GTL is a technology that uses natural gas as the raw materials and produces petroleum products such as naphtha, kerosene and diesel oil through chemical reactions and is also the general term for such products. GTL products are free of sulfur and aromatic content and represent an energy source in keeping with the environmental needs of the times. The introduction of GTL technology will open the way to a new source of liquid fuels based on natural gas available throughout the world and will undoubtedly contribute to the realization of energy security in Japan. This paper introduces the activities of GTL technology and projects in the world and Japan.

Because of countermeasures against air pollution in big cities, diversification of fuels, and CO₂ reduction for global warming, commonplace non-petroleum automotive fuels are expected. Gas to liquid (GTL) and Dimethyl ether (DME) are good for energy security, DME is good for countermeasure against air pollution in big cities with its soot-free combustion. Biofuels, such as Bioethanol and Biodiesel, are good for CO₂ emission reduction with their‘carbon-neutral’characteristic. Investigation of a variety of new fuels has been actively conducted for those purposes. In this report, R&D trends of GTL, biodiesel fuel, and DME are introduced as typical non-petroleum automotive fuels.

Effects of turbulent intensity on the flame structure in an opposed jet burner have been investigated for a methane/air mixture by conducting time-series temperature fluctuation, OH-LIPF, and double-probe ion current measurements. Combustion regime of the flames also has been discussed. With an increase of turbulent intensity under the condition of Karlovitz number larger than unity, the results show that the preheat zone thickness of local turbulent flamelet increases, while the reaction zone thickness keeps almost constant or gets thinner compared to that of laminar premixed flames. Flames of Karlovitz number larger than unity are more reasonable to be classified to the thin reaction zones regime rather than the distributed reaction zone regime.

A high emphasis is placed on reducing environmental pollutant in combustion gas, because of an increasing concern about global environmental problem. Honeycomb catalyst is commonly used for NO reduction in exhaust gas. But, the measurement of concentration in the honeycomb is very difficult, because it is assembled with a lot of millimetersized channels. So, it is necessary to investigate the physical quantity by the numerical simulation and to understand the phenomenon in the honeycomb. The detailed elementary reaction kinetics for CH4-air combustion gas and Rh catalytic surface are considered. The details of NO reduction in a channel, such as mass fraction in the gas and catalytic surface and coverage are obtained. Especially, the effects of exhaust gas composition on NO deoxidization by catalytic reaction are estimated, and the catalytic reaction mechanism becomes clear.