OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
the emissions would not only be zero, but negative, so that not only the emissions, but the absolute amount of
CO 2 in the atmosphere would be reduced.
3. Energy Fuels by CO2 Sequestration
The process of underground storage of CO2 and consequent changes in the viscosity of fluids in depleting oil
reservoirs can provide additional fuel for energy. The CO2 will mix with the crude and by changing the oil
properties will help flush out remaining reserves making it flow easily. At the surface the gas mixture containing
both CO2 and natural petroleum gas will have to be separated from the oil before it is sent for refining. The
stripped CO2 can be recycled back into the oil fields to extract more oil. CO2 management through this approach
will be a highly challenging task. It will have to be adopted when all the conventional methods of enhanced oil
recovery have failed. A CO2-EOR (CO2-Enhanced Oil Recovery) project designed to minimize CO2 emissions
back to the atmosphere with appropriate incentives would have an important role in assuring energy security.
Like oilfields, unmineable coal seams can also prove to be potential reservoirs for CO2 storage. On average three
molecules of CO2 are absorbed for displacing one molecule of methane (CH4). By injecting CO2 in coal seams,
coal bed methane recovery can be enhanced. Three main CO2 capture processes under development for power
generation are as follows[7][10]:
3(a) Pre combustion Capture Systems
It takes the syngas produced from coal gasification and convert it via – a – steam based chemical reaction into
separate streams of CO2 and H2. It facilitates the collection and compression of CO2 into a supercritical fluid
like form suitable for transportation and geological storage.H2 is being separated from CO2 to be able to be
used for combustion in gas turbines which is primarily done by Pressure Awing Adsorption(PSA) , amine
scrubbing and membrane reactors.
3(b) Post combustion Cycle
It separate CO2 from the flue gases produced by the combustion of coal in air.Post combustion CO2 capture
technology based on chemical absorption processes is large scale technology to be deployed for power
generation purpose.
3(c), Oxy – fuel combustion
It involves combustion of coal in pur O2 rather than air, to fuel a steam generator.By avoiding N2 into the
combustion cycle , the amount of CO2 in the power station exhaust stream is greatly concentrated making it
easier to capture and compress.
Globally, research in CCS has grown by almost 100 per cent in the last five years as compared to previous five
years block in USA. In India, research is still in its infancy. Under the National Programme on CO2
Sequestration (NPCS), research started in DST in 2006; the following thrust areas are identified as :
• CO2 Sequestration through Micro-algae Bio-fixation
• Carbon Capture Process Development
• Terrestrial Agro-forestry Sequestration Modeling Network
• Policy Development Studies.
Further studies for Cost of Electricity(COE)comparisons for different power plants with CCS are stated in
Table-2.
TABLE – 2 : EXPECTED COST OF ELECTRICITY (COE) FOR DIFFERENT POWER PLANTS WITH
CCS in USA[7]
Sl.No. Power Plant Pulverised Coal Natural Gas
Combined Cycle
Integrated Gasification
Combined Cycle
1 COE without CCS ( 43- 52) (31 – 50) ( 41 – 61)
(US $ / MWh)
2 COE with CCS
( US $ / MWh)
(63 – 99) ( 43 – 77) (55 – 91)
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