Carbon Capture and Storage (CCS) - My Understanding in 30 Minutes.

Since I’m interested in environmental engineering, I think CCS is a very important topic for me to cover, although I have come across it briefly during my Chemistry A Level.

Carbon Capture and Storage is quite self-explanatory; to capture CO2 emissions from various industrial sites and essentially store the CO2 in geological formations deep underground in order to prevent it from reaching and damaging our atmosphere. CCS uses a chemical plant, but there are also smaller scaled plants for training students such as on CCS pilot plants. The CCS process works with three main steps, capturing the C02, transporting the C02 and finally storing the C02. C02 is captured with either of the following methods, pre-combustion capture, post-combustion capture or oxy-fuel combustion systems. I will my understanding on the method of post-combustion:

• Fuel enters a boiler where it is then combusted with air, this creates steam which can be used to power a turbine, whilst a mixture of the gases of C02, Nitrogen and H20 are taken to a chemical wash
• The C02 is separated from the other gases at the chemical wash, where is is captured, compressed and dehydrated ready for transportation. 
• The C02 can be transported via pipelines or shipment to a suitable underground storage such as old oil and gas fields.
• The C02 is injected into the storage area deep underground where it is then blocked by impermeable rock and thus the C02 is now stored.

My understanding is that after the C02 has been stored it takes the natural process of forming into a useful fossil fuel, although I am not sure over how many years... I imagine many. This is a vital process in order to reduce greenhouse gas emission and put a stop to climate change. However, still in October of 2014 there were only 22 major CCS projects.



Sources used:
[1] http://www.ccsassociation.org/what-is-ccs/
[2] http://ichemeblog.org/2015/05/17/ccs-carbon-capture-and-students-day-355/#more-8668