A study evaluating the economics of replacing older coal plant with carbon capture and storage (CCS) found integrated gasification combined cycle (IGCC) plant with pre-combustion CO2 capture offered the best profit for plant operators.
The study, ‘An economic and environmental assessment of carbon capture and storage (CCS) power plants: a case study for the City of Kiel’ published by the Journal of Environmental Planning and Management assessed three different types of coal fired power stations power plant, all with CCS, for their environmental impact and profitability.
The designs have been proposed as replacements for the existing coal fired power station in Kiel, Germany.
The power plants were an IGCC plant with pre-combustion carbon capture; a pulverized coal (PC) plant with post-combustion carbon capture and a pulverized coal plant with oxyfuel combustion carbon capture.
The profitability of alternative coal fired power plants with CCS was assessed using three scenarios of possible future CO2 permit prices, fuel prices and power revenues to plant owners. Results of the profit analysis suggest an IGCC plant with pre-combustion capture would be the best option in terms of economic returns for plant owners.
An IGCC plant with CCS requires the least amount of fuel to operate the capture unit and is therefore more efficient than the other two types of plant. Oxyfuel technology is the most costly option for carbon capture.
In addition, the study investigated retrofitting CCS to an existing coal power station, either an IGCC plant or a PC plant. In both cases, fitting a CCS unit after the power plant has been built is less profitable than a plant with a CCS unit installed initially.
A life cycle analysis was used to compare the environmental impact of the different power plants. Although CCS considerably reduces CO2 emissions from all plants, the reduction is not as great as estimated by other studies, which suggest reductions of up to 99 per cent.
These figures typically refer to emissions only from the plant and do not take into account the increased energy demand of using CCS. For instance, life cycle emissions from a PC plant with CCS are only reduced by 67 per cent compared with a coal fired plant without CCS, according to this study.
For plants retrofitted with CCS units, the plant life cycle emissions increase the longer the delay in fitting the CCS systems.
Source: Lindner, S., Peterson, S., Windhorst, W. (2010) An economic and environmental assessment of carbon capture and storage (CCS) power plants: a case study for the City of Kiel. Journal of Environmental Planning and Management. 53: 1069-1088.
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