Change search
Refine search result
1 - 44 of 44
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1. Alander, E. M.
    et al.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Mechanisms of crystal agglomeration of paracetamol in acetone-water mixtures2005In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 44, no 15, p. 5788-5794Article in journal (Refereed)
    Abstract [en]

    The mechanisms governing the influence of the solvent composition on the agglomeration in a crystallization process have been investigated. Narrowly sieved paracetamol crystals were suspended in supersaturated acetone-water solutions, and were allowed to grow at isothermal conditions, after which the agglomeration was recorded. In all experiments the same sieve size fraction was used as well as the same magma density. In each experiment the supersaturation was kept constant. Experiments were performed in different solvent compositions at different supersaturation, crystal growth rate, solution viscosity, and agitation rate. For a statistically sufficient number of particles from each experiment, the number of crystals in each product particle was determined by image analysis and multivariate data evaluation. From the resulting number distributions of crystals per product particle, parameters defining the degree of agglomeration were extracted. The experimental results clearly establish that there is an influence of the solvent composition on the degree of agglomeration, which cannot be explained by differences in crystal growth rate, or differences in solution viscosity. The degree of agglomeration is found to decrease with increasing solvent polarity. It is, suggested that the mechanism by which the solvent influence relates to the crystal-solvent interaction and the physicochemical. adhesion forces between crystals in the solution.

  • 2. Allouche, Joachim
    et al.
    Tyrode, Eric
    FIRP Laboratory, Universidad de Los Andes, Mérida.
    Sadtler, Veronique
    Choplin, Lionel
    Salager, Jean-Louis
    Single- and Two-Step Emulsification To Prepare a Persistent Multiple Emulsion with a Surfactant-Polymer Mixture2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 17, p. 3982-3988Article in journal (Refereed)
    Abstract [en]

    The regions corresponding to different emulsion morphol. occurrences have been clearly identified on a bidimensional formulation-compn. map. Multiple emulsions spontaneously form when there is a conflict between the formulation and compn. effects. In such systems the most external emulsion is found to be unstable when the formulation effect is produced by a single surfactant. The use of a proper surfactant-polymer mixt. allows one to strongly inhibit the mass transfer and to considerably lengthen the equilibration between interfaces. As a consequence, the multiple emulsion can be stable enough to be used in encapsulation and controlled-release applications. The area where multiple emulsions occur and their characteristics (cond. and amt. of encapsulated external phase) are reported for a system contg. a sorbitan ester lipophilic surfactant and a diblock poly(ethylene oxide)-poly(propylene oxide) hydrophilic polymer, as a function of the formulation and compn., for a single-step process in which a specific amt. of mech. energy (stirring) is supplied. An increase in the oil viscosity is found to alter the map and to modify the multiple emulsion characteristics. The application of the results to emulsion-making technol. is discussed.

  • 3.
    Aulin, Christian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Ström, Göran
    Multilayered Alkyd Resin/Nanocellulose Coatings for Use in Renewable Packaging Solutions with a High Level of Moisture Resistance2013In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 52, no 7, p. 2582-2589Article in journal (Refereed)
    Abstract [en]

    A surprisingly simple and rapid methodology for large-area, lightweight, and thin laminate coatings with remarkable moisture barrier properties is introduced. Commercially available paperboards are coated with thin layers of nanocellulose. The nanocellulose coating induces a surface smoothening effect on the coated sheets as characterized by environmental scanning electron microscopy and white light interferometry. A moisture-protective layer of renewable alkyd resins is deposited on the nanocellulose precoated sheets using a water-borne dispersion coating process or lithographic printing. Through an auto-oxidation process, the applied alkyd resins are transformed into moisture sealant layers. The moisture barrier properties are characterized in detail by water vapor permeability measurements at different levels of relative humidity. The water vapor barrier properties of the nanocellulose precoated substrates were significantly improved by thin layers of renewable alkyd resins. The effect of the alkyd resin properties, coating technologies, and base paper substrates on the final barrier performance of the sheets were studied. It was found that the nanocellulose coating had a notable effect on the homogeneity and barrier performance of the alkyd resin layers and in particular those alkyd resin layers that were applied by printing. The concept is environmentally friendly, energy-efficient, and economic and is ready for scaling-up via continuous roll-to-roll processes. Large-scale renewable coatings applicable for sustainable packaging solutions are foreseen.

  • 4.
    Backström, Eva
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Odelius, Karin
    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.
    Trash to Treasure: Microwave-Assisted Conversion of Polyethylene to Functional Chemicals2017In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 56, no 50, p. 14814-14821Article in journal (Refereed)
    Abstract [en]

    An effective microwave-assisted process for recycling low-density polyethylene (LDPE) waste into value-added chemicals was developed. To achieve fast and effective oxidative degradation aimed at production of dicarboxylic acids, nitric acid was utilized as an oxidizing agent. Different conditions were evaluated, where recycling time and concentration of oxidizing agent were varied and the end products were characterized by FTIR, NMR, and HPLC. After just 1 h of microwave irradiation at 180 degrees C in relatively dilute nitric acid solution (0.1 g/mL), LDPE powder was totally degraded. This transformation led to few well-defined water-soluble products, mainly succinic, glutaric, and adipic acids, as well as smaller amounts of longer dicarboxylic acids, acetic acid, and propionic acid. The length of the obtained dicarboxylic acids could to some extent be tuned by adjusting the reaction time, temperature, and amount of oxidizing agent. Finally, the developed process was verified by recycling LDPE freezer bags as model LDPE waste. The freezer bags were converted mainly into dicarboxylic acids with a yield of 71%, and the carbon efficiency of the process was 37%. The developed method can, thus, contribute to a circular economy and offers new possibilities to increase the value of plastic waste.

  • 5. Bakhtiary-Davijany, Hamidreza
    et al.
    Dadgar, Farbod
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Hayer, Fatemeh
    Phan, Xuyen Kim
    Myrstad, Rune
    Venvik, Hilde J.
    Pfeifer, Peter
    Holmen, Anders
    Analysis of External and Internal Mass Transfer at Low Reynolds Numbers in a Multiple-Slit Packed Bed Microstructured Reactor for Synthesis of Methanol from Syngas2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 42, p. 13574-13579Article in journal (Refereed)
    Abstract [en]

    The possibility of mass transfer limitations in an integrated micro packed bed reactor-heat exchanger (IMPBRHE) for methanol synthesis was experimentally investigated. Experiments were performed with three different particle size distributions (50-200 mu m) of a Cu-based catalyst at 80 bar and 215-270 degrees C. Negligible effects of pore diffusion limitations on the performance of the reactor under methanol synthesis conditions for catalyst particle diameters up to 125 mu m were found. Due to a very low Reynolds numbers (similar to 1) and dominance of molecular diffusion, variation of the total pressure was applied as a suitable technique to alter the diffusivities of reactants in the gas mixture by dilution, while keeping the reactant flow and partial pressure constant. No significant change in the CO conversion was observed in the temperature range 235-255 degrees C, pressure range 50-90 bar, and for reactant contact times of 105-308 ms.g/mL. The same procedure was applied to a laboratory. fixed bed reactor with similar results. Possible heat transfer effects associated with the dilution were shown to be negligible. We therefore conclude that both reactor systems operate in the absence of external mass transfer limitations.

