carbon capture and storage processes

Carbon capture and storage

The number of projects for capturing green house gases from power plants and cement factories edged up 2010 despite soaring costs and slow progress in U.N. led efforts to slow climate change a study reported.

The focus of carbon capture and storage (CCS) projects also shifted more to U.S. from Europe even though U.S. President Barack   Obama has failed to persuade the senate to legislate caps on U.S. green house gases it said.

The global CCS institute said 234 CCS projects were active or planned world wide at the end of 2010, at net rise of 26 from 2009 despite cancellations including Netherlands and Finland.

CCS aims to capture planet warming carbon dioxide in fossil fuels such as  from coal fired power plants or cement factories and bury it in depleted oil and gas reservoir or under ground stores-no commercial  scale  projects yet exist.

“ The global commitment to carbon capture and storage remains strong” according to Australian island institute, whose members include major businesses and government of top emitter led by China , U.S.,Russia and India.

But the study published on institute website pointed to rising costs that have discouraged investments due to sluggish economic growth many developed countries. U.N.reports have suggested CCS could be an important this century as a shift to renewable energies such as wind and solar power in curbing global green house gases emission.

But U.N. climate negotiators have failed to agree a treaty to limit emissions that would help set a global penalty on carbon emissions to provide a surge investments in CCS.

OUR  global industrial and energy systems are built on carbon bared technologies and unsustainable resource demands that threaten to destroy  our society and our planet. Massive loss of wealth, expanding poverty and suffering disastrous climate change, water scarcity and deforestation are the end result of this broken system.

War on carbon

The systems does not change themselves- the same state emergency will continue to endanger our safety, our  lively hood and our planet. We need new thinking, new leadership, and innovation to create a post carbon economy. Our goal not to undo industry, but to remake it  into force for sustainable wealth generation.

Governments and traditional no-profit do initial work and their effort to change global opinion and policy essential  in this fight. However awareness and policy reform are not enough. It is time to reinvent our economic system-it is time to act-it is time to implement solutions. We can no longer afford to be intimidated by the scope and magnitude the climate crises. It is essential that our most talented and driven individuals come together to win this war.

CCS technologies have potential to reduce emissions from fossil fuel power stations (and other industrial plants)by at least 90 percent. They capture CO2 before it reaches the atmosphere and put  it in  an under ground location. Many of these processes have been demonstrated on relatively small scale including some commercial applications in other industries but they have yet to be demonstrated together on a commercial scale on  a power station. Until this is done, CCS will remain  too costly to be used widely and certainty will remain about whether CCS can be viable on commercial scale.



Technology choices

Three methods CO2 capture that are closest to commercial deployment at coal-based fire power plants are

Post combustion

Processes that separate CO2 from the exhaust gasses produced by combustion (burning)of fuel (coal, natural gas, oil or bio-mass) in the air. CO2 is captured using a liquid solvent such as aqueous  amine solution. Once  absorbed by the liquid solvent, CO2 is then released by heating. Post combustion capture has been carried out successfully, but so far on relatively small scale.

Pre combustion

Processes that convert fuel into gaseous mixture of hydrogen and CO2 . The CO2 is then separated and the hydrogen can be burned without producing any CO2  in the exhaust gas. Pre combustion capture is used in industrial processes but it has not been demonstrated in much larger examples of coal gasification.

Oxy -fuel combustion

Oxy-fuel combustion processes that use oxygen rather than air for combustion fuel. This produces exhaust gas that is mainly water vapor and CO2. The exhaust gas has relatively high CO2 concentration (greater than 80 percent by volume) oxy -fuel combustion systems are being developed on a small scale in a  laboratory or demonstration projects.

All these three options are feasible for new coal burning power plants, through certain coal types-such as the high ash coal often found in India are unsafe for pre combustion technologies. Many existing coal plants could be retro-fitted probability with post combustion technology.

Once captured CO2 is then transported by a pipe or for power plants on coast possibly by ship to a site when it can be stored. Oil fields, gas fields ,deep saline formations (aquifers ) and un-mineral coal seams have been suggested as a geological storage site. Here various physical e.g.(highly impermeable cap rock) and geo-chemical trappings mechanism would prevent CO2 escaping to the surface. Other ways of using rock formations-such as the potential for mineralization in basalt rocks-are under investigation.

Co2 is some times injected into declining oil fields to increase oil recovery (known as enhanced oil recovery  while this option has an economic benefit-the additional oil recovered- the environmental cost of extracting more fossil fuels must be seriously considered.

The safety of storage sites-that is how securely they will retain the CO2 is still investigated. There are many sites considered safe, but even they will require continuously monitoring to ensure there is no leakage.

As technology develops the CCS will help to prevent  global green gas emissions and reduce heating of this planet. Scientists and engineers working with carbon capture and storage processes should dedicate  for developing sophisticated technology  sooner as possible  to help global community for reduction of  global warming on the earth.