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OVERVIEWExcerpted from the National Renewable Energy Laboratory Vehicles and Fuels BasicsWe can improve the fuel economy of our cars, trucks, and buses by designing them to use the energy in fuels more efficiently. And we can help to reduce our nation's growing reliance on imported oil by running our vehicles on renewable and alternative fuels. Advanced vehicles and fuels can also put the brakes on air pollution and improve our environment.At least 250 million vehicles are in use in the United States today. They include all kinds of passenger cars, trucks, vans, buses, and large commercial vehicles. It takes an enormous amount of fuel to operate these vehicles every year. To reduce the costs and risks of these imports and improve the environment, researchers are developing newer, more energy-efficient fuels and vehicles and finding ways to make fossil fuels like gasoline and diesel fuel last longer.Environmental Impact and Benefits: Some fuels have a reputation of being inherently “clean” but in today’s vehicles and engines, it is not the fuel alone but rather the sophisticated integration of engine, fueling, exhaust and evaporative emission control system designs that determine how clean a vehicle will be. Conversion to alternative fuels can be environmentally beneficial, but conversion does not necessarily reduce pollution. Cost and Range: The cost of running a vehicle on an alternative fuel will depend on fuel price and on how far you can travel on each unit of fuel. The amount of fuel you need will depend on the fuel’s energy density (kJ/g that can be produced via combustion of the fuel), and on whether the converted vehicle is optimized to take advantage of the alternative fuel characteristics. Operating costs may be either higher or lower for a conversion than for the original configuration. Electricity, gaseous fuels, and alcohol fuels are generally less energy dense than gasoline and diesel fuel. Depending on how much alternative fuel you can store onboard, you may not be able to travel as many miles on a “fill-up” and may need to refuel more frequently.Biobutanol DossierExcerpted from the US Dept of Energy Alternative Fuels Data Center is a 4-carbon alcohol (butyl alcohol) produced from the same feedstocks as ethanol including corn, sugar beets, and other biomass feedstocks, including cellulose and algae. Biobutanol can be used as an oxygenate and blended with gasoline in concentrations up to 11.5% by volume. Biobutanol blends of 85% or more with gasoline are alternative fuels under the Energy Policy Act of 1992.Biobutanol is an alternative to conventional transportation fuels, including petroleum-derived gasoline. The benefits of biobutanol include:Higher Energy Content—Biobutanol's energy density is just 10% to 20% lower than gasoline's, which makes its energy content relatively high among gasoline alternatives.Increased Energy Security—Biobutanol can be produced domestically from a variety of feedstocks, while creating U.S. jobs.Fewer Emissions—Carbon dioxide captured by growing feedstocks reduces overall greenhouse gas emissions by balancing carbon dioxide released from burning biobutanol.More Flexibility—Biobutanol blends well with gasoline and ethanol, and it can improve blends of gasoline with ethanol. Also, it can be produced using existing ethanol production facilities with few modifications.Excerpted from the USDA Agricultural Research Service website offers several advantages over ethanol. It can be transported in existing pipelines, is less flammable and less prone to water contamination, can be mixed with gasoline or used alone in internal combustion engines, and packs more energy per gallon than ethanol.Up until the mid-20th century, biobutanol was produced from fermented sugars, such as glucose in corn or molasses. But low yields, coupled with high recovery costs and the increased availability of petroleum feedstocks after World War II, sidelined fermentation-based systems for biobutanol production.Exceprted from article on biobutanol in biobutanol processing methods, namely the discovery and development of genetically modified microorganisms, has set the stage for biobutanol to surpass ethanol as a renewable fuel. Biobutanol shows great promise as a motor fuel due to its favorable energy density, and it returns better fuel economy and is considered a superior motor fuel (when compared to ethanol).Biobutanol ProductionBiobutanol is derived mainly from the fermentation of the sugars in organic feedstocks (biomass). Historically, up until about the mid-1950s, biobutanol was fermented from simple sugars in a process that produced acetone and ethanol, in addition to the butanol component. The process is known as ABE (Acetone Butanol Ethanol) and has used unsophisticated (and not particularly hearty) microbes such as Clostridium acetobutylicum. The problem with this type of microbe is that it is poisoned by the very butanol it produces once the alcohol concentration rises above approximately 2 percent. This processing problem caused by the inherent weakness of generic-grade microbes, plus inexpensive and abundant (at the time) petroleum gave way to the simpler and cheaper distillation-from-petroleum method of refining butanol.In recent years, scientists have revisited the fermentation of sugars for the manufacturing of biobutanol. Great strides have been made by researchers in creating “designer microbes” that can tolerate higher