Are Biofuels more Env. Sustainable

amt of crude oil + natural gas → present today → limited in supply components of crude oil could be used to make other useful chemicals if they are not used as fuel.

$C{O}_2$ is 1 of main products of burning crude oil and natural gas.

• $C{O}_2$ is a greenhouse gas → contributes to global warming other pollutants like sulfur dioxide → also produced.

• we still use crude oil and natural gas as fuels → as getting energy from combustion of crude oil and natural gas → still considered most economical and convenient method.

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Biofuels

Definition

Biofuels are alternative renewable energy sources to crude oil and natural gas #BiologyDefinitions

• come from plants / animals
• can be replaced relatively quicker after use. e.g. ethanol can be obtained after fermentation of sugar in sugarcane plants. as sugarcane plants can be regrown + replaced in a short period of time → ethanol generated from sugarcane is considered renewable source.

ethanol produced from plants such as sugarcane or corn → also know as bioethanol when used as an alternative to fossil fuels.

Process of Converting Sugarcane into bioethanol

1. Sugarcane is crushed
2. Forms sugarcane bagasse (fibrous remains after juice extraction)
3. Undergoes acid / alkali treatment
4. Undergoes fermentation with yeast.
5. Then undergoes fractional distillation
6. Forms bioethanol and waste products.

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Burning of bioethanol → considered more env. friendly compared to use of fossil fuels.

• as sugarcane grows → it absorbs $C{O}_2$ during photosynthesis → which offsets the $C{O}_2$ produced when bioethanol is burnt

When ethanol is burnt in excess $O_2$ → chemical equation written as:

• ethanol + oxygen → carbon dioxide + water
• $C_2{H}_{5}OH(l)+3O_2(g)\to 2C{O}_2(g)+3H_{2}O(g)$

However to produce enough bioethanol for use → lot of sugarcane plants need to be planted + transported for treatment. These processes may require use of fossil fuels or other valuable resources. More $C{O}_2$ may also be produced in these processes.

When determining env. impact of using biofuels → carbon dioxide generated during → production + transportation processes should also be considered. hence more research must be done to produce biofuels at a low cost with less impact on the environment.

Other biofuels → include biodiesel from vegetable oil and liquid animal fats, green diesel from algae and other plant sources As well as biogas from the methane in decomposed organic waste.

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