| 1. |
- Aktij, Sadegh Aghapour, et al.
(författare)
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Feasibility of membrane processes for the recovery and purification of bio-based volatile fatty acids : A comprehensive review
- 2020
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier BV. - 1226-086X .- 1876-794X. ; 81, s. 24-40
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Tidskriftsartikel (refereegranskat)abstract
- Volatile fatty acids (VFAs) can be produced from fermentation/anaerobic digestion of wastes and are a valuable substrate for numerous applications, such as those related to the food, tanning, petrochemicals, pharmaceuticals, cosmetics, and chemicals industry. They are also inexpensive raw materials for developing alternative sources of energy. However, the separation and purification of VFAs produced from fermented wastewaters are not straightforward goals, due to the low concentration of these compounds in the fermentation broths and owing to the complexity of these mixtures. Cost-effective and sustainable technologies must be developed to recover VFAs efficiently and allow their beneficial use. In this paper, a comprehensive review of VFAs recovery/purification methods is provided, with focus on membrane-based processes. First, the VFAs production methods, application, and conventional processes (distillation, precipitation, adsorption, and extraction) for their recovery are briefly reviewed. Then, the ability of various membrane-based techniques to separate and purify VFAs are evaluated and discussed in detail. This discussion includes the processes of microfiltration/ultrafiltration, nanofiltration, reverse osmosis, forward osmosis, membrane distillation, electrodialysis, membrane contractor, and pervaporation. Extensive background and examples of applications are also provided to show the effectiveness of membrane processes. Finally, challenges and future research directions are highlighted.
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| 2. |
- Björk, Emma, et al.
(författare)
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A shelf-life study of silica- and carbon-based mesoporous materials
- 2021
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier Science INC. - 1226-086X .- 1876-794X. ; 101, s. 205-213
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Tidskriftsartikel (refereegranskat)abstract
- Mesoporous silica- and carbon-based materials, including bioactive glasses, have proven potential as components of medical devices and as drug carriers. From an application perspective, knowledge about the shelf-life stability of these materials under various conditions is vital. Here, mesoporous bioactive glasses (MBGs) synthesized by aerosol-assisted spray-drying and by a batch sol-gel method, mesoporous silicas of SBA-15 type, and mesoporous carbons CMK-1 and CMK-3 have been stored under varying conditions, e.g. at different temperature and relative humidity (RH), and in different storage vessels. The results show that the silica-based materials stored in Eppendorfs are sensitive to humidity. Spray dried MBGs decompose within 1 month at a RH >5%, whilst sol-gel MBGs are more stable up to a RH >60%. Changing the storage vessel to sealed glass flasks increases the MBGs lifetime significantly, with no degradation during 2 months of storage at a RH = 75%. SBA-15 stored in Eppendorfs are more stable compared to MBGs, and addition of F- ions added during the synthesis affects the material degradation rate. Mesoporous carbons are stable under all conditions for all time points. This systematic study clearly demonstrates the importance of storage conditions for mesoporous materials which is crucial knowledge for commercialization of these materials. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.
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| 3. |
- Jafari, Mohammad, et al.
(författare)
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Study effects of conventional flotation reagents on bioleaching of zinc sulfide
- 2019
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier. - 1226-086X .- 1876-794X. ; 78, s. 364-371
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Tidskriftsartikel (refereegranskat)abstract
- Although flotation and bio-extraction of metals from its products are extensively investigated, there are few studied which evaluated the effects of reagents on bioleaching process. Both structure and concentration of flotation reagents are effective factors on microorganism activities. In this study, Kendall’s tau (τ) as a statistical method was used to statistically access the effect of typical sulfide flotation surfactants (collectors: potassium amyl-xanthate, potassium isobutyl-xanthate, sodium ethyl-xanthate, potassium isopropyl-xanthate, and Dithiophosphate), and frothers: pine oil and methyl isobutyl carbinol) on the bioleaching of Zn sulfides in a mixed culture (Leptospirillum ferrooxidans, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans). To consider both structure and concentration of these reagents, their molarities were used for the statistical evaluations. The Kendall assessments indicated that by increasing in the molarity of reagents, the pH value (the most effective factors of bioleaching) was increased (τ: 0.56) while the ORP value (τ: -0.54), Fe ratio (τ: -0.51) and numbers of oxidizing bacteria (τ: -0.38) in the solution were decreased. Therefore, as a result of these multi-interactions, by increasing the molarity of reagents, Zn recovery was decreased (τ: -0.45). These results potentially can be used for selection of flotation reagents when bioleaching would be the metallurgical metal extraction method.
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| 4. |
- Josefsson, Peter, et al.
(författare)
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Controlled seasoning of scots pine chips using an albino strain of ophiostoma
- 2006
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Ingår i: Journal of Industrial and Engineering Chemistry. - : American Chemical Society (ACS). - 1226-086X .- 1876-794X .- 0888-5885 .- 1520-5045. ; 45:7, s. 2374-2380
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Tidskriftsartikel (refereegranskat)abstract
- Traditional seasoning of wood chips normally results in significant yield losses and brightness reduction due to the uncontrolled action of microorganisms. Techniques for reduction of the amount of wood extractives with minimal yield and brightness loss are therefore of interest for the pulp and paper industry. To study a biotechnological approach for reduction of wood extractives, wood chips from sapwood of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) were treated with a commercial albino strain of the sap stain fungus Ophiostoma piliferum. During 2 weeks of controlled seasoning, the content of wood extractives decreased by approximately 40% for Scots pine and 25% for Norway spruce, where the triglyceride contents were degraded to a greater degree. Thermomechanical pulps were produced from untreated and pretreated pine chips. The properties of these pulps and corresponding laboratory sheets were investigated. The pretreated pulps showed less shortened fibers, lower amounts of triglycerides, and enhanced strength properties. The mechanisms behind these effects are discussed. Furthermore, the ability of the albino Ophiostoma piliferum to displace mould growth from wood chips was investigated in a series of experiments. It was concluded that the fungus should preferably be inoculated on fresh chips in order to repress mould growth.
