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Permalink Reply by Ruth Anthony-Gardner on March 7, 2013 at 5:02pm

Here's a solution to using arable land for biofuel. Collect duckweed from polluted lakes

Duckweed as a cost-competitive raw material for biofuel production

... 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. It grows fast, thrives in wastewater that has no other use, does not impact the food supply and can be harvested more easily than algae and other aquatic plants.

They describe 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. Oil would have to cost only about $72 per barrel for larger duckweed refiners to be cost-competitive.

And the next plant-based fuel is … duckweed

Growing the plant for fuel could at the same time address the serious problem of livestock-based wastewater pollution.

Industrial-scale hog farms currently store animal waste in large open-air “lagoons” that contribute to air pollution. Duckweed can use the nutrients in that waste to reduce that pollution and clean the water.

Permalink Reply by Ruth Anthony-Gardner on March 22, 2013 at 11:10am

Dinoflagellate algae is an even better biofuel source which doesn't compete for cropland.

Microalgae Could Be a Profitable Source of Biodiesel

Dinoflagellate microalgae could be used as a raw material to obtain biodiesel easily and profitably.

The scientists carried out the whole production process in exterior cultures, in natural conditions, without artificial light or temperature control, in cultivation conditions with low energy costs and subject to seasonal fluctuations. Detailed analysis of all costs over 4 years gives promising results: microalgae cultures are close to producing biodiesel profitably even in uncontrolled environmental conditions.

"If we make simple adjustments to completely optimise the process, biodiesel obtained by cultivating these marine microalgae could be an option for energy supplies to towns near the sea," points out Sergio Rossi, an ICTA researcher at the UAB.

Among these adjustments, scientists highlight the possibility of reusing leftover organic pulp (the glycerol and protein pulp that is not converted into biodiesel) and using air pumps and more efficient cultivation materials. [emphasis mine]