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  • 1.
    Alevanau, Aliaksandr
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Ersson, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Jönsson, Pär
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kuznechik, Olgerd
    Belarussian State University.
    Vyhoniailo, Oleksandr
    Mechanically assisted low temperature pyrolysis of hydrocarbons2014In: Proceedings of the XVII International Conference Foundations & Advances in Nonlinear Science, September 29 - October 3, Minsk 2014, 2014Conference paper (Refereed)
    Abstract [en]

    We report experimental setups and conditions leading to pyrolysis (cracking) of such gaseous hydrocarbons as methane, mixed propane and butane, at the temper-atures of the heater below 200oC. The process was mechanically assisted by putting the substances being decomposed into a dynamic interaction with the tin and bismuth alloy. The alloy had periodically changing phase state thus creating fractal interfaces between its surface and the gases. Interaction of the gases with mechanically produced fractal surfaces of the alloy made possible gas decomposition even at lower temperatures of the heater (150oC). At this temperature the heater couldn't melt the alloy in the heated volume with the gas.

  • 2.
    Alevanau, Aliaksandr
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Study of the effects of gaseous micro-expansion on the efficiency of convective heat transfer during pyrolysis2013In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 106, p. 253-261Article in journal (Refereed)
    Abstract [en]

    Measurements of temperature in the proximity of wood pellets (8 mm diameter) and thin wooden stick slices (5 cm diameter and 5 mm thickness) were conducted to estimate the effects of mixing between the evolving volatiles and hot steam (T > 700°C) flowing around the particles. Measurements of mass loss of the slices were conducted to estimate the apparent kinetic parameters of their pyrolysis. A simple kinetic model of the process (type II by Pyle and Zaror (1984) [20]) was investigated. The experiments showed a plateau-like part in the graphs of temperature measured in the proximity to the samples. The existence of this plateau-like part agrees with the general data of calorimetric measurements of pyrolysis, which show extensive energy consumption in the beginning of an active production of volatiles. A hypothesis regarding feedback on the process due to the micro-expansion and mixing of volatiles in the convective boundary layer is discussed.

  • 3.
    Cuvila, Carlos Alberto
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Mellin, Pelle
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Saffaripour, M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Hye, A.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effect of zeolite on product yield and composition during pyrolysis of hydrothermally pretreated SpruceManuscript (preprint) (Other academic)
  • 4.
    Cuvila, Carlos Alberto
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Mellin, Pelle
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Saffaripour, M.
    Hye, A.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effect of zeolite on product yield and composition during pyrolysis of hydrothermally pretreated SpruceManuscript (preprint) (Other academic)
  • 5.
    Cuvila, Carlos Alberto
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    The Impact of a Mild Sub-Critical Hydrothermal Carbonization of Pretreatment on Umbila Wood: A Mass and Energy Balance Perspective2015In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 8, no 3, p. 2165-2175Article in journal (Refereed)
    Abstract [en]

    Over the last years, the pretreatment of biomass as a source of energy has become one of the most important steps of biomass conversion. In this work the effect of a mild subcritical hydrothermal carbonization of a tropical woody biomass was studied. Results indicate considerable change in carbon content from 52.78% to 65.1%, reduction of oxygen content from 41.14% to 28.72% and ash slagging and fouling potential. Even though decarboxylation, decarbonylation and dehydration reactions take place, dehydration is the one that prevails. The mass and energy balance was affected by the treatment conditions than the severity of the treatment.

  • 6.
    Cuvila, Carlos Alberto
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Said, Mahir
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Saffaripour, M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effect of mild hydrothermal pretreatment on biomass pyrolysis characteristics and vapors: A Mass and Energy Balance PerspectiveManuscript (preprint) (Other academic)
  • 7.
    Cuvila, Carlos Alberto
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Said, Mahir
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Saffaripour, M.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effect of mild hydrothermal pretreatment on biomass pyrolysis characteristics and vapors: A Mass and Energy Balance PerspectiveManuscript (preprint) (Other academic)
  • 8.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Arato, Samantha
    Persson, Henry
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Reduction of brominated flame retardants (BFRs) in plastics from waste electrical and electronic equipment (WEEE) by solvent extraction and the influence on their thermal decompositionIn: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456Article in journal (Refereed)
    Abstract [en]

    Consumption of electronics increases due to modern society’s growing needs, which leads to increasing generation of waste electrical and electronic equipment (WEEE). Recycling of WEEE has been a global concern during the last few decades because of the toxic compounds that are produced during recycling. Different recycling techniques have been adapted on a commercial scale in order to overcome this issue, but the recycling of WEEE still lacks the technology to treat different kinds of feedstocks and to maximise the recycling rates. Pyrolysis is an alternative that has not been commercialised yet. One of the challenges for the implementation of this technology is the toxic brominated organic compounds that can be found in the pyrolysis oils.

