process). The treated flue gas is then reheated and re-humidified before the expansion in the gas turbine.

    A Norwegian consortium has developed the concept and feasibility studies have been performed for 100 MW and 400 MW power plants based on natural gas in Norway. The produced carbon dioxide is intended for storage in the Norwegian oil and gas fields in order to enhance the oil recovery. The suggested localizations of the power plants have been chosen accordingly. The design study is based on the same gas turbine and steam cycle as used in the commercial Pressurized Fluidized Bed Combustion (PFBC) cycle. PFBC plants are presently fired with coal but the fluid bed combustor for coal will be replaced by a gas combustor if natural gas is used. A key advantage is that the process can be built solely from commercially available components.

    This report is an assessment of the features, capabilities, advantages and future possibilities of the suggested power cycle with integrated CO2 removal. A power plant for 100 MW power output and based on natural gas is considered suitable as a first demonstration plant to be built in Hammerfest, Norway. A permit application has been turned in. For such a demonstration plant the process simulations have indicated that an efficiency of about 40% can be obtained, including the penalties from CO2 capture and compression. Further improvements, e.g. supercritical steam cycle or more advanced gas turbine increases the efficiency and for a 400 MW power cycle a net efficiency of about 44-48% has been simulated (including CO2 capture and compression). The cycle may also be suitable for CO2 removal from coal-fired plants.

  • 319.
    BRÄNNSTRÖM, SARA
    KTH, School of Chemical Science and Engineering (CHE).
    En studie om hur koncentrerad saltsyra vid hög temperatur påverkar PP, PVC och CPVC2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hydrochloric acid is commonly used in pickling plants where temperatures may be up to 90 °C. In such corrosive environments, pipes or containers of metals cannot be used and the use of plastic materials is therefore a more suitable option. For example it may be possible to use polypropylene (PP), polyvinyl chloride (PVC) and chlorinated PVC (CPVC) for these applications. Plastics are not standardized materials; therefore the chemical resistances of commercially available plastics need to be tested individually.

    The effect of hydrochloric acid (HCl) at high temperatures on commercially available materials from different manufacturers was studied. Totally five PP, five PVC and two CPVC materials were investigated. The materials were exposed to concentrated HCl at 60 °C for up to 8 weeks. The chemical changes were analyzed with Fourier Transfer Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) was used to measure the Oxidative Induction Time (OIT). The mechanical properties were studied with Charpy impact testing and tensile testing. An indicator technique was used to measure the diffusion of HCl in the materials. Quantification of how much HCl the materials absorb was performed with Ion chromatography (IC).

    The results showed that the PP samples lost antioxidants as seen in both FTIR spectra and changes in OIT. The PVC materials had a decrease in filler content where the acid had penetrated. The mechanical properties seemed to be unchanged after exposure for 8 weeks. Only two PVC materials seemed to have a decrease in stress at yield. Concluding, most of the tested PVC and CPVC materials are suitable for the use in contact with concentrated HCl. All PP, PVC and CPVC materials can be used in contact with concentrated HCl in 60 oC up to 8 weeks.

  • 320.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Finnveden, Maja
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Razza, Nicolo
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Martinelle, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sangermano, Marco
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Tailoring Thermo-Mechanical Properties of Cationically UV-Cured Systems by a Rational Design of Vinyl Ether Ester Oligomers using Enzyme Catalysis2018In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 219, no 21, article id 1800335Article in journal (Refereed)
    Abstract [en]

    There is a demand for new sustainable polymeric materials. Vinyl ethers are, in this context, attractive oligomers since they polymerize fast, are non-toxic, and can be polymerized under ambient conditions. The availability of vinyl ether oligomers is, however, currently limited due to difficulties in synthesizing them without using tedious synthesis routes. This work presents the synthesis of a series of vinyl ether ester oligomers using enzyme catalysis under solvent-free conditions and the subsequent photoinduced cationic polymerization to form polymer thermosets with T(g)s ranging from -10 to 100 degrees C. The whole process is very efficient as the synthesis takes less than 1 h with no need for purification and the crosslinking is complete within 2 min.

  • 321.
    Brännvall, Elisabet
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Jansson, Zheng
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Characterisation of dissolved spruce xylan in kraft cooking2011In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 26, no 4, p. 380-385Article in journal (Refereed)
    Abstract [en]

    Xylan dissolved during kraft cooking and later redeposited on fibre surfaces has been demonstrated to affect paper strength properties. Earlier studies have demonstrated that it is the xylan characteristics, rather than simply the amount of xylan, that influence the strength-enhancing effect of xylan. To use xylan optimally, it is useful to understand xylan’s beneficial characteristics and how cooking conditions affect them.

    In this study, spruce chips were kraft cooked under various cooking conditions and the xylan in the black liquor was characterized. We found that dissolved spruce xylan had a much higher amount of bound lignin than found in previous studies of xylan dissolved from hardwoods. The ionic strength of the cooking liquor affected the amount of dissolved xylan as well as the uronic acid content of the xylan.