  • 6.
    Beretta, A.
    et al.
    Dipartiemento Energia- Politecnico di Milano.
    Groppi, G.
    Dipartiemento Energia- Politecnico di Milano.
    Lualdi, Matteo
    Dipartiemento Energia- Politecnico di Milano.
    Tavazzi, I.
    Dipartiemento Energia- Politecnico di Milano.
    Forzatti, P.
    Dipartiemento Energia- Politecnico di Milano.
    Experimental and modeling analysis of methane partial oxidation: transient and steady-state behavior of rh-coated honeycomb monoliths2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 8, p. 3825-3836Article in journal (Refereed)
    Abstract [en]

    The present study consists of an experimental and theoretical study of the performance of Rh-coated honeycomb monoliths for methane partial oxidation. The thermal behavior of Rh-coated honeycomb monoliths was studied under representative operating conditions, at steady state and during light-off. Model analysis (based on a dynamic heterogeneous reactor model that incorporates a kinetic scheme of the process independently developed, and well-assessed correlations for heat and mass transfer) provided a key for interpreting the observed effects. The comprehension of how transport phenomena and surface kinetics affect the reactor behavior leads to the conclusion that the feasibility of small-scale production of syngas via CH(4) catalytic partial oxidation relies on thermal management of the short contact time reactor and not the obtainment of high syngas yields (which is not a challenging task). Severe operating conditions (and high surface temperatures) can deplete the catalyst activity and cause unstable reactor operation. Guidelines for optimal reactor design are proposed.

  • 7.
    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.

  • 8. Creaser, Derek
    et al.
    Nilsson, Marita
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Pettersson, Lars J.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Dawody, Jazaer
    Kinetic Modeling of Autothermal Reforming of Dimethyl Ether2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 20, p. 9712-9719Article in journal (Refereed)
    Abstract [en]

    A global kinetic model was developed for the autothermal reforming of dimethyl ether (DME) over a Pd-Zn/Al2O3 catalyst on a cordierite monolith. A kinetic model consisting of five key overall reactions was found to capture the main features of experimental data. The modeling also accounted for heat transport effects in the reactor that are of importance when coupling the exothermic oxidation reactions with endothermic steam reforming reactions. The modeling confirmed that oxidation reactions dominate near the inlet of the reactor, generating a local hot spot. The heat from oxidation reactions accelerates the reforming reactions. Water adsorption was found to have a weak detrimental influence on the activity. On the basis of the model, the influence of the reactor scale and oxygen supply by air feed on the performance of the reactor was examined.

  • 9.
    Danielsson, Sverker
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Kisara, Koki
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Lindström, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Kinetic study of Hexenuronic and Methylglucuronic acid reactions in pulp and in dissolved xylan during kraft pulping of hardwood2006In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, no 7, p. 2174-2178Article in journal (Refereed)
    Abstract [en]

    During kraft pulping, the side group in the xylan backbone, 4-O-methyl-D-glucuronic acid, is partly converted to hexenuronic acid. Simultaneously, degradation reactions of these side groups take place. The rates of these reactions were studied during the kraft pulping of hardwood and were shown to be strongly affected by the location of the x Ian; dissolved xylan had markedly higher methylglucuronic acid and hexenuronic acid contents than pulp xylan did. The degree of substitution of methyl-lucuronic acid in dissolved xylan was found to be higher at reduced cooking temperatures; no such change was seen for pulp xylan. A kinetic model was developed that included the energies of activation for formation (129 U/mol) and degradation (143 U/mol) of hexenuronic acid and dearadation (141 kJ/mol) of methylglucuronic acid and bulk delignification (118 kJ/mol, in accordance with earlier studies). Decreased cooking temperatures thus increase the number of acidic charged groups in the pulp and in dissolved xylan.

  • 10.
    Eriksson, Malin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Torgnysdotter, Annsofie
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Surface modification of wood fibers using the polyelectrocyte multilayer technique: Effects on fiber joint and paper strength properties2006In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, p. 5279-5286Article in journal (Refereed)
    Abstract [en]

    Polyallylamine hydrochloride (PAH) and poly(acrylic acid) (PAA) were used to modify wood fibers by means of the polyelectrolyte multilayer (PEM) technique. Hand sheets and fiber crosses were prepared from the PEM-treated fibers. The sheet strength and fiber-fiber joint strength were evaluated, and the contact zone of the fiber-fiber joint was characterized using a recently developed staining technique. The nonjoined surface area of the paper sheets was estimated by determining nitrogen adsorption via BET analysis, and the results were compared with those of the light scattering measurements frequently used to determine the degree of "bonding" in paper. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy was used to analyze chemical effects. It was shown that the PEM treatment of fibers increased the strength properties of the sheets through an increase in the number of fiber-fiber joints, increasing the degree of contact in a fiber-fiber joint and creating covalent bonding in the fiber-fiber joint.

  • 11. Gane, P. A. C.
    et al.
    Ridgway, C. J.
    Lehtinen, E.
    Valiullin, Rustem
    KTH, Superseded Departments, Chemistry.
    Furo, Istvan
    KTH, Superseded Departments, Chemistry.
    Schoelkopf, J.
    Paulapuro, H.
    Daicic, J.
    Comparison of NMR cryoporometry, mercury intrusion porosimetry, and DSC thermoporosimetry in characterizing pore size distributions of compressed finely ground calcium carbonate structures2004In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 43, no 24, p. 7920-7927Article in journal (Refereed)
    Abstract [en]

    This work investigates for the first time how mercury intrusion porosimetry (MIP), NMR-based cryoporometry, and DSC-based thermoporosimetry compare in revealing the porous characteristics of ground calcium carbonate structures compacted over a range of pressures. The comparison is made using the same source samples throughout. MIP, a much-used method in the characterization of porous structures, has the drawback that the high pressure needed to intrude the mercury may either distort the skeletal porous structure of the sample, especially when compressible materials such as cellulose or binders/latex are present, or lead to a reduction in the measured number of large pores due to the shielding by smaller pores. These effects have previously been addressed using bulk modulus corrections and by modeling the structure permeability to account for the potential shielding. Cryoporometry gives detailed information about the pore size distribution of an imbibition saturated structure. Thermoporosimetry is a relatively new candidate in this field, and it yields both pore size distribution and pore volume. Currently it is somewhat limited in the pore size range detectable, but it is relevant to pigmented coatings. Its potential is identified for capturing the pores involved in the progress of imbibition before saturation is reached.

