Carbon Fixation
The process of taking an inorganic compound e.g. Carbon Dioxide to organic compounds. If it happens in a living organism its called biological carbon fixaton.
Biofuel
A hydrocarbon by or from a living organism that humans can use to power something e.g. cars or any hydrocarbon produced by or from a living organism in a short period of time.
Biomass
Organic matter, dead material that was once living e.g. kernel of corn sugar cane etc. It is used to make biofuels and this makes biofuel more renewable as biomass can be reproduced in a short time.
Examples of biofuel vs its fossil fuel counterparts
| Biofuel | Fossil Fuel | Differences |
| Ethanol | Ethane/ Gasoline | Ethanol burns cleaner than gasoline but it only has half the energy per unit mass of gasoline. Thus it produces less carbon monoxide but more ozone which contributes substantially to smog |
| Biodiesel | Diesel | Burns cleaner than diesel, produce less particulate and fewer sulfur compounds. However, it is corrosive to the engine thus modifications have to be done for the engine to take biodiesel. Has only slightly less energy per unit mass than diesel |
| Methanol | Methane | Easier to transport as compared to methane as it’s in the liquid form. Only has one third to half as much energy per unit mass as methane. |
| Biobutanol | Butane/ Gasoline | Can run in any car that uses gasoline, contains almost the same energy per unit mass as gasoline |
Alcohols contain very little or no sulfur thus combustion of alcohol produces very little sulfur dioxide and sulfuric acid. However, alcohols are derived from plant and animal matter thus containing a lot of nitrogen. This is bad as it will produce a lot of nitric oxides and other nitrogenous compounds which contributes to acid rain in the long run
However, burning alcohols and biodiesel produces less carbon monoxide as compared to petrol diesel.
Production of biofuels from biomass
Biofuel: Ethanol
Biomass: sugar cane, corn, wheat, sugar beets, industrial sweet potatoes
Method of production: Biochemical Conversion
Enzymes and microorganisms Catalyse the conversion of biomass or biomass-derived compounds into desirable products. Enzymes such as Cellulase break down the carbohydrate fractions of biomass to five- and six-carbon sugars via hydrolysis, Yeast and bacteria then ferment the sugars into products
https://energy.gov/eere/energybasics/articles/biofuel-conversion-basics
http://www.eesi.org/topics/bioenergy-biofuels-biomass/description