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Title: Hydrogen production from high moisture content biomass in supercritical water

By mixing wood sawdust with a corn starch gel, a viscous paste can be produced that is easily delivered to a supercritical flow reactor by means of a cement pump. Mixtures of about 10 wt% wood sawdust with 3.65 wt% starch are employed in this work, which the authors estimate to cost about $0.043 per lb. Significant reductions in feed cost can be achieved by increasing the wood sawdust loading, but such an increase may require a more complex pump. When this feed is rapidly heated in a tubular flow reactor at pressures above the critical pressure of water (22 MPa), the sawdust paste vaporizes without the formation of char. A packed bed of carbon catalyst in the reactor operating at about 650 C causes the tarry vapors to react with water, producing hydrogen, carbon dioxide, and some methane with a trace of carbon monoxide. The temperature and history of the reactor`s wall influence the hydrogen-methane product equilibrium by catalyzing the methane steam reforming reaction. The water effluent from the reactor is clean. Other biomass feedstocks, such as the waste product of biodiesel production, behave similarly. Unfortunately, sewage sludge does not evidence favorable gasification characteristics and is not a promisingmore » feedstock for supercritical water gasification.« less
Authors:
;  [1]
  1. Univ. of Hawaii, Honolulu, HI (United States). Hawaii Natural Energy Inst.
Publication Date:
OSTI Identifier:
305624
Report Number(s):
NREL/CP--570-25315-Vol.2; CONF-980440--Vol.2
ON: DE98007508; TRN: IM9906%%304
DOE Contract Number:
FC36-94AL85804
Resource Type:
Technical Report
Resource Relation:
Conference: US DOE hydrogen program technical review meeting, Alexandria, VA (United States), 28-30 Apr 1998; Other Information: PBD: Aug 1998; Related Information: Is Part Of Proceedings of the 1998 U.S. DOE Hydrogen Program Review: Volume 2; PB: 390 p.
Research Org:
National Renewable Energy Lab., Golden, CO (United States)
Sponsoring Org:
USDOE, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 08 HYDROGEN FUEL; HYDROGEN PRODUCTION; WOOD WASTES; STARCH; MIXTURES; SUPERCRITICAL GAS EXTRACTION; METHANE; CHEMICAL REACTION YIELD; STEAM REFORMER PROCESSES; SEWAGE SLUDGE; EXPERIMENTAL DATA