  • 12.
    Ge, Xinlei
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Materials Process Science.
    Wang, Xidong
    Estimation of Freezing Point Depression, Boiling Point Elevation, and Vaporization Enthalpies of Electrolyte Solutions2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 4, p. 2229-2235Article in journal (Refereed)
    Abstract [en]

    A novel approach is presented in this work for predicting the values of freezing point depression and boiling point elevation for electrolyte solutions at different concentrations on the basis of the Pitzer theories. This method treats the enthalpy change of the solution between the normal freezing point or boiling point and the real ones to be linear temperature dependence. Compared with the literature values, this method performs very well; also, the temperature-dependent parameters of some salts are incorporated to investigate temperature effects of this method. Furthermore, a method based on the Clausius-Clapeyron equation is derived for estimation of the enthalpy of vaporization of very high concentration solutions at different temperatures, and the predicted results are highly positive.

  • 13.
    Gracin, Sandra
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Rasmuson, Åke C.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Prediction of Solubility of Solid Organic Compounds in Solvents by UNIFAC2002In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 41, no 20, p. 5114-5124Article in journal (Refereed)
    Abstract [en]

    Predictions of solubility of nine different solid organic fine chemical compounds in water and organic solvents of relevance to industrial processing are examined. UNIFAC interaction parameters are taken from standard reference literature, extracted from liquid-vapor equilibria. For most systems, predicted solubilities deviate more than 15% from experimental values. Deviations are due to uncertainties in the estimation of the activity of the pure solid as well as to deficiencies in the estimation of activity coefficients in the solution. By comparison with results from ab initio quantum chemical calculations of the elecrostatic potential on the molecular surface of the solutes, it can be shown that a key assumption of the UNIFAC approach is not necessarily fulfilled. The properties of a functional group may depend significantly on the properties of the rest of the molecule.

  • 14. Hadera, Hubert
    et al.
    Labrik, Rachid
    KTH. ABB Corporate Research, Germany .
    Sand, Guido
    Engell, Sebastian
    Harjunkoski, Iiro
    An Improved Energy-Awareness Formulation for General Precedence Continuous-Time Scheduling Models2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 5, p. 1336-1346Article in journal (Refereed)
    Abstract [en]

    Efficient frameworks for scheduling of energy-intensive industries are important enablers for the industrial implementation of the demand-side management concept (DSM). DSM enables enterprises to cut their energy cost as well as to support the grid in dealing with fluctuating availability of energy. In this work, we present an improvement of the energy-aware production scheduling strategy reported in Hadera et al.,(1) which is based upon a continuous-time scheduling formulation. The improvement concerns the modeling of the coupling between the scheduling problem and the computation of the energy bill. The resulting optimization problem is solved by the heuristic bilevel decomposition from Hadera et al.(2) Numerical studies showed that although the proposed formulation and heuristic decomposition does not guarantee to obtain the global minimum it does provide good quality solutions within reasonable solution times. The new energy-awareness formulation reduces the number of binary variables and constraints and results in shorter solution times.

  • 15. Halvarsson, Soren
    et al.
    Edlund, Hakan
    Norgren, Magnus
    Manufacture of High-Performance Rice-Straw Fiberboards2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 3, p. 1428-1435Article in journal (Refereed)
    Abstract [en]

    Rice straw, a waste agriculture material grown and harvested in Willows, CA, was used,is a raw material in the production of thin medium- and high-density fiberboards (MDFs and HDFs). The rice straw was cleaned, size-reduced, and soaked in water before being refined. Defibration was performed in it pressurized pilot-plant single-disk refiner, OHP 20". The fiber production capacity reached a level of 63 kg/h. and the proper fiber quality for MDF/HDF production was established. Analysis of the produced fiber showed an average fiber length of approximately 0.9 mm, in average fiber width of 31 mu m, a shive weight of below 24%, and a dust content of less than 30%. Production of fiberboards was performed by addition of 3%, 4%, and 5% methylene diphenyl diisocyanate (MDI). The flexural properties, internal bond strength, and thickness swelling of the produced fiberboards were evaluated according to ASTM methods. The finished fiberboards based on rice straw and MDI resin showed excellent properties. The internal bond (IB) reached levels of 2.6 MPa, and the modulus of rupture (MOR) and modulus of elasticity (MOE) showed levels comparable to those of wood-based fiberboards and were acceptable according to the requirements or medium-density fiberboard (MDF) for interior applications (American National Standards Institute, ANSI A208.2-2002). The water-repelling properties of the 3-min rice-straw fiberboards were encouraging; the thickness swelling, (TS) was in the range of 15-30%. Two different methods to avoid adhesion between the press plates and the resinated fiber material during hot pressing were investigated: protective paper sheets were placed between the fiber mat and press plates, or a press-release agent was sprayed oil steel plates that were then placed ill the press before pressing Satisfactory results were obtained with both methods, and no adhesion was observed between the fiberboard and the steel plates. The method of using press-release agent during pressing had no notable negative effects oil the fiberboard properties.

  • 16.
    Kebede, Mebatsion L.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Bäbler, Matthäus U.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rozada-Sanchez, Raquel
    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. Batch Operation Mode2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 41, p. 13445-13453Article in journal (Refereed)
    Abstract [en]

    Solid supported evaporation (SSE) is a simple method to isolate dissolved compounds as a solid material. The solution is put in contact with granular porous polymer beads onto which the compounds deposit upon evaporation of the solvent. This brings some advantages over direct evaporation to dryness in terms of safety and handling of the solids. In this paper, SSE in batch mode is explored where the solution is added to the polymer beads at once, i.e. opposite to the semicontinuous mode where the solution is sprayed over a bed of beads. A number of compounds varying widely in their physical and chemical properties is studied. It is found that all compounds could be loaded onto the beads; however, the loading capacity depends on the properties of the compound and in general was lower than in the semicontinuous operating mode studied in an accompanying paper. For highly soluble compounds, higher loadings could be achieved when solvent evaporation was slow. In cases where tested, bead loading was found to be homogeneous within a batch. Recovery of compound from loaded beads was achieved by dispersing the beads in a solvent and washing of the filter cake after filtration. A relatively large amount of solvent is required to achieve full recovery.

