Conversion of monosaccharides into levulinic acid/esters: impacts of metal sulfate addition and the reaction medium

Abstract

BACKGROUND: Inorganic salts could be used as catalysts for the effective conversion of sugars. In this study, the impacts of various metal sulfates (Na 2 SO 4 , K 2 SO 4 , MnSO 4 , CoSO 4 , NiSO 4 , ZnSO 4 , CuSO 4 , Fe 2 (SO 4 ) 3 , La 2 (SO 4 ) 3 and Ce(SO 4 ) 2 ) on the conversion of glucose/fructose to levulinic acid in varied reaction media were evaluated. RESULTS:The sulfates strongly chelated with the sugars, preventing their dehydration reactions in the presence of sulfuric acid and leading to polymerization of the sugars. The sulfates themselves showed varied activity and selectivity for the conversion of the sugars to levulinic acid/esters or 5-hydroxymethylfurfural (HMF), depending on the coordination with the reaction medium. K 2 SO 4 or Na 2 SO 4 could catalyze the production of HMF from glucose/fructose in water, while in DMSO the yield of HMF was substantially higher. In THF, nevertheless, almost no HMF was formed, while other sulfates such as NiSO 4 in THF could effectively catalyze the conversion of fructose to HMF. In alcohols, Fe 2 (SO 4 ) 3 was the most effective sulfate for the conversion of the sugars to levulinic acid/esters, and the alcohols could effectively suppress the polymerization of the sugars. CONCLUSION:The distinct catalytic performances of the sulfates in the varied reaction media originated from their different coordination or chelation with the sugars and the reaction medium.

Sulfated TiO2 nanosheets catalyzing conversion of biomass derivatives: influences of the sulfation on distribution of Brønsted and Lewis acidic sites

“…17 HMF, as a valuable chemical, has also been paid increasing attention for its production and extensive applications. 18,19 HMF can be obtained from the hydrolysis of cellulose in biomass or biomass derivatives, C6 sugars, 20 which can be further upgraded to highly valuable compounds such as dimethylfuran, 21,22 tetrahydrofuran-dimethanol 23 and levulinic acid/esters, 24 which can be used as suitable fuel additives. 25 As mentioned above, the productions of LA and HMF involve the acidic catalysis process, and acid catalysts play prominent roles for their effective and selective productions.…”

“…Taking glucose as an example, the process involves the isomerization of glucose to fructose, the dehydration of fructose to 5‐hydroxymethylfurfural (HMF) and the further decomposition of HMF to LA in water or to levulinic esters in alcohol solvents . HMF, as a valuable chemical, has also been paid increasing attention for its production and extensive applications . HMF can be obtained from the hydrolysis of cellulose in biomass or biomass derivatives, C6 sugars, which can be further upgraded to highly valuable compounds such as dimethylfuran, tetrahydrofuran‐dimethanol and levulinic acid/esters, which can be used as suitable fuel additives .…”

Investigation into Properties of Carbohydrate Polymers Formed from Acid‐Catalyzed Conversion of Sugar Monomers/Oligomers over Brønsted Acid Catalysts

“…In addition to the dehydration of sugars, their polymerization might also be affected by the accessibility/abundance of hydrogen ions in the reaction medium. Polymerization is a major challenge for the selective conversion of sugars into the platform chemicals such as HMF and LA . Up to now, there have been some methods/processes developed for tackling the polymerization of sugars via using varied atmosphere, reaction medium, and so on.…”

Using taurine to increase mesopores in Ce‐based metal–organic framework for enhancing the production of 5‐hydroxymethylfurfural and 5‐ethoxymethylfurfural from fructose

“…[1][2][3][4][5][6][7] HMF can be obtained from lignocellulose derivatives. 1,2 For the conversion of abundant and cheap fructose-based biomass into HMF or its derivatives, the activity of the catalyst and the reaction media can greatly influence fructose conversion and product selectivity. 8,9 Ethanol is considered a desirable green solvent because it can be produced from cellulosic biomass, such as wheat straw and corn stalks.…”

“…HMF has been identified as one of the most important biomass‐based platform chemicals, because it can be transformed into many value‐added chemicals 1–7 . HMF can be obtained from lignocellulose derivatives 1,2 .…”