ON THE ALTERNATIVE FUELS FOR MARINE ENGINES

The Authors, of, respectively, the (Japanese) Ship Research Institute and Ishikawajima-Harima H.I., discuss the alternative fuels which Japan might have to use in the future for general and marine purposes in the event of a world shortage of oil. The criteria which alternative sources of energy would need to meet are discussed in relation to a wide variety of fuels, with more detailed consideration being given to the potentialities of natural gas, coal, methanol, and hydrogen. (Nuclear power is not considered, but the availability of ports is mentioned as a primary requirement for operating nuclear ships). Natural gas is one of the most promising alternative energy sources for Japan (among other countries). Coal has very great potentialities; research and development work on this fuel includes research by the British Coal Utilisation Research Association and others on fluidised-bed combustion. Some information is given on solvent refined coal (STC) and other coal products. Natural gas, coal (including pulverised coal, water slurry, and coal-in-oil mixture), methanol, and hydrogen are further discussed with special reference to their use as marine fuels, and several conclusions are drawn on this particular application. Hydrogen will remain too expensive to consider in the forseeable future; there are already well-established techniques for using natural-gas boil-off in boilers, Diesel engines, and gas turbines. Methanol can be burned relatively easily in boilers and gas turbines; its use in Diesel engines seems possible, and a system for this is under development in Sweden. However, there are further problems in the use of methanol, including a high dependence on international relations. Coal is the most promising fuel from the point of view of resources, and is expected to play a very important role in the period between the era of oil and the era of new energy systems; it has serious drawbacks, but recent developments in coal fluidisation for power stations are expected to become available for marine engines, and may overcome the disadvantages. Order from BSRA as No. 49,661.