Program will develop ultra-supercritical coal-gen materials

Citation

(2003), "Program will develop ultra-supercritical coal-gen materials", Anti-Corrosion Methods and Materials, Vol. 50 No. 2. https://doi.org/10.1108/acmm.2003.12850bad.006

Program will develop ultra-supercritical coal-gen materials

Program will develop ultra-supercritical coal-gen materials

Keywords: Materials, Coal, Powerplants

A program composed of major private and public energy R&D entities will conduct an unprecedented effort, presently funded at $15 million, to develop and prove new materials for more efficient, ultra-high temperature coal-fired power plants.

The group includes Alstom, McDermott Technologies with its affiliate Babcock and Wilcox, Foster Wheeler, Babcock Borsig Power, EPRI, the Coal Development Office of the Ohio Department of Development, the US Department of Energy's National Energy Technology Laboratory (NETL), and Oak Ridge National Laboratory.

The DOE initiative is largely designed to help American companies compete with their European and Japanese counterparts in producing stronger materials for ultra-high temperature coal-fired power plants. DOE will provide $10.5 million over the next 5 years. Energy Industries of Ohio, a consortium of the major US boiler manufacturers, EPRI, Oak Ridge and the Ohio Coal Development Office, will provide an additional $4.8 million. NETL will manage the effort, act as a liaison between the consortium and the utility industry, and advise the consortium on environmental and systems issues.

Higher operating temperatures in coal-fired plants can lead to higher efficiencies, meaning that more electricity can be generated from a given amount of coal. By developing materials that can withstand higher temperatures, DOE hopes to boost boiler steam temperatures from today's average of 1,004 F, to steam cycles up to 1,400 F. As a result, plant efficiencies would increase from today's average of 35 percent to more than 50 percent (LHV basis) – and the release of carbon dioxide and other emissions would be reduced by nearly 40 percent.

The project centers around five main goals:

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  identifying materials that limit operating temperatures and thermal efficiency of coal-fired plants,

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  developing improved alloys, fabrication processes and coating methods that allow boilers to operate at 1,400 F,

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  participating in the certification process of the American Society of Mechanical Engineers and generating data to lay the groundwork for ASME-code-approved alloys,

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  defining issues affecting the design and operation of ultrasupercritical plants operating at 1,600 F, and

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  working with alloy makers, equipment vendors and utilities to develop cost targets and promote the commercialization of alloys and processes expected to emerge from this effort.

At the end of 5 years, a family of pipes and components made of advanced steel capable of withstanding operating temperatures up to 1,400 F is to be produced. The project also contains provisions for developing advanced alloys suited to 1,600 F, if needed. Foreign boiler makers' products are typically designed to operate at temperatures approaching 1,300 F, boiler manufacturers regain an important competitive edge in an area they had pioneered almost half a century ago. In the early 1950s, American manufacturers began developing ultra-supercritical steam generators designed for 1,200 F, and pressures reaching 5,000 psi. When they encountered unexpected problems, such as superheater corrosion and creep cracking that occurs when pipes are stretched out of shape and are weakened because of excessive temperatures and pressures, manufacturers began building plants to operate under less-severe conditions.

On the other side of the Atlantic, however, Europeans and the Japanese began building a new generation of coal plants within the last decade. With a limited supply of coal available to them, they had to extract as much energy from the fuel as possible. Efficiency and environmental performance, therefore, became salient features and foreign interest resurfaced in ultra-supercritical power plants.

US boiler manufactures stayed abreast of foreign developments, largely through teaming arrangements with Japanese and European boiler manufactures. Joint studies showed that with minor changes in boiler materials, steam plants operating at 1,100 F and 4,500 psi could be built.

The goal of American utilities is to continue to burn coal under strict environmental regulations, a goal that is shared by Europe and Japan, both of which are experimenting with advanced ferritic steels capable of operating at 1,200 F. Japan, for example, is building a new line of supercritical steam generators with steam temperatures that would reach 1,148 F.

Amid this environment, DOE has begun developing the Vision 21 concept for an ultra-high efficiency, virtually pollution-free power plant of the future. DOE's new project to advance boiler materials could become part of the Vision 21 effort.