Bio Chemical Assgn.docx

Production of Alcohol from molasses

Fermentation: Sugar industries produce molasses from the sugar cane processing. Molasses have 50 -55% concentration of sugar in the form of sucrose, with chemical formula C12H22O11. This source of compound is used for preparing ethyl alcohol. Ethanol in the form of absolute and rectified spirit can be made from molasses. Basis raw materials for an industry to produce 1 ton of ethyl alcohol requires, molasses up to 5.6 tons, sulfuric acid 27 kg and ammonium sulphate 2.5 kg. The chemical reactions involved for ethanol production from molasses: Main reaction: C12H22O11 + H2O → 2C6H12O6 ,with enzyme invertase. C6H12O6 → 2C2H5OH + 2CO2

-31.2 KCal ,with enzyme zymase.

Side reaction: 2C6H12O6 + H2O → ROH +RCHO (high molecular weight alcohols C2H5OH)

Enzymes Mostly invertase and zymase. They are used for the fermentation fo sugar to form ethanol and carbon dioxide. invertase breakes sucrose anaerobically into glucose and fructose. zymase(or alcohol dehydrogenase) breaks glucose anaerobically to ethanol and CO2. Yeasts are unicellular fungi and one of their known characteristics is the ability to ferment sugar for the production of ethanol (due to the enzymes present in yeast). Yeast is often taken as a vitamin supplement as it has 50% protein and its a rich source of vitamin B, niacin and folic acid. Major enzymes found in different species of yeast are: invertase and zymase

Throughout the pre-treatment process of the sugarcane molasses, the following enzymes were used Termamyl 120L, which corresponds to the thermostable α-amylase of bacterial origin and AMG 200L, which corresponds to thermostable amyloglucosidase of fungal origin. The declared enzymatic activities are 120 KNU g-1 and 200 AGU mL-1, respectively. The α-amylase enzyme has maximum activity at 95 oC, and can be inactivated at low pH, after the addition of hydrochloric acid (HCl 1 M) and boiling for 5 min. The amyloglucosidase enzyme achieves maximum activity at 45 oC.

Substrate Sugarcane molasses from sucrose crystallization process was used as substrate. The molasses donated for this study had the characteristics Characteristics of sugarcane molasses Brix (concentration in percent of sugar by weight according to the Brix scale)

76.70

Pol (percentage by mass of apparent sucrose, %)

53.13

RS (reducing sugars, g L-1)

8.10

TRS (total reducing sugars, g L-1)

640.03

Purity (%)

67.60

Density (g cm-3 at 25 ºC)

1.4015

Fermentor Growth of microorganisms during batch fermentation confirms to the characteristic growth curve, with a lag phase followed by a loga-rithmic phase. This, in turn, is terminated by progressive decrements in the rate of growth until the stationary phase is reached. This is because of limitation of one or more of the essential nutrients. In continuous fermentation, the substrate is added to the fermneter continously at a fixed rate. This maintains the organisms in the logari-thmic growth phase. The fermentation

products are taken out conti-nuously. The design and arrangements for continuous fermentation are somewhat complex. Aerobic fermentations A number of industrial processes, although called 'fermentations',

Aerobic fermentation is carried on by microorganisms under aerobic conditions. In older aerobic processes it was necessary to furnish a large surface area by exposing fermentation media to air. In modern fermentation processes aerobic conditions are maintained in a closed fermenter with submerged cultures. The contents of the fermenter are agitated with au impeller and aerated by forcing sterilized air. Anaerobic fermentations Basically a fermenter designed to operate under micro-aerophilic or anaerobic conditions will be the same as that designed to operate under aerobic conditions, except that arrangements for intense agitation and aeration are unnecessary. Many anaerobic fermentations do, how-ever, require mild aeration for the initial growth phase, and sufficient N agitation for mixing and maintenance of temperature.

INSTITUTE OF CHEMICAL ENGINEERING AND TECHNOLOGY PUNJAB UNIVERSITY LAHORE

ASSIGNMENT: FERMENTATION PROCESS SUBJECT: BIOCHEMICAL ENGINEERING

SUBMITTED BY: MUHAMMAD ASIF IQBAL SUBMITTED TO: DR. NADIR AWAN ROLL NO: MS-16-S-22