  • 322. Buchert, Johanna
    et al.
    Bergnor, Elisabeth
    Lindblad, Gunnar
    Viikari, Liisa
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Significance of xylan and glucomannan in the brightness reversion of kraft pulps1997In: TAPPI Journal, ISSN 0734-1415, Vol. 80, no 6, p. 165-171Article in journal (Refereed)
    Abstract [en]

    The brightness reversion of kraft pulps is caused by the presence of residual lignin, chlorinated extractives, or oxidized carbohydrates. The effect of hemicellulose content, i.e., xylan (I) and glucomannan (II), on the thermal stability of modern bleached kraft pulps was investigated. Different O-delignified hard- and softwood kraft pulps were bleached with different bleaching sequences contg. ClO2, H2O2, or O3. Hemicellulose-degrading enzymes, i.e., xylanase or mannanase, were used for selective removal of the resp. hemicellulose from the pulps, and the role of partially removed I and II on the brightness stability of these pulps was studied. Because of the structure of kraft I, enzymic removal of I also resulted in a decreased carboxyl group content in the pulps, whereas II removal did not affect the carboxyl group content. By decreasing the carboxyl groups in the pulps in conjunction with I removal, the thermal aging of the pulps was significantly decreased. The role of II was less significant. Thus, the uronic acids present in the pulp participate in the brightness reversion of kraft pulps.

  • 323. Buchert, Johanna
    et al.
    Bergnor, Elisabeth
    Lindblad, Gunnar
    Viikari, Liisa
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    The role of xylan and glucomannan in yellowing of kraft pulps.1995In: Proceedings 8th Int. Symp. Wood Pulp. Chem., 1995, p. 43-48Conference paper (Refereed)
    Abstract [en]

    The effects of xylan and glucomannan on the thermal stability of unbleached, partially bleached, and fully bleached pine and birch kraft pulps were studied.  The choice of bleaching chems. strongly affected the brightness reversion.  Compared with hydrogen peroxide or chlorine dioxide, bleaching with ozone reduced the amt. of carboxyl groups and subsequently the pc-nos. of oxygen-delignified pulps.  Xylan removal reduced also the amt. of carboxyl groups in the pulps and this was reflected in improved brightness stability whereas glucomannan removal had no effect.  Thus, the uronic acids bound to pulp xylan were found to participate in the brightness reversion of kraft pulps.

  • 324. Buchert, Johanna
    et al.
    Tenkanen, Maija
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Teleman, Anita
    Vuorinen, Tapani
    Effect of pulping and bleaching on pulp carbohydrates and technical properties.1996In: Proceedings Int. Pulp Bleaching, 1996, p. 39-42Conference paper (Refereed)
    Abstract [en]

    Pulping and bleaching have a profound effect on the carbohydrate chem. of kraft pulps.  The chem. structure of xylan is modified due to the conversion of methylglucuronic acid side groups to hexenuronic acid side groups.  Pulping conditions strongly affect the amt. of hexenuronic acid present in the pulp and subsequently modified kraft pulps have different carboxyl group profiles as compared with conventionally cooked pulps.  Due to its reactivity, hexenuronic acid is readily degraded when chlorine dioxide or ozone are used as bleaching chems.  However, TCF-pulps bleached with peroxide and oxygen contain high amts. of hexenuronic acid.  Thus, depending on the pulping and bleaching method, the quality and quantity of carboxylic acids in different types of pulps varies significantly.  The differences in the uronic acid content are in turn reflected in the macroscale properties of the pulps, such as brightness stability.       

  • 325. Budinova, T.
    et al.
    Ekinci, E.
    Yardim, F.
    Grimm, Alejandro
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Björnbom, Emilia
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Minkova, V.
    Goranova, M.
    Characterization and application of activated carbon produced by H3PO4 and water vapor activation2006In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 87, no 10, p. 899-905Article in journal (Refereed)
    Abstract [en]

    Activated carbons have been prepared from woody biomass birch by using various activation procedures: a) treatment with phosphoric acid and pyrolysis at 600 degrees C in inert atmosphere, b) the same as in (a) followed by steam activation at the same temperature and c) treatment with phosphoric acid and direct pyrolysis in a stream of water vapor at 700 degrees C. The surface area and the porosity of the activated carbons were strongly dependent on the treatment after impregnation with H3PO4 (pyrolysis in inert atmosphere, steam pyrolysis or combination of both). Activated carbon, prepared by impregnation with phosphoric acid followed by steam pyrolysis (steam activation) had highly developed porous structure and the largest surface area among all prepared carbons (iodine number 1280 mg/g and BET surface area 1360 m(2)/g). The adsorption capacity of this sample for Hg(II) from aqueous solution was studied in varying treatment conditions: contact time, metal ion concentration and pH. The adsorption followed Langmuir isotherms and the adsorption capacity for Hg(II) at 293 K was 160 mg/g.

  • 326.
    Bujak, Klaudia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Kartläggning av analysmetoder för mikroplaster från konstgräsplaner2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The presence of microplastics in marine and sedimentary environments is a relatively new problem. Presently, there are no clear standards to which methods that should be implored with sampling, treating and analysing microplastics. Because of this, some troubles occur when estimating field concentrations and comparing microplastics flow and composition.

    Artificial turf plants have been considered to be the second largest source of microplastic emissions in Sweden. Pre-emptive measures have been taken in several regions in Sweden in order to decrease spreading of microplastics. Because of this, it is important to be able to measure the amount of microplastics in marine environment and sediment in order to monitor how it changes when using different methods.

    The purpose of this study is to increase the knowledge of the methods available and suitable for sampling, treatment and analysis of microplastics from artificial turf in water and sediment environments.

    The aim is to provide a suggestion of measurement methods that may be suitable for analysis of microplastics from artificial turf in Ältasjön.

    In order to clarify the importance of a holistic view of the microplastics, an analytical chain has been developed. It is regarded to be a useful tool in order to further the develop a standardized method for the entire analytical process, from sampling to interpretation of results. This analytical chain is comprised by four major steps: sampling, laboratory preparation of samples, analysis and interpretation of the results.

    Sampling will be of crucial importance for the evaluation of final results, because the sampling efficiency has direct impact on the content of the sample which will proceed to the analysis. There are no standardized procedures for sampling of microplastics with regard to location, sampling equipment, volumes and sampling time. This results in a limited comparability with previous studies.

