Carbon dioxide emitted when hydrocarbons are combusted with oxygen that present in atmospheric air. A simple fuel as methane contains one carbon atom in it is structure. It produce 275 kg of carbon dioxide when 1 kg of methane is burned completely similarly, gasoline have average of 8 carbon atom and it produce 309 kg of carbon dioxide per 1 kg of gasoline. Diesel has 12 carbon atoms on average and it emits 311 kg of CO2 per 1 kg of diesel. Fuel oil has 25 carbon atoms this give out 312 kg of carbon dioxide per 1 kg of it. This is lots of carbon dioxide accumulating in air. Our planet cannot survive if carbon dioxide is generated continuously at present rates. Carbon capture is one best solution for this problem.
Solid fuel, coal also has one carbon atom in its molecular structure and it gives 367 kg of carbon dioxide for 1 kg of coal burned completely in the presence of air. The above calculations are simple material balance that gives an ideal how much carbon dioxide is left into air during the combustion process. We generate day-by-day vast amount of carbon dioxide into the Earth’s atmosphere. However, a simple carbon capture technology is that by recycle carbon dioxide into liquid fuel will help in preventing fossil fuel consumption for automobile and vehicles.
Important techniques used for carbon capture:
- Clathrate hydrates
- Membrane separation
- Cryogenic separation
- Gas expanded liquids
What can we do with captured carbon dioxide?
We have technique of capturing the CO2. Now we need a solution to use it without harming the environment. One of the ideas was using it to make recycle fuel and other was using it for forestation. With less energy, CO2 can be converted to fuel by the help of microorganisms. Using solar energy algae consumes carbon dioxide and produce biomass.
Another technique is by electro catalysis and with photo electrochemical methods the CO2 converted to methanol and its derivatives.
Carbon Capture Technology to convert CO2 to CH3OH/ DME:
Carbon dioxide can be converted into methanol and as well as to the fuel which can be used in diesel engines as dimethyl ether is the objective of the technology. If automobile fuel is produced with this technology than most of, the carbon dioxide issue can be resolved because major part of carbon emission is from vehicles only. In addition, this technology can be directly applied at the industries furnaces that generate carbon dioxide as flue gas. The flue gas containing carbon dioxide and carbon monoxide directly sent into electrochemical section to converts CO2 to CH3OH and then CH3OCH3.
Carbon capture by gas expanding liquid formation:
Energy needed to turn carbon dioxide gas into liquid is more than its gas-expanded liquid form. Organic liquid are pressurised with carbon dioxide gas form a CO2 expanded solvent. This technique produce a unique form of phase that contains gas dispersed in liquid in stable form.