"In a time when a foreseeable complete transformation from a petroleum-based economy to a bio-based global economy finds itself in its early infancy, biowastes (e.g. agricultural wastes, municipal and solid wastes, sludge, wastewater and foodwastes), currently seen as low-valued materials, are beginning to be recognized as resources for the production of a variety of eco-friendly and sustainable products, with second-generation liquid biofuels being the leading ones."
The climate benefits of biofuels such as ethanol and biodiesel have been debated for many years. Attempts to compare these fuels with one another and fossil-derived fuels such as gasoline and diesel confront many uncertainties, not all of which can be resolved through further data analysis. By scrutinizing the greatest sources of uncertainty and grounding analysis in the areas of high certainty such as combustion chemistry and the terrestrial carbon cycle, this paper sheds light on this challenging subject and points the way toward new strategies for addressing CO2 emissions from transportation fuels.
This National Research Council (NRC) report assesses the potential to achieve twin goals of reducing petroleum use and cutting greenhouse gas (GHG) emissions from U.S. cars and light trucks to 80 percent below the 2005 level by 2050.
ABSTRACT. Improving the fuel efficiency of automobiles (cars and light trucks) is an important means of addressing transportation oil demand and greenhouse gas (GHG) emissions. This report examines the efficiency attainable through evolutionary changes in U.S. automobiles that have fueling characteristics as well as performance, size and other attributes similar to those of today. The analysis combines results from previous engineering studies of powertrain efficiency and load reduction with new examinations of rates of technology change and cost reduction.