Ethanol

Ethanol has been known to humans since prehistory as the active ingredient of alcoholic beverages. Its isolation as a relatively pure compound was probably achieved first by Islamic alchemists who developed the art of distillation[1].

Ethyl alcohol, also called ethanol, absolute alcohol, or grain alcohol, is a clear, colorless, flammable liquid with a pleasant odor. It is associated primarily with alcoholic beverages, but it has numerous uses in the chemical industry. The word alcohol is derived from the Arabic word al kuhul, which was a fine powder of the element antimony used as a cosmetic. In Medieval times, the word al kuhul came to be associated with the distilled products known as alcohols. The hydroxyl group, -OH, bonded to a carbon, characterizes alcohols. Ethyl is derived from the root of the two-carbon hydrocarbon ethane.

In the BP 2009, the term ‘alcohol’; used without other qualification refers to ethanol containing ≥99.5% v/v of C2H6O. The term‘alcohol’, without other qualification, refers to ethanol 95.1–96.9% v/v. Where other strengths are intended, the term ‘alcohol’ or ‘ethanol’is used, followed by the statement of the strength. In the PhEur 6.0, anhydrous ethanol contains not less than 99.5% v/v of C2H6O at 208℃. The term ethanol (96%) is used to describe the material containing water and 95.1–96.9% v/v of C2H6O at 208℃.

Ethyl alcohol is a colorless, volatile, flammable liquid with a sweet, fruity odor. The Odor Threshold is 0.135
5 ppm.

Ethyl alcohol is a colorless flammable liquid with a typical lower alcohol odor and is miscible in water in all proportions. It is stable and hygroscopic. It is incompatible with strong oxidizing agents, peroxides, acids, acid chlorides, acid anhydrides, alkali metals, ammonia, and moisture. Ethyl alcohol forms explosive mixtures with air. Ethyl alcohol is the most common solvent used in aerosols, cosmetics, pharmaceuticals, alcoholic beverages, vinegar production, and in the chemical synthesis of a large variety of products in different industries. For instance, in the manufacture of plastics, lacquers, polishes, plasticizers, perfumes, adhesives, rubber accelerators, explosives, synthetic resins, nitrocellulose, inks, preservatives, and as a fuel.