    The treatment is usually comprised of volume reduction, density separation and chemical or enzymatic purification. These treatment methods need to be adapted in regard to the expected content of the sample and the chosen analytical method.

    Analysis of microplastic could be done with the help of optical, spectrophotometric or chromatographic methods. The optical analysis enables to monitor the particles physical properties such as size, shape, colour and degree of degradation. The spectrophotometric and chromatographic methods provide information about chemical composition, polymer type and the additive content of microplastics. These methods investigate different properties and therefore they result in different answers. Each technique should be thought of and analysed from the information that is provided. Also, all analytic methods have different detection limits. These detection limits vary between and it is important to take into consideration when choosing the correct analytical method.

    If different studies use the same methods to gain the desired information, the results will be more easily compared. The combined results will help to complete more of the missing information and improve the monitoring of microplastics spreading to marine environments and sediment. Provided that all studies not only follow the same methods but also the same analytical chain from sampling to analyzing the results.

    From the information and knowledge that was gathered, it is expected that Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM-EDS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has the biggest potential to efficiently measure microplastics from artificial turf in water environment and sediment. Both SEM-EDS and ICP-MS makes it possible to detect all types of granulate and plastic straws from artificial turf even when the grain is between 10 and 20 mm. Further studies of these methods are recommended to build a reference library for each respective method and to find a working standard method when analysing microplastic from artificial grass.

  • 327.
    Bundy, Kenneth
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Karlsson, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Lundqvist, Anton
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    An electrochemical impedance spectroscopy method for prediction of the state of charge of a nickel-metal hydride battery at open circuit and during discharge1998In: Journal of Power Sources, Vol. 72, no 2, p. 118-125Article in journal (Refereed)
    Abstract [en]

    A multivariate method for predicting state of charge, from electrochemical data, of a nickel-metal hydride (NiMH)-battery is presented. Partial least square (PLS) regression is used to evaluate electrochemical impedance spectra and predict state of charge. The impedance spectra are analysed in the frequency range 239-0.6 Hz. The impedance is measured for different states of charge at open-circuit conditions and during continuous discharge at loads ranging between 0.2 C and 0.8 C. When measuring the impedance during discharge, the AC-current signal is imposed on the DC-current. The predictive capability of the method is tested by a cross validation procedure and the root mean square error of prediction is 7% when using the outlier identification capability of the PLS-regression method. The state of charge is evaluated with a single model, independently of whether the cell is subjected to open-circuit or polarised conditions. The predictive performance of the present model decreases at state of charge values less than 10%. © 1998 Elsevier Science S.A.

  • 328.
    Burman, Lina
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Chromatography and extraction techniques for new evaluation methods of polyolefins long-term performance2005Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Chromatography and extraction techniques, and also chemiluminescence have been utilized to develop new rapid and informative tools in the evaluation of long-term properties and environmental effects of polymeric materials.

    Methods were developed for classification of materials and for early and rapid degradation detection. Degradable polyethylene films were classified on the basis of their incorporated prooxidant systems using chromatographic fingerprinting of carboxylic acids, the dominating type of degradation product. The fingerprints were also shown to be useful for prediction of the degradation states and evaluation of the degradation mechanisms. Classification and prediction models were obtained by Multivariate Data Analysis, where the diacids were grouped according to both their type of prooxidant system and their state of degradation. The use of total luminescence intensity (TLI) measurements was also investigated as a means of classifying films and for the early detection of degradation. Comparisons were carried out with common techniques, e.g. FTIR and DSC, after both thermal and UV oxidation. TLI gave an earlier detection of degradation and was more sensitive than carbonyl index and crystallinity measurements to relative differences in degradation between the materials. It furthermore offered complementary information regarding changes in activation energies during the course of the degradation. The results were compared with the chromatographic fingerprints.

    A new way to evaluate the low temperature long-term stabilisation efficiency of antioxidants was investigated. A prooxidant was used to obtain catalytic oxidation, instead of using thermal acceleration, to evaluate the stabilisation efficiency of antioxidants at low temperatures but still during reasonably short aging times. Comparisons were made between polypropylene films stabilised with primary antioxidants (Irganox 1076, Irganox 1010 and α-tocopherol) with and without the prooxidant manganese stearate at different temperatures. The relative efficiencies of the antioxidants obtained under prooxidant acceleration test correlated better than thermal acceleration test with the results of a long-term low temperature test.

    Additives in plastic packaging materials may affect the environment after migration from the packaging to e.g. their contents, especially if they consist of organic aqueous solutions or oils. The use of Solid-Phase Microextraction (SPME) for the specific task of extraction from an organic aqueous solution such as a simulated food or pharmaceutical solution consisting of 10 vol-% ethanol in water was investigated. Methods were developed and evaluated for extraction both with direct sampling and with headspace sampling. If the extraction method and temperature were selected to suit the concentration levels of the analytes, it was possible to quantify several degradation products simultaneously. Comparisons made with Solid Phase Extraction showed the advantage of SPME for this purpose.