    In this study, tetrabromobisphenol A (TBBPA), one of the major flame retardants, is reduced in three different WEEE fractions through solvent extraction as a treatment prior to pyrolysis. Two solvents have been experimentally investigated: isopropanol and toluene, the latter of which can be derived from pyrolysis oil. The results indicate that TBBPA was extracted during pre-treatment. Moreover, the total bromine content of WEEE material was reduced after the treatment with a maximum reduction of 36.5%. The pyrolysis experiments indicate that reduction of several brominated organic compounds was achieved in almost all the tested cases, and two brominated compounds (2,4,6-tribromophenol and 2,5-Dibromobenzo(b)thiophene) reached complete removal. Also, the thermal decomposition behaviour of the raw samples and the treated was investigated, showing that the reduction of TBBPA influences the decomposition by shifting the starting decomposition temperature.

  • 9.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Arvelakis, Stylianos
    National Technical University of Athens.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental investigation of low temperature pyrolysis of printed circuit boards (PCBs) and printed circuit board components (PCB sockets)Manuscript (preprint) (Other academic)
    Abstract [en]

    Printed circuit boards (PCBs) are the heart of all electronics due to their compact size and the broad spectrum of applications but very challenging when their life ends. Recycling of these components is problematic since they consist of different metallic parts packed on plastic compressed cover. The present study focuses on low temperature pyrolysis of PCBs since this process can separate the organic fraction from the inorganics. The latter, enables further separation and purification of the metals which are not oxidized during mild treatment. The low Br content of the resultant char after treatment at 320 oC for 30 min indicates that it could be used as solid fuel if efficient separation from the inorganic part would be performed. Moreover, the liquids obtained by this process can be used for feedstock recycling since the results indicates that toxic bromine containing on the organic compounds has been decreased both by increasing the residence time of pyrolysis process or by increasing the temperature conditions.

  • 10.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental Investigation of Pyrolysis of Printed Circuit Boards for Energy and Materials Recovery under Nitrogen and Steam Atmosphere2017In: 8th International Conference on Applied Energy, ICAE 2016; Beijing; China; 8 October 2016 through 11 October 2016, Elsevier, 2017, Vol. 105, p. 986-991Conference paper (Refereed)
    Abstract [en]

    Printed circuit boards (PCB) are one of the most challenging fractions of e-waste in terms of material recycling and energy recovery. In this study, pyrolysis of PCBs in inert and steam atmosphere has been investigated as a valuable alternative for energy recovery of the organic fraction with simultaneous recycling of metals. The decomposition of two different PCB fractions has been investigated by means of thermogravimetric analysis (TGA) and lab scale pyrolysis experiments in steam and nitrogen atmospheres. The composition of the gas obtained from the pyrolysis experiments was strongly influenced by the reactive atmosphere. The characterization of the solid residue by X-ray Powder Diffraction (XRD) and scanning electron microscopy (SEM) showed high influence of steam to the migration of the antimony in the produced vapors.

  • 11.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental investigation of the influence of reaction atmosphere on the pyrolysis of printed circuit boards2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 204, p. 1065-1073Article in journal (Refereed)
    Abstract [en]

    Printed circuit boards (PCB) are one of the most challenging fractions of waste electrical and electronic equipment (WEEE) in terms of recycling due to their complexity and diversity. Pyrolysis seems to be a promising alternative for production of energy carriers from its organic fraction with simultaneous recovery of metals. Reaction atmosphere is among the process parameters that affects the thermal decomposition as well as the products’ formation and distribution. In this study, the decomposition of two different PCB fractions in inert and steam atmospheres has been investigated by means of thermogravimetric analysis (TGA) and lab scale fixed bed reactor experiments. It was found that the decomposition of the tested materials in steam atmosphere starts at lower temperatures and proceeds slower compared to the N2 atmosphere. Moreover, a two-step decomposition has been observed on the PCB sockets fraction due to the fact that high amount of antimony oxide was present, a common additive for improving the flame retardancy, which have been also observed on previous studies (Wu et al., 2014). The presence of steam influence the pyrolysis gas composition and promotes additional vaporisation of antimony as verified by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Finally, the liquid fraction has been qualitatively analysed using a GC/MS in order to determine the brominated compounds as well as other compounds that are produced from this process.

  • 12.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Investigation of the thermal decomposition of printed circuit boards (PCBs) via thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS)2015In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 115, p. 337-343Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is to experimentally investigate the pyrolytic behavior of printed circuit boards (PCBs) waste fraction at a temperature range of 400 °C to 900 °C by means of thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS) was carried out. The experimental results reveal that the chemical composition of the PCBs and the relatively high ash content (=79% w/w) are strongly connected with the high quantity of metals and ceramic materials. The main decomposition of PCBs occurs between 250 °C and 370 °C. The pyrolysis of PCBs showed a varying production of aromatic compounds such as phenol, bromophenol, styrene, methylstyrene, and bisphenol A as well as non-aromatic compounds such as acetone and bromomethane, which are strongly related with the initial chemical composition of PCBs. Moreover, Py-GC/MS revealed that temperature increase favours the production of aromatic hydrocarbons, while the phenol which is the most abundant compound produced, shows an opposite trend, as a result of its further decomposition to simpler products. Furthermore, brominated compounds produced, such as bromomethane and bromophenol, are derived from the flame retardant used during the manufacturing process and in that case the Py-GC/MS showed a slight decrease of brominated compounds with increase in temperature.

