International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Volume 3 Issue 1, January 2014 www.ijsr.net A Review on Available Evidence for Effects of Ethanol Fuels on Air Pollutant Emissions from Motor Vehicles Sumit Sharma 1 , Ashish Nayyar 2 1 M.Tech Scholar, Dept. of Mechanical Engineering, SKIT, Jaipur, India 2 Reader, Dept. of Mechanical Engineering, SKIT, Jaipur, India Abstract: This paper is based on the available evidence for the air quality impacts of using ethanol fuels in transport and also focuses on regulated and unregulated air pollutant emissions from vehicles running on ethanol fuels. Fuel options for reducing emissions include reformulating conventional fuels to reduce or increase particular components, or use of alternative fuels such as ethanol. Ethanol is a liquid alcohol that is manufactured by the fermentation of a wide variety of biological materials. These materials include grains such as wheat, barley, corn, wood, and sugar cane. Agricultural crops particularly grains are likely to be used in some countries because they have both high productivity and high levels of carbohydrates needed for ethanol manufacture. The review begins with a general overview of the air quality impacts of burning fuels in vehicle engines, listing the types of pollutants normally produced and their impacts on human health and the environment. The specific impacts of using ethanol in both petrol and diesel engines are compared. Control of fuel composition and characteristics provides an important option for limiting pollutant emissions from motor vehicles. By reducing fuel components known to contribute to particular pollutant emissions, it is possible to produce reductions in those pollutants. However, changes to fuel specifications may require design changes to different vehicle subsystems such as engine, fuel system and emission controls. Keywords: Greenhouse gas emissions, Conventional fuels, Ethanol, Pollutant emissions etc. 1. Introduction Ethanol is a clear liquid alcohol that is made by the fermentation of different biological materials. This alcohol is known to have many uses, but one in particular is becoming more popular. Ethanol, the most widely used biofuel, is made in a process similar to brewing beer. The ethanol in the end is blended with gasoline to improve vehicle performance and reduce air pollution. Ethanol is best produced from lower value grains such as barley, corn and feed wheat. Higher value “bread” wheats would remain in ample supply for export sales, when Canada begins major ethanol manufacturing. Also, poor quality (weather damaged, immature) grains which are less suitable for either human or livestock use are excellent for ethanol production [1]. Corn and starch based crops are the most common medium used in ethanol production. This indicates that once ethanol is in high demand, the prices of these crops will increase. For this reason other alternatives are being studied [5]. Ethanol is miscible (mixable) in all proportions with water and with most organic solvents. It is useful as a solvent for many substances and in making perfumes, paints, lacquer, and explosives. Alcoholic solutions of nonvolatile substances are called tinctures; if the solute is volatile, the solution is called a spirit. Ethanol is a water-free alcohol and there for can withstand cooler temperatures. Its low freezing point has made it useful as the fluid in thermometers for temperatures below -40°C, the freezing point of mercury, and for other low temperature purposes, such as for antifreeze in automobile radiators. Commercial Alcohols have grown to be the largest manufacturer and supplier of industrial grade alcohol (ethyl alcohol or ethanol) in Canada. Its 1700 customers use the product in industrial applications (such as solvents, detergents, paints, printing inks, photo-chemical applications, latex processing, dyes, etc.), the beverage market, medicinal, pharmaceutical and food products and is the sole Canadian manufacturer and supplier to the fuel market in central and eastern Canada. 1.1 Air pollution from motor vehicles Combustion of fuels in internal combustion engines always generates some undesirable products in the engine exhaust systems. Additionally, vehicle fuel systems give off unburnt fuel vapours, and open-vented engine crankcases give off escaped combustion products and vaporized lubricating oil. In high enough concentrations, these emissions can be harmful to human health and the environment, and modern vehicle systems and fuels are designed to prevent these emissions exceeding specified limits [2],[3]. The main pollutant components of vehicle emissions are: 1.1.1 Carbon Monoxide (CO) A toxic compound which reduces the blood’s ability to carry oxygen to tissues and is associated with a number of adverse health effects, particularly in people with cardiovascular disease (WHO 2005) 1.1.2 Hydrocarbons These contribute to formation of ground-level ozone and in some cases are known to have direct adverse effects on human health. Paper ID: 02013807 331