MIT offers answers to reduce CO2 emissions from coal

A new report today out of Cambridge, Mass.-based Massachusetts Institute of Technology offers insight on how to reduce carbon dioxide emissions from existing coal plants.

The report, unveiled by Professor Ernest Moniz, director of the MIT Energy Initiative and former undersecretary of the U.S. Department of Energy, identifies possible suggestions for policy makers and industry leaders involved in CO₂ emissions mitigation.

The document is based on a March 2009 MIT symposium about retrofitting existing coal plants with post-combustion capture technology—the capture of CO₂ from flue gases after coal is combusted. The symposium included 54 experts from a variety of stakeholder groups.

The symposium also addressed a topic MIT has been researching. Two previous studies provided interim steps to get carbon capture and storage projects adopted, showing that partial capture can be economical and that more research is needed into capillary trapping coefficients (see MIT unlocking carbon capture and storage).

According to the most recent MIT report, some technology options to reduce CO₂ emissions include: efficiency retrofits; co-firing of coal plants with low-carbon fuels; rebuilding existing subcritical units to ultra-supercritical units with capture; more extensive rebuilds; and repowering existing boilers with alternative fuels such as biomass or natural gas.

Entergy CEO Wayne Leonard, who co-chaired the MIT symposium, spoke about a primary issue with existing plants, saying, “these coal plants are going to continue to operate for decades, even as our industry turns to carbon-free electric power generating technologies. Once built, coal plants are, in most cases, the cheapest source of base load power generation and will not be phased out absent very high CO₂ prices. It’s basic economics,” according to a news release.

Key findings from the report include:

• Large, high-efficiency coal plants already outfitted with desulfurization and nitrogen oxide emissions controls are the top candidates for post-combustion capture retrofit;
• The main focus of research and development for existing coal plants should be on cost reduction of post-combustion capture;
• The federal government needs to expand the scale and scope of utility-scale commercial demonstration of coal plants with CO₂ capture;
• Significant reduction of CO₂ emissions can’t be achieved without participation from coal plants in the U.S. and China. The cost of doing so, however, hasn’t been easy. The government of New York pulled out of plans with Princeton, N.J.-based NRG Energy (NYSE:NRG) for a clean coal power plant, citing the rising costs of the $1.5 billion facility (see New York drops plans for clean coal plant).