Effects of CO2 on the environment
Carbon dioxide occurs naturally in the atmosphere. It is an essential ingredient of photosynthesis and a by-product of respiration. Post the industrial revolution, the atmospheric CO2 levels have been seen to rise alarmingly. The primary causes for this are deforestation and the burning of fossil fuels. As carbon dioxide levels have risen, so have its effects on air pollution, causing global warming, drastic climatic changes, acid rain, etc. The effects of carbon dioxide can be seen and felt far from their sources, making their impacts on air pollution more serious. One way to cut down on it is through a carbon capture: a chemical technique that removes CO2 from emissions, preventing it from entering the atmosphere. The captured CO2 can then be either recycled or stored away in gas or liquid form, a process known as sequestration.
Carbon Capture & Storage
In carbon capture and storage (CCS) processes, CO2 has to be separated from the exhaust gas streams before the subsequent transportation and storage. Membrane separation technology is one of the efficient solutions for carbon capture. Carbon capture can be done using so-called “high-performance membranes”, which are polymer filters that can specifically pick out CO2 from a mixture of gases, such as those coming out of a factory’s flue. These membranes are environmentally-friendly.
A membrane should satisfy a few requirements to capture CO2
- It should have high CO2 permeability
- It should have high CO2/N2 selectivity
- The membrane should have high thermal and chemical stability
- The manufacturing costs of the membrane should not be too high
The membrane materials include cellulose acetate, polyamides, polysulfone, and polycarbonates, which don’t generate waste and can intensify chemical processes. In fact, they are now considered as one of the most energy-efficient routes for reducing CO2 emissions.
Is this the best way forward?
Due to the lack of their high-temperature stability, the use of polymeric membranes for capturing CO2 in large-scale power production plants still presents an inefficient solution. The main drawback of the removal of carbon dioxide using commercially available membranes is the higher energy penalties on power generation efficiency with respect to a conventional chemical absorption process.
However, extensive research works are currently going on to improve upon this technique. We may see some efficient solutions very soon. What do you think about this? Feel free to share your views on this in the comments section.