  • 13. Evangelopoulos, Panagiotis
    et al.
    Persson, Henry
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology. KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Pyrolysis of waste electrical and electronic equipment (WEEE) on a single screw reactor for bromine free oil productionManuscript (preprint) (Other academic)
    Abstract [en]

    This study focuses on pyrolysis on waste electrical and electronic equipment or WEEE as it is usually referred in the literature. A new auger reactor has been designed and tested with WEEE material. The performance of the reactor as well as the fate of the bromine has been investigated and evaluated in order to be used for designing of industrial process. The mass balance calculations performed for the tested cases of 400, 500 and 600 °C, showed a high gas yield (44%) at the temperature of 600 °C, which can be used to fulfil the process energy needs. At the low temperature of 400 °C the oil production reach its maximum yield, while the bromine content of the oil has also a maximum percentage of 0.5% wt. Several valuable compounds have been detected in the oil composition, which can be used either as fuels or for feedstock recycling.

  • 14.
    H. Moud, Pouya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology. KTH.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    J. Andersson, Klas
    Engvall, Klas
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Biomass pyrolysis gas conditioning over an iron-based catalyst for mild deoxygenation and hydrogen production2017In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 211, p. 149-158Article in journal (Other academic)
    Abstract [en]

    Bio-crude is a renewable source for production of valuable energy carriers. Prior to its utilization, a conditioning step of the raw pyrolysis gas can be beneficial before the bio-crude is converted via catalytic hydrodeoxygenation (HDO) into liquid hydrocarbon products, or via steam reforming (SR) to synthesis gas/hydrogen. An experimental small industrial scale study for the chemistry of atmospheric pressure pyrolysis gas conditioning resulting in bio-crude deoxygenation and a hydrogen-rich gas using an iron-based catalyst without addition of hydrogen or steam is presented and discussed. Following a short catalyst stabilization period with fluctuating bed temperatures, the catalyst operated near 450°C at a space velocity of 1100 h-1 for 8 hours under stable conditions during which no significant catalyst deactivation was observed. Experimental results indicate a 70-80% reduction of acetic acid, methoxy phenols, and catechol, and a 55-65% reduction in non-aromatic ketones, BTX, and heterocycles. Alkyl phenols and phenols were least affected, showing a 30-35% reduction. Conditioning of the pyrolysis gas resulted in a 56 % and a 18 wt% increase in water and permanent (dry) gas yield, respectively, and a 29 % loss of condensable carbon. A significant reduction of CO amount (-38 %), and production of H2 (+1063 %) and CO2 (+36 %) over the catalyst was achieved, while there was no or minimal change in light hydrocarbon content. Probing the catalyst after the test, the bulk phase of the catalyst was found to be magnetite (Fe3O4) and the catalyst exhibited significant water gas shift (WGS) reaction activity. The measured gas composition during the test was indicative of no or very limited Fischer-Tropsch (FT) CO /CO2 hydrogenation activity and this infers that also the active surface phase of the catalyst during the test was Fe-oxide, rather than Fe-carbide. The results show that iron-based materials are potential candidates for application in a pyrolysis gas pre-conditioning step before further treatment or use, and a way of generating a hydrogen-enriched gas without the need for bio-crude condensation.

  • 15. Kantarelis, E.
    et al.
    Donaj, Pawel
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zabaniotou, A.
    Sustainable valorization of plastic wastes for energy with environmental safety via High-Temperature Pyrolysis (HTP) and High-Temperature Steam Gasification (HTSG)2009In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 167, no 1-3, p. 675-684Article in journal (Refereed)
    Abstract [en]

    In the present study the energetic valorization of electric cable shredder residues (mixed plastics) has been investigated. Thermochemical conversion by means of High-Temperature Steam Gasification (HTSG) and High-Temperature Pyrolysis (HTP) was studied. The effects of temperature and reaction time - process parameters - were investigated. Comparison of the results showed that HTSG seems a more suitable process in terms of produced syngas quality (64%. v/v and 13 MJ/Nm(3)) than HTP because of higher H-2 yield and lower tar content.

  • 16.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Catalytic Steam Pyrolysis of Biomass for Production of Liquid Feedstock2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The current societal needs for fuels and chemical commodities strongly depend on fossil resources. This dependence can lead to economic instabilities, political problems and insecurity of supplies. Moreover, global warming, which is associated with the massive use of fossil resources, is a dramatic “collateral damage” that endangers the future of the planet.

    Biomass is the main renewable source available today that can, produce various liquid, gaseous and solid products. Due to their lignocellulosic origin are considered CO2 neutral and thus can generate CO2 credits. Biomass processing can meet to the challenge of reducing of fossil resources by producing a liquid feedstock that can lessen the “fossil dependence” and /or meet the increased demand via a rapidly emerging thermochemical technology: pyrolysis.

    The ultimate goal of this process is to produce liquid with improved properties that could directly be used as liquid fuel, fuel additive and/or feedstock in modern oil refineries and petrochemical complexes.

