Technical and Economic Evaluation of a 70MWe Biomass IGCC using Emery Energy's Gasification Technology

摘要

Emery Energy Company has developed a new gasification process for the conversion of carbonaceous feed-stocks into syngas. Prior technology has been developed at Emery's 25-ton/day pilot plant gasifier in Utah and has formed the basis of the Emery gasification technology. Following testing and operations of our pilot plant in 1998, Emery conducted additional process and plant engineering and development of their gasification technology in order make improvements upon what was learned. These improvements led Emery to apply for monies from the U.S. DOE Biomass Power program. Emery received an award from U.S. DOE and conducted the following technical and economic feasibility analysis of the new Emery technology when applied to large-scale biomass power applications. Emery's subcontractors in this project included: The Idaho National Engineering and Environmental Laboratory (INEEL); Combustion Resources LLC; The Biomass Energy Foundation; and, The Southeastern Public Service Authority (SPSA); and, GE Power Systems. Under this contract with the U.S. DOE, Emery evaluated the technical and economical feasibility of the Emery Biomass Gasification Power System (EBGPS). The novel Emery process for this project was an oxygen-blown, pressurized, non-slagging gasification process that integrates both fixed-bed and entrained-flow gasification processes into a single vessel. The unique internal geometry of the gasifier vessel will allow for tar and oil destruction within the gasifier. Additionally, the use of novel syngas cleaning processes using sorbents is proposed which will eliminate or reduce the size of traditional acid gas clean up and sulfur recovery systems. The work scope within this project included: (1) one-dimensional gasifier modeling; (2) overall plant process modeling in ASPEN; (3) feedstock assessment and availability; (4) analysis on Emery's multi-pollutant control process for synthesis gas (syngas) cleaning; (5) preliminary plant design and layout, (6) economic analysis of capital costs, (7) operating costs and the resulting costs of electricity as a function of the cost of fuel; and, (8) the creation of a technology development roadmap necessary to support commercialization of the Emery technology. Process modeling was used to evaluate both combined cycle and solid oxide fuel cell power configurations. Ten (10) cases were evaluated in an ASPEN model. Nine (9) cases were IGCC configurations with fuel-to-electricity efficiencies ranging from 38 - 42% and one (1) case was an IGFC solid oxide case where 53.5% overall plant efficiency was projected. The cost of electricity was determined to be very competitive at scales from 35 - 71 MWe. Market analysis of feedstock availability showed numerous market opportunities for commercial development of the technology. Modular capabilities were considered for various plant sizes based on feedstock availability and power demand. Emery is currently constructing a new prototype gasification system indicative of recent design advancements. The new gasification system is being cost-shared with additional U.S. DOE monies and is expected to begin test operations in November of 2003.