Carbon Capture involves the production of a pure stream of CO2 from a combustion process. There are two main ways in which this can be done, pre-combustion and post-combustion capture. In pre-combustion a series of reactions is used to produce H2 and a pure stream of CO2 from a hydrocarbon fuel. The H2 can then be burned in (for example) a specially modified gas turbine, or a fuel cell. Post combustion capture can be done in a number of ways: Solvent Capture (including MEA or amine scrubbing), uses some form of solvent to reversibly react with CO2 from the flue gas (i.e. after the fuel has been burned, a post-combustion technology), with heat being applied to remove the CO2 and produce a pure stream of CO2. In Oxyfuel combustion, the fuel is burned in pure O2 (thereby forming a pure stream of CO2) and some of the CO2 from the exhaust is recycled back to the combustor to moderate the flame temperature. Integrated Gasification Combined Cycle (IGCC, a pre-combustion technology) involves the gasification of the fuel by burning it in a small amount (far less than required to burn it completely) of O2, to produce a gas which is rich in CO and H2. Further treatment produces separate streams of CO2 (for sequestration) and H2 (which can be burned without any climate change effects). The Calcium looping cycle (post-combustion) uses the ability of CaO from natural limestone (CaCO3) to reversibly react with CO2 in the flue gas, again to produce a pure stream of CO2. The ZECA process has aspects of the calcium looping cycle associated with it. Using a complicated series of reactions, described below, the ZECA process (joint research with Cambridge University) produces hydrogen which is used in a fuel cell to generate electricity with an extremely high thermodynamic efficiency (60 – 70 %) from a standard fuel. Chemical looping combustion is effected by the use of a metal oxide to carry oxygen from air to a fuel (either gaseous, or otherwise), meaning that the combustion of the fuel produces a pure stream of CO2. Direct carbon fuel cells and artificial leafs (removing CO2 from the air) are also under investigation.