Glucose decomposition

In 2008, Xiuyang et al. made an in-depth experimental study on the glucose decomposition in High Temperature Liquid Water (HTLW) from 180 to 220°C [73]. Interestingly, at 220°C, 100% of glucose was consumed within 90 min without addition of any catalyst. Analysis of the crude revealed that the main products of the reaction were HMF, levulinic acid, humic matter, and two unidentified soluble compounds. The maximum yield of HMF was obtained after 30 min of reaction (32%). 

Kinetics of Glucose Decomposition During Dilute-Acid Hydrolysis of Lignocellulosic Biomass... 

Index Entries Reaction kinetics glucose decomposition dilute acid hydrolysis kinetic modeling acid-soluble lignin acid-base catalysis rules. 

We have therefore studied the kinetics of cellulose hydrolysis and glucose decomposition under extremely dilute H2S04 (0.05-0.2 wt%, pH 1.5-2.2) and high-temperature (200-230°C) conditions. Our ultimate goal is to better understand the kinetics of dilute-acid hydrolysis of biomass and develop promising acid hydrolysis processes that can give both high... 

Fig. 2. Profiles and trend lines of glucose decomposition at various pH values and 200°C.

From the experimental results in Figs. 1 and 2, the first-order reaction trend lines could not be traced back to the origin (time at 0 and a glucose fraction at 1) on extrapolation. This phenomenon can be observed in most previously reported data. It indicates that the reversible reactions are much faster than irreversible glucose decomposition and equilibrium is attained at early phase of the reaction. Conner et al. (9) suggested an... 

Fig. 5. Glucose decomposition affected by presence of ASL and by presence of metals.

The kinetic model established by our work can accurately predict the rate constants of glucose decomposition over a broad range of acid concentrations including extremely low acid conditions (pH 1.5-2.2) in which Saeman s model fails to hold. 

To elucidate the influence of the preparation procedure (dynamic or static) two series of gluocose based adsorbents were pre-deposited on the surface of silica gel Si-100. The proportions of glucose to silica gel were the same for the static (S) and dynamic (D) series of carbosils. Additionally, the influence of water (formed during glucose decomposition) on the porous structure of silica was analyzed. 

Endo, G, Noike, T., and Matsumoto, J. 1982. Characteristics of cellulose and glucose decomposition in anaerobic phase of anaerobic digestion. Proc. Soc. Civ. Engrs.,325, 61-68 (In Japanese.)... 

Christiani, H. Glucose decomposition during the faotory operation. Arch, suik-erind, Vol. 20, pp. 1701-1712. 

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