This literature review examines the ongoing debate between fossil fuels and alternative fuels, drawing on a range of peer-reviewed sources to explore environmental, economic, and social dimensions of the transition away from petroleum-based energy. The paper categorizes fuel types, outlines the depletion of finite fossil fuel reserves, and assesses biofuels as replacements for both diesel and gasoline. It evaluates the environmental benefits of reduced greenhouse gas emissions, the economic advantages for agricultural communities, and the social implications of energy independence. It also addresses hybrid technologies and the critical concern that limited arable land constrains biofuel's capacity to fully replace fossil fuels.
Fossil fuels have been a primary fuel source for the industrial world for centuries. Today, numerous alternative fuels have been developed — and continue to be developed — to compete with fossil fuel usage. When comparing the two fuel types, the literature on this topic uncovers numerous facets centering on environmental, economic, and social factors.
According to Demirbas (2008), energy sources are generally divided into three categories: renewable sources, fossil fuels, and nuclear sources. Petroleum, natural gas, and coal products are the primary fuels that fall into the fossil fuel category. In contrast, Demirbas defines alternative fuels as "substitute fuel sources to petroleum" (p. 1473), noting that they fall into the renewable sources category. A popular alternative fuel is biofuel. Ethanol produced from cellulosic biomass plants is a popular target for biofuel research because these plants have a life cycle that allows for annual growth and harvest. In fact, there are very few countries that are not either engaged in or planning to engage in the production of biofuel (Mol, 2007).
There are four primary classifications of materials used for biofuel production, according to Mol (2007). Cereals, sugar crops, grains, and other starch crops are commonly used in biofuel production because they can be fairly easily fermented to manufacture bio-ethanol. This bio-ethanol can be used by itself or blended with other fuels. Oilseed crops are a second common type used in biofuel production. Sunflowers, soy, grape seeds, palm, and jatropha can all be converted into methyl esters, commonly known as biodiesel, which can then be used as pure biodiesel or blended with conventional petroleum diesel.
Cellulosic biomass materials constitute the third type of material that can be used to manufacture biofuel; however, making the conversion process more efficient is still being developed. Biomass materials include trees, grasses, crop residuals, waste from wood processing facilities, and even municipal solid waste. Through enzymatic breakdown or acid hydrolysis and fermentation, these materials are converted into bio-ethanol. The fourth type of material used in biofuel production is among the newest and is still under development. The Fischer-Tropsch process synthesizes biodiesel from biomasses such as organic waste materials using gasification. While fossil fuels remain the most commonly used category of fuels, they are also the one category being steadily depleted.
Unlike renewable fuel sources, fossil fuel reserves are finite. Demirbas (2008) surmises that in less than half a century, the world's fossil fuel reserves will be depleted at the current rate of consumption. For this reason, many developed nations are working toward implementing technologies such as biofuels and other alternative fuels as replacements for fossil fuels. High fuel prices and environmental damage, according to Archer, Self, Guha, and Engelken (2008) and Mushrush, Mose, Wray, and Sullivan (2001), are among the motivators behind research into and implementation of cleaner alternative fuels. The 1990 Clean Air Act and the high cost of further improving automobile emissions, according to Hahn (1995), have also served as an impetus for alternative fuel research, in addition to the finite supply of fossil fuel.
However, some alternative fuels utilize a small amount of fossil fuel in their production. With a limited amount of fossil fuel on the planet, the use of fossil fuel within biofuels is a concern. Although these biofuels would slow the consumption of petroleum-based products, consumption of this finite resource would still occur. Instead of exhausting fossil fuel reserves in fifty years, the world's supply might last 200 years — but the end result of completely depleted fossil fuel reserves remains the same.
According to Demirbas (2008), most motor vehicles in use today run on fossil fuels, typically either gasoline or diesel, both of which are primarily derived from petroleum. As Demirbas notes, "Diesel fuel consists of hydrocarbons with between 9 and 27 carbon atoms in a chain as well as a smaller amount of sulfur, nitrogen, oxygen, and metal compounds" (p. 1474). Because of this molecular structure, there are four alternative fuels that can be fairly easily used in engines originally designed for conventional diesel: biodiesel, vegetable oil, dimethyl ether (DME), and Fischer-Tropsch fuel.
However, as Pimentel and Patzek (2006) point out, biofuel has its limitations. Green plants in America collect approximately 52 exajoules of energy from sunlight every year, yet Americans consume more than twice that amount of energy. While biofuels produced from cellulosic biomass and corn could replace some fossil fuel consumption in the United States, they could not replace all of it. In 2006, 18 percent of the American corn crop was converted into 4.5 billion gallons of ethanol; however, this only replaced one percent of the petroleum consumed by Americans. Even if the entire corn crop had been devoted to ethanol, it would still only replace six percent of the fossil fuel consumed in the United States. Compounding this challenge is the fact that America has lost more than a third of its agricultural topsoil, making a large increase in corn crop production simply impractical.
As Demirbas (2008) notes, "Gasoline is a blend of hydrocarbons with some contaminants, including sulfur, nitrogen, oxygen, and certain metals. The four major constituent groups of gasoline are olefins, aromatics, paraffins, and naphthenes." There are six types of alternative fuels available as gasoline replacements. Five of these are: liquefied petroleum (LP) gas, alcohol, hydrogen, compressed natural gas, and electricity. The sixth is bioethanol, which, when blended with petrol at a 10 percent mixture rate, can be used in gasoline engines without altering the engine specifications.
LP gas has had some success as an alternative fuel source for fleet vehicles, taxis, and municipal buses; however, it requires new infrastructure for filling stations and has yet to gain popularity among private vehicle owners. Hydrogen requires not only significant engine design changes but also entirely new infrastructure for distribution and retail sales. Electrically powered vehicles hold promise and have been developed in limited instances; however, the technology is not yet advanced enough to make full electric vehicles cost-effective and practical at scale.
"Emissions reductions, crop residues, and agricultural economic gains"
"Energy independence, food security, and land use tensions"
"Hybrid vehicle technology as a transitional solution"
"Synthesis of biofuel benefits and land scarcity drawbacks"
You’re 38% through this paper. Sign up to read the remaining 4 sections.
Sign Up Now — Instant Access Already a member? Log inAlways verify citation format against your institution’s current style guide requirements.