1 / 12

Production of Ethanol by Fermenting Sugars

Production of Ethanol by Fermenting Sugars. ETHANOL. One method of making ethanol is to use plant material which contains starch. The reaction is called fermentation where the sugar is converted into an alcohol. Fermentation is an enzyme-controlled

vin
Download Presentation

Production of Ethanol by Fermenting Sugars

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Production of Ethanol by Fermenting Sugars

  2. ETHANOL

  3. One method of making ethanol is to use plant material which contains starch. The reaction is called fermentation where the sugar is converted into an alcohol. Fermentation is an enzyme-controlled reaction that takes place inside living yeast cells in which glucose is broken down into alcohol and carbon dioxide with the release of energy.

  4. The carbohydrates in the food must be broken up first to form sugars. This is done by hydrolysing the carbohydrate. Hydrolysis is a reaction in which water molecules (‘hydro’=water) react with larger molecules to split them (‘lysis’= split apart) into two or more smaller molecules.

  5. part of a starch molecule H H H O O O H H H water molecules individual glucose molecules

  6. The sugar is then converted into alcohol. The equation for the reaction is : glucose → ethanol + carbon dioxide C6H12O6 → 2C2H5OH + 2CO2 Fermentation is an enzyme-controlled reaction that takes place inside living yeast cells in which glucose is broken down into alcohol and carbon dioxide with the release of energy.

  7. Reactions that are catalysed by enzymes normally produce the best results at temperatures around 40OC. The reactions will be slower at lower temperatures and at higher temperatures, over 70OC, the enzyme will stop working because the high temperature denatures the enzyme.

  8. The fermentation process takes place inside living cells therefore if the yeast dies then the reaction will stop. When the alcohol concentration reaches about 14% the it begins to kill the yeast. Fermentation reactions therefore have a limit to the percentage of alcohol they can produce.

  9. Biological Action Yeast: • Living organism • Microscopic fungus • Feeds on sugars • Is a biological catalyst • Therefore classed as an enzyme

  10. Conditions for Fermentation pH: prefer a neutral pH (or round about) if it is too acidic or alkaline the yeast will die. Temperature: Room temperature is ideal; too cold and the yeast stops working (goes into a “sleep” state) and too warm and it dies. Alcohol concentration: yeast does not like alcohol, about 14% alcohol the yeast dies

  11. Distilling The Alcohol The alcohol concentration can be increased by separating the alcohol from the water, this is carried out via a process called distillation. The separation by distillation is an easy process as ethanol boils at 78OC and water boils at 100OC although both liquids will evaporate to some extent at any temperature.

More Related