Introduction
Carbon dioxide is the main byproduct in a brewery. Accordingly, we have identified source of carbon dioxide, as an exhaust gas produced in a brewery. This report explains how such a source of carbon dioxide can be harnessed for future use.
Air extraction technology to capture atmospheric carbon dioxide
We understand that due to excessive burning of fossil fuels there is abundance or more than expected amounts of carbon dioxide in the atmosphere. Accordingly, carbon dioxide can be extracted from atmospheric conditions using various technologies. This technology of carbon dioxide capture is a step wise process, which is called air extraction (Zeman and Lackner, 2004). In this technology, the ambient air containing carbon dioxide is first acted upon by soluble sodium hydroxide to give sodium carbonate solution as the product. Sodium carbonate solution, in the second step, is treated with calcium hydroxide. The product generated in the second step is sodium hydroxide and calcite. In the last step, calcite is subjected to thermal decomposition to give rise to calcium carbonate and carbon dioxide. So, this technology yields carbon dioxide in its last step. Moreover, this method is little a cumbersome and cost intensive.
Carbon capture and storage (CCS)
There are several technologies aiming at carbon capture and storage. The aim of CCS is to reduce the amount of carbon dioxide in the atmosphere and use it for several processes. In our case, we plan to use such captured carbon dioxide obtained as a byproduct of brewery. Pre and post combustion carbon captures are the two most commonly used methods (Hester and Harrison, 2010). In case of pre- combustion capture of CO2, due to the removal of carbon dioxide, the primary fuel does not combust. In this method, physical solvents like Rectisol or Selexol are used to separate CO2 from hydrogen using pressure. The CO2 captured is then filled in cylinders for future use while the hydrogen can be used for electricity generation. However, post- combustion CO2 capture process is relatively simple and involves clearing of combust/ exhaust gases using amines or ammonia. CO2 cleaning is accomplished by dissolution of CO2 in a chemical solvent followed by the release of CO2 using temperature swing process in a reboiler. Thus, the separated CO2 is then dehydrated, compressed and filled in cylinders for future use. So, we recommend post combustion technology to harness CO2 obtained as a byproduct of our brewery.
References
- Hester, R.E, & Harrison, R.M (2010). Carbon Capture. Sequestration and storage. Vol. 29. RSC Publishing. The Royal Society of Chemistry. Cambridge. UK
- Zeman, F.S, & Lackner, K.S (2004). World Resource Review Vol. 16 No.2. Capturing Carbon dioxide directly from the atmosphere. Department of Earth and Environmental Engineering. Columbia University. New York, NY, 10027 USA.