    However, the liquids derived from biomass thermal processing are problematic with respect to their handling and end use applications. Thus, alternative routes of advanced liquid feedstock production are needed. Heterogeneous catalysis has long served the oil refining and petrochemical industries to produce a wide range of fuels and products. The combination of biomass pyrolysis and heterogeneous catalysis (by bringing in contact the produced vapours/liquids with suitable catalysts) is a very promising route.

    In this dissertation, the exploitation of biomass to produce of liquid feedstock via pyrolysis over a multifunctional catalyst and in a steam atmosphere is investigated. 

    Steam pyrolysis in a fixed bed reactor demonstrated that steam can be considered a reactive agent even at lower temperatures affecting the yields and the composition of all the products. The devolatilisation accelerates and the amount of final volatile matter in the char.

    Fast pyrolysis in the presence of steam results in improved and controlled thermal decomposition of the biomass; higher liquid yields and slightly deoxygenated liquid products are also obtained.

    Steam pyrolysis over a bi-metallic Ni-V catalyst can produce liquids of improved quality (lower O content) and also provide routes for selective deoxygenation. However, a decrease in liquid yield was observed.

    The combination of metal and acid catalysts (Ni-V/HZSM5) shows enhanced deoxygenation activity and increased H preservation in the produced liquid. The final O content in the liquid was 12.83wt% at a zeolite (HZSM5) loading of~75wt%; however, the yield of the obtained liquid was substantially decreased. Moreover, increased coke formation on the catalyst was observed at highest zeolite rate.

    The increased catalyst space time (τ) results in a lower liquid yield with reduced oxygen (7.79 wt% at τ =2h) and increased aromatic content. The coke deposited per unit mass of catalyst is lower for longer catalyst space times, while the char yield seems to be unaffected.

    The evaluation of the stability of the hybrid catalyst showed no significant structural defects and activity loss when the catalyst was regenerated at a low temperature (550οC).

  • 17.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Thermochemical treatment of electric and electronic waste for energy recovery2009Licentiate thesis, comprehensive summary (Other academic)
  • 18.
    Kantarelis, Efthymios
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Javed, R.
    Stefanidis, S.
    Psarras, A.
    Iliopoulou, E.
    Lappas, A.
    Engineering the Catalytic Properties of HZSM5 by Cobalt Modification and Post-synthetic Hierarchical Porosity Development2019In: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 62, no 7, p. 773-785Article in journal (Refereed)
    Abstract [en]

    Hierarchical zeolites have been identified as special catalytic materials with improved catalytic properties. In this study, hierarchical bifunctional ZSM5 based catalysts were prepared by desilication for controlled mesoporosity development and have been modified by Co doping. Their performance in the catalytic pyrolysis of oak in a lab scale reactor was evaluated. Desilicated counterparts were proven more active in deoxygenation of bio oil, while carbon deposition on the catalysts reduced compared to non-desilicated counterparts. Increased Lewis acidity favors decarboxylation reactions, while higher olefins as well as PAH content indicate easier diffusion within and from the porous network and interactions in the mesopores. The conversion of bulky lignin molecules (alkoxy phenols) is enhanced by the mesopores, while acidity is of secondary importance. Coke deposition inside the pores is more profound in the desilicated catalysts due to larger pore size. Carbon deposition on the catalysts is reduced in the following order: HZSM5 > Co/HZSM5 > Ds-HZSM5 > Co/Ds-HZSM5. GC–MS characterization of the CH2Cl2 soluble coke indicated that for the desilicated counterparts the main coke precursors are the bulky lignin molecules which are partially deoxygenated.

  • 19.
    Kantarelis, Efthymios
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Javed, Rashed
    Stefanidis, Stylianos
    Psarras, Antonios
    Iliopoulou, Eleni
    Lappas, Angelos
    Upgrading biomass pyrolysis vapors over hierarchical Co/HZSM5: Activity and coking characteristics2018In: 18th Nordic Symposium on Catalysis Book of Abstracts, Copenhagen, 2018, p. 29-29, article id O3.2Conference paper (Refereed)
  • 20.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Liu, Junli
    Yang, Weihong
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Sustainable Valorization of Bamboo via High-Temperature Steam Pyrolysis for Energy Production and Added Value Materials2010In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 24, p. 6142-6150Article in journal (Refereed)
    Abstract [en]

    Bamboo is an abundant plant in many Asian countries and especially in China, it has an extremely rapid growing rate, and It can be considered as a sustainable wood resource In this paper a comparative study of pyrolysis of bamboo in the presence of high temperature steam and an inert atmosphere (N-2) as well as characterization of products has been conducted Evaluation of experimental results showed that faster devolatilization can be achieved in the presence of high-temperature steam Furthermore, the gas composition indicates interaction of steam with vapors and solid species even at low temperatures Analysis of the obtained liquid after steam pyrolysis at 797 K revealed that the H/C and O/C ratios in the liquid are 1 54 and 0 16, respectively The characteristics of the products indicate possible exploitation of derived char as an activated carbon precursor, a reducing agent in metallurgical processes, or a solid fuel for gasification and combustion processes The composition of the liquid fraction suggests further exploitation as a liquid fuel and/or chemical feedstock

