| 1. |
- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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| 2. |
- Murzin, D. Yu., et al.
(författare)
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Arabinogalactan hydrolysis and hydrolytic hydrogenation usingfunctionalized carbon materials
- 2015
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Ingår i: Catalysis Today. - : Elsevier BV. - 0920-5861 .- 1873-4308. ; 257, s. 169-176
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Tidskriftsartikel (refereegranskat)abstract
- Hydrolysis of the hemicellulose arabinogalactan was studied in this work over several functionalized carbon materials, which were specifically treated to increase their acidities. Hydrolytic hydrogenation of arabinogalactan was investigated using the same materials in a mechanical mixture with ruthenium supported on active carbon. Application of these mixtures resulted in formation of polyols, suppressing simultaneously the generation of side products hydroxymethylfurfural (HMF) and furfural. Formation of high molecular weight compounds (aggregates of sugars and humins) was still quite substantial with a mechanical mixture of Ru/C and a carbon material prepared from sucrose by activation with zinc chloride to increase porosity. Post-treatment of this carbonaceous material with sulphuric acid significantly influenced kinetics of high molecular weight products formation resulting also in elevation of sugar alcohols yields.
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| 3. |
- Privalova, Elena, et al.
(författare)
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CO2 capture from biogas : absorbent selection
- 2013
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Ingår i: RSC Advances. - : RSC Publishing. - 2046-2069. ; 3:9, s. 2979-2994
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Tidskriftsartikel (refereegranskat)abstract
- The development of proper biogas upgrading technology offers a viable means to utilize biogas in conventional power systems. In this paper, various molecular and ionic solvent systems were evaluated for CO2 removal from biogas in a loop reactor system. The performance of amine solutions, ionic liquids and their mixtures, amino acid salts and solutions blended with piperazine was compared in terms of their CO2 loading capacity. The experimental results revealed that addition of small amounts of piperazine can increase the efficiency of abovementioned solutions on average by 30 vol%. The CO2 capturing capacity of the most promising solvents was in the range of 50-60 L CO2/L absorbent. The regeneration of the solvent mixtures can be challenging since the solvents could loose 16-43 vol% of their initial efficiency upon CO2 release. Ionic liquid [C4mim][acetate] was found to be an efficient VOCs scrubbing media. Moreover, upon use of this ionic liquid, the amount of identified volatile organic compounds (VOCs) in the studied samples was reduced by 65 wt%, while the use of 15 wt% aqueous N-methyldiethanolamine (MDEA) resulted only in 32 wt% reduction in the amount of VOCs.
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| 4. |
- Birgersson, Henrik, et al.
(författare)
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An investigation of a new regeneration method of commercial aged three-way catalysts
- 2006
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Ingår i: Applied Catalysis B. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 65, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- The ability to modify aged three-way catalysts (TWC) by regaining part of the fresh catalyst surface structure has been verified by both bulk and surface-sensitive characterisation techniques. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM/EDX) techniques were applied to fully evaluate the efficiency of a regeneration procedure of commercial three-way catalysts targeting the washcoat surface. The regeneration comprised combined thermal and liquid chlorine treatments. Structural changes of the washcoat were further investigated with nitrogen adsorption-desorption (BET) and Laser Ablation methods. The investigation showed that the regeneration treatments resulted in an enrichment of the washcoat surface with palladium, thereby increasing the number of catalytically active surface sites. Furthermore, the observed removal of phosphorous and sulphur contaminants resulted in an increase of the relative amount of small pores between 1 and 10 nm and washcoat surface area. An increased catalytic activity regarding CO, NOx, and HC emissions was observed after regeneration. providing proof of the proposed concept.
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| 5. |
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| 6. |
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| 7. |
- Hajek, J., et al.
(författare)
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Processing of gluconic acid derivatives to value added monosaccharides via oxidative degradation
- 2012
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Konferensbidrag (refereegranskat)abstract
- One of the components that can be efficiently obtained, e.g., via fermentation of polysaccharide containing waste or biomass, is glucose and some of its derivatives. Degradation of C6 carbohydrates yields corresponding C5 sugars. In case of gluconic acid, the product is arabinose. The reaction, illustrating a valuable synthetic route, e.g., for the abatement of waste streams containing gluconic acid is shown. In spite of high yields, the reaction is characterized by complex analytics due to the presence of organic as well as inorganic by-products. Under optimized conditions, yields between 70-80% could be achieved. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).
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| 8. |
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| 9. |
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| 10. |
- Hyvärinena, S., et al.
(författare)
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Sugars and sugar derivatives in ionic liquid media obtained from lignocellulosic biomass : comparison of capillary electrophoresis and chromatographic analysis
- 2014
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Ingår i: Catalysis Today. - : Elsevier. - 0920-5861 .- 1873-4308. ; 223, s. 18-24
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Tidskriftsartikel (refereegranskat)abstract
- Processing of woody lignocellulosic biomass, under heating in combination with ionic liquids (ILs) was studied in order to obtain simple (fermentable) sugars. Due to the new environmental challenges, finding greener ways to produce platform chemicals and/or bio-fuels has become a popular research area. Various industrial, pilot or laboratory scale technologies for the depolymerization or fractionation of lignocellulosic polysaccharides to monomers are known. One of the new, interesting, methods is to utilize ILs in biomass pre-treatment procedures with an aim to bypass other pre-treatment methods. Furthermore, in order even to initiate studies whether ILs can contribute to catalytic depolymerization, there has to be a robust way to analyze the IL-treated lignocellulosics. This is a major issue since woody samples that contain any salts such as ILs can indeed be quite challenging from the analytic point of view. The applied capillary electrophoresis was found to be an excellent analytical method providing substantial improvements compared to the earlier used chromatographic methods.In this work it was demonstrated that application of ILs, at elevated temperatures, contributes to hydrolysis and depolymerization of lignocellulose. The effect is time and temperature dependent: in harsh conditions sugars degrade but too low processing temperatures or short treatment times result in no meaningful effect. The formation of the degradation products of the monosaccharides is a good indicator of the harshness of the applied chemical conditions. Evidently, furfural and 5-(hydroxymethyl)furfural formed in rather short treatment times.
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