Mechanism of the Kyoto Protocol. At COP16 in 2010, The Subsidiary Body for Scientific and Technological Advice, at its thirty-third session, issued a draft document recommending the inclusion of CCS in geological formations in Clean Development Mechanism project activities. At COP17 in Durban, a final agreement was reached enabling CCS projects to receive support through the Clean Development Mechanism. Environmental effects Alkaline solvents CO2 can be captured with alkaline solvents at low temperatures in the absorber and released CO2 at higher temperatures in a desorber. Chilled ammonia CCS plants emit ammonia. "Functionalized Ammonia" emits less ammonia, but amines may form secondary amines that emit volatile nitrosamines by a side reaction with nitrogen dioxide, which is present in any flue gas. Alternative amines with little to no vapor pressure can avoid these emissions. Nevertheless, practically 100% of remaining sulfur dioxide from the plant is washed out of the flue gas, along with dust/ash. Natural gas processing and enhanced oil recovery The Institute for Energy Economics & Financial Analysis has criticised companies for not reporting greenhouse gas emissions from the use of their products. from natural-gas processing is often used for EOR. It has been suggested that enhanced oil recovery only be allowed to use anthropogenic and should only receive financial incentives such as tax credits when carbon negative, which is generally only in the early years of a project. Gas and coal-fired power plants Although the global total emitted by fossil fuel power plants is very large, coal plant flue gas typically only contains 10–14% , and gas power plants only 4–5% . Cost per tonne increases as the capacity factor decreases (the plant is used less - for example only for times of highest demand or in emergencies). The extra energy requirements deriving from CCS for natural gas combined cycle (NGCC) plants range from 11 to 22%. Fuel use and environmental problems (e.g., methane emissions) arising from gas extraction increase accordingly. Plants equipped with selective catalytic reduction systems for nitrogen oxides produced during combustion require proportionally greater amounts of ammonia. A 2020 study concluded that half as much CCS might be installed in coal-fired plants as in gas-fired: these would be mainly in China and India. However a 2022 study concluded that it would be too expensive for coal power in China. For super-critical pulverized coal (PC) plants, CCS' energy requirements range from 24 to 40%, while for coal-based gasification