Influence of phenol on glucose degradation during supercritical water gasification

Abstract

International audienceBiomass is the ideal alternative renewable energy that might help decrease CO2 emissions. Super Critical Water Gasification (SCWG) is a recent treatment method which is still being developed as regards wet biomass. Above its critical point, water has specific properties and is able to convert wet biomass into gas, and especially into hydrogen. In order to propose a general reaction scheme of the SCWG as regards the lignocellulosic biomass conversion, the interactions between lignin and cellulose must be highlighted. Lignocellulosic biomass could be modelled with phenol (substitute for lignin) and glucose (substitute for cellulose).In a continuous flow tubular reactor, the gasification of solutions containing phenol and glucose or either of the two pure compounds is more efficiently performed when in presence of an alkaline catalyst. The comparison of global parameters, such as the Total Organic Carbon content (TOC), the composition of the liquid product phase (glucose, phenol, etc.), the volume and composition of the gas phase (H2, CO2, CH4, etc.), showed that a small quantity of phenol in a glucose solution dramatically decreased the efficiency of the solution's conversion

Supercritical Water Gasification of Biomass: A Literature and Technology Overview

“…Gasification and hydrogen production yields were lower than those calculated values which led the authors to suggest that even in real biomass, interactions between each component occurred. Similar results have been observed by other authors: Weiss-Hortala et al [61] observed a significant decrease in gas yields even when a small portion of phenol (a lignin decomposition compound) was blended with glucose. Goodwin and Rorrer [62] could not attain a 100% carbon gasification efficiency for xylose and phenol mixtures even at 750 °C.…”

Gasification Rate of Various Biomass Feedstocks in Supercritical Water

“…Sawdust contains lignin, which is notorious in retarding 60) showed that gasification is inhibited by lignin in supercritical water using the batch-type reactor. Weiss-Hortala et al 61) showed that phenol, the main structure of lignin, retards glucose gasification in supercritical water. Without these manures, the homogeneous reaction can be expressed by a single straight line in the Arrhenius plot, with pre-exponential factor of 50.0 s -1 and activation energy of 67.9 kJ/mol.…”

Supercritical Water Gasification of Municipal Sludge: A Novel Approach to Waste Treatment and Energy Recovery

“…Many of these techniques have been repeatedly demonstrated in laboratory experiments to thoroughly destroy wet wastes such as sewage and oily sludges with efficiencies exceeding 99% (Cao et al, 2011). This high level of destruction is possible due to supercritical water's unique properties that change from standard phases, to allow for solvation of organic substances, diffusivity into solid materials and modified reactivity, leading to the degradation of organic substances into carbon dioxide, carbon monoxide, water, and thermal energy in a single reactor system (Byrd et al, 2008;Savage, 2009;Weiss-Hortala et al, 2010).…”