  • 329.
    Burman, Lina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Evaluation of Long-Term Performance of Antioxidants Using Prooxidants instead of Thermal Acceleration2005In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 43, no 19, p. 4537-4546Article in journal (Refereed)
    Abstract [en]

    Evaluation of stabilization efficiencies of different antioxidants in polymers at low temperature and relatively short time was performed using incorporation of a prooxidant for catalytic oxidation. Comparisons were made between polypropylene films stabilized with primary antioxidants (Irganox 1076, Irganox 1010, and α-tocopherol), with or without the prooxidant manganese stearate at different temperatures. A faster degradation was obtained in the presence of a prooxidant than without it. The relative efficiency of the antioxidants at prooxidant acceleration correlated better to low temperature long-term test than at the thermal acceleration. The results were affected by initial differences in the amounts of the antioxidants present after the processing of the films. These differences were corrected for by a recalculation using microwave-assisted extraction (MAE) and high performance liquid chromatography analysis from the exponential decrease in the amount of antioxidant in the films. The fastest comparison of the antioxidants efficiency was obtained from oxidation induction times, using total luminescence intensity measurements, but reliable results could also be obtained from the time to apparent failure.

  • 330.
    Burman, Lina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Indicator products and chromatographic fingerprinting: New tools for degradation state and lifetime estimation2008In: CHROMATOGRAPHY FOR SUSTAINABLE POLYMERIC MATERIALS: RENEWABLE, DEGRADABLE AND RECYCLABLE, Berlin: Springer Verlag , 2008, Vol. 211, p. 1-22Chapter in book (Refereed)
    Abstract [en]

    The demands on polymeric products are growing both with respect to their function and purity. There is a need for new high-throughput characterisation tools for rapid quality control and evaluation of materials. Precise control over degradation rate and service-life are also prerequisites for successful use of degradable polymers in an increasing number of applications. The chromatographic fingerprinting and indicator product concepts, presented in the current paper, are novel and attractive alternatives for rapid evaluation of the product quality, degradability, durability and service-life. The sensitivity of these techniques allows for detection of small initial changes in the materials and signs of early degradation. The possible applications include evaluation of different pro-oxidants or antioxidants, optimisation of processing parameters, evaluation of long-term properties or storage stability and lifetime prediction. The same principal could also be applied to process control and monitoring, acceptance or rejection of raw materials, intermediate and final products. The usefulness of indicator products and chromatographic fingerprinting is shown for estimation of the degradation state of degradable polyethylene. in addition, chromatographic fingerprinting together with multivariate data analysis is utilised to classify degradable polyethylene materials based on their incorporated pro-oxidant systems.

  • 331.
    Burman, Lina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Höglund, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Solid-Phase Microextraction for Qualitative and Quantitative Determination of Migrated Degradation Products of Antioxidants in an Organic Aqueous Solution2005In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1080, no 2, p. 107-116Article in journal (Refereed)
    Abstract [en]

     Low molecular weight aromatic substances may migrate out from plastic packaging to their contents, especially if they consist of organic aqueous solutions or oils. It is, therefore, extremely important to be able to identify and quantify any migrated substances in such solutions, even at very low concentrations. We have in this work investigated and evaluated the use of solid-phase microextraction for the specific task of extraction from an organic aqueous solution such as a simulated pharmaceutical solution consisting of 10 vol.% ethanol in water. The goal was furthermore to investigate the possibility of simultaneously identifying and quantifying the substances in spite of differences in their chemical structures. Methods were developed and evaluated for extraction both with direct sampling and with headspace sampling. Difficulties appeared due to the ethanol in the solution and the minute amounts of substances present. We have shown that a simultaneous quantification of migrated low molecular weight degradation products of antioxidants using only one fibre is possible if the extraction method and temperature are adjusted in relation to the concentration levels of the analytes. Comparions were made with solid-phase extraction.

  • 332.
    Bursell, Martin
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Attempts to innovative solutions regarding research and development of fuel cells and batteries2001Licentiate thesis, comprehensive summary (Other scientific)
  • 333.
    BURSELL, Martin
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    BJÖRNBOM, Pehr
    KTH, Superseded Departments, Chemical Engineering and Technology.
    A METHOD FOR STUDYING MICROELECTRODES BY MEANS OF MICROMANIPULATORS AS APPLIED TO CARBON AGGLOMERATES FROM OXYGEN REDUCTION ELECTRODE CATALYST1990In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 137, no 1, p. 363-365Article in journal (Refereed)
  • 334.
    Bussmann, Jenny
    KTH, School of Chemical Science and Engineering (CHE).
    Natural Polyphenols as DPP-IV inhibitors - Enzyme Kinetics and a Comparative Study of Assays2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 335.
    Butchosa, Nuria
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Leijon, Felicia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Bulone, Vincent
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Zhou, Qi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Stronger cellulose microfibril network structure through the expression of cellulose-binding modules in plant primary cell walls2019In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, no 5, p. 3083-3094Article in journal (Refereed)
    Abstract [en]

    Cellulose-binding modules (CBMs) are non-catalytic domains typically occurring in glycoside hydrolases. Their specific interaction with diverse polysaccharides assists hydrolysis by the catalytic subunits. In this work, we have exploited the interactions between a CBM from family 3 (CBM3) and cell wall polysaccharides to alter the structure and mechanical properties of cellulose microfibrils from BY-2 tobacco cell suspension cultures. A CBM3 from Clostridium thermocellum was overexpressed in the cells using Agrobacterium-mediated transformation. Water suspensions of cellulose microfibrils were prepared by the removal of the non-cellulosic components of the primary cell walls, followed by mild disintegration using sonication. The morphology of the microfibrils was characterized by transmission electron microscopy and atomic force microscopy. These cellulose microfibrils were further hydrolyzed with 64wt% sulfuric acid to produce cellulose nanocrystals (CNCs). The average length of CNCs prepared from the CBM3-transformed cells was 201nm, higher than that from the wild-type cells (122nm). In addition, the mechanical properties and deformation mechanism of nanopapers prepared from suspensions of cellulose microfibrils were investigated. The nanopapers obtained from the CBM3-transformed cells exhibited enhanced tensile strength and work of fracture, 40% and 128% higher than those prepared from wild-type tobacco cells, respectively. [GRAPHICS] .

