Excessive amount of carbon dioxide is harmful as it causes rise in global temperature which will eventually sparks off other problems. Therefore, carbon dioxide especially those produced from the burning of fossil fuels; the world’s main energy source must be captured and stored underground safely. There are several ways to capture carbon dioxide. In one of the ways, two towers are used: one contains chemicals that could segregate carbon dioxide from other gases where as the other separates carbon dioxide from the chemical. Another approach is by burning fossil fuel with pure oxygen. This eventually makes storage of carbon dioxide easier as it can be done by just condensing water vapour. However, it is expensive to obtain pure oxygen; hence it is not feasible. A more advanced method to generate power from coal introduces a simpler way to capture carbon dioxide. Synthetic gas produced by burning coal is added with steam and catalyst, consequently converting carbon monoxide to carbon dioxide which can then be filtered out. Several underground storage sites have been investigated. Depleted oil and gas fields serve as good storage sites. Meanwhile, carbon dioxide helps to recover oil trapped by underground rocks. Nevertheless, this method is not practical as the amount of such fields is insufficient to accommodate increasing amount of carbon dioxide. Perhaps, using sedimentary rocks that contain brine and formed at more than 800 meters deep is a better alternative. Sedimentary rocks are abundantly available but the main concern lies on the reliability of these sites to securely store carbon dioxide without releasing it to the atmosphere after a period of time. The problem of leakage has lead to another possible storage site: sediments beneath the ocean floor. High pressure from the sea water keeps carbon dioxide stored without leaking. Other than the above methods, technique based on natural processes could also be developed. Carbon dioxide can be injected to the sea to form other safer chemical compounds. In conclusion, thorough strategies and storage locations must be mapped out carefully to solve this problem as the excessive amount of carbon dioxide emitted is harmful.
References:
National Academy of Engineering. (2008). Develop carbon sequestration methods. Grand challenges for engineering. Retrieved March 27, 2008 from http://www.engineeringchallenges.org/cms/8996/9077.aspx
5 comments:
Hi Lai Shan, I think the summary is concise and clear, all the main ideas are pointed out in a very attractive way, as various type of sentence structures and connectors are used skilfully. I think the sentence ‘This eventually makes storage……water vapour’, the word ‘capture’ should be used instead of ‘storage’ due to the sequence of the process, and also to make the sentence more concise. Please correct me if I’m wrong ^^ Anyway, it’s really a good piece of work!
hi lai shan. first up, nice summary! i could picture everything i read from the original article by just reading your summary, which means you captured most of the important ideas in the text. yes, i have to agree with wern fei that your sentence type are diverse. about your sentence, 'This eventually makes storage……water vapour’, i think that the word 'storage' is alright and it does not change the meaning of the sentence as you are talking about the ease of storing carbon dioxide after burning with pure oxygen.
Thanks Wen Hui and Calvin for commenting. I agree that the word "storage" doesn't fit well in the sentence mentioned in both comments. Perhaps "capture" should have been used.
Hi Lai Shan,
I was surprised that we share the same idea. In my opinion, your summary is quite good thanks to a variety of words and sentence structures.However, I think you make a mistake of passive voice here "using sedimentary rocks that contain brine and formed at more than 800 meters deep is a better alternative". Maybe it should be "are formed"
Thanks Kim. I still don't see the mistake you mentioned. If i were to use "are formed", i think the sentence should be in this way: using sedimentary rocks that are formed at more than 800 meters deep and contain brine is a better alternative.
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