Engineering Commons^™

What Are The Advantages Of Replacing Fossil Fuels With Biofuels?, Amr Shaalan

English Language Institute

Fossil fuels’ negative impact on the environment is leading many people to worry In addition to that, fossil fuels are running out as every day goes by. Thus, finding a renewable and environmentally friendly source of energy has now become a necessity. Biofuels offer clean energy that comes with numerous economic and environmental benefits. Furthermore, biofuels can absorb more carbon from the air than they would produce when burnt. Giving a chance to clear the air from fossil fuel’s carbon.

Efficient Dehydration And Recovery Of Ionic Liquid After Lignocellulosic Processing Using Pervaporation, Jian Sun, Jian Shi, N. V. S. N. Murthy Konda, Dan Campos, Dajiang Liu, Stuart Nemser, Julia Shamshina, Tanmoy Dutta, Paula Berton, Gabriela Gurau, Robin D. Rogers, Blake A. Simmons, Seema Singh

Biosystems and Agricultural Engineering Faculty Publications

Background: Biomass pretreatment using certain ionic liquids (ILs) is very efficient, generally producing a substrate that is amenable to saccharification with fermentable sugar yields approaching theoretical limits. Although promising, several challenges must be addressed before an IL pretreatment technology can become commercially viable. One of the most significant challenges is the affordable and scalable recovery and recycle of the IL itself. Pervaporation (PV) is a highly selective and scalable membrane separation process for quantitatively recovering volatile solutes or solvents directly from non-volatile solvents that could prove more versatile for IL dehydration.

Results: We evaluated a commercially available PV system for …

The Bifunctional Alcohol And Aldehyde Dehydrogenase Gene, Adhe, Is Necessary For Ethanol Production In Clostridium Thermocellum And Thermoanaerobacterium Saccharolyticum, Jonathan Lo, Tianyong Zheng, Shuen Hon, Daniel G. Olson, Lee Lynd

Dartmouth Scholarship

Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are anaerobic thermophilic bacteria being investigated for their ability to produce biofuels from plant biomass. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is present in these bacteria and has been known to be important for ethanol formation in other anaerobic alcohol producers. This study explores the inactivation of the adhE gene in C. thermocellum and T. saccharolyticum. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In both adhE deletion strains, fermentation products shifted from ethanol …

Eight Principles Of Uncertainty For Life Cycle Assessment Of Biofuel Systems, Adam J. Liska

Adam Liska Papers

New environmental regulations in the USA and Europe require a reduction of greenhouse gas (GHG) emissions from transportation fuels as a component of climate change mitigation policy. The US Energy Independence and Security Act of 2007 (EISA) requires GHG emission reductions from the life cycles of biofuels compared to gasoline, by 20% for ethanol from maize grain (maize-ethanol), 60% for cellulosic ethanol, and 50% for other advanced biofuels. To determine these reductions, the US Environmental Protection Agency (EPA) employs life cycle assessment (LCA) methods which were not used previously in national environmental regulations. These regulations, entitled the “Renewable Fuel Standard …

Characterization Of Genetically Modified High Biomass Producing Tobacco Plant, Pankaj Singh Kuhar

Department of Biological Systems Engineering: Dissertations and Theses

Global warming and peak oil has clouded our energy security. In light of this situation, bioethanol as emerged as one of the most amenable solutions to the problem. However bioethanol has its own shortcomings and transgenics seem imperative to exploit its full potential. A high biomass producing line in transgenic tobacco (Nicotiana tabacum cv. Xanthi) was identified during a routine genetic transformation, termed giant recombinant (GR). To characterize the phenotype of the giant line, growth rate and lignocellulosic composition was analyzed relative to the non-transgenic control line. The GR line accounted for 240% more biomass than the untransformed line …

Co2 Recycling Using Microalgae For The Production Of Fuels, Michael H. Wilson, John Groppo, Andrew Placido, S. Graham, S. A. Morton Iii, Eduardo Santillan-Jimenez, Aubrey Shea, Mark Crocker, Czarena Crofcheck, Rodney Andrews

Center for Applied Energy Research Faculty and Staff Publications

CO₂ capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO₂ source. Algae productivity of 39 g/(m² day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m² day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic …

