Grand Challenges in Bioenergy and Biofuel Research: Engineering and Technology Development, Environmental Impact, and Sustainability

of Energy (NSF-DOE) Workshop report (Huber, 2007) concluded that liquid biofuels produced from lignocellulosic biomass can significantly reduce our dependence on oil, create new jobs, improve the rural economy, reduce greenhouse emissions, and ensure energy security. The report also emphasized that the bottleneck for lignocellulosic biomass-derived fuels is the lack of technology for the efficient conversion of biomass into liquid fuels. New technologies are thus needed to replace fossil fuels with renewable and sustainable energy resources. For example, in the US reliable estimates of renewable and sustainable lignocellulosic forest, agricultural biomass, and MSW (likewise mostly biomass) range from 1.5 to 2 billion dry metric tons per year (Huber, 2007); these biomass resources thus could contribute 10 times more to the US primary energy supply (PES) than now. Another forecast in the same report (Huber, 2007) claims that all forms of biomass and MSW have the potential to replace up to 60% of US consumption of crude oil; and that lignocellulosic biomass resources are significantly cheaper (at the equivalent of US$ 15 per barrel o) than petroleum. Since lignocellulosic biomass is the fibrous, woody (mainly hemicellulose and lignin), and generally inedible portion of plants, there is no tradeoff with the production of food crops (i.e., cellulosic biomass). As biomass widely available in many parts of the world, environmentally friendly, and renewable, its potential to help meet the world energy demand has been widely recognized. In a review, Kırtay (2011) concluded that biomass energy has the potential to be “modernized” worldwide, that is, it could Grand challenges in bioenergy and biofuel research: engineering and technology development, environmental impact, and sustainability