Conversion of sugars to ethylene glycol with nickel tungsten carbide in a fed-batch reactor: high productivity and reaction network elucidation
作者:Roselinde Ooms、Michiel Dusselier、Jan A. Geboers、Beau Op de Beeck、Rick Verhaeven、Elena Gobechiya、Johan A. Martens、Andreas Redl、Bert F. Sels
DOI:10.1039/c3gc41431k
日期:——
Bifunctional nickel tungsten carbide catalysis was used for the conversion of aqueous sugar solutions into short-chain polyols such as ethylene glycol. It is shown that very concentrated sugar solutions, viz. up to 0.2 kg L−1, can be converted without loss of ethylene glycol selectivity by gradually feeding the sugar solution. Detailed investigation of the reaction network shows that, under the applied reaction conditions, glucose is converted via a retro-aldol reaction into glycol aldehyde, which is further transformed into ethylene glycol by hydrogenation. The main byproducts are sorbitol, erythritol, glycerol and 1,2-propanediol. They are formed through a series of unwanted side reactions including hydrogenation, isomerisation, hydrogenolysis and dehydration. Hydrogenolysis of sorbitol is only a minor source of ethylene glycol. To assess the relevance of the fed-batch system in biomass conversions, both the influence of the catalyst composition and the reactor setup parameters like temperature, pressure and glucose addition rate were optimized, culminating in ethylene glycol yields up to 66% and separately, volume productivities of nearly 300 gEG L−1 h−1.
[EN] ISOMERISATION OF C4-C6 ALDOSES WITH ZEOLITES<br/>[FR] ISOMÉRISATION D'ALDOSES EN C4-C6 AVEC DES ZÉOLITES
申请人:UNIV DANMARKS TEKNISKE
公开号:WO2014033311A1
公开(公告)日:2014-03-06
The present invention relates to isomerization of C4-C6 aldoses to their corresponding C4-C6 ketoses. In particular, the invention concerns isomerization of C4-C6 aldoses over solid zeolite catalysts free of any metals other than aluminum, in the presence of suitable solvent(s) at suitable elevated temperatures. C6 and C5 aldose sugars such as glucose and xylose, which are available in large amounts from biomass precursors, are isomerized to fructose and xylulose respectively, in a one or two-step process over inexpensive commercially available zeolite catalysts, containing aluminum as the only metal in the catalyst. The ketoses obtained are used as sweeteners in the food and/or brewery industry, or treated to obtain downstream platform chemicals such as lactic acid, HMF, levulinic acid, furfural, MMHB, and the like. FIG. 7
(1) d-Erythrulose was formed by the hydrolysis of diazo-ketone which was obtained by condensing diazo-methane with acetone-d-glyceric acid chloride.(2) Potassium salt of acetone-d-glyceric acid ([α]D15 = +23.7°), acetone-d-glyceric acid chloride ([α]D15) = +14.9°) and acetone-d-glyceric acid amide ([α]D16 = +39.1°) were obtained.
[EN] A PROCESS FOR THE PREPARATION OF METHIONINE ALPHA-HYDROXY ANALOGUES FROM SUGARS AND DERIVATIVES THEREOF<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ANALOGUES D'ALPHA-HYDROXYLATION DE L-MÉTHIONINE À PARTIR DE SUCRES ET DE DÉRIVÉS DE CEUX-CI
申请人:HALDOR TOPSOE AS
公开号:WO2016174231A1
公开(公告)日:2016-11-03
A process for the preparation of methionine a-hydroxy analogue and derivatives thereof comprising contacting one or more sugars or derivatives thereof with a metallo-silicate composition in the presence of a compound comprising sulphur and a solvent.
Selective terminal C–C scission of C5-carbohydrates
作者:Frits van der Klis、Linda Gootjes、Jacco van Haveren、Daan S. van Es、Johannes H. Bitter
DOI:10.1039/c5gc01012h
日期:——
Selective terminal C–C scission of non-edible C5-carbohydrates over Ru/C to C4-polyol building blocks was achieved under mild reaction conditions (138 °C, 6 bar H2).
通过Ru/C在温和反应条件下(138°C,6 bar H2),实现了对非食用C5碳水化合物的选择性C-C断裂,生成C4多元醇构建块。