  • 21.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Biomass pyrolysis  for energy and fuels production2013In: Technologies for Converting Biomass to Useful Energy: Combustion, Gasification, Pyrolysis, Torrefaction and Fermentation / [ed] Erik Dahlquist, CRC Press, 2013, p. 245-277Chapter in book (Refereed)
  • 22.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effect of zeolite to binder ratio on product yields and composition during catalytic steam pyrolysis of biomass over transition metal modified HZSM52014In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 122, p. 119-125Article in journal (Refereed)
    Abstract [en]

    Catalytic pyrolysis of biomass over metal modified zeolites (multifunctional catalysts) is a very promising route for production of hydrocarbons and less oxygenated liquid feedstock suitable for fuels and/or chemicals. In this work the effect of zeolite to binder ratio (Z/B) of a metal modified HZSM5, on products yields and composition during steam pyrolysis of biomass has been investigated. Increased zeolite content resulted in lower liquid yield and increased coke formation; however, more deoxygenated liquids obtained at higher zeolite loadings. Char yield is not significantly affected by the zeolite content. Declining catalytic activity is observed at longer time on stream because of coke deposition. While acidic function of the catalyst deoxygenates carboxylic acids and carbonyls, metal functions seem to selectively convert phenols and methoxy phenols. Competitive steam adsorption on the acid sites of the zeolite seems to lower the conversion to aromatics. The high availability of acid sites, at higher zeolite loading, increases aromatics concentration exponentially. Increased yields of hydrogenated products have been obtained indicating that the Ni-V/HZSM5 catalyst exhibits some hydrogenation activity.

  • 23.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Effects of Silica-Supported Nickel and Vanadium on Liquid Products of Catalytic Steam Pyrolysis of Biomass2014In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 28, no 1, p. 591-599Article in journal (Refereed)
    Abstract [en]

    Catalytic steam pyrolysis of biomass was performed in a bubbling fluidized-bed reactor at 450 degrees C, and the effects of silica-supported transition metals (Ni and V) on product yields and compositions have been investigated. Both metals seem to be catalytically active and altered the liquid composition. An interesting finding is the in situ reduction of the supported nickel oxide to metallic Ni during the pyrolysis reactions, which can enhance H-transfer. Vanadia-containing catalysts show higher selectivity in reduction of carboxylic acids and ketones. An increased aldehyde content, especially for the bimetallic Ni-V catalyst, suggests that selective deoxygenation can take place via the Mars van Krevelen (MvK) mechanism. Ni catalysts showed activity for aromatics formation, while both metals showed selectivity in producing phenols instead of catechols. Assessment of the catalytic performance indicates that both metals could be interesting candidates for incorporation in other support materials and evaluation of the derived modified catalysts in biomass steam pyrolysis.

  • 24.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Investigation on the effect of space time of nickelvanadium modified HZSM5 on products and coke formation during catalytic steam pyrolysis of biomassManuscript (preprint) (Other academic)
  • 25.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Production of Liquid Feedstock from Biomass via Steam Pyrolysis in a Fluidized Bed Reactor2013In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 27, no 8, p. 4748-4759Article in journal (Refereed)
    Abstract [en]

    The nature of liquids derived from biomass fast pyrolysis is far from typical oil, and thus, different approaches for bio-oil production and upgrading are needed. In this paper the steam pyrolysis of a pine and spruce wood mixture in a bubbling fluidized bed is investigated. Particularly, the effect of steam to biomass ratio and temperature in relation to products yields and composition has been studied. Products analyses indicate that steam presence affects the yields and composition of all the products (gas, char, liquid) and promotes oxygen removal from the liquid. Increased liquid yields with significantly lower amount of carboxylic acids and higher effective hydrogen index (EHI) were obtained, which makes them more suitable for further upgrading. The levoglucosan (LGA) concentration in the produced liquid is higher compared with conventional N-2 pyrolysis, which suggests that steam pyrolylsis can be regarded as an alternative for production of fermentable sugars. Polycondensation reactions are hindered by steam presence while steam seems to act as a hydrogen donor; however, increased water content is a problem that has to be considered as well.

  • 26.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Forsgren, C.
    Zabaniotou, A.
    Thermochemical treatment of E-waste from small household appliances using highly pre-heated nitrogen-thermogravimetric investigation and pyrolysis kinetics2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 3, p. 922-929Article in journal (Refereed)
    Abstract [en]

    The EU directive on waste of electrical and electronic equipment (WEEE) 2002/96/EC has set a goal of recovering 70-80% in terms of materials and energy. Nowadays, thermal cracking (pyrolysis) of such waste streams is receiving renewed attention, due to the energy and material recovery that can be achieved and therefore the sustainable waste management. However, it still lacks the kinetic background which is of great importance for a successful design of thermochemical processes. In this study the kinetic parameters of WEEE (originating from small household appliances) pyrolysis using highly pre-heated nitrogen under six different heating rates (1-2.5 K/s) have been estimated using a combination of model-free and model fitted methods. Even though WEEE is heterogeneous material, similar behavior at each of the six different heating rates applied was observed. The activation energy of the pyrolysis process determined with two different model-free methods gave comparable results. Pre-exponential factor and reaction order were determined using the Coats-Redfern method. The estimated kinetic parameters for the WEEE pyrolysis are: E = 95.54 kJ/mol, A = 1.06 x 10(8) and n = 3.38.