  • 17.
    Lanza, Roberto
    et al.
    Università di Padova.
    Canu, Paolo
    Universita` di Padova, Dipartimento di Principi e Impianti di Ingegneria Chimica.
    Dalle Nogare, Daniela
    Universita` di Padova, Dipartimento di Principi e Impianti di Ingegneria Chimica.
    Gas Phase Chemistry in Cellulose Fast Pyrolysis2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 3, p. 1391-1399Article in journal (Refereed)
    Abstract [en]

    We experimentally and theoretically studied cellulose pyrolysis at high temperature and short residence time. We investigated the gas phase chemistry with dedicated experiments and feeding intermediates. Results have been also compared with equilibrium calculations, both single (gas) phase and allowing for solid C formation. Our aim was to understand the cellulose degradation mechanism and particularly the role of gas phase chemistry. We provided evidence of a simplified mechanism, where CO formation is a first, fast step that can be related to levoglucosan ring opening, while H(2) comes from a totally different route, based on hydrocarbon reforming reactions, which also provide further CO. In addition, butadiene was identified as a key intermediate in the decomposition sequence. The different paths and rates of CO formation and H2 formation explain why the ratio of CO to H(2) is not constant, particularly at short residence time. A two-stage process or longer contact time is required, if aiming at syngas production.

  • 18.
    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.

  • 19.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yu, Xi
    Aston University, European Bioenergy Research Institute (EBRI), Birmingham B4 7ET, U.K..
    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.
    Influence of Reaction Atmosphere (H2O, N2, H2, CO2, CO) on Fluidized-Bed Fast Pyrolysis of Biomass Using Detailed Tar Vapor Chemistry in Computational Fluid Dynamics2015In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 54, no 33, p. 8344-8355Article in journal (Refereed)
    Abstract [en]

    Secondary pyrolysis in fluidized bed fast pyrolysis of biomass is the focus of this work. A novel computational fluid dynamics (CFD) model coupled with a comprehensive chemistry scheme (134 species and 4169 reactions, in CHEMKIN format) has been developed to investigate this complex phenomenon. Previous results from a transient three-dimensional model of primary pyrolysis were used for the source terms of primary products in this model. A parametric study of reaction atmospheres (H2O, N2, H2, CO2, CO) has been performed. For the N2 and H2O atmosphere, results of the model compared favorably to experimentally obtained yields after the temperature was adjusted to a value higher than that used in experiments. One notable deviation versus experiments is pyrolytic water yield and yield of higher hydrocarbons. The model suggests a not overly strong impact of the reaction atmosphere. However, both chemical and physical effects were observed. Most notably, effects could be seen on the yield of various compounds, temperature profile throughout the reactor system, residence time, radical concentration, and turbulent intensity. At the investigated temperature (873 K), turbulent intensity appeared to have the strongest influence on liquid yield. With the aid of acceleration techniques, most importantly dimension reduction, chemistry agglomeration, and in-situ tabulation, a converged solution could be obtained within a reasonable time (∼30 h). As such, a new potentially useful method has been suggested for numerical analysis of fast pyrolysis.

  • 20. Mira, Isabel
    et al.
    Zambrano, Noelia
    Tyrode, Eric
    Marquez, Laura
    Pena, Alejandro A.
    Pizzino, Aldo
    Salager, Jean-Louis
    Emulsion Catastrophic Inversion from Abnormal to Normal Morphology. 2. Effect of the Stirring Intensity on the Dynamic Inversion Frontier2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 1, p. 57-61Article in journal (Refereed)
    Abstract [en]

    The stirring intensity has a complex effect on the catastrophic inversion of emulsions in the direction of change from abnormal to normal morphol. At both low and high stirring energy, the inversion takes place early, after a low amt. of the internal phase is added and through the occurrence of a multiple emulsion. At some intermediate stirring energy, the inversion appears to be delayed and it takes place without the occurrence of multiple emulsions. [on SciFinder (R)]

  • 21.
    Musavi, Zahra S.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Pettersson, Lars J.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Engvall, Klas
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Modeling, Design, and Verification of a Burner for Partial Oxidation of Biomass Product Gas in an Autothermal Reformer2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 36, p. 9687-9697Article in journal (Refereed)
    Abstract [en]

    There is global interest in utilization of biomass energy through thermochemical processes such as gasification. The crucial step in many gasification processes is the upgrading of the produced gas, removing for example problematic components, such as tar, preferably with a flexible solution that adapts to several feedstock compositions, gasification technologies, and conditions. The present work focuses on the underpinning modeling for the development of a burner for partial combustion in an autothermal tar reformer. A design and modeling study considering the effect of the burner geometry and inlet locations on flame stability was performed. The model and the constructed burner is verified and validated against experimental results, displaying a successful operation of the combustion zone, verifying and validating the developed model against specific requirements. The verified model was finally applied for an extended process window.

  • 22.
    Nilsson, Fritjof
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Hallstensson, K.
    YKI.
    Johansson, K.
    YKI.
    Umar, Z.
    Materials Technology Research Institute.
    Hedenqvist, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Predicting Solubility and Diffusivity of Gases in Polymers under High Pressure: N-2 in Polycarbonate and Poly(ether-ether-ketone)2013In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 52, no 26, p. 8655-8663Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to develop a model that predicts the gas solubility and the sorption and desorption kinetics in polymer granulates over large temperature and pressure intervals. Besides the part predicting the solubility and diffusivity, the model involves the simultaneous solution of the diffusion equation and the heat equation in three dimensions using a finite element method (FEM). When the temperature- and pressure-dependent solubility of a specific polymer/gas combination is not known, an improved version of the non-equilibrium lattice fluid model (NELF) is used to predict the solubility. The improvement of the NELF model includes the use of Hansen's solubility parameters, and it uses pressure-volume-temperature (PVT) data from two new empirical models, which accurately estimate polymer densities over a wide range of temperatures and pressures. The new solubility model predicted the solubility-pressure data of N-2 in poly(ethyl methacrylate) and N-2 and CH4 in polycarbonate (PC) at pressures below 4.5 MPa, without using any adjustable interaction parameters. The model was used to predict the solubility of N-2 in poly(ether-ether-ketone) (PEEK) and PC at a very high pressure (67 MPa). Experimental N-2 solubility data were obtained with a specially built reactor yielding high pressure and temperature. For PEEK, it was possible to predict the very high pressure solubility using a gas-polymer interaction parameter obtained from data taken at low pressures In addition, a new free-volume-based diffusivity model requiring no adjustable interaction parameters was developed, and it successfully predicted the desorption kinetics of N-2 from PEEK and PC.

