Point Source Capture
Point source capture technology involves methods of collecting carbon dioxide (CO2) directly from power plants to lower power plant emissions, which constitute a large percentage of all anthropogenic CO2 emissions. This process either involves rebuilding the plant entirely with the new technology added, or adding the technology to an existing plant, a process called "retrofitting". Plants typically retire within approximately 40 years and have to be rebuilt at that time to continue power production (IEA Clean Coal Centre, 2005). While these technologies reduce plant emissions, they do decrease the plant's total efficiency and increase the amount of money spent per kWh of electricity produced. In our plan, all new plants that would be rebuilt would be more efficient than current average plants.
Point source capture in coal-fired power plants is referred to as a "clean coal" technology, but this term is slightly misleading. The technologies under this category only help to prevent most of the CO2 from reaching the atmosphere. Although there is no actual decrease in CO2 output, its purification allows for easier handling and storage (World Coal Institute, 2009).
Point source capture is currently only implementable on fuel burning power processes and cannot reduce emissions contributed by all industries that contribute to CO2 output. The steel industry, for example, produces, on average, 1.7 tonnes of CO2 per tonne of steel produced, with more than 200 Mt of steel produced per year. (World Steel Association, n.d.). These emissions may be reduced if the steel industry changes its technology from the more popular method (using blast furnaces), to a more efficient one (using electric arc furnaces), which emits less CO2 per tonne of steel produced (Mines and Communities, 2007). Other methods currently in development are molten oxide electrolysis production of steel, and using hydrogen as a reducing agent in a blast furnace. This emission reduction, however, is not a form of point source capture.
There are three main types of point source capture:
Many would agree that post-combustion technology is the most favorable for retrofits, though oxy-fuel technology may also be retrofitted.