  • 336.
    Butchosa Robles, Núria
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Tailoring Cellulose Nanofibrils for Advanced Materials2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cellulose nanofibrils (CNFs) are nanoscale fibers of high aspect ratio that can be isolated from a wide variety of cellulosic sources, including wood and bacterial cellulose. With high strength despite of their low density, CNFs are a promising renewable building block for the preparation of nanostructured materials and composites. To fabricate CNF-based materials with improved inherent rheological and mechanical properties and additional new functionalities, it is essential to tailor the surface properties of individual CNFs. The surface structures control the interactions between CNFs and ultimately dictate the structure and macroscale properties of the bulk material. In this thesis we have demonstrated different approaches, ranging from non-covalent adsorption and covalent chemical modification to modification of cellulose biosynthesis, to tailor the structure and surface functionalities of CNFs for the fabrication of advanced materials. These materials possess enhanced properties such as water-redispersibility, water absorbency, dye adsorption capacity, antibacterial activity, and mechanical properties.

    In Paper I, CNFs were modified via the irreversible adsorption of carboxymethyl cellulose (CMC). The adsorption of small amounts of CMC onto the surface of CNFs prevented agglomeration and co-crystallization of the nanofibrils upon drying, and allowed the recovery of rheological and mechanical properties after redispersion of dried CNF samples.

    In Paper II, CNFs bearing permanent cationic charges were prepared through quaternization of wood pulp fibers followed by mechanical disintegration. The activation of the hydroxyl groups on pulp fibers by alkaline treatment was optimized prior to quaternization. This optimization resulted in individual CNFs with uniform width and tunable cationic charge densities. These cationic CNFs demonstrated ultrahigh water absorbency and high adsorption capacity for anionic dyes.

    In Paper III, via a similar approach as in Paper II, CNFs bearing polyethylene glycol (PEG) were prepared by covalently grafting PEG to carboxylated pulp fibers prior to mechanical disintegration. CNFs with a high surface chain density of PEG and a uniform width were oriented to produce macroscopic ribbons simply by mechanical stretching of the CNF hydrogel network before drying. The uniform grafted thin monolayer of PEG on the surface of individual CNFs prevented the agglomeration of CNFs and facilitated their alignment upon mechanical stretching, thus resulted in ribbons with ultrahigh tensile strength and modulus. These optically transparent ribbons also demonstrated interesting biaxial light scattering behavior.

    In Paper IV, bacterial cellulose (BC) was modified by the addition of chitin nanocrystals (ChNCs) into the growing culture medium of the bacteria Acetobacter aceti which secretes cellulose in the form of entangled nanofibers. This led to the in situ incorporation of ChNCs into the BC nanofibers network and resulted in BC/ChNC nanocomposites exhibiting bactericidal activity. Further, blending of BC nanofibers with ChNCs produced nanocomposite films with relatively lower tensile strength and modulus compared to the in situ cultivated ones. The bactericidal activity increased significantly with increasing amount of ChNCs for nanocomposites prepared by direct mixing of BC nanofibers and ChNCs.

    In Paper V, CNFs were isolated from suspension-cultured wild-type (WT) and cellulose-binding module (CBM) transformed tobacco BY-2 (Nicotiana tabacum L. cv bright yellow) cells. Results from strong sulfuric acid hydrolysis indicated that CNFs from transgenic cells overexpressing CBM consisted of longer cellulose nanocrystals compared to CNFs from WT cells. Nanopapers prepared from CNFs of transgenic cells demonstrated significantly enhanced toughness compared to CNFs of WT cells.

  • 337. Bylin, Susanne
    et al.
    Olsson, Carina
    Westman, Gunnar
    Theliander, Hans
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Solvation behavior of cellulose and xylan in the MIM/EMIMAc ionic liquid solvent system: Parameters for small-scale solvation2014In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 9, no 1, p. 1038-1054Article in journal (Refereed)
    Abstract [en]

    Ionic liquid treatment has been reported by several researchers as a possible step in the process of fractionating lignocellulosic biomass within the biorefinery concept. However, understanding how solvation can be achieved and how the feedstock biopolymers are affected is needed prior to a viable implementation. An effective two-component solvent system for the wood components cellulose and xylan has been developed. Furthermore, the solvation of these components in the system consisting of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate (EMIMAc) in a novel combination with the co-solvent 1-methylimidazole (MIM) is investigated. Focused beam reflectance measurement (FBRM) particle characterization in combination with microscopic analysis and molecular weight determinations (xylan) shows that cellulose and xylan can be most efficiently solvated using only 3 to 4% IL (n/n anhydro-glucose units and n/n anhydro-xylose units) and 9% IL, respectively, while still avoiding any significant polymer degradation. A model for a two-step process of cellulose solvation in the present system is proposed.

  • 338.
    Bäbler, Matthäus
    ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci.
    A collision efficiency model for flow-induced coagulation of fractal aggregates2008In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 54, no 7, p. 1748-1760Article in journal (Refereed)
    Abstract [en]

    A model for flow-induced collisions of fractal aggregates is developed. The model is based on the analysis of the relative trajectories between a pair of aggregates that takes into account their hydrodynamic and their colloidal interactions. Regarding the former, the aggregates are modeled as permeable spheres where the Brinkman equation is used to describe the flow inside the aggregates. Interparticle forces are incorporated by considering the forces between the primary particles in the two aggregates that are the nearest. The model results in a collision efficiency that depends on the masses of the colliding aggregates, the fractal dimension, and a nondimensional Hamaker constant characterizing the interparticle forces. The collision efficiency model is used to investigate the dynamics of a suspension undergoing coagulation. Significant deviations with respect to existing collision efficiency models are evidenced. 