  • 23.
    Nilsson, Marita
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Karlsson, Anders
    Lindström, Bård
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Pettersson, Lars J.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Study of a reactor concept for hydrogen generation from diesel fuelIn: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045Article in journal (Other academic)
  • 24. Norgren, Magnus
    et al.
    Mackin, Sofia
    Sulfate and Surfactants as Boosters of Kraft Lignin Precipitation2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 10, p. 5098-5104Article in journal (Refereed)
    Abstract [en]

    In the spirit of the biorefinery concept, an increasing interest in further utilization of technical lignins outside the pulp mills has arisen. In this context optimization of the precipitation process to increase the yield of the lignin recovered is of great importance. The objectives of this investigation have been to study how specific salts and surfactants affect kraft lignin yield during precipitation and washing. From the results it was seen that additions of sodium sulfate increased the yield of precipitation at elevated temperatures at much lower concentrations than sodium chloride. Earlier studies of the effect of monovalent salts on kraft lignin stability have shown that specific ions either increase or decrease the fort-nation of precipitates during kraft lignin aggregation. Thus, the presented results in this study further strengthen this dependency concerning divalent anions. Regarding the role of surfactants as precipitation enhancers, cationic surfactants gave rise to fast aggregation and relatively high yields. This was found mainly due to attractive electrostatic interactions between the cationic surfactant headgroup and the oppositely charged groups on the kraft lignin macromolecules, introducing an increased degree of hydrophobicity of the lignin and thus a decreased stability. The nonionic surfactants tested affected the system very differently. In some cases the aggregation was fast and the aggregates became relatively large before settling, whereas some surfactants induced the formation of relatively dense precipitates that settled rapidly. Concerning kraft lignin precipitate washing, calcium chloride at concentrations in the millimolar region decreased the lignin losses dramatically.

  • 25.
    Olin, Pontus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Hyll, Caroline
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Ovaskainen, Louise
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Ruda, Marcus
    Schmidt, Oskar
    Turner, Charlotta
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Development of a Semicontinuous Spray Process for the Production of Superhydrophobic Coatings from Supercritical Carbon Dioxide Solutions2015In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 54, no 3, p. 1059-1067Article in journal (Refereed)
    Abstract [en]

    Superhydrophobic surfaces have been fabricated in a continuous spray process, where an alkyl ketene dimer (AKD) wax is dissolved in supercritical carbon dioxide (scCO(2)) and sprayed onto the substrate. The mass of extracted AKD from scCO2 has been investigated as well as the pressure, temperature, and flow of CO2 at the steady-state spray conditions. Several different substrates such as glass, aluminum, paper, poly(ethylene terephthalate) (PET), and polytetrafluoroethylene (PTFE) have been successfully coated, and the superhydrophobic properties have been evaluated by measurement of water contact angle, water drop friction, scanning electron microscopy (SEM), and surface topography. The most efficient spray process, considering surface properties and mass of extracted AKD, is obtained at the lowest temperature investigated, 67 degrees C, and the highest pressure evaluated in this study, 25 MPa. We also show that the influence of preexpansion conditions (p, T) on the surface temperature at the selected spray distance (3 cm) is negligible by measurement with an infrared camera during spraying.

  • 26. Pattison, Richard C.
    et al.
    Touretzky, Cara R.
    Johansson, Ted
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Harjunkoski, Iiro
    Baldea, Michael
    Optimal Process Operations in Fast-Changing Electricity Markets: Framework for Scheduling with Low-Order Dynamic Models and an Air Separation Application2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 16, p. 4562-4584Article in journal (Refereed)
    Abstract [en]

    Today's fast-changing markets often require the granularity of production schedules to be refined to time scales comparable to the time constants of a chemical process. Consequently, the process dynamics must be considered explicitly in production scheduling. High dimensionality, nonlinearity, and the associated computational complexity make incorporating dynamic models in scheduling calculations challenging. We propose a novel scheduling approach based on scheduling-oriented low-order dynamic models identified from historical process operating data. We introduce a methodology for selecting scheduling-relevant variables and identify empirical models that capture their dynamic response to production target changes imposed at the scheduling level. The optimal scheduling calculation is then formulated as a dynamic optimization aimed at minimizing operating cost. We apply these concepts to an industrial-size model of an air separation unit operating under time-sensitive electricity prices. Our approach reduces computational effort considerably while preserving essential information required for the optimal schedule to be feasible from a dynamic point of view. Extensive simulations show that significant savings can be derived from operating in a transient regime, where the production rate is increased when energy prices are low, and reduced during peak price periods, while taking advantage of available storage capacity.

  • 27. Pino-Garcia, O.
    et al.
    Rasmuson, Åke C.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Primary nucleation of vanillin explored by a novel multicell device2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 20, p. 4899-4909Article in journal (Refereed)
    Abstract [en]

    A novel multicell apparatus is designed, constructed, and used to investigate crystal nucleation of vanillin in water/2-propanol solution (20 mass % of 2-propanol on a solute-free basis). The device contains 15 nucleation cells, with volumes of about 6 cm(3) each, in which the induction times for nucleation are measured simultaneously. The nucleation in the cells is continuously video-recorded and analyzed offline. The induction time for nucleation of vanillin is determined at various levels of supersaturation and temperature, and by classical nucleation theory the solid-liquid interfacial energy is estimated to 7.3 +/- 0.2 mJ m(-2). A large variation in the experimental data is observed, and this variation is analyzed by statistical methods.

  • 28. Salager, Jean-Louis
    et al.
    Marquez, Laura
    Pena, Alejandro A.
    Rondon, Miguel
    Silva, Felix
    Tyrode, Eric
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Current Phenomenological Know-How and Modeling of Emulsion Inversion2000In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 39, no 8, p. 2665-2676Article in journal (Refereed)
    Abstract [en]

    This paper encompasses classic trends as well as recent advances in the understanding of emulsion inversion phenomena. The generalized formulation issue is first discussed from hydrophilic-lipophilic balance to the most recent concepts. The so-called std. inversion line on the formulation-compn. map exhibits several branches, referred to as transitional and catastrophic inversions, that bound normal and abnormal emulsion regions. Dynamic inversion is also discussed with its hysteresis zones, where both types of emulsions may be attained, depending upon the system's previous history of the formulation-compn. map. Recent findings are reported concerning the effect of variables with practical relevance (i.e., stirring energy, viscosity of phases, surfactant concn., and partitioning) on the std. and dynamic inversion patterns. State-of-the-art emulsion inversion modeling is briefly discussed. [on SciFinder (R)]

  • 29. Salager, Serge E.
    et al.
    Tyrode, Eric C.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Celis, Maria-Teresa
    Salager, Jean-Louis
    Influence of the Stirrer Initial Position on Emulsion Morphology. Making Use of the Local Water-to-Oil Ratio Concept for Formulation Engineering Purpose2001In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 40, no 22, p. 4808-4814Article in journal (Refereed)
    Abstract [en]

    The initial location of the stirrer in the emulsification vessel can induce the resulting emulsion type. The interpretation in terms of mixing phenomena leads to the use of the local water-to-oil ratio (WOR) concept in the formulation-compn. map. The know-how assocd. with this phenomenol. allows us to interpret in a straightforward way the kind of complex procedures commonly employed in emulsion manufg., particularly those assocd. with inversion and multiple emulsion attainment. [on SciFinder (R)]

