Fuels from microbes Biology B3

Ethanol

Made by anaerobic fermentation of sugar.

Glucose --> ethanol + carbon dioxide + energy

Sugar cane juices can be used/glucose derived from maize starch by action of carbohydrase. Ethanol distilled to seperate it from yeast & left over glucose. In some countries cars have been altered to run on a mix of ethanol and petrol (called gasohol)

Biogas

Made by anaerobic fermentation of waste material. Usually 70% methane & 30% carbon dioxide. Different microbes used to ferment biogas, ferment plant and animal waste that contains carbohydates. Sludge waste (sewage works etc) used to make biogas on large scale. Made in simple fermenter/digestor. Need to be kept at constant temperature so microbes can respire.…