Hot Topic Hour on March 1, 2012 reveals progress on Advanced “Ultra Supercritical Coal-fired Boilers”

Dr. Jeff Phillips, a Senior Program Manager at the Electric Power Research Institute, provided an update on the joint project of the US Dept. of Energy and the Ohio Coal Development Office to develop "advanced ultra-supercritical" or A-USC boilers and steam turbines capable of operating with steam temperatures as high as 1400°F or 760°C. In the past year, one of the materials developed by the project has received approval by the ASME Boiler Code committee and progress has been made on other fronts as well. This project could ultimately allow coal-fired power plants to operate with thermal efficiencies as high as 47 percent on an HHV basis.

A short overview of the world's first supercritical circulating fluidized bed (CFB) coal-fired power plant was also presented.  The power plant, located in Lagisza, Poland, was designed by Foster Wheeler and has nameplate net capacity of 439 MW. The boiler is designed to operate with up to 10 percent biomass.

Debbie Fox prepared and Bob McIlvaine presented an analysis which shows that replacement of old coal-fired boilers with ultra-supercritical boilers makes both economic and environmental sense even if those boilers are retired after 25 years.

Bob McIlvaine then initiated a discussion on how to win over the environmentalists to a program which embraces “clean coal.” It is best to start with the question as to why environmentalists are against clean coal. The reason is practical. Environmentalists only have limited funds. The effort to close down existing coal-fired power plants was beyond their capability, but they could use the funds available to effectively prevent the construction of any new coal-fired power plants.

It is not that they are completely unreasonable but they assumed that any new coal-fired power plant would just add to the problem and furthermore would still be in operation 40 years after start-up. So we can draw some conclusions:

§  Environmentalists are interested in minimizing coal-fired boiler emissions.

§  Under the legal system, there was no way to effect a reduction except through opposition to new coal-fired power plants.

§  Environmentalists should be receptive to a new game plan which better achieves their goals.

Progressively Cleaner Coal should be the title of the program rather than “Clean Coal.” The concept of waiting until carbon sequestration is cost effective can mean decades of lost time.

Here are some arguments for the progressive program:

§  Ultra-supercriticals can replace old coal-fired power plants now and reduce emissions by 80 percent.

§  Carbon capture and sequestration can be added to these plants in the future.

§  Advanced re-designs can be added when available.

§  Because of the savings in coal, an ultra-supercritical can be installed today and retired in 25 years at less cost than adding lots of air pollution control equipment to an old plant and operating it for another 25 years.

§  A nationwide time table to reduce coal-fired power plant emissions can be agreed upon by environmentalists and the utility industry.

§  The route to achieve the time table can then be determined by cost and not by arbitrary actions.

§  The coal saved by the more efficient boilers can be converted to gasoline and address one of the more serious problems facing the nation.

The question arises as to whether the new plants should be greenfield sites or retrofits at existing sites. There are technologies to convert existing coal-fired boilers to ultra-supercritical. Novel space saving concepts such as building vertical will make this possible. So the ultra-supercriticals can be built on existing sites.

Advanced Coal plants could theoretically be carbon negative. With 90 percent CO₂ removal and 20 percent biomass in the fuel, there would be a net 10 percent CO₂ reduction. This makes Advanced Coal the top technology for greenhouse gas reduction. There are tremendous opportunities to further increase the environmental benefits of Advanced Coal. 

Co-locating municipal sewage treatment plants will allow power plants to use treated wastewater as intake for cooling towers and to use sewage as an additional boiler fuel. Other innovative uses for low pressure steam can greatly improve the economics and environmental impacts. It is time to take a different approach and that approach should be “Progressively Cleaner Coal.”

The Bio and Abstract information is linked below.

BIO AND ABSTRACT - JEFF PHILLIPS - EPRI - 3-1-12.htm