Vogelbusch designs facililities that can process ethanol from a comprehensive range of agriculturally derived starches and sugars, including wheat, corn, milo, barley, rye, potatoes, cassava, sweet potatoes and wet milling by-products, as well as sweet sorghum, sugar cane and sugar beet in the form of molasses, thick juice or syrups.
End product specifications include potable alcohol, and industrial and fuel ethanol.
Milled grain is mixed with water, enzymes, and chemicals and heated to ensure uniform gelatinization. The starch mash is then converted by enzymes to fermentable sugars.
The mash, now rich in fermentable sugars, is pumped to the first stage of continuous fermentation. Some of the treated mash is also fed to prefermenters where the yeast required for continuous fermentation is grown. The fermenting mash of the first stage overflows to the second stange and so on, through four to seven stages of fermentation. During fermentation CO2 and alcohol are produced. Fermenting mash in each stage is continuously cooled by circulation through a heat exchanger.
The alcohol rich mash from fermentation is heated and fed to the mash column where the first separation of alcohol/water vapors from fermented grain residue or slops occurs. Alcohol/water vapors leave the mash column at about 100 proof. The vapors are further concentrated in the rectification column and then dried in the molecular sieve dehydration unit for a 200 proof product.
The slops from the bottom of the mash column are further processed by centrifuge and multi-stage evaporation to DDGS. The evaporator operates as an integrated heat recovery system to minimize energy requirements.
The DDGS slops from the decanting centrifuges and evaporators are mixed and dried in a flash or rotary steam tube dryer to produce dry DDGS animal feed product, at about eight percent moisture.
The plant in Casselton, North Dakota utilizes technology licensed by Vogelbusch, including the Multicont continuous fermentation process, and is currently operating at a capacity of 130 million gallons per year (1.4 million liters per day), making it one of the largest dry corn milling ethanol facilities in the world.
Hydrous ethanol imported from Brazil is the feedstock for a molecular sieve dehydration facility set up by EthylChem at their Pointe-a-Pierre refinery in Trinidad. It has a production capacity of 100 million gallons per year (1,081,000 litres per day) of fuel ethanol with a purity of over 99.9 per cent that is intended for export primarily to the US.