Biomethane: A Fuel From Pure Grass

This is highly optimal. In Austria, cars can now fill up on a renewable, locally-produced fuel. The fuel is called “biomethane”, and it’s created by fermenting meadow grass (Poa pratensis). The grass is grown without the input of synthetic fertilizers or pesticides. And it’s a true ‘cellulosic biofuel’ — it doesn’t rely on grains and oilseeds.

It’s known in the U.S. as Kentucky bluegrass, and it’s an important meadow species found extensively in Austria’s grasslands, where it is used by grazing livestock like cattle and sheep.

The fuel is being produced by a company called Salzburg AG, and they’ve opened the first biomethane gas station in the city of Eugendorf, Austria. From December onwards, customers can fill up their natural gas vehicles with blend of 20% CO2-neutral biogas and 80% natural gas, at a price that beats all other transport fuels.

Salzburg AG built the first part of a new dedicated gas infrastructure – a 2 kilometer pipeline – which feeds the upgraded biogas into its existing local natural gas grid. In 2008, the company will supply this ‘Bioerdgas’ to 14 similar stations that currently offer natural gas in the city and federal state of Salzburg . The regional energy administration is the station’s first customer and will run its fleet on the clean gas.

Given that all the grass is converted into a useable fuel and organic fertilizer, one could consider biogas production a form of ‘cellulosic biofuel’: it doesn’t require easily fermentable sugars or starches – as do first generation liquid biofuels which rely on grains and oilseeds. As the Austrian project shows, a transport biofuel can be obtained from a cellulosic biomass feedstock like pure grass. Yield estimates for the biogas from grass are as follows: one hectare can yield between 2,900–5,400 cubic meters of pure methane per year, enough to fuel a passenger car for 40,000 to 60,000 kilometers (one acre of crops can power a car for 10,000 to 15,000 miles).

Via: Biopact