Humin-like substances formed under the conditions of industrial hydrolysis of wood

Sumerskii, Ivan; Krutov, S. M.; Zarubin, M. Ya.

doi:10.1134/s1070427210020266

Cited by 131 publications

(170 citation statements)

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“…Polymeric humins derive from acid-catalyzed transformations of HMF [20][21][22][23] and aggregation of galactose when arabinose is removed from the side chain of the hemicellulose [19].…”

Section: Non-catalytic Hydrolysis and Hydrolytic Hydrogenationmentioning

confidence: 99%

“…Their formation mechanism has been related to polycondensation reactions giving a network of furan rings linked by ether or acetal bonds [20]. At the same time infrared spectroscopy studies [23] did not support the concept of acetal bonds formation advanced by Sumerski et al [20]. Patil et al [21,22] pointed out the involvement of a 2,5-dioxo-6-hydroxyhexenal intermediate formed by rehydration of HMF in the condensation process.…”

Section: Introductionmentioning

confidence: 96%

“…Mechanistic aspects of humins formation have recently been addressed [20][21][22][23][24][25]. Their formation mechanism has been related to polycondensation reactions giving a network of furan rings linked by ether or acetal bonds [20]. At the same time infrared spectroscopy studies [23] did not support the concept of acetal bonds formation advanced by Sumerski et al [20].…”

Section: Introductionmentioning

confidence: 96%

“…Furthermore, substantial formation of high molecular weight compounds, that is, aggregates of sugars and humins (polydispersed heterogeneous carbonaceous materials), occurred. Mechanistic aspects of humins formation have recently been addressed [20][21][22][23][24][25]. Their formation mechanism has been related to polycondensation reactions giving a network of furan rings linked by ether or acetal bonds [20].…”

Section: Introductionmentioning

confidence: 99%

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Hemicellulose arabinogalactan hydrolytic hydrogenation over Ru-modified H-USY zeolites

Murzin

Kusema

Murzina

et al. 2015

Journal of Catalysis

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a b s t r a c tThe hydrolytic hydrogenation of hemicellulose arabinogalactan was investigated in the presence of protonic and Ru (1-5 wt.%)-modified USY zeolites (Si/Al ratio = 15 and 30). The use of the purely acidic materials was effective in depolymerizing the macromolecule into free sugars. While the latter partly dehydrated into 5-hydroxymethylfurfural and furfural, the generation of high molecular-weight compounds (aggregates of sugars and humins) was not favored, in contrast to previous evidences over beta zeolites. Application of the bifunctional Ru/USY catalyst, comprising well-dispersed metallic nanoparticles on the aluminosilicate support, resulted in the formation of galactitol and arabitol, in the suppression of dehydration side products, and further inhibition of polymerization reactions, which only yielded low molecular-weight oligomers. Detailed analysis of the reaction pathways as well as kinetic modeling of hydrolytic hydrogenation was performed with an advanced reaction mechanism.

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“…Polymeric humins derive from acid-catalyzed transformations of HMF [20][21][22][23] and aggregation of galactose when arabinose is removed from the side chain of the hemicellulose [19].…”

Section: Non-catalytic Hydrolysis and Hydrolytic Hydrogenationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hemicellulose arabinogalactan hydrolytic hydrogenation over Ru-modified H-USY zeolites

Murzin

Kusema

Murzina

et al. 2015

Journal of Catalysis

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“…1a also shows that at 220 C, the furfural yield starts to decrease earlier in the solution with increasing initial xylose concentration. This phenomenon could be well explained by a side reaction between furfural and xylose (or intermediate compounds), 10,38 which is, probably, promoted by increasing temperature. These results suggest that differences in reaction temperature and other conditions might explain the contradiction between previous reports either concluding the furfural yield to be independent on the xylose concentration 12 or observing an almost linear decline in furfural yield when initial xylose concentration was increased.…”

Section: 38mentioning

confidence: 99%

The role of xylulose as an intermediate in xylose conversion to furfural: insights via experiments and kinetic modelling

et al. 2015

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An experimental work has been performed to study the relevance of xylulose as an intermediate in xylose conversion to furfural in aqueous solution. The furfural formation was investigated at the temperature range from 180 to 220 C during non-catalyzed and acid-catalyzed conversion of xylose in a stirred microwaveassisted batch reactor. The separate experiments on xylulose and furfural conversions were carried out under similar conditions. The maximum furfural yields obtained from xylose were 48 mol% and 65 mol% for the non-catalyzed and the acid-catalyzed processes, respectively. It was shown that the furfural yield is significantly lower from xylulose than from xylose. Furthermore, the effects of initial xylose concentration and the formation of xylulose were investigated in a mechanistic modeling study. A new reaction mechanism was developed taking into account the xylulose formation from xylose. Based on the experimental results and the proposed reaction model, it was concluded that xylose isomerization to xylulose with subsequent furfural formation is not a primary reaction pathway. The obtained kinetic parameters were further used for plug flow reactor simulations to evaluate furfural yields achievable by an optimized continuous operation.

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Novel One‐Step Process for the Production of Levulinic Acid from Furfural over Hierarchical Zeolites in a Microwave Reactor

Velaga

Peela

2020

Advanced Sustainable Systems

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Here, a novel one‐step process is reported for the production of levulinic acid (LA) from furfural over hierarchical zeolites in a microwave reactor. The furfural conversion and product distribution are determined as a function of formalin concentration (CF) in water, catalyst properties, and heating mode. 20 wt% formalin is found to be the critical concentration, above and below which the 5‐hydroxymethylfurfrual and the LA are formed, respectively. The conversion and LA yield over H‐zeolite are higher by 2.3 and 17 times, respectively, as compared to those over Na‐zeolite. The Brønsted to Lewis acid sites ratio is found to be a crucial catalytic parameter to obtain the best activity and LA yield. Under optimal reaction conditions and with the best catalyst, 42% LA yield is obtained at 90% furfural conversion. The humins formed during the process are characterized using Fourier transformed infrared spectroscopy and thermogravimetric analysis. The humins yield, functionality, and decomposition temperatures are varied with both CF and catalyst properties. The reaction pathways and intermediates are also postulated. The integration of the developed process/route with the existing C6 routes allows the utilization of the entire carbohydrate content of the lignocellulosic biomass to produce LA, and consequently, the overall process becomes more economical.

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Humin-like substances formed under the conditions of industrial hydrolysis of wood

Cited by 131 publications

References 1 publication

Hemicellulose arabinogalactan hydrolytic hydrogenation over Ru-modified H-USY zeolites

Hemicellulose arabinogalactan hydrolytic hydrogenation over Ru-modified H-USY zeolites

The role of xylulose as an intermediate in xylose conversion to furfural: insights via experiments and kinetic modelling

Novel One‐Step Process for the Production of Levulinic Acid from Furfural over Hierarchical Zeolites in a Microwave Reactor

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