Carbon Capture: What is it?
Extract from Paper written by Rebecca Fayad (Year 13) in a global STEAM writing competition.
Original title: ‘Feasability of Carbon Capture - will it save us?”
What is carbon capture?
Carbon capture and storage (CCS) is starting to happen. A plethora of CCS projects have emerged in the last year, large and small in scope, as well as energy-intensive industries beyond the oil and gas value chain. This spate of individual projects is a promising sign for a technology on which much hope rests – CCS could account for one-third of the emissions reduction required to meet the global net-zero target by 2050. By itself, critics argue it won’t cure climate change, though its developments and new technologies beg to differ.
Is it a matter of time, or a matter of principle?
All we can do is wait, fund, and see.
Carbon Dioxide (CO2) has been the most famous gas, related to global warming because many energy and industrial related processes release an extensive amount of CO2. As shown, CO2 makes up 80% of the greenhouse gasses emitted by energy facilities, machinery, cars, the burning of fossil fuels, etc... This increase in greenhouse gases dates back to the industrial revolution, where more and more machinery and energy developments were made without looking at sustainability or efficiency.
This is where carbon capture and storage (CCS) come into play.
Evidently, carbon is captured by machinery and then stored depending on the form it has been collected in. So far, we have four technologies in use, three of which are in the industry during combustion. The three direct technologies are: Pre-Combustion, Post-Combustion, and Oxyfuel Combustion.
Carbon Capture is not complete without its storage. After collecting all the carbon, it usually either travels in pipelines, by boats or trucks to be injected into the ground under cap rocks which were former sites of oil, deep saline and gas collection. This process is called Geological Sequestration.
These methods capture CO2 before, during, and after its combustion, but before its release in the atmosphere. Fortunately, a newly invented method can absorb air, react the CO2 to separate it, and then react the CO2 with hydrogen to create fuel. This method is called Direct Air Capture (DAC).
That CO2 absorbed from the air can be stored or reacted again using the Fischer-Tropsch Process to create octane (a fuel) and H2O to sell again and monetise the project. The latter would make the project carbon neutral rather than carbon negative. This would decrease cracking for finite resources, as fuel is generated from the carbon captured. This fuel could be sold, making the project profitable, yet carbon neutral. If the machinery was cheaper, then some of this carbon could be sequestered underground as explained earlier, which would make the overall technology carbon negative.
Having conquered all the modern technologies available, we can now address the feasibility of the scale-up and usage of CCS.
It is important to note that to reach the 2 degrees global target; it isn’t enough to just be carbon neutral, by using renewable energy, but the removal of already present CO2 should be a priority too. Some might argue that the best CCS available is our nature, such as trees and plants, while photosynthesising.
Despite its logic, we don’t have enough space, initiative, and money to plant enough trees to do the work. This is also considering that renewable energy won’t require the deforestation of plants for space or the staling of land for biofuels.
For CCS technology to grow, competitive carbon markets and strategic identification of storage systems should be developed, as their high costs and potential leakages are a barrier to their growth. Scientists are relentlessly trying to scale up CCS, whose greatest barrier so far is price. Government subsidies and funds will have to play a role at the beginning of the research process until they can manage the costs of the industry. A good example of this is the XPRIZE foundation (by Tesla) set to pay $100 million to whoever finds efficient and sustainable carbon capture technology. To win, projects must show they can remove at least 1,000 tons of CO2 annually, keep the carbon sequestered for at least 100 years, achieve lower cost at scale, and have a realistic path to scaling up to the gigaton level — a billion tons annually.
Both, renewable energy and CCS should be employed to reach the global carbon emission level by 2050.