ruchikavera
New Member
- Joined
- Feb 26, 2011
- Messages
- 3
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- Female
- HSC
- 2013
I know there have been many posts on this but they were all a bit confusing :S So, I'm hoping to clear this up ![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Here's what I've gathered from various sources about the steps, please correct me if I'm wrong:
Here's what I've gathered from various sources about the steps, please correct me if I'm wrong:
- Grains from sugar cane are passed through hammer mills and ground to a fine powder.
- This meal is sent to a mashing system, where it is mashed together with enzymes and water.
- This then undergoes hydrolysis (decomposition by water), catalysed by the enzyme, invertase:
C12H22O11(aq) + H2O(l) --> C6H12O6(aq) + C6H12O6(aq)
(sucrose) + (water) --> (glucose) + (fructose) - The sugars are filtered: the solid residue is continually hydrolysed with more acid until it too has broken down into sugars.
- Ca(OH)2 is added to the acidic sugar solution (filtrate) to neutralise it.
- The neutralised sugar solution is filtered to remove the solid residue of CaSO4.
- Ferment the sugar solution, using enzymes produced by the yeast called zymase, to produce ethanol:
C6H12O6(aq) ---> 2C2H5OH(aq) + 2CO2(g)
- Yeast used is Saccharomyces cerevisiae
- Small amounts of yeast nutrients are added, such as phosphoric acid or urea
- Mixture is kept at 37 degrees Celsius.
- Oxygen is excluded - Fermented product (6-10% ethanol) is sent to the purification section.
- Distillation of the ethanol/water produces a higher concentration of ethanol (96%).
- This is then dehydrated to remove the last water molecules and impurities. After this, the ethanol can be sold commercially.