Alcohol fuel

About: Alcohol fuel is a(n) research topic. Over the lifetime, 2030 publication(s) have been published within this topic receiving 42757 citation(s).

Progress and recent trends in biodiesel fuels

Abstract: Fossil fuel resources are decreasing daily. Biodiesel fuels are attracting increasing attention worldwide as blending components or direct replacements for diesel fuel in vehicle engines. Biodiesel fuel typically comprises lower alkyl fatty acid (chain length C14–C22), esters of short-chain alcohols, primarily, methanol or ethanol. Various methods have been reported for the production of biodiesel from vegetable oil, such as direct use and blending, microemulsification, pyrolysis, and transesterification. Among these, transesterification is an attractive and widely accepted technique. The purpose of the transesterification process is to lower the viscosity of the oil. The most important variables affecting methyl ester yield during the transesterification reaction are the molar ratio of alcohol to vegetable oil and the reaction temperature. Methanol is the commonly used alcohol in this process, due in part to its low cost. Methyl esters of vegetable oils have several outstanding advantages over other new-renewable and clean engine fuel alternatives. Biodiesel fuel is a renewable substitute fuel for petroleum diesel or petrodiesel fuel made from vegetable or animal fats; it can be used in any mixture with petrodiesel fuel, as it has very similar characteristics, but it has lower exhaust emissions. Biodiesel fuel has better properties than petrodiesel fuel; it is renewable, biodegradable, non-toxic, and essentially free of sulfur and aromatics. Biodiesel seems to be a realistic fuel for future; it has become more attractive recently because of its environmental benefits. Biodiesel is an environmentally friendly fuel that can be used in any diesel engine without modification.

Palladium-Based Electrocatalysts for Alcohol Oxidation in Half Cells and in Direct Alcohol Fuel Cells

Abstract: Direct alcohol fuel cells (DAFCs) are attracting increasing interest as power sources for portable applications due to some unquestionable advantages over analogous devices fed with hydrogen.1 Alcohols, such as methanol, ethanol, ethylene glycol, and glycerol, exhibit high volumetric energy density, and their storage and transport are much easier as compared to hydrogen. On the other hand, the oxidation kinetics of any alcohol are much slower and still H2-fueled polymer electrolyte fuel cells (PEMFCs) exhibit superior electrical performance as compared to DAFCs with comparable electroactive surface areas.2,3 Increasing research efforts are therefore being carried out to design and develop more efficient anode electrocatalysts for DAFCs.

Fuel processing for low-temperature and high-temperature fuel cells: Challenges, and opportunities for sustainable development in the 21st century

Abstract: This review paper first discusses the needs for fundamental changes in the energy system for major efficiency improvements in terms of global resource limitation and sustainable development. Major improvement in energy efficiency of electric power plants and transportation vehicles is needed to enable the world to meet the energy demands at lower rate of energy consumption with corresponding reduction in pollutant and CO2 emissions. A brief overview will then be given on principle and advantages of different types of low-temperature and high-temperature fuel cells. Fuel cells are intrinsically much more energy-efficient, and could achieve as high as 70–80% system efficiency (including heat utilization) in electric power plants using solid oxide fuel cells (SOFC, versus the current efficiency of 30–37% via combustion), and 40–50% efficiency for transportation using proton-exchange membrane fuel cells (PEMFC) or solid oxide fuel cells (versus the current efficiency of 20–35% with internal combustion (IC) engines). The technical discussions will focus on fuel processing for fuel cell applications in the 21st century. The strategies and options of fuel processors depend on the type of fuel cells and applications. Among the low-temperature fuel cells, proton-exchange membrane fuel cells require H2 as the fuel and thus nearly CO-free and sulfur-free gas feed must be produced from fuel processor. High-temperature fuel cells such as solid oxide fuel cells can use both CO and H2 as fuel, and thus fuel processing can be achieved in less steps. Hydrocarbon fuels and alcohol fuels can both be used as fuels for reforming on-site or on-board. Alcohol fuels have the advantages of being ultra-clean and sulfur-free and can be reformed at lower temperatures, but hydrocarbon fuels have the advantages of existing infrastructure of production and distribution and higher energy density. Further research and development on fuel processing are necessary for improved energy efficiency and reduced size of fuel processor. More effective ways for on-site or on-board deep removal of sulfur before and after fuel reforming, and more energy-efficient and stable catalysts and processes for reforming hydrocarbon fuels are necessary for both high-temperature and low-temperature fuel cells. In addition, more active and robust (non-pyrophoric) catalysts for water–gas-shift (WGS) reactions, more selective and active catalysts for preferential CO oxidation at lower temperature, more CO-tolerant anode catalysts would contribute significantly to development and implementation of low-temperature fuel cells, particularly proton-exchange membrane fuel cells. In addition, more work is required in the area of electrode catalysis and high-temperature membrane development related to fuel processing including tolerance to certain components in reformate, especially CO and sulfur species.

Dimethyl ether (DME) as an alternative fuel

Abstract: With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking non-petroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer–Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NOx, SOx, and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

Recent advances in the development of direct alcohol fuel cells (DAFC)

Abstract: Recent developments into technology of proton exchange membrane fuel cells (PEMFC) now allow serious consideration to be given to a direct alcohol fuel cell (DAFC) based on a PEMFC, in which alcohol is used directly as the fuel. This is particularly advantageous for mobile applications, since this will avoid the use of a bulky and expensive reformer. However, the relatively complex reaction mechanism, leading to a low electroreactivity of most alcohols, even methanol, needs the investigation of new platinum-based electrocatalysts, particularly active for breaking the CC bond when alcohols other than methanol are to be used. Moreover, in order to overcome the deleterious effect of alcohol crossover through the proton exchange membrane, it is necessary to develop new oxygen reduction electrocatalysts insensitive to the presence of alcohols.