Baseload, Bioenergy

The Project: POET’s Project Liberty

Issue 6 and Volume 17.

In September, POET-DSM Advanced Biofuels, a joint venture of Royal DSM and POET LLC proved that its technology that converts agricultural residue into renewable fuel is viable during the grand opening of its first commercial cellulosic ethanol plant in Emmetsburg, Iowa.

Project LIBERTY converts baled corncobs, leaves, husk and stalk into renewable fuel. The plant has now officially started up, processing its first batch of biomass into cellulosic ethanol and is moving forward toward continuous operation. At full capacity, it will convert 770 tons of biomass per day to produce ethanol at a rate of 20 million gallons per year, later ramping up to 25 million gallons per year. Click through to see the slideshow of project images.

Pretreatment: Exterior tanks in the pretreatment area, where the process begins for breaking down biomass (cellulose) to get access to sugars to produce ethanol.

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Fermentation: Fermentation tanks, where yeast converts the sugars into ethanol.

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Stackyard: The biomass stackyard is a 22-acre area used to store as much as 30,000 tons of material for the plant, enough for about four weeks of operation.

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Solid/Liquid separation: Large filter presses help separate the solid and liquid waste streams. The solid “filter cake” goes to the solid fuel boiler to produce steam. The “filtrate” goes to the anaerobic digester to produce methane.

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Solid/Liquid Separation2: Large filter presses help separate the solid and liquid waste streams. The solid “filter cake” goes to the solid fuel boiler to produce steam. The “filtrate” goes to the anaerobic digester to produce methane.

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Solid Fuel Boiler: The solid fuel boiler area, where the solid waste stream is converted to steam to power the cellulosic ethanol plant and the adjacent starch ethanol plant.

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Evaporation: Evaporation is part of the process to purify the ethanol.

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Net Wrap Removal: Bales of corn cobs, leaves, husk and some stalk are loaded onto a conveyor where the net wrap is removed. The material is then sent to a grinder.

All images courtesy POET DSM.