Comparative Efficiency And Driving Range Of Light- And Heavy-Duty Vehicles Powered With Biomass Energy Stored In Liquid Fuels Or Batteries, Mark Laser, Lee R. R. Lynd

Dartmouth Scholarship

This study addresses the question, "When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?" In considering the question, the level of assumed technological maturity significantly affects the comparison, as does the intended transportation application. Results from the analysis indicate that for light-duty vehicles, over ranges typical in the United States today (e.g., 560-820 miles), field-to-wheels performance is similar, with some scenarios showing biofuel to be more efficient, and others indicating the two pathways to be essentially the same. Over the current range of heavy-duty vehicles, the field-to-wheels efficiency is …

Review Of Us And Eu Initiatives Toward Development, Demonstration, And Commercialization Of Lignocellulosic Biofuels, Venkatesh Balan, David Chiaramonti, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Advanced biofuels produced from lignocellulosic biomass offer an exciting opportunity to produce renewable liquid transportation fuels, biochemicals, and electricity from locally available agriculture and forest residues. The growing interest in biofuels from lignocellulosic feedstock in the United States (US) and the European Union (EU) can provide a path forward toward replacing petroleum-based fuels with sustainable biofuels which have the potential to lower greenhouse gas (GHG) emissions. The selection of biomass conversion technologies along with feedstock development plays a crucial role in the commercialization of next-generation biofuels. There has been synergy and, even with similar basic process routes, diversity in the …

Feasibility, Economics, And Environmental Impact Of Producing 90 Billion Gallons Of Ethanol Per Year By 2030, Todd West, Katherine Dunphy-Guzman, Amy Sun, Len Malczunski, David Reichmuth, Richard Larson, James Ellison, Robert Taylor, Vincent Tidwell, Lennie Klebanoff, Patricia Hough, Andrew Lutz, Christopher Shaddix, Norman Brinkman, Candace Wheeler, David O'Toole

US Department of Energy Publications

This paper addresses a national interest in investigating the potential of displacing a large fraction of U.S. gasoline use by 2030 with ethanol. This study assesses the feasibility, implications, limitations, and enablers of producing 90 billion gallons ethanol per year by 2030. We developed a dynamic supply chain model, the Biofuels Deployment Model (BDM), and conducted sensitivity analyses to determine the parameters that most affect the feasibility, cost-competitiveness, and greenhouse gas impact of large-scale ethanol production. Though we found no theoretical barriers to achieving the stated goal, we identified a number of practical obstacles that need to be addressed. In …

Biofuel Feedstock Assessment For Selected Countries, Keith L. Kline, Gbadebo A. Oladosu, Amy K. Wolfe, Robert D. Perlack, Virginia H. Dale, Matthew J. Mcmahon

Economics & Finance Faculty Publications

Findings from biofuel feedstock production assessments and projections of future supply are presented and discussed. The report aims to improve capabilities to assess the degree to which imported biofuel could contribute to meeting future U.S. targets to reduce dependence on imported oil. The study scope was focused to meet time and resource requirements. A screening process identified Argentina, Brazil, Canada, China, Colombia, India, Mexico, and the Caribbean Basin Initiative (CBI) region for initial analysis, given their likely role in future feedstock supply relevant to U.S. markets. Supply curves for selected feedstocks in these countries are projected for 2012, 2017 and …

Biomass And Biofuels In Maine: Estimating Supplies For Expanding The Forest Products Industry, Jonathan Rubin, Kate Dickerson, Jacob Kavkewitz

Energy & the Environment

This paper estimates the renewable energy potential of Maine’s forest resources, and how much energy these resources could potentially provide the state. Using the most recent state-specific data available, and a methodology similar to the Billion Tons Report, we find that ethanol production from Maine’s forest residues could potentially provide 18% of Maine’s transportation (gasoline) fuels with a fermentation wood to ethanol process. Making Fischer-Tropsch diesel (F-T diesel) using forest residues can replace 39% of Maine’s petro-diesel consumption. Actual levels of biofuels that can be produced will depend on conversion factors and forestry residue removals that are subject to uncertainty.