Following Hurricane Katrina and record high gas prices in 2005, GEO Specialty Chemicals¹ Cedartown plant modified an existing Keeler water tube boiler to burn yellow grease (YG) as an alternative fuel. The boiler was originally designed for #5 oil thus simplifying the conversion to YG. Typical modifications including a bulk YG storage tank, circulation and preheating system, and a filtration system were required as part of the project scope.

Our existing State of Georgia boiler air permit was modified to include YG as a fuel source. Previous YG characterization and testing by the University of Georgia prior to 2001 indicated a significant reduction in NOx, CO and SO2 emissions when burning YG. The permit modification was quickly accepted and approved by the Georgia Environmental Protection Agency in 4-5 weeks.

Each month, the Cedertown plant compares the cost of gas, #2 oil and YG and selects a low cost fuel for boiler operations. In addition to low cost, the primary advantage of burning YG is the significant improvement in fuel-to-steam (F/S) boiler efficiency. With a properly tuned boiler, F/S efficiencies of 82-83% are observed in comparison to natural gas F/S efficiencies of 77-79%.

Yellow Grease gives our plant an opportunity to save money and burn a fuel recovered from spent cooking oil and animal fats. With all the hype on green and renewable energy sources, I want to do our part to conserve fuel resources and protect the environment.

Larry Waddell
Plant Engineer
GEO Specialty Chemicals