What is Second-generation Biofuels?

According to the Wikipedia, Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass here means plant materials and animal waste used especially as a source of fuel.

Advanced biofuels are renewable fuels derived from renewable biomass that achieve a fifty percent greenhouse gas emissions reduction over conventional biofuels. The definition of advanced biofuels includes cellulosic biofuels, biomass-based diesel, biobutanol, green gasoline and other proven and potential renewable transportation fuels.

Second-generation biofuels are made from different feedstocks and therefore may require different technology to extract useful energy from them. Second generation feedstocks include lignocellulosic biomass or woody crops, agricultural residues or waste, as well as dedicated non-food energy crops grown on marginal land unsuitable for food production.