  • 339.
    Bäbler, Matthäus
    ETH Zurich.
    Modelling of aggregation and breakage of colloidal aggregates in turbulent flows: Diss., Eidgenössische Technische Hochschule ETH Zürich, Nr. 17139, 20072007Doctoral thesis, monograph (Other academic)
  • 340.
    Bäbler, Matthäus U.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Kebede, Mebatsion L.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Rozada-Sanchez, Raquel
    Åslund, Per
    Gregertsen, Björn
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Isolation of Pharmaceutical Intermediates through Solid Supported Evaporation. Semicontinuous Operation Mode2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 45, p. 14814-14823Article in journal (Refereed)
    Abstract [en]

    Solid supported evaporation (SSE) is a simple, nonselective method for isolating nonvolatile compounds from a solution. The solution is put in contact with porous polymer beads onto which the compound deposits upon evaporation of the solvent. This brings some advantages over direct evaporation to dryness in terms of safety, thermal decomposition, and solid handling, as the loaded beads form a free flowing granular material that is easily recovered. In this paper, SSE in a semicontinuous operating mode is investigated where the solution is continuously fed to (respectively sprayed over) an agitated bed of dry beads put under vacuum. It is found that under conditions where the solvent evaporation fate is high with respect to the feed rate, high bead loadings can be achieved before extensive sticking of beads and compound to the vessel walls occurs. The type of compound and solvent had little influence on the process performance, and, in cases where this was explored, the bead loading was found to be homogeneous. Based on a balance equation for the solvent fed to the system, a model is developed that results in a simple scale up criterion. The latter was successfully applied for transferring SSE from lab to the kilo lab scale.

  • 341.
    Bäbler, Matthäus
    et al.
    ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci.
    Mazzotti, Marco
    Soos, Miroslav
    Morbidelli, Massimo
    Breakup and aggregation in turbulently stirred vessels2009In: 13th European Conference on Mixing, 2009Conference paper (Refereed)
    Abstract [en]

    The breakup and aggregation of small solid particle aggregates in hetero-geneous °ows is modeled through a multizonal population balance model. Breakupand aggregation are described through comprehensive rate expressions that takeinto account the local properties of the turbulent °ow. Two approaches are pursuedto de¯ne the zones: in the ¯rst approach the zones are prede¯ned and computational°uid dynamics is used to compute the zone properties. In the second approach thezone properties are directly ¯tted to experimental data. Model results compare wellwith experiments for the aggregation of a polystyrene latex in a stirred tank evenwhen only two zones are used.

  • 342.
    Bäbler, Matthäus
    et al.
    ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci.
    Morbidelli, M.
    Analysis of the aggregation-fragmentation population balance equation with application to coagulation2007In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 316, no 2, p. 428-441Article in journal (Refereed)
    Abstract [en]

    Coagulation of small particles in agitated suspensions is governed by aggregation and breakage. These two processes control the time evolution of the cluster mass distribution (CMD) which is described through a population balance equation (PBE). In this work, a PBE model that includes an aggregation rate function, which is a superposition of Brownian and flow induced aggregation, and a power law breakage rate function is investigated. Both rate functions are formulated assuming the clusters are fractals. Further, two modes of breakage are considered: in the fragmentation mode a particles splits into w ≥ 2 fragments of equal size, and in the erosion mode a particle splits into two fragments of different size. The scaling theory of the aggregation-breakage PBE is revised which leads to the result that under the negligence of Brownian aggregation the steady state CMD is self-similar with respect to a non-dimensional breakage coefficient θ. The self-similarity is confirmed by solving the PBE numerically. The self-similar CMD is found to deviate significantly from a log-normal distribution, and in the case of erosion it exhibits traces of multimodality. The model is compared to experimental data for the coagulationof a polystyrene latex. It is revealed that the model is not flexible enough to describecoagulation over an extended range of operation conditions with a unique set of parameters. In particular, it cannot predict the correct behavior for both a variation in the solid volume fraction of the suspension and in the agitation rate (shear rate).

  • 343.
    Bäbler, Matthäus
    et al.
    ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci.
    Morbidelli, M.
    Baldyga, Jerzy
    Modelling the breakup of solid aggregates in turbulent flows2008In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 612, p. 261-289Article in journal (Refereed)
    Abstract [en]

    The breakup of solid aggregates suspended in a turbulent flow is considered. The aggregates are assumed to be small with respect to the Kolmogorov length scale and the flow is assumed to be homogeneous. Further, it is assumed that breakup is caused by hydrodynamic stresses acting on the aggregates, and breakup is therefore assumed to follow a first-order kinetic where K-B(x) is the breakup rate function and x is the aggregate mass. To model K-B(x), it is assumed that an aggregate breaks instantaneously when the surrounding flow is violent enough to create a hydrodynamic stress that exceeds a critical value required to break the aggregate. For aggregates smaller than the Kolmogorov length scale the hydrodynamic stress is determined by the viscosity and local energy dissipation rate whose fluctuations are highly intermittent. Hence, the first-order breakup kinetics are governed by the frequency with which the local energy dissipation rate exceeds a critical value (that corresponds to the critical stress). A multifractal model is adopted to describe the statistical properties of the local energy dissipation rate, and a power-law relation is used to relate the critical energy dissipation rate above which breakup occurs to the aggregate mass. The model leads to an expression for K-B(x) that is zero below a limiting aggregate mass, and diverges for x -> infinity. When simulating the breakup process, the former leads to an asymptotic mean aggregate size whose scaling with the mean energy dissipation rate differs by one third from the scaling expected in a non-fluctuating flow.

