“Multi-emissions Control” Hot Topic Hour on October 27, 2011 covers Lots of Options

With the CSAPR now in effect and the Utility MACT to be finalized in a few weeks, EGU operators will need to address PM, SO₂, SO₃, NO_x, CO, HCl and Hg all at once. They will face unprecedented challenges because, at the same time, they are also facing stringent byproduct utilization and disposal requirements and water use and wastewater disposal issues. Many power plants also have space limitations.

Fortunately during the past years, designers of APC equipment have also learned a lot about the co-benefits to be derived from a system designed to control a single pollutant such as NO_x or SO₂ as well as some negative impacts. In addition, these APC designers have invested considerable effort to maximize the co-benefits and minimize the negatives so that a single piece of equipment can potentially significantly reduce two or more of the regulated pollutants. They are also designing systems that will effectively control the primary pollutants while minimizing the byproduct and water issues.

The following speakers discussed the technology and equipment available or under development that provides multi-emissions control and can be implemented by EGU operators to achieve compliance with the CSAPR and MACT limits.

John Buschmann, Technology Manager at ALSTOM Power Inc., provided an overview of the proposed Utility MACT emission values and discussed the implications for utilities seeking compliance not only under Utility MACT but also under CSAPR and various other existing and anticipated regulations. The solution is not a one-size-fits-all approach but rather a careful balancing of combinations of AQCS technologies that make up an overall compliance plan.

There are various mercury control options from milling carbon on site to lowering the consumption to adding bromium compounds with the fuel. One of the scrubbing options is NID which has similar characteristics to circulating fluid bed scrubbing but has a smaller footprint.

Keith Day, United Conveyor Corporation (UCC), described the results from several recent dry sorbent injection tests for simultaneous SO₂ and HCl removal. Dry injection can achieve high removal efficiencies at low cost. There is a backlog of testing but the design and construction period is less than with scrubbers. So if you need to do something in a hurry this is a good route. In fact you can start with a portable unit and then move to a permanent unit later.

Dr. Yougen Kong, P.E., Technical Development Manager at Solvay Chemicals, Inc., discussed dry injection of Trona or sodium bicarbonate, a low-cost solution to meet the SO₂ and HCl limits in CSAPR, Utility MACT and Boiler MACT. Both Trona and Sodium bicarbonate are effective in reducing SO₂ and HCl. Trona is slower to react and therefore less effective on SO₂ but possibly better if all you want is HCl removal. Lots of the bicarbonate will be tied up in SO₂ removal. So if you want to just remove HCl Trona may be the answer.

The Bios and Abstracts are linked below.
BIOS, PHOTOS, ABSTRACTS - October 27, 2011.htm