Ethyl alcohol production

ethyl alcohol fermentation for beverage produuction

1. Ethyl Alcohols Production Mrs. Praveen garg VITS College, satna

2. INTRODUCTION Ethyl alcohol is the most common solvent and raw material. It is next to water and is used in laboratory and chemical industry. Much of this alcohol is obtained synthetically from ethylene. However , its production from microbial fermentation using sugary substrates is commercially important. The microorganisms used must have a high tolerance for alcohol, must grow and produce a large quantity of alcohol.

3. There are two main processes for the manufacture of ethanol: The fermentation of carbohydrates (the method used for alcoholic beverages) The hydration of ethylene. Fermentation involves the transformation of carbohydrates to ethanol by yeast cells perticularly Saccharomyces cerevisiae .

4. ETHANOL FERMENTATION Ethanol fermentation, also called alcoholic fermentation. It is a biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as by-products. Alcoholic fermentation is considered an anaerobic process. Ethanol fermentation has many uses, including the production of alcoholic beverages, the production of ethanol fuel, and bread cooking.

5. Biochemical process Alcoholic fermentation converts one mole of glucose into two moles of ethanol and two moles of carbon dioxide, producing two moles of ATP in the process. The overall chemical formula for alcoholic fermentation is: The enzyme  invertase  cleaves the  glycosidic linkage between the glucose and fructose molecules. C 6 H 12 O 6  → 2 C 2 H 5 OH + 2 CO 2

6. EFFECT OF OXYGEON Fermentation does not require oxygen. If oxygen is present, some species of yeast (e.g.,  Kluyveromyces lactis  or  Kluyveromyces lipolytica ) will oxidize  pyruvate  completely to carbon dioxide and water in a process called cellular respiration. These species of yeast will produce ethanol only in an anaerobic environment (not cellular respiration). This phenomenon is known as the Pasteur effect.

7. Alcohol fermentation was the first fermentation that was carried out by human beings. Substrates used in fermentation of ethyl alcohol are saccharides , starchy and cellulosic material. The bacteria as well as fungi can ferment sugar to alcohol. Biological process of alcohol production

8. The microorganism used for fermentation depends upon the type of raw material used for fermentation. If Starch and sugar are used as substrate then the fermentation organism used is  Saccharomyces cerevisiae or Saccharomyces ellipsoideus . Fermentation of alcohol from dairy waste  Candida pseudotropicalis   is used . If the Sulphite waste liquor is used from the paper industry then  Candida utilis  strain is used for fermentation. Micro-organism used in fermentation

9. The strain used should give high yield of product. The strain should be fast growing and tolerate high concentration of sugar so it can give high yield of product. The microorganism should be genetically stable. Property of Strain or Micro-organism

10. Inoculum added in fermentation tank is of a yeast culture. A large  amount of inoculum is required in the ethanol fermentation process. Inoculum added in fermentation process is generally 4 % but in sometimes 8 % inoculum may be added. The composition of nutrient media used for inoculum preparation is similar to the composition of fermentation media. During the process of inoculum preparation the nutrient media is facilitated with high amount of aeration and agitation. It is important for fast growth of cells. The optimum temperature maintained is about 28° C to 30 ° C and optimum pH used is 4.8 to 5. The maintenance of optimum conditions in innoculum preparation media is important for growth and production of cell mass. Inoculum preparation

11. A variety of industrial waste and agricultural waste is used as a raw material for fermentation of ethanol. Cellulosic material used contains sulphite waste liquor, straw. Starchy material like corn starch, potato starch and wheat flour. Saccharides like sugar cane molasses, beet molasses,   hydrol , fruit juices are used. Raw material use for fermentation

12. It should be easily available. The agricultural waste is used (molasses) as a raw material for ethanol fermentation. The agricultural waste used should be pre-treated for removal of unwanted, toxic products. So this sugar can be easily utilized by inoculum and produce high amount of ethanol. The beet molasses is also added in the medium as a source of biotin as it is one of the important growth factor. Nitrogen source is added in the form of ammonium sulphate or ammonium phosphate in a concentration of about 0.015 %. The optimum pH maintained of the fermentation media is about 4.8 to 5 and optimum temperature maintained is 28° C to 30 ° C. Fermentation medium

13. Recovery The fermented broth is allowed to stand still for settling down of product. It is distilled by fraction distillation process. The product is distilled by using analyser and rectifier column the distilled product obtained is ethyl alcohol and fusel oil. The product obtain is 95  %  ethyl alcohol and 5 % water.

14. By products The by products obtained after fermentation The distillery effluent – The distillery effluent is nothing but fusel oil. This fusel oil is used in perfume manufacture, used in paint industries, spent wash contain potassium salts used in manufacture of potassium fertilizers. The residual yeast cells are used in fodder preparation. The carbon dioxide produced is purified and used as dry ice or used in soft drinks.  

15. Thank you