  • 344.
    Bäbler, Matthäus
    et al.
    Swiss Fed Inst Technol, Inst Proc Engn.
    Moussa, Amgad S.
    Soos, Miroslav
    Morbidelli, Massimo
    Structure and Kinetics of Shear Aggregation in Turbulent Flows: I. Early Stage of Aggregation2010In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 26, no 16, p. 13142-13152Article in journal (Refereed)
    Abstract [en]

    Aggregation of rigid colloidal particles leads to fractal-like structures that are characterized by a fractal dimension d(f) which is a key parameter for describing aggregation processes. This is particularly true in shear aggregation where d(f) strongly influences aggregation kinetics. Direct measurement of d(f) in the early stages of shear aggregation is however difficult, as the aggregates are small and few in number. An alternative method for determining d(f) is to use an aggregation model that when fitted to the time evolution of the cluster mass distribution allows for estimating d(f). Here, we explore three such models, two of which are based on an effective collision sphere and one which directly incorporates the permeable structure of the aggregates, and we apply them for interpreting the initial aggregate growth measured experimentally in a turbulent stirred tank reactor. For the latter, three polystyrene latexes were used that differed only in the size of the primary particles (d(p) = 420, 600, and 810 nm). It was found that all three models describe initial aggregation kinetics reasonably well using, however, substantially different values for 4 To discriminate among the models, we therefore also studied the regrowth of preformed aggregates where d(f) was experimentally accessible. It was found that only the model that directly incorporates the permeable structure of the aggregates is able to predict correctly this second type of experiments. Applying this model to the initial aggregation kinetics, we conclude that the actual initial fractal dimension is d(f) = 2.07 +/- 0.04 as found from this model.

  • 345.
    Bäbler, Matthäus
    et al.
    ETH, Inst Chem & Bioengn, Dept Chem & Appl Biosci.
    Sefcik, J
    Morbidelli, M
    Baldyga, J
    Hydrodynamic interactions and orthokinetic collisions of porous aggregates in the Stokes regime2006In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 18, no 1, p. 013302-Article in journal (Refereed)
    Abstract [en]

    The hydrodynamic interaction of two neutrally buoyant porous aggregates is investigated under creeping flow conditions for the case where the undisturbed velocity of the surrounding flow field is a linear function of position. In this framework, the relative velocity between two aggregates is given by the deformation of the undisturbed flow expressed through the rate of strain and the angular velocity of the flow field, and by two flow-independent hydrodynamic functions, typically referred to as A and B, which account for the disturbance of the flow field due to the presence of the particles [G. K. Batchelor and J. T. Green, J. Fluid Mech. 56, 375 (1972)]. In the present paper, the analysis of thehydrodynamic interaction that is known for the case of two impermeable, solid particles is extended to the case of porous aggregates by applying Brinkman's equation to describe the flow within the aggregates. A reflection scheme is applied to calculate A and B and the obtained expressions are applied to interpret the orthokinetic aggregation ofaggregates in diluted suspensions, where the collision frequency is computed using the method of relative trajectories of a pair of aggregates.

  • 346.
    Bäckström, Eva
    KTH, School of Chemical Science and Engineering (CHE).
    Covalently modified starch with novel graphene oxide as biomaterial2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today there is a large interest to develop new biomedical material to treat medical conditions. These materials need to be biocompatible and preferably bioresorbable. One option is the common biopolymer starch. Typically it needs reinforcement to allow usage. Nano-sized Graphene Oxide (GO) is promising reinforcing filler since it is nontoxic and strong. A method to produce starch-based hydrogels reinforced with nano-sized graphene oxide was demonstrated in this work. Graphene Oxide was derived from starch by microwave irradiation followed by oxidation. In turn the produced GO were covalently attached to starch by an esterification reaction using DCC and DMAP in DMSO to get the reinforced starch (STGO). Both GO and STGO were carefully investigated by TEM, SEM, DLS, AFM, NMR, FTIR, TGA and XRD. Starch hydrogels containing GO and STGO were produced in the presence of glycerol. Mineralization test on the gel proved that the carboxyl group present in GO functions as an anchoring site for the mineral Hydroxyapatite that is fundamental for enamel. Higher concentration of reinforced starch in the hydrogels showed better results with a higher density of mineral growth and a stoichiometric mineral. The STGO starch hydrogels thus show great potential to be utilized in dental applications to regenerate the demineralized teeth.

  • 347.
    Bäckström, Marie
    KTH, School of Chemical Science and Engineering (CHE).
    Global Manufacturing Training: The localization of the Powerformer Field Operator curricula at the Notre Dame de Gravenchon Refinery2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Global Manufacturing Training (GMT) project aims at homogenizing and raising the level of competency of the workforce at ExxonMobil plants in all countries where the company is active. This report presents and introduces the main structures of the GMT venture. It deals with important aspects of the project on a global scale, but it also details the implementation of training on a local level. The different pedagogical strategies are outlined, along with the resulting system of training documents.

    A global team of experts developed general training documents, called global modules in order to set the standard for the various training documents. The inherent differences between the plants in the ExxonMobil corporation makes it necessary to adapt the global modules to fit with the site in question. The differences between the plants are of both technical character, but also concern working procedures. The process of adapting each document according to the GMT outline is called Localization.

