GM has announced a partnership in second generation biofuels.

GM chairman and CEO Rick Wagoner said in Detroit that it is partnering with Coksata to use its technology to produce ethanol from plant waste, old tyres and even rubbish. The partnership includes an undisclosed equity stake for GM, joint research and development into emissions technology and investigation into making ethanol from GM facilities' waste and non-recyclable vehicle parts.

GM said Coskata's propriety process uses microorganisms and bioreactors to produce ethanol for less than $1 a gallon, and plans to bring commercially produced ethanol to market by 2011.

There is a growing interest in second generation biofuels, which do not use valuable food crops in their production, and can reduce CO2 emissions by significantly more than some first generation biofuels.

According to Argonne National Laboratory, which analysed Coskata's process, for every unit of energy used, it generates up to 7.7 times that amount and reduces CO2 emissions by up to 84% compared with a well-to-wheel analysis of petrol. Coskata's process also uses less than a gallon of water to make a gallon of ethanol compared to three gallons or more for other processes.

Wagoner said that GM could partner Coskata in markets such as China.

Last month US president Bush signed the Energy Independence and Security Act, which calls for a dramatic increase in biofuels - from 7.5bn gallons in 2012 to 36bn gallons in 2022. Corn- and other grain-based ethanol are expected to account for up to 15bn gallons of that new standard with 21bn gallons coming from cellulosic and biomass sources.

Last October, Volkswagen and Daimler took a similar step by investing in the German company Choren to help develop a market for second generation biofuels.