MedicalA solution of 70-85% of ethanol is commonly used as a disinfectant and it kills organisms by denaturing their proteins and dissolving their lipids. It is effective against most bacteria and fungi, and many viruses, but is ineffective against bacterial spores. This disinfectant property of ethanol is the reason that alcoholic beverages can be stored for a long time[9]. Ethanol also has many medical uses, and can be found in products such as medicines, medical wipes and as an antiseptic in most antibacterial hand sanitizer gels. Ethanal can also be used as antidote. It competitively blocks the formation of toxic metabolites in toxic alcohol ingestions by having a higher affinity for the enzyme Alcohol Dehydrogenase (ADH). Its chief application is in methanol and ethylene glycol ingestions. Ethanol can be administered by the oral, nasogastric or intravenous route to maintain a blood ethanol concentration of 100-150 mg/dl (22-33 mol/L)[10].FuelEthanol is flammable and burns more cleanly than many other fuels. Ethanol has been used in cars since Henry Ford designed his 1908 Model T to operate on alcohol. In Brazil and the United States, the use of ethanol from sugar cane and grain as car fuel has been promoted by government programs[11]. The Brazilian ethanol program started as a way to reduce the reliance on oil imports, but it was soon realized that it had important environmental and social benefits[12]. The fully combusted products of ethanol are only carbon dioxide and water. For this reason, it is environmental friendly and has been used to fuel public buses in the US. However, pure ethanol attacks certain rubber and plastic materials and cannot be used in unmodified car engines[13].The alcohol-based alternative fuel that is blended with gasoline to produce a fuel with a higher octane rating and fewer harmful emissions than unblended gasoline. A mixture containing gasoline with at least 10% ethanol is known as gasohol. Specifically, gasoline with 10% ethanol content is known as E10. Another common gasohol variant is E15, which contains 15% ethanol and 85% gasoline. E15 is only appropriate for use in Flex Fuel vehicles or a very small percentage of the newest vehicles[14]. In addition, E85 is a term used for a mixture of 15% gasoline and 85% ethanol. E85 keeps the fuel system clean because it burns cleaner than regular gas or diesel and doesn't leave behind gummy deposits. Beginning with the model year 1999, a number of vehicles in the U.S. were manufactured so as to be able to run on E85 fuel without modification. These vehicles are often labeled dual fuel or flexible fuel vehicles, since they can automatically detect the type of fuel and change the engine's behavior to compensate for the different ways that they burn in the engine cylinders[15].The use of ethanol-diesel fuel blends is growing around the world, and are designed to provide renewable, cleaner burning fuel alternatives for off-road equipment, buses, semi-trucks and other vehicles that run on diesel fuel. With the addition of ethanol and other fuel additives to diesel, the characteristic black diesel smoke is eliminated and there are significant reductions in particulate matter, carbon monoxide, and nitrogen oxide emissions. It is also possible to use ethanol for cooking as a replacement for wood, charcoal, propane, or as a substitute for lighting fuels, such as kerosene[16].Brazil and the United States lead the industrial production of ethanol fuel, accounting together for 89% of the world's production in 2008. In comparison with the USA and Brazil, Europe ethanol for fuel production is still very modest. Brazil is the world's second largest producer of ethanol fuel and the world's largest exporter[17].BeverageSignificant volumes of ethanol are produced for the beverage and industrial markets from agricultural feedstock. Ethanol produced for these industries differs from ethanol for fuel only in its strength, which can vary between 96% and 99.9% and in its purity, depending on the end use. Beverage and drinks industry may be the best-known end-user of ethanol. It is used to make many kinds of spirits, such vodka, gin and anisette. High standards and processes are required for ethanal used in the production of spirit drinks.OthersThe ethanol used as an intermediary product by the chemical, pharmaceutical or cosmetics industry is in many cases of the highest and purest possible quality. These are premium markets due to the additional steps in the alcohol production process that are necessary to achieve the required purity. Same high standards and purity requirements apply in food industry, such as flavors and aromas extraction and concentrations, as well as paints and thermometers. Ethanol can be used in de-icer or anti-freeze to clear the car windscreen. It also is contained in perfumes, deodorants, and other cosmetics[18].

One of the most prominent uses of ethyl alcohol is as a fuel additive and increasingly as a fuel itself. Ethyl alcohol is added to gasoline to increase its oxygen content and octane number. In the United States, the Environmental Protection Agency has mandated that oxygenated fuels be used in certain geographic areas to help meet air quality standards for carbon monoxide, especially in winter. A gasoline blended for this purpose may contain a few percent ethyl alcohol. Gasoline blended with ethyl alcohol is called gasohol. A typical gasohol may contain 90% gasoline and 10% ethanol. Gasohol reduces several common air pollutants including carbon monoxide, carbon dioxide, hydrocarbons, and benzene. Conversely, nitrogen oxides increase with gasohol.

Ethanol is used primarily as a solvent — animportant industrial solvent for resins, lacquers, pharmaceuticals, toilet preparations,and cleaning agents; in the production of rawmaterials for cosmetics, perfumes, drugs, andplasticizers; as an antifreeze; as an automotive fuel additive; and from ancient times, inmaking beverages. Its pathway to the bodysystem is mainly through the consumption ofbeverages. It is formed by the natural fermentation of corn, sugarcane, and other crops.

Suitable for use in the precipitation of nucleic acids.

Most ethyl alcohol is used in alcoholic beverages in suitable dilutions. Other uses are as solvent in laboratory and industry, in the manufacture of denatured alcohol, pharmaceuticals (rubbing Compounds, lotions, tonics, colognes), in perfumery, in organic synthesis. Octane booster in gasoline. Pharmaceutic aid (solvent).

Ethanol is manufactured by the controlled enzymatic fermentation of starch, sugar, or other carbohydrates. A fermented liquid is produced containing about 15% ethanol; ethanol 95% v/v is then obtained by fractional distillation. Ethanol may also be prepared by a number of synthetic methods.