Ethanol has a bright future. This renewable, bio-based fluid is in demand as a fuel, octane booster and oxygenate -- particularly as a replacement for controversial additive MTBE as an essential component of reformulated gasoline.
Ethanol can be derived from almost any cellulosic material. Today, corn and other grains are the prime feedstock. In the future almost any low-value, enzymatically converted biomass may be used, such as agricultural wastes, forestry residues and even municipal solid wastes. In addition, the protein value of corn is not wasted in ethanol production: only the starch is used, while the protein is returned to the feed-processing stream in the form of distiller's dried grains or gluten meal.
Broin & Associates, Inc. of Sioux Falls, SD (www.broin.com) is a key player in ethanol production. Broin designs and builds turnkey dry mill ethanol plants throughout the corn-growing regions. Recently the company completed ethanol complexes for North East Missouri Grain, Exol, Agri-Energy, Pro-Corn and Ethanol2000, in Minnesota, Missouri and South Dakota.
Working with Broin and others, Croll Reynolds has emerged as the leading supplier of high performance vacuum systems to the ethanol industry. CR steam ejectors play a vital role in the evaporation process, and the company's multi-nozzle thermocompressors improve plant reliability and efficiency.
A thermocompressor is essentially an ejector used to entrain and compress a low-pressure fluid to a reusable pressure/temperature. CR thermocompressors provide the reclamation and reuse of heat energy so important to an efficient ethanol production process.
Frank Blaine, a Broin process engineer, explains that CR thermocompressors are commonly employed in the evaporator area of the plant, where thin stillage is concentrated into a syrup. Vapor recompression from the multi-nozzle CR thermocompressors is an essential part of the process.