concentrations of butanol without being killed off. The ability to withstand harsh high concentration alcohol environments, plus the superior metabolism of these genetically enhanced bacteria has fortified them with the endurance necessary to degrade the tough cellulosic fibers of biomass feedstocks such as pulpy woods and switchgrass. The door has been kicked open and the reality of cost competitive, if not cheaper, renewable alcohol motor fuel is upon us.Excerpted from the website for (a commercial site, likely biased). What are the feedstocks for biobutanol?Biobutanol can be prepared from any number of biomass feedstocks. ?It is easier to produce biobutanol directly from a source of sugar, such as corn or sugar beets. ?However, a number of active programs exist which will enable biobutanol production from crop wastes to energy grass. ?Do feedstocks for biobutanol compete with food?Biobutanol can be produced from feedstocks which do not compete with food. ?For example, efforts are on the way to convert algae biomass and waste wood particles to biobutanol. ?Several of these require only a 10th or 20th the amount of land resources as corn production. ?In January 2011, U. of Alabama-Huntsville reported fermenting glycerol waste from biodiesel production to produce n-butanol. ?Additionally, a number of companies are focused on converting waste biomass from spoiled foods or from food processing plants to produce n-butanol. ?A pilot plant currently takes sewage waste and converts it to biobutanol at a New York waste water treatment facility.Algal biodiesel dossier?Excerpted from Chemistry in the Community 6th ed. Unit 3 Second DIn the US and worldwide, a variety of raw materials are used to produce biodiesel. These include vegetable oil grown specifically for biodiesel production, waste vegetable oil, animal fats, and algae. However, soybean oil grown specifically for this purpose is by far the most common starting material used. When it is combusted, biodiesel releases 32,960 kJ/L, while combustion of petroleum diesel releases 34,790 kJ/L. Both types of fuels require similar amounts of energy to produce, about 6,600 kJ/L. Biodiesel and petroleum diesel have similar CO2 emissions when combusted, but studies have shown that biodiesel burning produces less CO, fewer unburned hydrocarbons, and more NOx than the burning of petroleum diesel. Excerpted from the US Dept. of Energy, Alternative Fuels Data Center Fuel BasicsBiodiesel is a replacement for petroleum diesel fuel. It is nontoxic and biodegradable. Biodiesel is a liquid fuel made primarily of fatty acid methyl esters, formed by reacting triglycerides (from algae, vegetable oil, etc.) with methanol in a transesterification reaction. The products of this reaction are methyl esters of long fatty acids, which become the fuel, and glycerol as a byproduct. Like petroleum diesel, biodiesel is used to fuel compression-ignition engines. Its cetane number (CN) is in the range from 48-65, its density is 7.3 lb/gal, and its boiling point is 315-350 degrees C. It becomes cloudy and viscous at low temperatures (-3 to 15 degrees C).Excerpted from the National Renewable Energy Laboratory R&DBiodiesel represents a significant energy resource and could someday supply 3% to 5% of the distillate fuel market. According to an NREL biodiesel life cycle analysis, roughly 81% of the “well to wheel” energy of biodiesel is renewable and can be used to replace petroleum. Based on discussions with industry, several issues that currently prevent broader market penetration for biodiesel are being addressed by NREL researchers:Ensuring Fuel StabilityEngine and fuel injection equipment manufacturers are concerned that biodiesel may undergo oxidationduring storage, handling, and use and form fuel system deposits. These deposits could cause plugging and damage engine fuel system components. NREL is examining biodiesel stability as part of the nationwide fuel quality surveys. Maximizing Environmental Benefits—Reducing NOx EmissionsAlthough the primary benefits of biodiesel use are petroleum replacement and carbon dioxide emission reductions, biodiesel also causes a reduction in the emissions of diesel particulate matter and toxic compounds. However, many studies have shown that NOx emissions can increase. NREL is measuring the extent of the NOx emissions increase in fully modern engines, and is working to develop fuel formulation, fuel additive, and engine operational strategies to eliminate it.Excerpt How Stuff Works to produce biofuelDid you know that half of algae's composition, by weight, is lipid oil? Various algae contain different levels of oil. Of all the algae out there, pond scum -- algae that sit on top of ponds -- is best suited for biodiesel.The most exciting part of algae biodiesel is the numbers game. Biodiesel makers claim they'll be able to produce more than 100,000 gallons of algae oil per acre per year depending on:? The type of algae being used? The way the algae is grown? The method of oil extractionOnce the algae are harvested, the lipids, or oils, are extracted from the walls of the algae cells. There are a few different ways to extract the oil from algae. The oil press is the simplest and most popular method. It's similar to the concept of the olive press. It can extract up to 75 percent of the oil from the algae being pressed. Basically a two-part process, the hexane solvent method (combined with pressing the algae) extracts up to 95 percent of oil from algae. First, the