The Wabash River Coal Gasification Repowering Project is one of two demonstrations of advanced integrated gasification combined cycle (IGCC) technology in the United States. It was selected by the U.S. Department of Energy (DOE) in September of 1991 as a Round IV Demonstration Project for the Clean Coal Technology (CCT) Program. The IGCC plant is a repowering facility in the sense that it was built to replace a dated conventional pulverized coal power plant. Construction began in July of 1993 near West Terre Haute, Indiana, followed by operational startup in November of 1995. The project demonstration phase was completed and turned over for commercial operation in December 1999. In 2005, the plant was re-started under new management. SG Solutions LLC (SGS) owns and operates the Syngas Plant, whereas Wabash Valley Power owns the power generation portion of the plant, which is operated by Duke Energy.
Project Participants
The Wabash River Coal Gasification Project Joint Venture was formed in 1990 by Destec Energy, Inc. of Houston, Texas and PSI Energy. PSI Energy was an investor-owned utility whose service covered 62 of the 69 counties in Indiana. Along with Cincinnati Gas & Electric Company, PSI was owned by Cinergy Corporation, formed in 1994 and acquired by Duke Energy in 2006. Destec was purchased by Houston-based NGC Corporation, in 1997, and changed its name to Dynegy, Inc. the following year. In December of 1999, Global Energy Inc. purchased Dynegy’s gasification assets and technology. This included Dynegy’s synthesis gas (syngas) facility at the Wabash River Coal Gasification Repowering Project, as well as the right, title and interest in Dynegy’s proprietary gasification technology and related patents. Dynegy’s gasification projects in development at the time were also part of the acquisition. In 2005, the facility was handed over to SGS, who currently owns and operates the plant.
The gasification technology, developed originally by Dow Chemical, was first applied to power applications at its Plaquemine, Louisiana, chemical complex. Following implementation at this facility, the technology was transferred to Destec, a partially held subsidiary of Dow Chemical. The technology was later acquired by ConocoPhillips. CB&I currently licenses this process technology under the name E-GAS™.
The gasification technology, developed originally by Dow Chemical, was first applied to power applications at its Plaquemine, Louisiana, chemical complex. Following implementation at this facility, the technology was transferred to Destec, a partially held subsidiary of Dow Chemical. The technology was later acquired by ConocoPhillips. CB&I currently licenses this process technology under the name E-GAS™.
Site Description
The demonstration site is located in a predominantly rural area on the Wabash River outside of West Terre Haute, Indiana. PSI’s Wabash River Station was originally a mine mouth plant, and most of the new facility is built over land which was previously shaft-mined in the early 20th century. The site is bounded by the Wabash River to the east, woodlands and agricultural areas, a reclaimed strip mine, and residential areas 0.2 miles to the southeast and 1.5 miles to the north. Downtown Terre Haute is about eight miles south and there are no nearby wilderness areas or national or state parks. The coal gasification repowering facility is located immediately northwest of PSI’s Wabash Generating Station on land which was donated by the Peabody Coal Company. This 15 -acre plot contains the gasification island, air separation unit, water treatment facility, and the gas turbine and heat recovery steam generator (HRSG) tandem are located adjacent to the existing station. A previously used ash pond was converted for wastewater and storm water use.
The Wabash River IGCC Power Plant is designed to use a variety of local coals with maximums of 5.9% sulfur content (dry basis) and a higher heating value of 13,500 Btu/lb (moisture and ash free). A high-sulfur Midwestern bituminous coal from the No. 6 seam at Peabody’s Hawthorn Mine in Indiana was selected for initial operation. In addition, petroleum coke and blends of coal and coke were tested at the facility.
Wabash River IGCC Power Plant
Plant Description
The design for the gasifier used in this project was based on Destec's Louisiana Gasification Technology, Inc. (LGTI) gasifier, which was of similar size and operating characteristics. The LGTI gasifier was operated for more than 34,000 hours from April 1987 through November 1995. Experience gained in that project was considered in the design of the Wabash River facility and eliminated much of the risk associated with scale-up and process variables.
Coal is first slurried with water and fed with 95%-pure oxygen to the first stage of the gasifier. The coal is partially combusted in this stage to maintain a temperature of approximately 2,500 °F (1,371 °C). The majority of the coal reacts at this temperature with steam to produce the raw syngas. Ash in the coal melts and flows out of the bottom of the gasifier vessel as slag. Additional coal slurry is added to the second gasification stage where it undergoes devolatilization, pyrolysis, and partial gasification to cool the raw syngas and enhance its heating value. The raw syngas is then further cooled to produce steam for power generation. The steam is generated at a pressure of about 1,600 psia.