  • 27.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Włodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Biomass pyrolysis for energy and fuel production2013In: Technologies for Converting Biomass to Useful Energy: Combustion, Gasification, Pyrolysis, Torrefaction and Fermentation, CRC Press , 2013, p. 245-278Chapter in book (Other academic)
    Abstract [en]

    Pyrolysis is the thermochemical decomposition of organic matter in the absence of oxygen and produces a wide range of useful products. The word is coined from the Greek-derived elements pyr "ρ-fire” and lysis "λUsσς-breakdown/separation” emphasizing the disintegration of matter due to heat. It is a standalone process or one of several reaction steps in gasification and combustion processes1 and is considered as the basic thermochemical process to produce valuable fuels and energy from biomass. Pyrolysis is also known as thermolysis, thermal cracking, dry distillation, destructive distillation, etc.; however, there are differences in those terms. During pyrolysis, complex macromolecules of biomass break down into relatively smaller molecules producing 3 major products which can be classified as follows: •a solid residue (which mainly consists of carbon and ash) known as char•gases (mainly CO, CO2, CH4, H2 and other light hydrocarbons)•Vapors/liquids known as bio-oil or bio-crude (mainly oxygenates, aromatics, water, products of low degree of polymerization, tars, etc.)

  • 28. Liu, J.
    et al.
    Jiang, J.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Sustainable exploitation of salix via high temperature steam pyrolysis for energy production and added value materials2013In: ICMREE 2013 - Proceedings: 2013 International Conference on Materials for Renewable Energy and Environment, 2013, Vol. 1, p. 249-255Conference paper (Refereed)
    Abstract [en]

    Salix is an abundant plant as the feedstock of biomass energy in many countries all over the world. It has an extremely rapid growing rate, and it can be considered as a sustainable raw material wood resource. In this study pyrolysis of salix in the presence inert atmosphere (N2) and high temperature steam (which combines the benefits of High Temperature Steam Gasification (HTSG) and steam pyrolysis) and characterization of products has been carried out. Evaluation of experimental results showed that faster devolatilization and char with increased surface area obtained in the presence of high temperature steam comparing to N2 while higher liquid production obtained at 823 K in the presence of high temperature steam. Analysis of the obtained liquid revealed that the H/C and O/C ratios in the liquid are 1.5 and 0.16 respectively. Further more gas composition during high temperature steam pyrolysis differs from gas composition derived from N2 pyrolysis which indicates interaction of steam with vapors and solid species even at low treatment temperatures. The derived products’ yields and characteristics indicate possible exploitation of derived char as activate carbon precursor or reducing agent in metallurgical processes or solid fuel for gasification and combustion processes. Liquid fraction composition makes it suitable for exploitation as liquid fuel and/or chemical feedstock.

  • 29.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    CFD approach to investigate fast pyrolysis by pre-heated steam, in a fluidized bed reactor2012Conference paper (Other academic)
  • 30.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Computational fluid dynamics modeling of biomass fast pyrolysis in a fluidized bed reactor, using a comprehensive chemistry scheme2014In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 117, no Part A, p. 704-715Article in journal (Refereed)
    Abstract [en]

    The CFD modeling for fast pyrolysis has previously focused on the major pyrolysis products; liquid, charand gas. This paper introduces a new approach to biomass pyrolysis; integrating a complex scheme of reactions including formation of such components as levoglucosan. The 3-D simulation takes into account the complex breakdown of each biomass subcomponent, the fluid dynamics of the process as well as the heat and momentum transfer of three Eulerian phases.

    The pyrolysis products include reference species that reflects the composition of the bio oil, gas fraction and char fraction. A number of reactions are in addition applied to account for the thermal cracking of tar compounds and the final compositions are compared to experimental yields. The results show that the predicted pyrolysis products reflect the experimental yields satisfactorily, apart from the water content which is under predicted. Most importantly though, the approach is computationally feasible and it should be useful for future work.

  • 31.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Processing of biomass to Hydrocarbons – using a new catalytic steam pyrolysis route2014Conference paper (Other academic)
    Abstract [en]

    Obtaining renewable transportation fuel has been identified as one of the main challenges for a sustainable society. Catalytic pyrolysis followed by hydrotreatment has been demonstrated as one possible route for producing transportation fuels. Using steam in this process could have a number of benefits as given by our research effort. For this paper, we will show that a catalyst together with steam prolongs the activity of the catalyst by preventing coking. This means that both steam and catalyst mutually benefits the deoxygenation. The presented mass and energy balance shows that up to 40% of the calorific value of biomass remains in the deoxygenated oil, on dry basis. This is in contrast to the mass yield, which for the same case was 25%; meaning that the oil is of significantly higher quality with a high content of hydrocarbons. In addition, CFD studies have shown steam is able to redistribute the heat flux and provide more uniform operating conditions compared to for example nitrogen. In conclusion, this route using steam shows promise for displacing fossil transportation fuels, by upgrading of the liquid in existing refineries or next-generation bio refineries. In additional support of this, we have published a number of papers describing conventional fast pyrolysis using steam, CFD modeling for further understanding and experimental work using a combination of steam and firstly a bimetallic catalyst (Ni, V) then a metal modified HZSM5 catalyst (Ni, V, Zeolite, Binder). This paper connects all these individual studies and provides further understanding of the role of steam and the role of steam in combination with a catalyst, in the fast pyrolysis process.

