For common applications, such as boilers and turbines, a Best Available Control Technology Analysis (BACT Analysis)typically must consider a Selective Catalytic Reduction (SCR) system as a potentially applicable technology for control of NOx. With the relatively recent (October 2004) industrial application of Babcock Power’s Regenerative Selective Catalytic Reduction (RSCR) system, a BACT Analysis that must consider SCR may likely require consideration of RSCR as well, especially for biomass fuel burning equipment.

SCR systems require a minimum temperature of approximately 575°F for the destruction of NOx. For applications where the process or equipment burns biomass fuels, a particulate control device is usually needed upstream of the SCR for it to function properly. However, by the time the flue gases pass through the particulate control device their temperature range is much less than required (between 57 and 61 percent) for the SCR to operate effectively. The traditional solution would be to install a natural-gas or oil fired burner between the SCR and particulate control device to re-heat the air to the appropriate temperatures. The economic burden of the capital costs associated with this control scenario, as well as the cost of the fuel required to operate the burners, is not cost effective given the amount of NOx removed.

As a solution, Babcock Power teamed with Pro-Environmental, Inc. (PEI) to combine Babcock’s SCR expertise with PEI’s Regenerative Thermal Oxidation (RTO) technology, capable of achieving heat recovery efficiencies of greater than 95 percent, to produce the RSCR technology. In 2005, a RSCR system installed at a 50MW power plant fired by wood and construction/demolition waste achieved a NOx emission rate of 0.07-lb/mmBTU. This emission rate equates to an 86% reduction in NOx emissions from wood waste combustion (AP-42 Chapter 1.6, Table 1.6-2 “Dry wood-fired boilers”).

If you would like more information on RSCR techology, visit Babcock Power’s website.

If you would like help completing your BACT Analysis, or any portion thereof, feel free to contact me.