press squeezes out the oil. Then, leftover algae is mixed with hexane, filtered and cleaned so there's no chemical left in the oil. Once the oil's extracted, it undergoes transesterification. The supercritical fluids method extracts up to 100 percent of the oil from algae. Carbon dioxide acts as the supercritical fluid -- when a substance is pressurized and heated to change its composition into a liquid as well as a gas. At this point, carbon dioxide is mixed with the algae. When they're combined, the carbon dioxide turns the algae completely into oil. The additional equipment and work make this method a less popular option.The process of extracting oil from the algae is universal, but companies producing algae biodiesel are using diverse methods to grow enough algae to produce large amounts of oil.Excerpt from recently-published study, "Pilot-scale data provide enhanced estimates of the life cycle energy and emissions profile of algae biofuels produced via hydrothermal liquefaction (HTL)," is a life cycle analysis of an algae cultivation and fuel production process currently employed at pre-commercial scales. The authors examined field data from two facilities operated by Sapphire Energy in New Mexico that grow and process algae into Green Crude oil. Sapphire Energy's Green Crude can be refined into gasoline, diesel and jet fuel.The study concluded that algae technologies at commercial scale are projected to produce biofuels with lower greenhouse gas emissions and EROI values that are comparable to first generation biofuels. Additionally, algae based biofuels produced through this pathway at commercial scale will have a significant energy return on investment (EROI), close to petroleum and three times higher than cellulosic ethanol. The system that was evaluated recycles nutrients, can accept an algae feed that is up to 90 percent water in the processing phase, and the final product can be blended with refinery intermediates for refining into finished gasoline or diesel product, resulting in significant energy savings throughout the process.Green diesel dossier?Excerpted from “Renewable Energy Primer” by Robert Rapier, at Energy Trends Insider Diesel DefinitionAnother form of renewable diesel is ‘green diesel.’ Green diesel is chemically the same as petroleum diesel, but it is made from recently living biomass. Unlike biodiesel, which is an ester and has different chemical properties from petroleum diesel, green diesel is composed of long-chain hydrocarbons, and can be mixed with petroleum diesel in any proportion for use as transportation fuel. Green diesel technology is frequently referred to as second-generation renewable diesel technology.There are several methods of making green diesel. One is to hydroprocess vegetable oil or animal fats.Hydroprocessing may occur in the same facilities used to process petroleum. HydroprocessingHydroprocessing is the process of reacting a feed stock with hydrogen under elevated temperature and pressure in order to change the chemical properties of the feed stock. The technology has long been usedin the petroleum industry to ‘crack’, or convert very large organic molecules into smaller organic molecules.In recent years, hydroprocessing technology has been used to convert lipid (fat/oil) feed stocks into distillate fuels. The resulting products are a distillate fuel with properties very similar to petroleum diesel, and propane (Hodge 2006). The primary advantages over first-generation biodiesel technology are: 1). The cold weather properties are superior; 2). The propane byproduct is preferable over the glycerol byproduct of biodiesel production; 3). The heating content is greater; 4). The cetane number is greater; and 5). Capital costs and operating costs are lower (Arena et al. 2006).Like biodiesel production, which normally utilizes fossil fuel-derived methanol, hydroprocessing requires fossil fuel-derived hydrogen. (Hydrogen is produced almost exclusively from natural gas.) No definitive life cycle analyses have yet been performed for diesel produced via hydroprocessing. Therefore, the energy return and overall environmental impact have yet to be quantified.Excerpted from the California Renewable Diesel Multimedia Evaluation Tier I Report by UC Davis and UC Berkeley diesel is derived from non-petroleum renewable resources, including, (but not limited to) plant and algae oils, animal fats and wastes, municipal solid waste, sludge and oils derived from wastewater, and other wastes. We focus here on Hydrogenation-derived renewable diesel (HDRD). HDRD is produced by refining fats or vegetable oils—typically in existing oil refineries. This process is also knownas the Fatty Acids to Hydrocarbon (Hydrotreatment) or FAHC Hydrotreatment process. In this process, renewable feedstocks such as vegetable oils and animal fats are converted into diesel fuel as well as propane, and other light hydrocarbons through treatment with hydrogen. Because it is free of ester compounds, renewable diesel has a chemical composition that is almost identical to petroleum-based diesel. Preliminary evaluations indicate several potential advantages of renewable diesel relative to FAME and petroleum-based diesel. These advantages include: Renewable diesel can be used directly in today’s diesel-powered vehicles without modification.Renewable diesel is compatible with current diesel distribution infrastructure and does not require new or modified pipelines, storage tanks, trucking infrastructure, or