  • 32.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhou, Chunguang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Simulation of Bed Dynamics and Primary Products from Fast Pyrolysis of Biomass: Steam Compared to Nitrogen as a Fluidizing Agent2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 30, p. 12129-12142Article in journal (Refereed)
    Abstract [en]

    Fast pyrolysis of biomass, using steam as a fluidizing agent, provides several benefits. In this paper, an unsteady multiphase computational fluid dynamics (CFD) model coupled with a comprehensive kinetic scheme for primary pyrolysis is used to obtain the formation rates of primary products and compare the profiles when operating with steam and nitrogen. The model only considers the physical effects of the fluidizing gas at the moment, although a literature review indicates the existence of various chemical and surface-interacting effects. At stabilized pyrolysis reaction rates, the product yields were compared to data found in the literature, which indicated similar yields; this supports the correct implementation of the kinetic model. However, the difference in overall rate and composition is very small when steam is compared to nitrogen. The simultaneous simulation of bed dynamics indicate a shifted formation rate of primary products toward the lower part of the fluidized bed, with an increase in solid vapor contact time and better temperature distribution as a result. More specifically, total heat flux to the biomass increased by 1396 in the lowest part of the reactor. In addition, more heat from the sand is carried through the gas phase when using steam: an increase by 9% in the overall reactor (25% in the lowest part), as indicated by the results. Finally, since no substantial differences in overall product formation rate and composition were found, the considerable effect of steam found in experiments and the literature is mainly (not exclusively) attributed to the chemical and surface-interacting mechanisms. Because of the complex nature of secondary pyrolysis in this process, a comprehensive gas-phase kinetic model is needed to investigate the effects of steam further. Coupling of both is difficult, because of computational constraints, as the present model already is very demanding. The obtained profiles of formation rate of primary products can however be used as an input to another model specifically made for studying homogeneous secondary pyrolysis reactions.

  • 33.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Wu, Yueshi
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    CFD Modelling of Heat Supply in Fluidized Bed Fast Pyrolysis of Biomass2014In: Proceedings of the 10th International Conference on Computational Fluid Dynamics in the Oil & Gas, Metallurgical and Process Industries (CFD 2014), 2014Conference paper (Other academic)
    Abstract [en]

    This paper investigates the heat supply to the fast pyrolysis process, by addition of oxygen in the fluidizing gas. Since the technology will be further developed, a solution for the heat supply in a large-scale reactor must be conceived, which is one option to achieve the primary target: to operate with as little extra heat as possible.

    Corrections for the granular bed material and the biomass particles are implemented in the simulation. User Defined Functions (UDF) is extensively used to describe interactions of heat and momentum between the phases and a chemistry model is employed to describe the chemical reactions after pyrolysis.

    The results are preliminary; however, the oxygen clearly reacts to provide heat. Primarily the secondary tar reacts and a loss of about 30% organic liquid yield is the result in this simulation, at an equivalence ratio of 0.026.

    If heat only can be recovered from the bed zone, through the bed material, then a higher equivalence ratio than what was investigated in this paper would be needed.

    If heat can be recovered from the whole reactor then a slight injection of oxygen would result in an autothermal system; which means the necessary heat to generate and pre-heat steam would be available.

    Temperature instability in the freeboard prevented investigation of higher equivalence ratios, which should be pursued in further work.

  • 34.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhang, Qinglin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    An Euler–Euler approach to modeling biomass fast pyrolysis in fluidized-bed reactors – Focusing on the gas phase2013In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 58, no 1-2, p. 344-353Article in journal (Refereed)
    Abstract [en]

    A developed 3D Euler–Euler CFD model, with an integrated pyrolysis model, is proposed as a way of predicting vapor phase dynamics and product distributions in the fluidized bed process for biomass fast pyrolysis. The main interest in this work is the gases resulting from the pyrolysis mixed with the fluidizing gas. We propose therefore a simple rendering of the solid material while directing attention to the vapor phase. At the same time the required computational resources for reaching stabilized conditions in the reactor are reduced. Temperature profile, velocity profile and pyrolysis products are predicted and globally verified by a series of parallel cases, which are compared to experimental measurements and known trends of liquid, solid and gas yields. The comparison of experimental measurements and model predictions satisfy the accuracy of the model and on a quantitative basis, the product yields agree with commonly known trends of bio oil versus temperature and residence time.

