![]() The most recent DOE study, published by Argonne National Laboratory in 2021, found that U.S. Scientific research completed over the past two decades using improved LCA methods has identified several key trends that were difficult to predict in earlier studies, rendering those previous findings and forecasts inaccurate. corn ethanol would produce 20% lower GHG emissions than gasoline. LCAs in the early 2000s relied on computer models and assumptions, which estimated that U.S. corn ethanol production rose from about 1.5 billion gallons in 2000 to 16 billion gallons in 2018. energy policy helped drive a significant increase in domestic ethanol production, largely to increase energy independence. An estimated 98% of all gasoline sold in the United States contains 10% ethanol. biofuel comes in the form of ethanol, which is made from corn starch and then blended into gasoline. Life Cycle Emissions Assessments of Corn Ethanol Over Time Department of Energy (DOE) has spent decades advancing the science behind biofuel emissions life cycle analysis (LCA). The GHG emissions of a biofuel depend on what it’s made from, how and where it’s made, and how it’s used-the full life cycle of the biomass, biofuel production, and use.Īs the world’s largest producer and consumer of biofuels, the United States is a critical leader in biofuel science, technology, and policy, and the U.S. However, not all biofuels are created equal. The recognised test methods are ASTM D4052 and ISO 12185, though many companies develop their own internal test methods based on these.Biofuels have been proven to emit significantly lower greenhouse gas (GHG) emissions than petroleum-based fuels, and recent scientific studies indicate that net-zero emission biofuels are not only possible, but achievable.Ĭorn ethanol and other biofuels are essential in America’s transition to a clean energy economy that creates good-paying jobs, increases energy independence, and supports the Biden Administration’s climate goals. This data can be read off a screen, printed out, or transferred to an appropriate electronic data storage system, e.g. An algorithm in the instrument translates the difference in the two frequencies to the density of the sample and the strength (concentration) of the ethanol. The two tubes are subjected to vibrational energy and the frequency of oscillation induced in each is measured electronically. A standard, normally copper inside a similar tube, is positioned alongside the sample tube in a temperature controlled cavity. In more detail, the procedure involves the introduction of the sample into a 1 mm glass U tube, avoiding the inclusion of air bubbles. The induced frequency will be a function of the density of the sample material. The principle applied in the most popular instruments relies on the measurement of the frequency of vibration induced in a sample placed in an oscillating glass U tube, compared to that of a material of known density. ![]() This method has largely been superseded in favour of much more sophisticated and accurate density meters, also called densitometers. ![]() The traditional method of density measurement was with appropriate hydrometers and the strength could be determined from density / strength tables, for a given temperature. Density variation with temperature is significant and must be catered for. Density of an ethanol water solution is an ideal measurement of ethanol content as there is a steady gradation in density from 0.7894 g/ml (pure ethanol at 20 0C) to 0.9982 g/ml for pure water at 20 0C. Since ethanol is miscible with water in all proportions, it is necessary to determine its strength (or concentration) for commercial purposes such as pricing (on pure ethanol content) and excise duty assessment. ![]()
0 Comments
Leave a Reply. |