Carbon Capture Flashcards
Which sectors can Carbon capture be applied to and not applied to
Industry, heating and electrical sector. It’s not really possible for the transport sector
What are the three CCS categories
Post, pre and oxy combustion .
Post - separate CO2 from gas after combustion
pre - separate CO2 from the fuel and combust the h2 from the fuel
oxy - combust fuel in oxygen
What is the advantage and disadvantage of chemical post combustion capture
The capture system can be placed at the end of any fuel processes, meaning that the processes need not be changed. However it does require 20% of the energy produced
Disadvantage of amine based post combustion capture
The amines can degrade into potentially harmful chemicals. To reduce degradation will require systems that use energy.
What is adsorption and what governs the level of adsorption
The adhesion of species to a solid surface. Governed by pressure, concentration and temperature. Heating up or reducing the pressure will cause the adsorbed species to fall of.
What are the two types of adsorption technologies for carbon capture
VSA (pressure/ vacuum) and TSA (temperature) . TSA captures more carbon but take longer to clean.
What is the benefit of adsorption CSS compared to chemical/ amine CSS
Less energy required
How does Pre combustion CSS work
The carbonaceous fuel, such as natural gas, is reacted with steam and a small amount of O2. This produces syngas a mixture of co2, co, ch4 and h2. This syngas is further reacted to form only co2 and h2. The co2 is then removed, keeping the h2
what are the four ways of precombustion CCS
adsorption, chemical absorption, distillation, physical absorption.
What is the main disadvantages of adsorption precombustion ccs
Complex process.
What is the main disadvantage of cryogenic distillation
Requires cooling the feed, which is not feasible unless co2 content is greater than 40%
Adv and disadv of precombustion CCS
lower energy penalty, efficient and uses widely used technologies
Complex process so low flexibility and quite high capital expenditure
What is oxy fuel combustion
The fuel is combusted in oxygen removed from the air and co2 which forms water and co2, the water vapour is released and the co2 is captured.
How is oxygen removed from the air for oxy fuel combustion and state the pros and cons
cryogenic distillation - mature tech, very high capacity, very high purity, high energy requirements
vacuum swing Adsorption - mature tech, medium capacity, high purity, low energy requirements
membranes - high purity, low capacity
How is captured carbon transported
As a supercritical liquid (high pressure, normal temp) or a normal liquid (normal pressure, low temperature). Both require large amounts of energy, as much as the capture itself.
Transported in pipes, ships or when in small scale (not often economically viable) trucks, rail
What is captured carbon used for
EOR - injection of co2 down into oil reserves to pump the oil out
Stored underground in caves
creation of plastics and other chemicals
What makes co2 separation easier
A more concentrated co2 flue composition. For example steel and cement plants have above 20% co2 mol so are easier to separate.
What is the problem with carbon transport
The pipes have to pass through many landowners’ land.
Why does greenhouse gas removal need to be performed earlier
The longer co2 remains in the atmosphere, the more of an effect it has (somehow) which means emitting 1 tonne of co2 now means more than 1 tonne needs to be removed later??
What is the pros and cons of Bioenergy with CCS
feasible tech, but has social stigmas as it seems like wasted land to grow crops for the sole reason of capturing carbon only to burn it again for energy,
What is the pros and cons of direct air capture (adsorption of co2 from air)
Technically feasible, socially acceptable but economically questionable. A less visible disadvantage is that it encourages corporations to use direct air capture instead of post combustion co2 capture. The co2 becomes diluted so this process is incredibly inefficient in comparison
barriers to deployment of CCS
policies. There is no penalty for not executing CCS properly so no incentive for trying to utilise it
There is little information of the entire operation of CCS as it hasn’t been deployed enough
It is expensive and does not generate revenue
The general public doesn’t care enough
co2 doesn’t have much value