  • 30.
    Sandin, Staffan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Karlsson, Rasmus K. B.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Catalyzed and uncatalyzed decomposition of hypochlorite in dilute solutions2015In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 54, no 15, p. 3767-3774Article in journal (Refereed)
    Abstract [en]

    Hypochlorite decomposition has been investigated by the combined measurement of aqueous concentrations of total hypochlorite, chlorate, and chloride, as well as that of evolved oxygen. In all experiments, the initial concentrations of NaOCl and NaCl were 80 mM, and the temperature was 80°C. The pH was kept constant in the range 5-10.5. The uncatalyzed decomposition of hypochlorite and the formation of chlorate and oxygen were all found to be third order of the form r<inf>i</inf> = k<inf>i</inf>[HOCl]2[OCl-], and k<inf>O</inf><inf>2</inf> was determined to be 0.046 M-2 s-1. A reaction mechanism in which oxygen and chlorate formation share an intermediate is proposed. Several compounds were tested for catalytic effects. The addition of chloride salts of cobalt and iridium showed catalytic effects on oxygen formation. The addition of iridium chloride also catalyzed the formation of chlorate with increasing selectivity for chlorate with increasing pH.

  • 31.
    Svärd, Michael
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Force Fields and Point Charges for Crystal Structure Modeling2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 6, p. 2899-2912Article in journal (Refereed)
    Abstract [en]

    Molecular simulation is increasingly used by chemical engineers and industrial chemists in process and product development. In particular, the possibility to predict the structure and stability of potential polymorphs of a substance is of tremendous interest to the pharmaceutical and specialty chemicals industry. Molecular mechanics modeling relies on the use of parametrized force fields and methods of assigning point charges to the atoms in the molecules. In commercial molecular simulation software, a wide variety of such combinations are available, and there is a need for critical assessment of the capabilities of the different alternatives. In the present work, the performance of several molecular mechanics force fields combined with different methods for the assignment of atomic point charges have been examined with regard to their ability to calculate absolute crystal lattice energies and their capacity to identify the experimental structure as a minimum on the potential energy hypersurface. Seven small, aromatic monomolecular crystalline compounds are used in the evaluation. It is found that the majority of the examined methods cannot be used to reliably predict absolute lattice energies. The most promising results were obtained with the Pcff force field using integral charges, and the Dreiding force field using Gasteiger charges, both of which performed with an accuracy of the same order of magnitude as the variations in experimental lattice energies. Overall, it has been observed that the best results are achieved if the same force field method is used to relax the crystal structure and calculate the energy, and to optimize and calculate the energy of the gas phase molecule used for the correction for changes in molecular geometry. The Pcff and Compass force fields with integral charges have been found to predict relaxed structures closest to the experimental ones. In addition, five different methods for determining point charges fitted to the electrostatic potential (ESP charges), available in the same software, have been evaluated. For each method, the molecular geometries of 10 small, organic molecules were optimized, and ESP charges calculated and analyzed for linear correlation with a set of reference charges of an accepted standard method, HF/6-31G*. Dmol-3 gives charges that correlate well with the reference charge. The charges from Vamp are not linearly scalable to the HF/6-31G*-level, which is attributed partly to the geometry optimization but mainly to the calculation of the ESP and the subsequent charge fit.

  • 32.
    Tavast, Daniel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Mansoor, Zaheer Ahmad
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Brännvall, Elisabet
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Xylan from Agro Waste As a Strength Enhancing Chemical in Kraft Pulping of Softwood2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 23, p. 9738-9742Article in journal (Refereed)
    Abstract [en]

    The possibility to use xylan from agro waste in order to improve the strength properties of spruce kraft pulp was examined. Xylan was extracted from wheat straw and rice husks, by subjecting the agro waste to kraft cooking. The extracted xylan was subsequently used at the end of a kraft cooking process of spruce, by replacing half of the black liquor with dissolved spruce xylan with white liquor containing agro waste xylan. The strength tests performed on the obtained softwood kraft pulps showed that even a small amount of rice husk or wheat straw xylan deposited on softwood fibers had a positive effect on the tensile index of the paper at given sheet density.

  • 33.
    Tyrode, Eric
    et al.
    Laboratorio FIRP, Ingeniería Química, Universidad de Los Andes, Mérida, Venezuela.
    Allouche, Joachim
    Choplin, Lionel
    Salager, Jean-Louis
    Emulsion Catastrophic Inversion from Abnormal to Normal Morphology. 4. Following the Emulsion Viscosity during Three Inversion Protocols and Extending the Critical Dispersed-Phase Concept2005In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 44, no 1, p. 67-74Article in journal (Refereed)
    Abstract [en]

    Three protocols are tested to invert an abnormal emulsion into a normal one: a dynamic process with continuous addn. of an internal phase, continuous stirring of a given emulsion with no addn. of an internal phase, and the combination of the previous ones, i.e., a standstill dynamic process in which the addn. of an internal phase is interrupted at some time and then followed by continued stirring. In situ follow-up of both cond. and viscosity data in a rheomixer vessel provides complementary information to corroborate the crit. dispersed-phase concept as a condition for the inversion to take place in all cases. Some applications are discussed. [on SciFinder (R)]

  • 34. Valavi, Masood
    et al.
    Svärd, Michael
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology. University of Limerick, Ireland.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology. University of Limerick, Ireland.
    Prediction of the Solubility of Medium-Sized Pharmaceutical Compounds Using a Temperature-Dependent NRTL-SAC Model2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 42, p. 11150-11159Article in journal (Refereed)
    Abstract [en]

    In this work, the NRTL-SAC and the Pharma UNIFAC models are evaluated with respect to the capability of prediction of solid liquid equilibria of pharmaceutical compounds in organic solvents. The original NRTL-SAC model is extended through the introduction of temperature-dependent binary interaction parameters, and the two versions of the model are parametrized using vapor liquid equilibrium (VLE) data. The performance of the NRTL-SAC models for correlation and prediction of the solubility of eight medium-sized flexible pharmaceutical or pharmaceutically similar molecules in multiple pure, organic solvents is examined: risperidone, fenofibrate, fenoxycarb, tolbutamide, meglumine, butyl paraben, butamben, and salicylamide. The performance of the Pharma UNIFAC model is evaluated using data for six of these compounds. In general, it is found that introducing a dependence on temperature to the binary interaction parameters of the NRTL-SAC model can improve its capability for modeling and prediction of the solubility of active pharmaceutical ingredients. For prediction of solubility data the Pharma UNIFAC model generally performs below the two NRTL-SAC models. Averaged over all evaluated systems where the solubility was predicted with each method, values of the root mean squared logarithmic error (RMSLE) in predicted mole fraction solubility obtained for Pharma UNIFAC (30 systems) and for the original and the modified temperature-dependent forms of the NRTL-SAC model (29 systems) are 1.64, 1.17, and 1.09, respectively. Comparing only those systems for which all models were evaluated (18 systems), the RMSLE values are 1.42, 1.06, and 0.87, respectively.

