Optimization is the Way to Meet CSAPR Rule - Hot Topic November 10, 2011

Optimization software can be purchased for far less than the equipment necessary to achieve modest reductions in NO_x and improvements in boiler efficiency. The efficiency improvements also result in lower air emissions per MW of electricity produced.

Peter Spinney, Director Marketing & Technology Assessment at NeuCo, Inc, addressed opportunities to use optimization to meet the Cross State Air Pollution Rule (CSAPR). He explained how BoilerOpt^® can improve overall unit performance, reduce NO_x, and increase boiler reliability which results in fewer adverse consequences associated with low-NO_x operations, including less slagging, water wall corrosion, ammonia slip and air heater fouling. He itemized the near term CSAPR compliance alternatives.

• De-rate units
  • Live with reduced revenue and increased cost for less efficient gas-fired generation.
• Change fuels.
• Stage deeper with LNBs and OFA.
  • Live with more erosion, tube leaks and slagging.

• Run SCRs and/or SNCRs harder.
  • Live with reagents costs, slips, plume and pluggage.
• Optimize boilers.
  • Reduced and less variable boiler NO_x.
  • Deeper staging with less slagging and corrosion.
  • Greater removal from SCRs/SNCRs with fewer side-effects.

• Minimize capital commitments for CSAPR while emerging regulatory changes make clear which units can survive and which cannot.
• Inform future capital decisions for surviving units with better understanding of true (optimal) baseline performance.
• Better equip surviving units to cope with:
  • Greater demands on existing emissions control hardware.
  • Process changes and variable costs for new emissions hardware.
  • Operational profiles associated with fundamentally altered markets.

• Influx of renewables with intermittent generation output profiles.
• Reduced capacity factor due to more efficient newer capacity coming on-line.
• Problems associated with aging assets and changes from design conditions.
• Greater operational challenges with fewer skilled operators and engineers.
• Ever-greater needs to “push the envelope” in order to “stay in the money.”

William “Bill” Poe, a consultant with Invensys Process Systems, provided an overview of optimization of NO_x reduction control systems and review of a few case studies with results. He indicated that optimizing combustion controls as well as SCR and SNCR systems can significantly impact NO_x emissions. He cited the following optimization opportunities and benefits.

Pre-Combustion

• Coal/fuel blending optimization – 1-2 percent production increase.
• Mill optimization – lower LOI, heat rate improvement, pluggage detection.

Combustion

• NO_x reduction – 10-30 percent.
• Heat rate improvement – 0.25-1.5 percent.
• Dynamic steam temperature control -- +/- 1 percent, reduce steam turbine cyclic life expenditure.
• Ramp rate improvement – up to 100 percent.
• Intelligent soot-blowing – up to 0.25 percent heat rate improvement, lower equivalent forced outage rate (EFOR).
• LOI reduction – 10-30 percent.

Post-Combustion

• SCRs – reduce NH₃ slip; lower capital equipment costs;      
  • 2 percent additional reduction in NO_x.
• FGDs – increase SO₂ removal efficiency with less limestone consumption.

The Bios and Abstracts are linked below.
Bios, Abstracts, Photos - November 10, 2011.htm