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| 5. |
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| 6. |
- Repo, E., et al.
(författare)
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Steel slag as a low-cost sorbent for metal removal in the presence of chelating agents
- 2015
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier BV. - 1226-086X .- 1876-794X. ; 27, s. 115-125
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Tidskriftsartikel (refereegranskat)abstract
- Industrial byproduct, steel slag was used as a low-cost sorbent for the removal of Co(II), Ni(II), Cd(II), and Pb(II) from aqueous solutions containing chelating agents; EDTA, citrate, and oxalate. Equilibrium and kinetic studies were conducted. Clear dependency between speciation of metals and their sorption behavior was observed. Precipitation and adsorption were suggested as main mechanisms. Diffusion played an important role in the kinetics of metal removal. Notable leaching of elements was observed when steel slag was in contact with the solutions under study. Modification with chitosan was successfully used to prevent leaching and improve the sorption capacity of steel slag.
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| 7. |
- Salminen, Eero, et al.
(författare)
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Kinetics upon Isomerization of α,β-Pinene Oxides over Supported Ionic Liquid Catalysts Containing Lewis Acids
- 2014
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Ingår i: Journal of Industrial and Engineering Chemistry. - : American Chemical Society (ACS). - 1226-086X .- 1876-794X .- 0888-5885 .- 1520-5045. ; 53:52, s. 20107-20115
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Tidskriftsartikel (refereegranskat)abstract
- Wood extractives such as α-pinene oxide and β-pinene oxide are important renewable chemicals for the synthesis of fine chemicals, pharmaceuticals, and value-added intermediates. In this work, catalytic transformations of biomass derived extractives, isomerization of α,β-pinene oxides were studied over supported ionic liquid catalysts (SILCAs). SILCAs consist of catalytic species (e.g., metal nanoparticles or metal complexes) in a thin layer of ionic liquid which is immobilized on a solid support material (e.g., active carbon cloth). The reaction kinetics of the isomerization reactions over supported ionic liquid catalysts were studied and modeled. Mechanistic kinetic models describing the differences in selectivity and activity of the catalysts containing different ionic liquids were developed, and the models described the reaction rates and product distributions very well.
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| 8. |
- Sarwono, Ariyanti, et al.
(författare)
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Optimization of ionic liquid assisted sugar conversion and nanofiltration membrane separation for 5-hydroxymethylfurfural
- 2019
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier. - 1226-086X .- 1876-794X. ; 69, s. 171-178
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides complete loop of ionic liquid (IL) assisted glucose conversion to 5-hydroxymethylfurfural (HMF), nanofiltration membrane (NF) based separation and recyclability. The optimum HMF yield of 65.6% was obtained with 8wt.% catalyst loading at 125°C reaction temperature in 120min reaction time. Ea for conversion was found to be 120kJ/mol. NF was adopted first time to separate IL and HMF. The percentage of recovered HMF using NF for 1st, 2nd and 3rd batches are 94.87, 84.35 and 71.65 respectively. The structures of regenerated IL and HMF, obtained from NF and liquid–liquid extraction, were confirmed by NMR.
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| 9. |
- Sjösten, Jerry, et al.
(författare)
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Effect of Particle Coating on Fluidized Bed Heat Transfer
- 2004
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Ingår i: Journal of Industrial and Engineering Chemistry. - : American Chemical Society (ACS). - 1226-086X .- 1876-794X .- 0888-5885 .- 1520-5045. ; 43, s. 5763-5769
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Tidskriftsartikel (refereegranskat)abstract
- Heat-transfer coefficients from a fluidized suspension to immersed stainless steel spheres and an aluminum cylinder were studied in a laboratory-scale bubbling fluidized bed using coated and uncoated silica sand particles from a 90-MWth circulating fluidized bed (CFB), as well as a 30-MWth bubbling fluidized bed (BFB). The experiments were carried out for gas-velocity-tominimum-fluidization-velocity ratios (u/umf) from 1 to 3.5 and mean particle diameters of 350and 635 ím. The heat-transfer coefficients for the coated particles were lower than those for the uncoated particles in all cases, with the difference between uncoated and coated sand particles being more significant for the CFB material than for the BFB sand.
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| 10. |
- Sorcar, Saurav, et al.
(författare)
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Facile electrochemical synthesis of anatase nano-architectured titanium dioxide films with reversible superhydrophilic behavior
- 2017
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Ingår i: Journal of Industrial and Engineering Chemistry. - : Elsevier BV. - 1226-086X .- 1876-794X. ; 46, s. 203-211
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Tidskriftsartikel (refereegranskat)abstract
- In the present work we report a facile and readily-scalable electrochemical anodization technique for preparation of superhydrophilic TiO2 films having reversible wettability properties. The electrochemically anodized Titanium (Ti) foils manifest nanoscale topographical features, interconnected nanowebs and nanofibrils, that enhance both surface roughness and light absorption. After 5 min of UV illumination a water contact angle (WCA) of 4.8 degrees is measured for a 5 mu L deionized water droplet, while after 5 min of whitelight illumination the WCA is 3.2 degrees. Moreover, under UV illumination the superhydrophilic Ti foils exhibit self-cleaning properties. Key factors contributing to the superhydrophilic character include surface topology, and surface chemical reactions.
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