retail station pumps. Renewable diesel can be produced using existing oil refinery capacity and does not require extensive new production facilities. Renewable diesel’s fuel properties, specifically its high cetane number, suggest it will provide similar or better vehicle performance than conventional ultra-low sulfur diesel (ULSD). Renewable’s ultra-low sulfur content enables the use of advance emission control devices. The production of renewable diesel through the FAHC process does not produce a glycerin co-product. Preliminary tests of renewable diesel emissions indicate that, relative to standard diesel, there is a potentialfor significantly better emissions profile during combustion with reduced particulate, NOx, hydrocarbons, and CO emissions. In addition to producing a fuel that uses recycled carbon, renewable diesel benefits include: a high level of quality control; compliance with ASTM standards; easy blending with biodiesel.OTHER INFO:Excerpted from the National Academy of Science, “What you need to know about energy” derived from biological material, or biofuel, is an appealing renewable alternative to fossil fuels. It is sustainable, reduces U.S. dependence on imported oil, and potentially generates lower greenhouse gas emissions than fossil fuels. However, its viability may depend greatly on government policies, including agricultural subsidies and requirements to reduce CO2 emissions, as well as market prices of other fuels.Grain-based ethanol—now chiefly made from corn and already commercially deployed—is at best a transitional technology, according to the AEF committee. One drawback of corn ethanol production is that it requires a large amount of land and fresh water, along with inputs of fertilizers and energy. In addition, the current technology is very energy intensive—two-thirds of the energy value of corn ethanol is used just to produce the fuel—and most of that energy comes from fossil fuel-based electricity or heating, offsetting much of the benefit. Nonetheless, corn-grain ethanol is already replacing a small amount of fossil-fuel use in vehicles.Many experts believe that ethanol-based biofuels will not provide much benefit until the technology is more developed. The Energy Independence and Security Act of 2007 stipulates that by 2022 the United States must produce 21 billion gallons of advanced biofuels, including cellulosic ethanol, biodiesel, and biobutanol. Unlike ethanol, which has to be transported by trucks and barges, biodiesel and biobutanol can be transported via existing infrastructure, such as petroleum pipelines. However, significant technical and cost challenges must still be overcome to ensure a major role for either of these biofuels in our energy future.Even with this increased focus on biofuels, it is uncertain how much projected gasoline consumption can be replaced in the next few decades. Experts predict that an aggressive program to develop these technologies would result, by 2035, in a 1.7 million barrels per day contribution of biofuels to the nation’s current 20 million barrels per day consumption of petroleum. Furthermore, biofuels contain carbon, and although they may burn “cleaner” than oil-derived fuels, they would not completely eliminate CO2 emissions. That situation could be different if the crops used to produce the biofuels were grown sustainably, drawing as much carbon from the atmosphere during their growth as they release when burned. BiomassOf all the renewable energy sources, biomass (biological matter that can be used as fuel or for industrial production) contributes the most to the U.S. energy supply. In 2008, 7% of our energy came from renewable sources, and nearly 4% of that was from biomass. Experts predict the contribution from biomass will likely increase more than 55% by 2030. Wood, the most common form of biomass, has been used by people for thousands of years to cook food and to keep warm. Grasses, agricultural crops (such as corn and sugar cane), landfill waste, and manure are other examples of biomass. Used for a variety of purposes, biomass provides energy to produce electricity, heat, chemicals, and transportation fuels (biofuels).Burning biomass releases about the same amount of carbon dioxide (CO2) as burning fossil fuels. However, biomass is more sustainable than fossil fuels because the CO2 it releases is balanced by the CO2 absorbed by plants growing for the next harvest. Any fossil energy that is used to grow, harvest, and process fuel from biomass releases some of that net CO2, but overall, biomass contributes significantly less to climate change than fossil fuels.Despite this hopeful picture, it is important to take into account the effect of converting intact ecosystems (such as forests, peatlands, savannas, or grasslands) to grain or fuel crop production. The resulting release of biomass and soil carbon to the atmosphere in the form of CO2 may greatly exceed the greenhouse-gas savings associated with biofuel production on such lands for many years. This phenomenon is referred to as a “carbon debt.”Experts predict the contribution from biomass will likely increase more than 55% by 2030. Much more research needs to be done on its use as an energy resource, but there is promise that it will reduce our nation's dependence on fossil fuels, decreasing the emission of greenhouse gases and lessening our reliance on foreign sources for our energy supply. ................
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