The Kinetics Studies on Hydrolysis of Hemicellulose

Abstract

The kinetics studies is of great importance for the understanding of the mechanism of hemicellulose pyrolysis and expanding the applications of hemicellulose. In the past years, rapid progress has been paid on the kinetics studies of hemicellulose hydrolysis. In this article, we first introduced the hydrolysis of hemicelluloses via various strategies such as autohydrolysis, dilute acid hydrolysis, catalytic hydrolysis, and enzymatic hydrolysis. Then, the history of kinetic models during hemicellulose hydrolysis was summarized. Special attention was paid to the oligosaccharides as intermediates or substrates, acid as catalyst, and thermogravimetric as analyzer method during the hemicellulose hydrolysis. Furthermore, the problems and suggestions of kinetic models during hemicellulose hydrolysis was provided. It expected that this article will favor the understanding of the mechanism of hemicellulose pyrolysis.

Kinetic Study of Acid Hydrolysis of Corn Cob to Xylose

“…In a second approach the two fraction model was applied (Table 4.9) showing (Adjusted R 2 ) closer to one in line with the research work of Aguilar et al, [14], Antonio et al, [18], Wang et al, [13] and Yuan et al, [1].…”

“…Xylose concentrations(mg/ml) were plotted from Table 4 In a first approach the model of seaman was applied to model xylose concentration. The result of fitting by the Saeman's model (Table 4.8) were unsatisfactory mainly showing the values of the statistical parameter (Adjusted R 2 < 0.9) as were also observed by Antonio et al, [18], Onyelucheya et al, [4], Soleimani et al, [15] and Yuan et al, [1]in their research works.…”

“…Also, Wang et al, [13] adopted the Saeman's models in their kinetic study on the hydrolysis of corncob residues to levulinic acid. And Yuan et al [1] equally applied the models in their kinetics studies on the hydrolysis of hemicellulose.…”

“…Many agricultural wastes are costless and renewable, and are widespread sources of useful chemicals in today's world. Even though in most cases the lignocellulosic materials are burned off (which is an application with very low added value with negative environmental impact), the lignocellulosic nature of these agricultural wastes still makes them suitable for processing chemicals with high added value end products [1].The chemical fractionation of lignocellulosic materials into products derived from their structural components (cellulose, hemicellulose and lignin) has turned out to be an attractive possibility which has led to an identified integral benefit to the feed stocks. And since the separation of the structural fractions will usually require the degradation of some of them, a possible first step in the process aimed at the fractionation of these lignocellulosic material scan then be based on the selective degradation of hemicelluloses by means of pre hydrolysis (conventionally carried out in an acidic media) or auto hydrolysis (where which water is reacted with the raw material).…”

Plant Polysaccharides in Engineered Pharmaceutical Gels

“…These conditions expand the cellulose’s surface area, promoting hemicellulose depolymerization, and lignin re-localization [ 73 , 75 ]. Additionally, an acidifier medium (dilute-acid) might boost hemicelluloses recovery compared to simple autohydrolysis [ 76 , 77 ]. As an example, subcritical water (100–374 °C; 0.1–22 MPa) has an acidic nature (increment in [H 3 O + ]) that intensifies the hydrolytic reactions of lignocellulosic components [ 73 ].…”