Development of the Advanced LIDS System as an Integral Part of the Babcock & Wilcox Low Emission Boiler System

Babcock & Wilcox (B&W) is currently developing an emissions control system capable of reducing SOx emissions to one-third of that allowed under the current New Source Performance Standards (NSPS) and particulate emissions to one-half of the NSPS while addressing the concerns of solid waste generation and air toxics regulation. The work is being performed as an integral part of S&W's development of an advanced low-emission boiler system in a project entitled "Engineering Development of Advanced Coal-Fired Low Emission Boiler Systems (LESS)." The program is sponsored by the U.S. Department of Energy's Pittsburgh Energy Technology Center (DOE - PETC). The overall goal of the DOE's program is to dramatically improve environmental performance and thermal efficiency of conventional, Rankine cycle, coal-fired power plants. The initial phase of the LESS multi-phase project required a thorough review and assessment of potential advanced technologies and techniques for control of power plant emissions. For the control of SOx and particulate emissions, numerous near-term advanced flue gas cleanup options were assessed and evaluated. On the basis of these results and other qualitative considerations, the S&W Limestone Injection With Dry Scrubbing (LIDSTM) process was selected for further development and evaluation in B&W's LEBS project. The B&W LIDS process is a limestone-based furnace injection/dry scrubbing S02 removal process. The process comprises the cost-effective integration of three commercially-proven flue gas cleanup technologies: furnace limestone injection, dry scrubbing, and pulse-jet fabric filtration. This paper describes the results of the B&W LIDS process development and evaluation. Highlights include: • Results of pilot-scale testing performed to demonstrate the feasibility of achieving the B&W LESS project S02 removal goal of 97% and particulate emissions goal of less than 0.015 Ib/106 Stu with a fully-integrated LIDS process under cost-effective operating conditions. • Mercury removal data. Mercury emissions from coal-fired power plants are a matter of intense debate. It seems likely that mercury emissions will be regulated in some manner in the latter half of the decade. • Relative boiler flue-gas S03 removal information. There is evidence that the injection of a calcium-based sorbent into the upper furnace of a boiler effectively removes S03 from the boiler flue gases. If true, there is the potential to reduce air heater flue gas exit temperature below current standards due to the elimination of acid condensation concerns - therefore improving boiler thermal efficiency. • Results of a LIDS solid by-product engineering study on disposal characteristics and possible utilization specifications. B&W is aggressively pursuing ways to reduce or utilize the solid waste produced by its various FGD processes - including the LIDS process - through a variety of development programs.