Developments Signal Boost for Coal Gasification

Developments Signal Boost for Coal Gasification

Jul 25 - Power Engineering

Integrated gasification combined cycle (IGCC) is broadly viewed as the holy grail of coal-fired generation, a technology offering the possibility of using the fuel representing 95% of U.S. fossil reserves (easily a 250-year supply) while producing little or no pollutants. Thus, IGCC could provide the energy equivalent of having the cake and eating it too. Although nuclear power and renewable forms of energy are also widely viewed as potential emission-free hydrogen producers - nuclear on a far larger scale - IGCC offers a potentially huge option in such a future energy mix scenario. A number of recent industry developments could indicate that IGCC will become a bigger player in the electric power sector sooner rather than later.

Among the major recent developments in the world of IGCC is GE Energy's acquisition of IGCC technology developed and owned by ChevronTexaco. ChevronTexaco's gasification technology business has been developing and licensing gasification-related technology for use in the chemicals, electric power and hydrogen producing industries for more than 50 years. In acquiring ChevronTexaco's coal gasification technology business, GE Energy broadens its gasification plant offerings and expands its ability to provide coal- fired generation that produces fewer air pollutants than conventional coal combustion.

No stranger to the IGCC industry, GE has supplied gas turbines for more than 60% of the world's operating IGCC plants. GE has also worked with ChevronTexaco on a number of IGCC projects including the application of IGCC at the 100 MW Cool Water plant in California, a dempnstration project completed in 1984, and Tampa Electric's 250 MW Polk Power Station that went into operation in 1990.

GE's acquisition of such a developed IGGG technology should serve to advance IGGG more rapidly than envisioned only several years ago, mueh as GE's purchase of Enron's wind turbine manufacturing business could not help but advance market appeptanpe of wind energy and stir accelerated technical development of wind turbines.

On another front, boiler manufacturer ALSTOM has announced participation in DOK? project to develop and verify a novel hybrid coinbustion=gasification chemical looping concept, ALSTOM will develop the, hybrid combustion gasification process Using high temperature chemical and thermal looping technologies. The process is based on the oxidation, reduction, catenation, and calcination of ealeium-based compounds to chemically react with coal, biomass, or opportunity fuels in two chemical loops and one thermal loop.

ALSTOM has completed engineering studies and benoh-scale tests on the chemical looping process and determined that this process has the potential to meet ultra-clean low emissions targets, including CO2 capture, at a cost and efficiency that is about the same as today's power plants. Project participants also include Parsons Energy & Chemical Group, ABB Lurarnus Global, and PEMM Corporation. Pilot-scale process testing is now underway at ALSTOM's Power Plant Laboratories research complex in Windsor, Conn.

The chemical looping process components can be configured alternately as a combustion-based steam power plant with or without CO2 capture or as a hybrid combustion-gasification process producing syngas. Ultimately, they could be integrated into a hybrid combustion-gasification process producing hydrogen for gas turbines, iuel cells or other hydrogen based applications while also producing a separate stream of CO2 for use or sequestration.

"By developing and deploying these configurations as independent steps," says John Marion, Director of Global R&D and Power Plant Laboratories for ALSTOM's Utility Boiler Business, "this new concept offers the promise to become the technology link from today's Rankine cycle steam power plants to tomorrow's advanced power generation plants."

In another development, ConocoPhillips and Excelsior Energy have signed a development and technology licensing agreement for an IGCC facility. ConocoPhillips' E-Gas technology converts coal and other low-grade feedstocks, including petroleum coke, into synthesis gas containing hydrogen. The process allows virtually all pollutant- forming impurities to be removed, including mercury from coal, and is readily adaptable for further removal of carbon in the future. Excelsior's 532 MW Mesaba Energy Project, to be located on the Iron Range of northeastern Minnesota, is expected to be in operational in 2010.

The 262 MW Wabash River Coal Gasification Repowering Project, in West Terre Haute, Ind., funded in part by DOE and developed by Destec Energy and PSI Energy, has been utilizing the E-Gas technology on a commercial basis since 1995. As part of DOE's Clean Coal Technology Program, Wabash has gasified more than three million tons of coal and petroleum coke over the past eight years, and can operate interchangeably on either fuel. Mesaba will implement further refinements of the E-Gas technology for higher efficiency and lower cost, including a hybrid particulate removal system, enhanced sulfur and mercury removal technologies as well as possibly utilizing an advanced combustion turbine integrated with other process units in the facility.

In May, ConocoPhillips also announced the signing of a worldwide alliance agreement with Fluor to facilitate the development, design and construction of new projects utilizing its E-Gas technology. Through the alliance, ConocoPhillips and Fluor will partner to provide project development and turnkey support for engineering, procurement, construction, operation and maintenance for solid fuel gasification facilities in both the chemical and energy segments.