ADA-ES – Electrical utility MACT preparations

Admin note: We recently invited ACC member and coal emissions reduction experts, ADA – Environmental Solutions to prepare an editorial for the Coalblog and quarterly newsletter. In this article, they describe how they are helping their clients prepare for the changes to the EPA MACT rules. We invite you to check out the article and ADAs website ( to learn more about their products and services.

Getting Ready for MACT

The EPA has announced that it is drafting new regulations for electrical generating units (EGUs) based upon the Maximum Achievable Control Technology (MACT) provisions of the Clean Air Act Amendments. The MACT process involves establishing emissions limitations on 187 listed Hazardous Air Pollutants (HAPS) based upon the best performing 12% of plants. EPA is required by a settlement of a lawsuit to issue a draft of the rule in March 2011 and have a final rule published by November 2011. Power plants will then have 36 months to specify and install control equipment to meet a compliance deadline of November 2014.

ADA Environmental Solutions (ADA) provides emission control technology to the coal-fired power industry. We are currently assessing this pending regulation so that we can help our customers develop strategies for meeting the regulation for plants with different equipment design and configurations and a variety of different coal types and characteristics. These strategies to address MACT must be made in a complex regulatory environment because in addition to HAPs, EPA is in the process of promulgating new emissions standards for NOx and SO2 (Transport Rule), as well as greenhouse gases such as carbon dioxide.

As we plan for the MACT regulation, we don’t know the specific emission limits, but we can look at the process EPA is going through, as well as a recent draft MACT for industrial boilers (IB). In deciding how to address the HAPs from those units that burn coal, EPA decided to focus on five subcategories of pollutants:

  • Mercury
  • Acid gases, using HCl as a surrogate for all the acid gases
  • Non-mercury metals (such as arsenic, lead, and selenium) using particulate matter (PM) as a surrogate
  • Dioxins and furans
  • Other organics

Other information that can be learned from the draft IB MACT is that there will not be a different standard for different types of coal, so the emissions limits will be the same for a plant burning PRB coal or a plant burning eastern bituminous coal. The MACT rule may allow the emissions of several boilers at one plant site to be averaged to meet the rule, which would allow facilities limited flexibility in how they comply from numerous boilers.

In working with power generators to develop an integrated control technology strategy that must meet a relatively tight four year compliance schedule, it is important to focus early on decisions related to large capital equipment such as scrubbers and fabric filters because of the length of time need to design, specify, and construct these systems. This will involve making decisions on fuel selection (PRB vs. bituminous) as well as developing assessments of current emissions and testing to determine whether expected emission limits can be achieved. Here are some of the issues to be addressed in the very near future to meet the tight compliance deadlines:

  • Scrubbers: depends on fuel selection, Transport rule limits, HCl emissions standard, volatile metals, mercury capture and reemission.
  • Replace ESP with fabric filter: determine if an existing ESP can achieve the expected 90% mercury reduction with activated carbon injection (ACI), PM limit for metals, control of organics and dioxins/furans with ACI.

ADA has already begun working with customers to obtain the information they need to make these important decision. We are expanding our capabilities for testing and measurement services to be able to evaluate all the various control options such as ACI for mercury and organics, coal additives, scrubber additives and acid gas controls. We are also using what we learned during the initial mercury control market in which 150 ACI systems were purchased by power plants to meet mercury limits in 19 states and Canada. To prepare for the larger market we are working to expand capacity to fabricate a more standard design system as the market is expected to grow to 600-800 systems over a three year period.

There will also be the need for expanded production of activated carbon (AC). To meet the shortage created by the State mercury market, we constructed a new coal-based AC production plant in northwest Louisiana that has the capability of making 150 million pounds of AC per year. To satisfy the demand for up to a billion pounds per year of AC that will be required for a Federal MACT rule, we are preparing to build additional AC production plants.. As with the decisions of our customers on large capital equipment commitments, it is important to begin early to be in a position to meet the rapidly approaching compliance schedule.

07. July 2010 by Jason Hayes
Categories: Emissions, Environment, Mercury, Policy | Comments Off on ADA-ES – Electrical utility MACT preparations