Benefit of emission reduction in coal-fired power plants demonstrated with environmental burden index


Source: The McIlvaine Company

Coal-fired power plant operators can make substantial reductions in actual greenhouse gases and huge reductions in other emissions.  Operating costs would be reduced while the cost of electricity and life cycle costs would not increase.  The large investment to accomplish this would greatly boost the U.S. economy.  This is the conclusion of the McIlvaine Company in its just completed analysis: Power Plant Environmental Burden Analysis.

Robert McIlvaine, president of McIlvaine Company says 'We do not have to wait until CO2 capture technologies are commercialized.  CO2 and other equivalent emissions can be reduced 85 percent with a low cost but innovative holistic approach.  By adopting the European strategy of replacing old coal-fired plants with new efficient ones, we can have our cake and eat it too: a better environment and a better economy and no rise in electricity cost.'

The concepts of eco-efficiency and sustainability of necessity require the assignment of numerical values to a range of environmental burdens.  McIlvaine has created an index which includes a range of air pollutants and greenhouse gases.  Most decisions to reduce air pollutants result in greenhouse gas increases.  The energy required to remove NOx from stack gases results in added electricity consumption and, therefore, increased CO2 emissions.  The reverse is occasionally true as well.  Increases in particulate emissions will lead to global cooling.  However, the harm caused by the increased particulate emissions would far outweigh the greenhouse gas benefits.

All air pollutants have been numerically equated based on the burden (harm) they cause.  Air toxics have been ranked based on the EPA draft 'Lesser Quantity Emission Rate (LQER)'.  NOx, SO2, and particulate have been ranked based on a variation of the LQER.  This equates particulate with the most benign toxic and equates NOx and SOx at 1/10 the most benign toxic.

Present total emissions from U.S. coal-fired plants for all pollutants have then been quantified based on their actual emissions in tons multipled by the environmental burden index.

Environmental Burden In Millions of Tons For U.S. Coal Plants

Benefit of emission reduction in coal-fired power plants demonstrated with environmental burden index

Actual CO2 emissions are less than two billion tons, but the burden of other emissions is 3.3 billion tons when CO2 is valued at $20/ton.  Since NOx trades at $2000/ton the burden of a ton of NOx is assumed to be 100x that of a ton of CO2.

There are many initiatives which can be undertaken to cost effectively reduce the emissions.  One is replacement of old coal plants with new efficient super critical boilers.  This is the route being taken in Europe.  Air pollution control technology has advanced to the point that 98 percent SO2 removal and 95 percent mercury removal can be cost effectively achieved.

Based on a relative CO2 value of $20/ton, a combination of full replacements and modification of existing coal-fired plants would result in a reduction from 5.3 billion tons of environmental burden to just 1.6 billion. This would be a 69 percent reduction.  30 percent less coal would be burned.  The total cost of electricity generation would not increase.  The capital investment of $450 billion would greatly benefit the economy by creating jobs in engineering, construction, and manufacturing.

Much more benefit could be taken with a holistic approach.  Europe has a program to eliminate landfills and convert waste to energy.  European coal-fired boilers routinely replace up to 15 percent of the coal with biomass.  Several plants make byproduct hydrochloric acid.  One coal plant in the U.S. will achieve 66 percent equivalent thermal efficiency by providing the waste heat to make ethanol.  This holistic approach is very low in cost and immediately employable.  It would reduce the environmental burden by 80 percent.  An additional capital investment of $200 billion would be needed for this holistic approach bringing the total investment requirement to $650 billion.  The reduced coal consumption, reduction in operating costs, and sale of byproducts would offset the depreciation increases.

Coal plants using the best available control technology can burn waste with lower net emissions than dedicated waste combustors.  Gasified chlorinated waste injected above the primary firing zone in coal-fired boilers reduces NOx and oxidizes mercury.  This soluble mercury compound is then efficiently captured in the SO2 scrubber.

These benefits are based on a trading value of CO2 at $20/ton.  Early programs in the U.S. are pegging allowances at $3/ton.  With this value the environmental burden reduction would be over 90 percent. Even at $10/ton there would be an 85 percent burden reduction.

Replacement of the existing fleet of coal-fired plants with new efficient ones could be accomplished in as little as seven years.  China has built this many new plants in just four years.  The stimulus to the economy would be very significant.  Emissions and greenhouse gases would be reduced more quickly than by investing in any other energy source.  Investments in wind, solar, and other renewable sources could take place simultaneously for further stimulus.

More information on this analysis is available in the McIlvaine publication Power Plant Air Quality Decisions.  A comprehensive analysis will be provided in the soon to be released Power Plant Greenhouse Gas Decisions.  To learn more about these services click on:

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