    In the current work, the localization of training documents for the Powerformer at the refinery in Notre Dame de Gravenchon-Port Jérôme (NDG-PJG) is detailed and explained. At the NDG-PJG refinery there are two units containing a Powerformer. The training documents concern the field operator, working on what is locally called the Reforming 2 position. The ensemble of the documents localized will be used for the habilitation of the process operator. Habilitation refers the preparatory training needed in order to be able to perform the tasks and procedures of a specific position. The work has resulted in the localization of 90 percent of the global documents concerning the Reforming 2 position.

  • 348.
    Börjesson, Erik
    KTH, School of Chemical Science and Engineering (CHE).
    Undersökning av jonvätskematrisers detektion på olika typer av MALDI plattor2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project was made to examine if there was a better ionic liquid matrix instead of the matrix 2,5-dihydroxybenzene. The aim of the project was also to investigate if there were any detection differences between anchorchip and groundsteel plate when testing matrix assisted laser desorption ionization masspectrometry (MALDI-MS). An ionic liquid matrix is a matrix that binds to a base used to protect the peptides from adducts. In the degree project 2,5-dihydroxybenzene was compared with the ionic liquid matrices which is 2,5-dihydroxybenzene combined with a base. The bases were ethylamine, diethylamine, diisopropylamine and N,N- ethyldiisopropylamine. All matrices were dissolved in ethanol, water or a liquid mix (0,1 % Trifluoroacetic acid in water and acetonitril in 7:3 volume). The tests were performed by mixing the matrix and the ionic liquid matrices with a peptide mix which contained 8 types of peptides. The matrix/ionic liquid matrices and peptide mix was deposited on a ground steel and anchorchip MALDI plate. After the mixture had evaporated and transformed to crystals/film, the plates were put in MADLI equipment. The results showed that N,N- ethyldiisopropylamine in ethanol and liquid mix had better detection than 2,5-dihydroxybenzene. Ethylamine and diethylamine had the same detection as 2,5-dihydroxybenzene in ethanol on anchorchip plate. There were detection differences between the anchorchip and ground steel plate. In favor of ground steel plate when detecting tyr-bradykinin, but for detecting the rest of the peptides anchorchip is favorable. If further studies would be performed in this area it would be done in the liquid mix and ethanol as solvent. For more comparable detection results the matrices concentration should be in mol/L instead of g/L.

  • 349. Cabeza, Luisa F.
    et al.
    Miro, Laia
    Oro, Eduard
    de Gracia, Alvaro
    Martin, Viktoria
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Kroenauer, Andreas
    Rathgeber, Christoph
    Farid, Mohammed M.
    Paksoy, Halime O.
    Martinez, Monica
    Ines Fernandez, A.
    CO2 mitigation accounting for Thermal Energy Storage (TES) case studies2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 155, p. 365-377Article in journal (Refereed)
    Abstract [en]

    According to the IPCC, societies can respond to climate changes by adapting to its impacts and by mitigation, that is, by reducing GHG emissions. No single technology can provide all of the mitigation potential in any sector, but many technologies have been acknowledged in being able to contribute to such potential. Among the technologies that can contribute in such potential, Thermal Energy Storage (TES) is not included explicitly, but implicitly as part of technologies such as energy supply, buildings, and industry. To enable a more detailed assessment of the CO2 mitigation potential of TES across many sectors, the group Annex 25 "Surplus heat management using advanced TES for CO2 mitigation" of the Energy Conservation through Energy Storage Implementing Agreement (ECES IA) of the International Energy Agency (AEI) present in this article the CO2 mitigation potential of different case studies with integrated TES. This potential is shown using operational and embodied CO2 parameters. Results are difficult to compare since TES is always designed in relation to its application, and each technology impacts the energy system as a whole to different extents. The applications analyzed for operational CO2 are refrigeration, solar power plants, mobile heat storage in industrial waste heat recovery, passive systems in buildings, ATES for a supermarket, greenhouse applications, and dishwasher with zeolite in Germany. The paper shows that the reason for mitigation is different in each application, from energy savings to larger solar share or lowering energy consumption from appliances. The mitigation potential dues to integrated TES is quantified in kg/MW h energy produced or heat delivered. Embodied CO2 in two TES case studies is presented, buildings and solar power plants.

  • 350.
    Caetano de Souza, Antonio Carlos
    et al.
    Department of Energy, São Paulo State University (UNESP), Brazil.
    Silveira, José Luz
    Department of Energy, São Paulo State University (UNESP), Brazil.
    Kiros, Yohannes
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Zanzi Vigouroux, Rolando
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    A low cost & safe system of hydrogen production utilizing NaBH4 and CoO catalysis2007In: 2nd International Congress University-Industry Cooperation (UNIDU07), 2007Conference paper (Refereed)
    Abstract [en]

    The objective of this study was to evaluate the hydrogen production through hydrolysisof sodium borohydride (NaBH4) utilizing catalysts containing CoO. The reactant is safe and stable(when dry) at room temperature. Few works and studies have presented results of investigationsutilizing catalysts containing cobalt; however utilizing catalysts containing CoO were not found yet.In this work simple and cheap hydrogen generation system was developed having reactions atnormal conditions of temperature and pressure. A solution containing a gravimetric composition of10% wt. NaOH, 10% wt. NaBH4 and 80% wt. H2O was utilized. The reaction was carried out atvarious times using the same catalyst to evaluate its performance. This catalyst presented highrates of hydrogen production, especially at its start-up (about 99% of the theoretical hydrogenvolume was produced) at room temperature. After start-up, e.g., when more solution was put, rateof hydrogen production decreased having its production performance also decreased. Probablythis fact occurred due to the formation of the solid phase products such as NaBO2 which might fillthe porous catalyst structure; decreasing the catalytic area. This catalyst is suggested in situationswhere high production rates are necessary such as start-up of fuel cells.

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