  • 35.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhang, Qinglin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhou, Chunguang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Accuracy and Potential Use of a Developed CFD-pyrolysis Model for Simulating Lab-scale Bio Oil Production2012In: The 20th EU BC&E Online Proceedings 2012, 2012, p. 953-959Conference paper (Other academic)
    Abstract [en]

    The paper describes development of a CFD¬pyrolysis model using an Eularian-Eularian framework with an implemented pyrolysis reaction model. The CFD¬pyrolysis model is used to simulate the bubbling fluidized bed reactor integrated in a new experimental fast pyrolysis process for bio oil production. The model is compared to experiments in aspect of outlet gas composition, temperature and bed height. Tar behavior and yield of bio oil are illustrated and a parametric study investigates impact of flow rate and temperature on bio oil yield. The results show a tolerable fit compared to measurements and reasonable tendencies in the parametric study.

  • 36.
    Persson, Henry
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Wood-derived acid leaching of biomass for enhanced production of sugars and sugar derivatives during pyrolysis: Influence of acidity and treatment time2017In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 127, p. 329-334Article in journal (Refereed)
    Abstract [en]

    Inorganic matter in biomass (especially alkali and alkaline earth metals) acts like intrinsic catalysts during pyrolysis and influences the composition of derived liquids. In this work, the influence of acidity and time on leaching of inorganics with wood pyrolysis-derived acids was investigated in order to understand their effect on the biomass characteristics and the composition of pyrolysis products, as well as to study the mechanism of leaching of different inorganic elements. Aqueous solutions of 5 and 10. wt% acetic acid (main acid in pyrolysis products and in similar concentrations) were used for demineralizing softwood at 85. °C for 30-90. min. Biomass characteristics, composition of intrinsic inorganics and primary pyrolytic vapors from different pretreatment cases are presented. Results show that removal of inorganics was in all cases enhanced by higher acidity; time of treatment was only seen to have a positive effect at lower acidity. The volatile matter of biomass was not affected by the pretreatment, confirming the conditions investigated being relatively mild. Results from Py-GC/MS of leached biomass show an increased selectivity towards sugars and sugar derivatives and simultaneous suppression of the relative composition of carbonyls and phenolic compounds in derived vapors. Sugars and sugar derivatives was enhanced by increasing the leaching time at higher acidity, without seeing a clear correlation to removal of alkali and alkaline earth metals. It is therefore suggested that other factors might influence the pathway of formation of primary pyrolysis products than what has previously been suggested by others. Because of the enhanced production of sugars and sugar derivatives from pyrolysis of leached biomass, this procedure might serve as a pathway to be enable the utilization of pyrolytic liquids as feedstock for existing fermentation-based biorefineries.

  • 37. Skoulou, V.
    et al.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Yang, W.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    CO2 integration in high temperature steam gasification (HTSG) of solid fuels and blends with waste2016In: European Biomass Conference and Exhibition Proceedings, ETA-Florence Renewable Energies , 2016, no 24thEUBCE, p. 970-977Conference paper (Refereed)
    Abstract [en]

    Aim of the present work is to investigate the viability of modifying the high temperature steam gasification process by adding CO2 in an attempt to tailor value added gas suitable for the energy - chemicals production industry. Such an integrated process investigates the concepts of high temperature steam gasification (HTSG) with aspects from steam gasification under a rich in CO2 atmosphere(CO2HTSG). The present study aimed at investigating the beneficial or detrimental effect of modifying the existing HTSG atmosphere by partially recycling CO2 in lab scale and ideally emerging from a conventional CO2 production process. The effect of the process parameters on the producer gas quality, char and tar yields when gasified non-food woody biomass (WB) of forest origin, swedish coal (SC) and pre-treated plastic waste (PW) studied, as well as their weak blends. Results of the present study indicated synergies when materials of lignocellulosic origin with coal are co-gasified under high temperature/steam conditions, while the modified with CO2 steam gasification environment and at elevated temperature did affect also the quality of the producer gas. This effect depends on the feeding properties and steam gasification conditions, It seems that gasification at elevated temperature with steam-carbon-dioxide decreased the reactivity of chars however blending with biomass at low percentages maximized the H2 and CO2 production. 

  • 38.
    Sun, Yunjuan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Jiang, Jianchun
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Xu, Junming
    Li, Linna
    Zhao, Shuheng
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Development of a bimetallic dolomite based tar cracking catalyst2012In: Catalysis communications, ISSN 1566-7367, E-ISSN 1873-3905, Vol. 20, p. 36-40Article in journal (Refereed)
    Abstract [en]

    In this study a bimetallic dolomite based tar cracking catalyst was developed and tested. It was enriched in Ni and Fe with BET surface area of 12.31 m(2)/g. The catalytic characterizations were tested with tar simulated by naphthalene, and with tar produced by biomass and coal co-pyrolysis. 93% naphthalene was decomposed at 950 degrees C. A first order apparent kinetic model was developed. Activation energy of 63.96 kJ/mol and pre-exponential factor of 396.2/s were calculated. Furthermore, reduction in char yield by 7%, when the catalyst was used in the biomass-coal co-pyrolysis, was observed.

1 - 38 of 38
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