SUPERCRITICAL WATER PARTIAL OXIDATION PHASE I - PILOT-SCALE TESTING / FEASIBILITY STUDIES FINAL REPORT

SPRITZER,M ; HONG,G

GENERAL ATOMICS

关键词: Supercritical Water Partial Oxidation;    Chars;    Oxidation;    Wastes;    Water;   

DOI  :  10.2172/875419
RP-ID  :  GA-C24239
RP-ID  :  FC36-00GO10529
RP-ID  :  875419

美国|英语

来源: UNT Digital Library

【 摘 要 】

Under Cooperative Agreement No. DE-FC36-00GO10529 for the Department of Energy, General Atomics (GA) is developing Supercritical Water Partial Oxidation (SWPO) as a means of producing hydrogen from low-grade biomass and other waste feeds. The Phase I Pilot-scale Testing/Feasibility Studies have been successfully completed and the results of that effort are described in this report. The Key potential advantages of the SWPO process is the use of partial oxidation in-situ to rapidly heat the gasification medium, resulting in less char formation and improved hydrogen yield. Another major advantage is that the high-pressure, high-density aqueous environment is ideal for reaching and gasifying organics of all types. The high water content of the medium encourages formation of hydrogen and hydrogen-rich products and is especially compatible with high water content feeds such as biomass materials. The high water content of the medium is also effective for gasification of hydrogen-poor materials such as coal. A versatile pilot plant for exploring gasification in supercritical water has been established at GA's facilities in San Diego. The Phase I testing of the SWPO process with wood and ethanol mixtures demonstrated gasification efficiencies of about 90%, comparable to those found in prior laboratory-scale SCW gasification work carreid out at the University of Hawaii at Manoa (UHM) as well as other biomass gasification experience with conventional gasifiers. As in the prior work at UHM, a significant amount of the hydrogen found in the gas phase products is derived from the water/steam matrix. The studies at UHM utilized an indirectly heated gasifier with an acitvated carbon catalyst. In contrast, the GA studies utilized a directly heated gasifier without catalyst, plus a surrogate waste fuel. Attainment of comparable gasification efficiencies without catalysis is an important advancement for the GA process, and opens the way for efficient hydrogen production from low-value, dirty feed materials. The Phase I results indicate that a practical means to overcome limitations on biomass slurry feed concentration and preheat temperatuare is to coprocess an auxiliary high heating value material. SWPO coprocessing of tow hgih-water content wastes, partially dewatered sewage sludge and trap grease, yields a scenario for the production of hydrogen at highly competitive prices. It is estimated that there are hundreds if not thousands of potential sites for this technology across the US and worldwide.