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Ethanol production, Lecture 07, Fuel Technology2.pptx

  1.  Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages, used as fuel.  It is most often used as a motor fuel, mainly as a biofuel additive for gasoline.  It is commonly made from biomass such as corn or sugarcane. Ethanol, also called drinking alcohol, is a chemical compound, a simple alcohol with the chemical formula C₂H₅OH. (CH₃−CH₂−OH or C₂H₅−OH), abbreviated as EtOH and has a boiling point of 78.37 °C, molar mass of 46.07 g/mol and a relative density 0.789 .  It is colorless volatile, flammable liquid which is produced by the natural fermentation of sugars(carbohydrates).  It is product of anaerobic catabolism of carbohydrates.  Carbohydrate →n Glucose →2n Pyruvate →2n Ethanol+2n CO2
  2. History of Ethanol Production  The fermentation of sugar into ethanol is one of the earliest organic reactions that man learned to carry out as dried ethanol residue have been found on 9000 year old pottery in China which indicates that Neolithic people in this part of the world may have consumed alcoholic beverages.  Fermented solutions have been distilled since ancient times in order to produce distilled beverages with a high ethanol content, as distillation was well known by the early Greeks and Arabs. Greek alchemists working in Alexandria during the first century A.D. carried out distillation.
  3. Structure of Ethyl Alcohol
  5. Methods for Ethanol Production  Consolidated bioprocessing (CBP), which integrates enzyme production and fermentation into a one-step process from starchy biomass.  To gain insights into starch-based ethanol production using CBP, an extensive screening was undertaken to identify naturally occurring yeasts that produce ethanol without the addition of any amylases.  Three yeast strains were capable of producing a significant amount of ethanol. Quantitative assays revealed that Scheffersomyces shehatae JCM 18690 was the strain showing the highest ethanol production ability. This strain was able to utilize starch directly, and the ethanol concentration reached 9.21 g/L. We attribute the ethanol-producing ability of this strain to the high levels of glucoamylase activity, fermentation potential and ethanol stress tolerance.
  6. Ethanol Production by the help of Enzymes
  7. Production of Ethanol from Wheat
  8. Ethanol Production from Sugarcane
  9.  It is interesting to note that fermentation process retains most of the energy of the sugar in the form of ethanol.  The heat of combustion of solid sucrose is 5.647 MJ mol-1, the heat of combustion of glucose is 2.816 MJ mol-1 but the heat release is 1.371 MJ mol-1.  The equations are given below  Thus the above reactions show that 97% sugar transforms into ethanol. But in practice, the fermentation yield of ethanol from sugar is about 46% or one hundred grams of pure glucose will yield 48.4 grams of ethanol, 46.6 g of CO2, 3.3 grams of glycerol and 1.2 g of yeast.
  10. Production Plant
  11. Uses of Ethanol  Found as major component in alcoholic drinks such as beer, brandy, or whiskey.  Ethanol is a powerful psychoactive substance.  It is commonly used in the medical field as an antiseptic and as a disinfectant as to sterilize the skin before injections, prevent the spreading of bacteria in hospitals and related facilities.  It can be used as a solvent for different products such as culinary extracts, essential oils, tinctures, concentrates, Solvent:- Resins, pharmaceuticals , cosmetics ,household cleaning products, industrial solvent  Fuel:- Used as a bio fuel , In internal combustion engines  Chemical intermediate -petroleum derived chemicals, Butadiene production
  12.  In 1826, Samuel Morey invented the first internal combustion engine that was built to run on alcohol — probably made from grain.  In 1860, German inventor Nicholas Otto uses ethanol as fuel in one of this engines. The first ethanol blended with gasoline for use as an octane booster occurred in the 1920s and 1930s, and was in high demand during World War II because of fuel shortages.  1975,Brazil launches its Programa Nacional do Álcool, a nation-wide program intended to promote ethanol fuel on the domestic market.  E85 ethanol is a fuel made from a blend of 85% ethanol and 15% unleaded gasoline. E85 was created for flexible fuel vehicles, or vehicles that can run on any blend of ethanol up to 85%. In the United States, the ethanol used in E85 is normally derived from corn.
  13. Advantages  Ethanol‐blended fuel as E10 (10% ethanol and 90% gasoline) reduces greenhouse gases by up to 3.9%.  Ethanol is considered a renewable energy resource because it is primarily the result of conversion of the sun's energy into usable energy.  It reduces greenhouse gases.  It reduces the amount of high‐octane additives.  The fuel spills are more easily biodegraded or diluted to non toxic concentrations.
  14.  Exhaust gases of ethanol are much cleaner , it burns more cleanly (more complete combustion)  The use of ethanol‐blended fuels such as E85 (85% ethanol and 15% gasoline) can reduce the net emissions of greenhouse gases by as much as 37.1%, which is a significant amount.  You can use any plant for production of bioethanol, it only has to contain sugar and starch. The best choice is sugar cane, but you can also use potatoes, barley , wheat etc.  It is carbon neutral i.e. the carbon dioxide released in the bioethanol production process is the same amount as the one the crops previously absorbed during photosynthesis DISADVA.
  15. Disadvantages  The energy content of the petrol is much higher than the one of bioethanol. Burning 1 litre of ethanol gives 34% less energy than burning the same amount of petrol  phosphorous and nitrogen used in the production have negative effect on the environment  During the production process of bioethanol a huge amount of carbon dioxide is released.  The production of ethanol fills the air with greenhouse gases (GHG) in the amounts comparable to the emissions of internal‐combustion engines
  16.  Transportation – ethanol is hygroscopic, it means that it absorbs water from the air and thus has high corrosion aggressiveness.  Biodiversity – A large amount of arable land is required to grow crops. This could see some natural habitats destroyed including rainforests.  The food V fuel debate – There is concern that due to the lucrative prices of bioethanol some farmers may sacrifice food crops for biofuel production which will increase food prices around the world.
  17. END