A halving of global greenhouse gas emissions is needed between now and 2050. This will require an energy technology revolution. All options must be used: energy efficiency, CO2-free fuels and CO2 capture and storage. The power sector will be especially affected and the global average carbon intensity of electricity needs to be reduced by one order of magnitude. A mix of renewables, nuclear and fossil fuels with CCS will be needed to achieve this goal. This development will affect gas turbine sales and their development.

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Gasification technologies enable conversion of low-grade resources to clean gases, and can generate electricity through gas turbine. However, gasified fuels contain nitrogenous compounds of NH3 and HCN that cannot be removed in the case of employing a hot/dry-type synthetic gas cleanup for improvement of plant thermal efficiency and are oxidized into fuel-NOx in combustion processes. Fuel-NOx emissions constitute the majority of NOx emissions in exhaust. In combustion processes of the CO, H2 and CH4 mixture fuels, the oxidation characteristics of nitrogenous compounds are different from cases of conventional hydrocarbon fuels, and influenced by fuel constituents and combustion methods. Author had clarified influence of gasified fuel constituents on fuel-NOx emissions through experiment. This paper clarifies that conversion rate of nitrogenous compounds to fuel-NOx is decided by both a CH4 concentration and primary equivalence ratio in the case of using two-stage combustion, while conversion rate is greatly affected by an H2 constituent in the case of gasified fuel containing no CH4. Consequently, a prediction methodology of conversion rate of fuel-N is established in the case of air-staging two-stage combustion.

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