carbon capture and storage for power plants

 Carbon capture and storage for power plants

Limitations

One limitation carbon capture and storage (CCS) is its energy penalty. The technology is expected to use  between 10 and 40 percent of energy produced by a power stations. Wide scale adoption of CCS may erase efficiency gains  of last 50 years and resource consumption by one -third. Even taking the fuel penalty into consideration however overall levels of CO2 abatement would remain high at approximately 80-90 percent compared to the plant without CCS. It is theoretically possible for CCS when combined with combustion bio-mass to result in net negative emission but this is not currently feasible given the lack of development of CCS technologies and limitations of bio-mass production.


The use CCS can reduce CO2 emission from stacks of coal power plants by 85-90 percent or more, but it has no effect on CO2 emissions due to mining and transport of coal. It  will actually “ increase such emissions and of air pollutants per unit of net delivered power and will increase all ecological, land use , air pollution and water pollution impacts from coal mining transport and processing, because CCS system requires 25 more energy this 25 percent more coal combustion than does system without CCS.

Another concern regards the permanence storing schemes. It is claimed that safe and permanent storage of CO2 cannot be guaranteed and that even very low leakage rates could under mine any dim ate mitigation effect. The IPCC concludes however  that the portion of CO2 retained in appropriately selected and managed geological reservoirs is very likely to exceed 99 per cent over 100 years and likely to exceed 99 percent over 1000 years.

Finally there is the issue of cost. Green Peace claimed that CCS could lead a doubling plant costs. CCS though may remain economically attractive in comparison to other  low -carbon electricity  generation . It is also claimed by opponents to CCS that  many spent on CCS will divert investments away from other solutions to climate change.

CCS cost

Although the process involved in CCS have been  demonstrated  in other industrial application no commercial scale projects which integrate these process exit, the costs therefore are some what uncertain. Some recent credible estimates indicate that a carbon price of U.S. dollar 60 per U.S. - ton is required to make capture and storage competitive. Corresponding  to an increase in electricity price of about U.S. 6c per Kwh( based on typical coal fired power plant emissions of 2.13 pounds per Kwh) . This would double the typical U.S. industrial electricity price now at around 6C  per Kwh )  and increase the typical retail residential electricity price by about 50 per cent. ( assuming 100 percent power is from coal, which may not necessarily be the case as this varies from state to state similar ( approximately )  price increases would likely to be expected in coal dependent countries such as Australia because the capture technology and chemistry as well as the transport and injection costs from such power plants would not, in overall sense vary significantly from country to country.

The reasons that CCS is expected to cause such power price increases are several . Firstly the increased energy requirement of capturing and compressing CO2 significantly raises the operating cost of CCS - equipped power plants. In addition these are added investment and capital costs. The process would increase fuel requirement of a plant with CCS by about 25 percent for a coal fired plant and 15 percent  for gas powered plant. The cost of this extra fuel, as well as storage and other system costs, are  estimated to increase the cost of energy from power plants with CCS by 30-60 percent depending on specific circumstances. Pre commercial CCS demonstrated projects are likely to be more expensive than mature CCS technology, the total additional cost of an large scale CCS demonstration projects are estimated to be C 5- 1.1 billion per project over project life time. Other applications are possible. In the belief that use of sequestered carbon could be harnessed to off-set  the cost of capture and storage, Walker Architects published the first CO2 gas  CAES application proposing  use of sequestered   CO2 for energy storage on October 24 ,2008. To date  the feasibility of such potential off-sets have not been examined.


The cost of CCS depends on capture and storage which varies according to method used. Geological storage in saline formations or depleted oil & gas fields typically cost U.S. dollar 0.5 to 8.00 per ton of CO2 injected plus additional U.S. dollars 0.10 to 0.30 for monitoring costs. When storage is combined with enhanced oil recovery to extract from oil fields , however  the storage could yield net benefits of U.S. dollar 10-16 per ton CO2 injected (based in 2003 oil prices) this would negate some of effect of carbon capture when oil was burnt as fuel. Comparisons of CCS with other energy sources can be found in wind energy, solar energy, and economics of new nuclear power plants.

Environmental effect on CCS

The theoretical merit of CCS systems in the reduction of CO2 emissions by up to 90 per cent depending on plant type. Generally environmental effects from use of CCS arise during power production CO2 capture, transport and storage issues relating to storage are discussed.

Additional energy required for CO2 capture and this means that substantially more fuel has to be used, depending on plant type. For super critical pulverized coal (PC) plants using current technologies the extra energy requirements range from 24- 40 percent, while natural gas combined cycle  (IGCC) plants range it is
14-25 per cent (IPCC 2005). Obviously  fuel use and environmental problem arising from mining and extraction of coal or gas increase accordingly. Plants equipped with flue gas De sulphurization  (FGD) systems for sulfur dioxide control require proportionally greater amount of lime stone  and systems equipped  with selective catalytic reduction systems for nitrogen oxide produced during combustion require proportionally greater amounts of Ammonia. IPCC has provided estimates of air emission from various CCS plant design. While CO2 is drastically reduced though never completely captured, emission of air pollutants increase significantly, generally due to energy penalty capture. Hence the use of CCS entails a reduction in air quality.

Carbon capture and storage  needs detailed investigation of additional cost and reduction of these costs developing carbon capture storage technology economically viable for capture of CO2 from power plants,  effects as new entrepreneurs to develop safe technology without incurring additional costs which will reduce global warming . Initial stage of CO2 capture, let us not discuss the effect of coal, and gas mining extraction environmental effects as CO2 capture its self  in elementary stage. As engineers and scientists  to study effectively detailed and economical carbon capture and storage process and innovate processes that reduce the cost .

Government to finance and promote carbon capture from power plants and encourage entrepreneurs to enter into the research and development. Even carbon capture may be better option instead of government proposing to levy carbon tax on coal burning  and producing power in plants which is better for environment. 


In addition to  developing sophisticated technologies carbon capture government  to encourage technocrats to invest in storing under ground or under sea and any method which useful for environment. The  technology needs innovation and needs investments and detailed investigation about carbon storage without leaking back to earth by  effecting environment.

If technology is available government to invite and encourage foreign investors to invest in these carbon capture and transportation and storage from power plants to save earth from global warming. Government need to develop infrastructure  to young engineers venture to carbon capture process transportation and storing for overall improvement of environment on this planet.