Glucose and fructose decomposition in subcritical and supercritical water: Detailed reaction pathway, mechanisms, and kinetics

Journal Article · Sun Aug 01 04:00:00 EDT 1999 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie9806390· OSTI ID:691430

Kabyemela, B M; Adschiri, T; Malaluan, R M; Arai, K ^[1]

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1. Tohoku Univ., Sendai (Japan). Dept. of Chemical Engineering

The authors are developing a new catalyst-free process of cellulose decomposition in supercritical water. In their initial study on the cellulose decomposition in supercritical water, the main products of cellulose decomposition were found to be oligomers of glucose (cellobiose, cellotriose, etc.) and glucose at short residence times (400 C, 25 MPa, 0.05 s). The kinetics of glucose at these conditions can be useful in understanding the reaction pathways of cellulose. Experiments were performed on the products of glucose decomposition at short residence times to elucidate the reaction pathways and evaluate kinetics of glucose and fructose decomposition in sub- and supercritical water. The conditions were a temperature of 300--400 C and pressure of 25--40 MPa for extremely short residence times between 0.02 and 2 s. The products of glucose decomposition were fructose, a product of isomerization, 1,6-anhydroglucose, a product of dehydration, and erythrose and glyceraldehyde, products of C-C bond cleavage. Fructose underwent reactions similar to glucose except that it did not form 1,6-anhydroglucose and isomerization to glucose is negligible. The mechanism for the products formed from C-C bond cleavage could be explained by reverse aldol condensation and the double-bond rule of the respective enediols formed during the Lobry de Bruyn Alberda van Ekenstein transformation. The differential equations resulting from the proposed pathways were fit to experimental results to obtain the kinetic rate constants.

• OSTI ID: 691430
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 8 Vol. 38; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CELLULOSE
CHEMICAL REACTION KINETICS
DECOMPOSITION
FRUCTOSE
GLUCOSE
HYDROLYSIS
SUPERCRITICAL GAS EXTRACTION