Ethanol

Currently, 100 ethanol plants are operating in the United States, with 41 new plants or expansions under construction. The industry produced 4.7 billion gallons of ethanol in 2005, and the renewable fuels standard will provide a market for nearly 8 billion gallons by 2012. The industry is expected to invest an estimated $6 billion to build 4.3 billion gallons of new ethanol capacity by 2012 to meet this growing demand. As the market adjusts to meet this projected growth, the size and location of new dry mill ethanol plants are changing-from the current typical profile of 40 million to 50 million gallon per year (mmgy) plants located in the Midwest (where electricity prices are generally low) to new 100 mmgy plants sited not only in the Midwest, but also in the Northeast and California, where ethanol demand is concentrated and electricity prices are generally higher. These market shifts and available financial incentives are making CHP an even more economical choice for new facility construction and fuel production.

Dry mill ethanol plants are an excellent fit for CHP. They have large and relatively constant power and steam demands, and they operate 24 hours a day, 365 days a year. The size of the electricity and steam loads at ethanol plants closely matches the size of commonly available CHP technologies. Energy represents a large potion of dry mill ethanol production costs, second only to the cost of the corn used as the feedstock.

Demand for ethanol is growing. Ethanol is the primary replacement for MTBE, which is now banned in 22 states because of its environmental effects. In addition, ethanol's relative value has increased as gasoline prices climb. The inclusion of a new renewable fuel standard and fuel production tax credit in the Energy Policy Act of 2005 is expected to dramatically increase demand for ethanol and construction of new dry mill ethanol plants in the near future.

• Generate electricity and steam reliably on-site
• Reduce energy and operating costs
• Reduce greenhouse gas emissions and other environmental impacts
• Optimize the use of alternative fuels

• Adkins Energy, LLC; Lena, IL; one 5-MW gas turbine
• U.S. Energy Partners, LLC; Russell, KS; two 7.5-MW gas turbines
• Northeast Missouri Grain, LLC; Macon, MO; one 10-MW gas turbine
• Otter Creek Ethanol; Ashton, IA; one 7-MW gas turbine
• East Kansas Agri Ethanol; Garnett, KS; one 1-MW recuperative thermal oxidizer/steam turbine

• Panhandle Energies, Dumas - 30 million gallons/year; feedstock is corn and milo; Announced late 2004
• White Energy, Hereford (Panhandle) - 100 million gallons/year; feedstock is corn and milo; Operational by May 2007
• Panda Energy, Hereford (Panhandle) - 100 million gallons/year; feedstock is corn and milo; fuel is cattle manure and cotton gin waste; Operational by second half of 2007
• Panda Energy, Sherman County (Panhandle) - 100 million gallons/year; feedstock is corn and milo; fuel is cattle manure biogas; Operational by fourth quarter of 2007
• Biofuels Energy Corporation, Raymondville - 4 million gallons/year; Texas' first cellulosic ethanol plant (demonstration project); Operational by third quarter of 2006
• Texas BioEnergy Marketing Associates, Central Texas - five distilleries at 12 million gallons/year each; feedstock is sweet sorghum; Announced June 2006
• Blackland Ethanol Corporation, Central Texas - 50 million gallons/year; feedstock is corn and milo; Announced July 2006

1. The most common CHP technology used in ethanol plants today consists of a gas turbine-electric generator unit, placed in tandem with a waste heat boiler. The turbine-driven generator provides electricity for the facility and the turbine exhaust is used in a waste heat boiler to produce process steam.
2. Interest in biomass and coal CHP is growing. Biomass can be an option for ethanol plants located near sources of agricultural or forest waste or for plants looking to use the process byproducts as a fuel source.
3. Ethanol plants with large thermal oxidizer loads can use a waste-heat boiler to produce steam from the oxidizer exhaust. High-pressure steam from the waste-heat boiler is used in a steam turbine-generator unit to produce electricity. Low-pressure steam from the back end of the turbine is used to meet process heat requirements.
4. Other CHP options are also being explored for ethanol plants, including the integration of dryer exhaust VOC destruction into gas-fired turbine-generator systems.