Carbon dioxide emission reduction from combined cycle with partial oxidation of natural gas

There is widespread and growing international concern about global climate change resulting from greenhouse effect. CO2 removal from natural gas gives one of the solutions to reduce emissions from the gas-based power plants. Partial oxidation of natural gas with the presence of steam and restricted air produces carbon monoxide and hydrogen. This carbon monoxide can be converted into carbon dioxide and hydrogen, in the presence of steam in a shift reactor. Carbon dioxide is absorbed before gas turbine combustion from the products of the shift reactor. The resulting fuel for combustion mainly consists of hydrogen and nitrogen, thus combustion (e.g. in a gas turbine) exhaust is virtually devoid of CO2.The paper discusses the selection of some important parameters necessary to obtain a maximum level of conversion of hydrogen from natural gas in the partial oxidation reactor. The parameters which influence the hydrogen production are air-to-methane ratio, steam-to-methane ratio and reactor pressure. The results showed that a net efficiency of 43%, with a 95.5% of fuel conversion can be obtained by combined cycle with dual pressure heat recovery steam generator based on present technological status.