Denver Post. Coors Brewing Company is doubling its current production of 1.5 million gallons of ethanol per year from beer waste by adding a second ethanol processing plant at its Aurora, Colorado brewery.
The ethanol is sold under a contract with Valero Energy Corp., which distributes the ethanol to Diamond Shamrock stations. The new $2.3-million plant will open later this month on the same site.
“We’ve always produced low-grade ethanol, so this was a logical step,” said Rick Paine, the co-products process manager at the Coors facility, referring to the alcohol-heavy grains and yeast used in beer-making. “The fact that we can do it all here is just an added bonus.”
The waste beer (the low-grade ethanol referred to above) is run through a production process which included a fractionation train, a molecular sieve dehydration unit, and product handling facilities.
The existing equipment vaporizes and strips the ethanol from the feed stream. The vapor stream from the distillation tower feeds the new molecular sieve unit which removes the remaining portion of the water. The finished product is then pumped to the storage and truck loading facilities.
Coors and Merrick are also building a second facility to process waste biomass to ethanol.
Coors brewing operations result in approximately 87,000 tons per year of brewer’s grains on a dry-matter basis from the brewing process plus nine other byproducts of the brewing process that contain fermentable starches or concentrations of ethanol.
The goal of the biomass-to-ethanol processing is to convert those various feedstocks into higher value-added products and provide a test-bed to commercialize emerging enzymatic technologies.
The biomass conversion plant will produce in excess of 4 million gallons per year of ethanol through conventional processes which include:
Low temperature cook section
Enzymatic conversion of starches to fermentable sugars
Yeast fermentation (two 250,000-gallon fermenters)
Stripping of ethanol from the mash
Molecular sieve dehydration of the alcohol
The residual wet distillers grain and solubles are consumed by cattle feeding and dairy operations in northeastern Colorado.
(A hat-tip to Jack Rosebro!)