Civil Insight: A Technical Magazine Volume 2 | Page 43

CIVIL INSIGHT 2018
STUDENTS’ SECTION
43
With increasing amounts of variable and non-dispatchable renewables in the power system, the need for extra
capacity for load balancing will increase because of higher variability in generation, especially for wind and
solar plants. It also supports other renewables for the energy generation balance. Many estimates of future
deployment of hydropower have been made, almost all predict a substantial increase globally. Hydropower
would be the best solution for clean energy if we work on river fl ow volume, variability, extreme fl ow events
like fl oods and sediment loads.
Carbon Capture Sequestration
Production of energy from fossil fuels is the backbone of the world economy but is seriously affecting the
global climate. Carbon capture and sequestration (CCS) is the process of capturing waste carbon dioxide (CO 2 )
from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing
it where it will not enter the atmosphere and underground geological formation.The aim is to prevent the
release of large amount of CO 2 in the atmosphere. It is one of the means for mitigating the contribution of
fossil fuel in global warming and ocean acidifi cation.The fi rst commercial example was the Weyburn-Midale
Carbon Dioxide Project in 2000[2]. CCS applied to a modern conventional power plant could reduce CO 2
emissions to the atmosphere by approximately 80-90% compared to a plant without CCS[2].
Carbon dioxide can be captured out of air or fossil fuel power plant fl ue gas using absorption (or carbon
scrubbing), membrane gas separation, or adsorption technologies. Amines are the leading carbon scrubbing
technology. Extracting CO 2 from air is also possible. Flue gas from the combustion of coal in oxygen has a large
concentration of CO 2 , about 10-15% CO 2 whereas natural gas power plant fl ue gas is about 5-10% CO 2 [2].
Broadly three different confi gurations of technologies for capture exist:
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•
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In post-combustion capture, the CO 2 is removed after combustion of the fossil fuel- this is the
scheme that would be applied to fossil-fuel burning power plants.
The technology for pre-combustion is widely applied in fertilizer, chemical, gaseous fuel (H 2 , CH 4 ),
and power production. In these cases, the fossil fuel is partially oxidized, for instance, in a gasifi er.
The resulting syngas (CO and H 2 ) is shifted into CO 2 and H 2 and the resulting CO 2 can be captured.
In oxy-fuel combustion, the fuel is burned in oxygen instead of air.
After capture, the CO 2 would have to be transported to suitable storage sites. This would most likely be done
by pipeline, which is generally the cheapest form of transport for large volume of CO 2 .
REFERENCES
[1] Letcher, Trevor M. (2014). Future Energy. 32 Jamestown Road, London NW1 7BY, UK 225, Elsevier Ltd.
[2] Fanchi, John R., & Fanchi, Christopher J. (2016). Energy in the 21st Century. World Scientifi c Publishing
Co Inc.
Best wishes to the team of Civil Insight’18 for
successfully launching the second volume of the
magazine
“Civil Insight”
Rajendra Thapa