Duckweed to the Biofuel Rescue

Tuesday, March 12, 2013 @ 05:03 PM gHale

The search for a less-expensive, sustainable source of biomass, or plant material, for producing gasoline, diesel and jet fuel is leading scientists to duckweed, that fast-growing floating plant that turns ponds and lakes green.

Duckweed, an aquatic plant that floats on or near the surface of still or slow-moving freshwater, is ideal as a raw material for biofuel production, according to Christodoulos A. Floudas, of the department of chemical and biological engineering, Princeton University, and Xin Xiao of the Langfang Engineering and Technology Centre, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China, and their team.

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Duckweed biomass would end up gasified in a thermochemical-based superstructure to produce gasoline, diesel, and kerosene using a synthesis gas intermediate.

The beauty of duckweed is it grows fast, thrives in wastewater that has no other use, does not impact the food supply and is easier to harvest than algae and other aquatic plants. However, few studies have occurred on the use of duckweed as a raw material for biofuel production.

Floudas’ team describes four scenarios for duckweed refineries that use proven existing technology to produce gasoline, diesel and kerosene.

Those technologies include conversion of biomass to a gas; conversion of the gas to methanol, or wood alcohol; and conversion of methanol to gasoline and other fuels. The results show that small-scale duckweed refineries could produce cost-competitive fuel when the price of oil reaches $100 per barrel. However, for larger duckweed refineries, oil would have to cost only about $72 per barrel to be cost-competitive.

Click here to view a paper on the subject.