  • 35.
    Wahlström, Niklas
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Harrysson, H.
    Undeland, I.
    Edlund, Ulrica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    A Strategy for the Sequential Recovery of Biomacromolecules from Red Macroalgae Porphyra umbilicalis Kützing2018In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 1, p. 42-53Article in journal (Refereed)
    Abstract [en]

    A nondestructive, multicomponent fractionation strategy has been developed to extract proteins and polysaccharides from the red macroalgae Porphyra umbilicalis collected along the west coast of Sweden and cultivated indoors under controlled conditions. First, a protein-rich fraction was extracted in an ice-cold alkaline solution. The overall protein content in Porphyra umbilicalis was estimated to be 30.6% of the dry weight, and out of that, 15.0% could be recovered. Water-soluble polysaccharides were then extracted from the insoluble residual fraction using sequential alkaline and acidic treatments at 90 °C for 4 h. Spectroscopic and chromatographic analyses of the polysaccharide fractions show that high-molecular-weight carrageenans were obtained from the alkaline extraction and a galactose-rich pectin substance was obtained from the acidic extraction. The insoluble fraction remaining after all extraction steps was rich in cellulose. An elemental analysis of Porphyra umbilicalis via scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS) showed the presence of C, O, Na, Ca, Mg, Al, Cl, and S. However, no heavy metals or other toxic elements, such as Pb, Hg, and As, were found.

  • 36. Wedin, R.
    et al.
    Dahlkild, Anders A.
    KTH, Superseded Departments, Mechanics.
    On the transport of small bubbles under developing channel flow in a buoyant gas-evolving electrochemical cell2001In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 40, no 23, p. 5228-5233Article in journal (Refereed)
    Abstract [en]

    A gas-evolving electrochemical cell with natural convection due to buoyancy is modeled using a hydrodynamic two-phase mixture model. Physical parameters are taken from the chlorate process, where hydrogen is evolved at the cathode. Constitutive closure laws, based on empirical relations developed for sedimenting particles, give the motion of the monodisperse gas phase relative to the mixture. Typical results display the effect of bubble size, channel width, and current density on the buoyant flow rate of the electrolyte through the channel. Results from the numerical simulations are also compared to data measured by Boissonneau and Byrne(1) on a cell with gas evolution on both the anode and the cathode. Qualitatively good agreement was found.

  • 37.
    Wetterling, John
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Department of Chemistry and Chemical Engineering, Chalmers University of Technology.
    Jonsson, S.
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology.
    Mattsson, Tuve
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Department of Chemistry and Chemical Engineering, Chalmers University of Technology.
    Theliander, Hans
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Department of Chemistry and Chemical Engineering, Chalmers University of Technology.
    The Influence of Ionic Strength on the Electroassisted Filtration of Microcrystalline Cellulose2017In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 56, no 44, p. 12789-12798Article in journal (Refereed)
    Abstract [en]

    The production of materials such as microfibrillated cellulose and cellulose nanocrystals is gathering significant research interest by combining mechanical strength and toughness with a low density, biodegradability and renewability. However, one of the challenges with production on an industrial scale is to obtain an energy-efficient solid-liquid separation which is difficult because of the high specific filtration resistance of these materials. This study investigates electroassisted filtration as a method to facilitate the dewatering of cellulosic materials and the influence of ionic strength on the electrofiltration behavior. Electroassisted filtration is found to improve the dewatering rate of the studied cellulosic material, and the potential improvement compared to pressure filtration increased with the specific surface area of the solid material. Increasing the ionic strength of the system increased the power demand of the electroassisted filtration, and the major potential for industrial application is thus for systems with a limited ionic strength.

  • 38.
    Woldemariam, Daniel
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Kullab, Alaa
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Martin, Andrew
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    District heat-driven water purification via membrane distillation: New possibilities for applications in Pharmaceutical Industries2017In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045Article in journal (Refereed)
    Abstract [en]

    Here, we presented a novel industrial application for membrane distillation (MD) in a pharmaceutical production facility’s wastewater treatment plant (WWTP). Two semi-commercial air gap MD module designs (Xzero and Elixir500) were studied for comparison, with experimental results of product yield and heat demand up-scaled for inclusion in system simulations. District heating was considered to drive the 3 m3/h capacity MD process, with heat recovery employed in various process streams and for heating purposes in offices. The selected configurations show a high degree of thermal integration with an increase of yearly district heating purchases of 2-13%. Economic assessments of the full-scale MD system indicate that unit costs of purification would be $1.3/m3 and $7/m3 for Elixier500 and Xzero MD modules respectively. Module heat losses should be considered in the future design of MD systems since the heat demand contributed to up to 77% of the specific costs.

  • 39.
    Wågberg, Lars
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Ondaral, Sedat
    Karadeniz Tech Univ, Fac Forestry, Dept Pulp & Paper Technol.
    Enarsson, Lars-Erik
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hyperbranched polymers as a fixing agent for dissolved and colloidal substances on fiber and SIO2 surfaces2007In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 46, no 7, p. 2212-2219Article in journal (Refereed)
    Abstract [en]

    Hyperbranched polymers (polyesteramides) were used as a cationic fixing agent to remove dissolved and colloidal substances (DCS) from the water phase in a fiber suspension. The relative turbidity, electrophoretic mobility, and average diameter of the colloidal particles were determined as a function of polyelectrolyte concentration. The results indicated that maximum removal of DCS was achieved at about zero electrophoretic mobility of the suspension where the negative surface charges of particles were neutralized by the oppositely charged hyperbranched polymer. The amount of hyperbranched polymers needed to maximize DCS fixation on the fibers was higher than the amount of poly-DADMAC (diallyldimethylammonium chloride) needed to reach the same effect. This was found to be due to the lower molecular weight and lower charge density of hyperbranched polymers. The lower molecular mass allowed penetration of these polymers into pores of fibers that resulted in higher polymer consumption before removal of the dissolved and colloidal substances from the fiber suspensions. A lower charge density further resulted in a higher saturation adsorption of the hyperbranched polymer. Experiments with both DCS and model-latex particles showed that the initial increase in relative turbidity was due to the aggregation of particles before fixation to fibers. The results from quartz crystal microbalance with dissipation (QCM-D) experiments showed that the efficiency of hyperbranched polymer and poly-DADMAC was similar even if they had different structure. Therefore, this study highlights the importance of molecular mass and charge density of the polymers as well as the surface structure of polymer layers which in turn gives implications for development of new structures of fixing agents.

