Dot Point 3.3.2 (1 Viewer)

[Whaddaya Know?]

Argh, still a little confoozed on the industrial production of ethanol from sugar cane. Does anyone have info on this topic?? My textbook (Conq Chem) seems a little vague on this point.

Thanks! :apig:

 

[Sush]

oh i feel your pain!! a couple of weekends ago i was goin through the exact same thing n i will tell u now i searched the entiiiiiiiiiiiiire internet high n low!!! n this is everythin i could find, so yeh this is the best i could do anyway, yeh i have chem contexts n i dont think it even mentioned it at all really

Summarise the processes involved in the industrial production of ethanol from sugar cane.

Cane sugar has a by-product, molasses, which is rich in sucrose C12H22O11, a simple sugar that would be able to be fermented for the production of ethanol. However, in the industrial production of ethanol this is not an economically viable feedstock. Therefore glucose and fructose must first be obtained from the molasses for either of these to be used in fermentation. For this to occur, water and yeast is added, to which the sucrose reacts with to form the products of glucose and fructose. This is represented in the following equation:

Sucrose + water ---> glucose + fructose

C12H22O11 + H2O ---> C6H1206 + C6H12O6

The glucose or fructose obtained can now be used in the process of fermentation; this takes place in a sealed anaerobic environment operating at 37C. Yeast is added and it is this microorganism that produces enzymes to catalyse the conversion of the glucose/fructose to ethanol. Carbon dioxide is also produced from the reaction. Once the ethanol concentration reaches 14-15% the yeast will no longer produce enzymes to make more ethanol, as they will have been deactivated.

Glucose or fructose ---> ethanol + carbon dioxide

C6H12O6 (aq) -----> 2C2H5OH(aq) + 2CO2 (g)

A 95% concentration of ethanol can then be achieved once the aqueous ethanol is distilled which is possible due to the difference in boiling points of water and ethanol; water having a boiling point of 100C as opposed to ethanol with a boiling point of 87.3C. This will give a 95% concentration; a purer concentration can be obtained only through then processing the solution through a molecular sieve, which works by attracting the water molecules away from the ethanol.

hope thats some sort of help!

 

[~*HSC 4 life*~]

You just need to know :
that glucose- which is a renweable product of photosynthesis can be converted into ethanol in the presence of zymase, a catalyst found in yeast. This catalyst initiates the reaction, and causes glucose to form ethanol and carbon dioxide. since zymase is abiological catalyst, reaciton is carried out at its optimal temperature of around 37 degrees, in the absence of oxygen (anerobic environment)