Developing Compact Equipment to Provide High-Efficiency, Industrial-Scale Ultra-Clean Power and Steam

A research team is developing a cost-effective, small- to medium-size gas turbine-based combined heat-and-power (CHP) system that can significantly increase energy efficiency while meeting stringent air-emissions regulations.

A cost-effective supplemental Ultra-Low-NOx (ULN) burner that eliminates the need for selective catalytic reduction (SCR) flue-gas treatment, reducing capital costs by up to 25% and eliminating the barrier to adoption for small- to medium-capacity facilities (15 MW or less) has been optimized.

The burner is integrated with a 65 kW microturbine and a heat recovery boiler, along with a new electronics control panel that merges the equipment with the various sensors and devices required for system operation into a single package.

Laboratory tests have shown total efficiency of over 85% and NOx emissions that are below stringent emission levels.

Field testing of the FlexCHP-65 system was successfully implemented at food-processing plant, Inland Empire Foods, in California.

The FlexCHP system demonstrated significant improvements in performance, both in terms of emissions and efficiency as compared to the microturbine operating alone. System efficiency increased from 23.6% to 82.4%-84.2%, with significant emissions reductions across the full range of firing rates—achieving NOx levels 50% below CARB limits.

Under full load conditions, NOx, CO, and THC emissions are reduced by 45%, 97%, and 78%, respectively. The resulting CHP packages promise to make CHP implementation more attractive, mitigate greenhouse gas emissions, improve the competitiveness of industry, and improve the reliability of electricity.

“When the FlexCHP is in operation, we achieve a 25% reduction in combined electric and gas utility costs, compared with purchasing an equivalent amount of electricity from the utility and generating an equivalent amount of steam with our conventional gas-fired boilers,” says Mark Sterner, CEO at Inland Empire Foods.

The FlexCHP system will provide CHP users with a highly efficient source of on-site heat for use with boilers and absorption chillers. The technology is environmentally superior and cost-competitive compared to state-of-the-art duct burner technology available on the market. The developed technical approach can be expanded to other combustion applications using TEG or preheated air as combustion air in situations where low combustion emissions are required.