  • 40.
    Yang, Huiqing
    et al.
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Zheng, Danning
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Zhang, Jingshun
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Chen, Ke
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Li, Junfeng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology. Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Wang, Li
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Zhang, Jinglai
    Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    He, Hongyan
    Chinese Acad Sci, Inst Proc Engn, Beijing Key Lab Ion Liquids Clean Proc, State Key Lab Multiphase Complex Syst, Beijing 100190, Peoples R China..
    Zhang, Suojiang
    Chinese Acad Sci, Inst Proc Engn, Beijing Key Lab Ion Liquids Clean Proc, State Key Lab Multiphase Complex Syst, Beijing 100190, Peoples R China..
    Protic Quaternary Ammonium Ionic Liquids for Catalytic Conversion of CO2 into Cyclic Carbonates: A Combined Ab Initio and MD Study2018In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 21, p. 7121-7129Article in journal (Refereed)
    Abstract [en]

    The mechanism of CO2 fixation catalyzed by protic hydroxyl-functionalized quaternary ammonium ionic liquids (ILs) is investigated by two different models, the Single-IL model and the Double-IL model. The relative sequence of catalytic activity calculated by the Single-IL model is contradictory with the experimental result. The situation is totally varied when the Double-IL model is utilized. In this system, ILs are not limited to the catalyst but solvent. The ILs are incorporated into the catalytic system to consider the solvent effect rather than by the existing solvent model. When the solvent effect is included, it is better to distinguish the catalytic activity of three ILs. According to the noncovalent interaction and the atoms in molecules analysis, the highest catalytic activity of tris(2-hydroxyethyl)ammonium bromide ([HTEA]Br) is attributed to its strongest nucleophilic attack and moderate hydrogen bond interaction between IL and reactant. It is necessary to consider the interaction between ILs to get a reliable result. Moreover, the solvent effect aroused by ILs should be carefully considered.

  • 41. Yang, Jie
    et al.
    Yu, Xinhai
    Yan, Jinyue
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Tu, Shan-Tung
    CO2 Capture Using Amine Solution Mixed with Ionic Liquid2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 7, p. 2790-2799Article in journal (Refereed)
    Abstract [en]

    It is a focus to reduce the energy consumption and operating cost of CO2 capture from low-pressure flue gas streams of power plants using an aqueous amine-based absorbent. In this study, CO2 capture experiments were conducted in an absorption-desorption loop system using amine-based absorbents. The gas mixture containing CO2, O-2, SO2, and N-2 in the composition range of flue gas from coal-fired power plant after flue gas desulfurization was selected as the feed gas. For an aqueous amine solution, the largest contribution to monoethanolamine (MEA) loss was made by evaporation during desorption, followed by the formation of sulfate and heat-stable salts. To reduce MBA loss and meanwhile decrease the energy consumption during CO2 desorption, an aqueous amine solution mixed with ionic liquid (30 wt % MBA + 40 wt % [bmim][BF4] + 30 wt % H2O) was proposed. The energy consumption of the mixed ionic liquid solution for absorbent regeneration was 37.2% lower than that of aqueous MEA solution. The MEA loss per ton of captured CO2 for the mixed solution was 1.16 kg, which is much lower than that of 3.55 kg for the aqueous amine solution. No ionic liquid loss was detected. In addition, the mixed ionic liquid solution showed a low viscosity of 3.54 mPa s at 323 K, indicating that the ionic liquid disadvantage of high viscosity can be overcome for absorbent delivery of CO2 capture.

  • 42. Zambrano, Noelia
    et al.
    Tyrode, Eric
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Mira, Isabel
    Marquez, Laura
    Rodriguez, Maria-Patricia
    Salager, Jean-Louis
    Emulsion Catastrophic Inversion from Abnormal to Normal Morphology. 1. Effect of the Water-to-Oil Ratio Rate of Change on the Dynamic Inversion Frontier2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 1, p. 50-56Article in journal (Refereed)
    Abstract [en]

    The rate of addn. of the internal phase affects the catastrophic inversion of emulsions in the direction of change from abnormal to normal morphol. At a low addn. rate, the inversion takes place after a small amt. of the internal phase is added, and it happens through the occurrence of multiple emulsion morphol. At a high addn. rate, the inversion appears to be delayed, and it takes place without the occurrence of a multiple emulsion. [on SciFinder (R)]

  • 43.
    Zhao, Weifeng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology. Sichuan University, China.
    He, Chao
    Nie, Chuanxiong
    Sun, Shudong
    Zhao, Changsheng
    Synthesis and Characterization of Ultrahigh Ion-Exchange Capacity Polymeric Membranes2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 36, p. 9667-9675Article in journal (Refereed)
    Abstract [en]

    A universal mold casting approach for the preparation of cation-exchange membranes (CEMs) and anion-exchange membranes (AEMs) with ultrahigh ion-exchange capacities (IECs) is developed based on in situ cross-linking polymerization of acrylic acid (AA) and 2-vinylpyridine (2VP), respectively. This new method produced ultrahigh IECs of 7.88 mequiv g(-1) for CEM and 6.27 mequiv g(-1) for AEM, which are 8.8 and 7.0 times that (0.89 mequiv g(-1)) of Nafion 117, respectively. Also, the prepared membranes demonstrate excellent thermal and chemical stability and acceptable conductivity. As a consequence, the membranes show relatively high performance for ion-exchange application and methanol barrier, exhibiting ion permeabilities of 2.06 x 10(-7) cm(2) s(-1) for Na+, 2.57 x 10(-7) cm(2) s(-1) for Ca2+, 1.45 x 10(-7) cm(2) s(-1) for Cu2+ regarding CEMs, and 7.72 x 10(-7) cm(2) s(-1) for methanol regarding AEMs. These results indicate that the CEMs and AEMs fabricated from the universal mold casting approach are promising candidates for targeting ultrahigh ion-exchange capacity membranes.

  • 44.
    Ålander, Eva M.
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Uusi-Penttila, Marketta S.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Rasmuson, Åke C.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Agglomeration of paracetamol during crystallization in pure and mixed solvents2004In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 43, no 2, p. 629-637Article in journal (Refereed)
    Abstract [en]

    The agglomeration of paracetamol during crystallization has been investigated. It is shown that the agglomeration behavior depends on the solvent composition. The following solvent systems were used in isothermal desupersaturation experiments: five different acetone-toluene-water mixtures and the pure solvents acetone, 2-propanol, acetic acid, and ethylene glycol. Sieving, image analysis processed by principal component analysis, and agglomerate strength measurements were used to characterize the product particles. Mixtures with a high concentration of acetone were found to produce a highly agglomerated product with strong agglomerates. In contrast, products from crystallization in ethylene glycol, 2-propanol, acetic acid, and acetone-toluene-water mixtures having a high concentration of water contained not only agglomerates but also a significant fraction of single crystals. Furthermore, the agglomerates formed in these solvents were much weaker than those produced in mixtures with a high content of acetone. The results were correlated with the polarity and the viscosity of the solvents.

1 - 44 of 44
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf