POET Biorefining & City of Macon, Missouri - 10 MW CHP Application - Case Study
Quick Facts
LOCATION: Macon, Missouri
ETHANOL CAPACITY: 50 million gallons per year
PROCESS STEAM REQUIRED: 85,000 lb/hr at 125 PSI
PRIME MOVER:
Solar MarsTM Natural Gas Turbine
GENERATING CAPACITY: 10 MW
HEAT RECOVERY EQUIPMENT:
Deltak Heat Recovery Steam Generator
CHP MAXIMUM THERMAL OUTPUT: 51,000 lb/hr at 125 PSI
IMPLEMENTATION COST SPLITS:
City of Macon – All CHP equipment
POET – Building, water/steam system controls
ANNUAL PLANT EXPENDITURE SPLITS:
City of Macon – 50% of fuel cost
- 100% of O&M cost
POET – 50% of fuel cost
- 100% of water treatment cost
ETHANOL PLANT ENERGY SAVINGS: 15-25% reduction in natural gas steam producing costs
AVOIDED OUTAGES: Ethanol plant maintained operation during numerous grid outages since 2003
BEGAN OPERATION: 2003
The City of Macon, Missouri, in partnership with POET Biorefining (formerly Northeast Missouri Grain, LLC) maintains a 10 Megawatt Combined Heat and Power (CHP) system. The CHP system provides nearly 60% of the steam requirements of the POET facility (which produces 50 million gallons of ethanol annually along with liquefied CO2, and dried distillers grains for animal feed) and provides full electrical backup power to the ethanol plant should the local utility grid experience a power outage.
The CHP system utilizes one 10 MW Solar Mars® 100 Gas Turbine Generator with Deltak heat recovery steam generator (HRSG) that captures the exhaust heat from the turbines to produce approximately 51,000 lbs/hr steam that can satisfy up to 60% of the thermal requirement of the ethanol production process. The ethanol plant also has two natural gas boilers (110,000 lbs/hr capacity) that supplement the thermal energy provided from the CHP system.
In normal operation, the power from the CHP system is fed directly into the power grid that serves the local area including the ethanol plant. However, with an electric substation installed at the plant as part of the CHP system, the ethanol plant has the capability to disconnect from the local grid should the grid experience an outage and have the CHP system supply the entire load required by the plant. According to Steve Murphy, the General Manager of ethanol plant, they have experienced numerous grid outages since CHP operations began in 2003 and have successfully maintained operation of the plant during these outages by switching the load totally to the CHP system.