Ethanol Production for Automotive Fuel Usage

The conceptual design of the 20 million gallon per year anhydrous ethanol facility a t Raft River has been completed. The corresponding geothermal gathering, extraction and reinjection systems to supply the process heating requirement were also completed. The ethanol facility operating on sugar beets, potatoes and wheat will share common fermentation and product recovery equipment. The geothermal fluid requirement will be approximately 6,000 gpm. It is anticipated that this flow will be supplied by 9 supply wells spaced at no closer than 1/4 mile in order to prevent mutual interferences. The geothermal fluid will be flashed in three stages to supply process steam at 250 F, 225 F and 205 F for various process needs. Steam condensate plus liquid remaining after the third flash will all be reinjected through 9 reinjection wells. The capital cost estimated for this ethanol plant employing all three feedstocks is $64 million. If only a single feedstock were used (for the same 20 mm gal/yr plant) the capital costs are estimated at $51.6 million, $43.1 million and $40. 5 million for sugar beets, potatoes and wheat respectively. The estimated capital cost for the geothermal system is $18 million.