The present status of production and utilization of biomass-derived fuels are reviewed for bio-ethanol, BDF (Bio-diesel fuel), BTL (Biomass to Liquids) F-T (Fischer-Tropsch) diesel fuel, and DME (Dimethyl ether) . These biomass-derived liquid fuels would contribute to reduction of CO₂ emissions due to their neutrality, sulphur free and aromatic nature. The fossil fuels, especially petroleum-derived liquid fuels would be substituted in future by biomass-derived liquid fuels leading to suppression of air pollution caused by automobiles.

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Biomass fuels or Biodiesel fuels are a viable alternative to petroleum fuels due to their renewability, low or no emission and the potential to provide energy security and local economic benefits. This paper presents the results of various oils being tested as diesel fuel alternatives, including coconut oil unblended and blended with diesel fuel. The effects on engine performance and efficiency, the corresponding problems associated with their use, the atomization characteristics in the process of spray formation, engine combustion and the mechanism of the effect is also discussed on the basis of emissions, combustion parameters and spray characteristics.

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The increase in world population and the concomitant growth in world economy especially in Asia has created a necessity for additional energy which should not come at the cost of CO2 emission. The situation can be solved by making use of fuel produced from biomass. Dimethyl ether (DME) is a promising fuel in view of its clean emission and relatively low technical problems to commercialize it for light duty and heavy duty trucks. The emission of the latest 20 ton truck is within the post 2005 challenge regulation (namely, 09 regulation, NOx: 0.23g/kWh, PM: 0.01g/kwh) . The low boiling temperature of DME (-24.8C) necessitates the use of blend fuel for the safety of marine engines. The viscosity of the blend fuel (30% DME and 70% palm oil) is close to that of diesel fuel giving a similar performance as that of diesel fuel. The higher DME content in the blend fuel decreases the soot from the engine. The carbon deposit in the combustion chamber should be burned by the use of neat or high content of DME blended fuel.

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The exhaust gas emitted from the marine diesel engines creates air pollution problems. Also, the quantity of petroleum fuel resources is decreasing, so a substitute for conventional petroleum fuel is needed. The thermal heat efficiency of diesel engine is high when their compression ratios are higher. Various types of fuel are widely used in diesel engines. Such fuels as light oil (diesel oil), A-heavy fuel oil, recycled bio-oil (soybean oil), fish oil, and waste plastic oil are recently substituted for diesel fuel oil., so we investigated the resulting efficiency and combustion characteristics. S.F.C. (specific fuel consumption) and concentrations of O₂, CO₂, CO, and NOx in the exhaust gas were measured on loads of 10 to 50%. The properties and characteristics of each fuel are discussed as a substitute fuel of diesel engine.

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For the purpose of achieving reduction both of NOx, PM (particulate matter) and CO₂ by applying DME (Dimethyl ether) to diesel fuel, HE Engineering Corp, Iwatani International Corp. and Daihatsu Diesel Mfg. Co., Ltd. are collaborating to develop a large DME diesel generation system under a subsidy from the METI's “DME Fuel Application Equipment Development Subsidy Program”. In this paper, we introduce investigated subjects on developing the DME diesel engine and present results.

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Dimethyl ether (DME) is the simplest ether having a chemical formula of CH₃OCH₃ and a colorless gas at an ambient condition. It is easily liquefied under light pressure because its vapor pressure is about 0.6 MPa at 25°C. Physical and chemical characteristics of DME are very similar to those of LP Gas. Therefore, DME can be distributed and stored by using LP Gas handling technology, which means DME does not need costly LNG tankers or LNG terminal. DME contains neither sulfur nor nitrogen, and its toxicity is very low, similar to LP Gas. Since a DME fueled diesel car emits neither soot nor PM (particle matters), it's a very clean substitute for diesel fuel. For the purpose of producing large quantity DME at low cost, JFE Corporation has been making remarkable progress in a development of direct DME synthesis technology. Based on the technology development, DME Development Company is conducting 100-ton-DME/day (100TPD) Demonstration Project from 2002 through 2006. This Direct DME Synthesis technology will open a new way to economical DME mass production.

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The combustion and emission characteristics for two waste cooking oils were investigated in detail. One fuel was the methyl esters in waste cooking oil. This fuel is in routine use in Kyoto City for a garbage collection vehicle with DI diesel engine (B100) and a city bus (B20; 80% by volume gas oil is mixed into B100) as an alternative fuel for gas oil. The other is fuel created by removing impurities from raw waste cooking oils. In order to improve the fuel properties, kerosene is mixed 70% by volume in this fuel. The mixed fuel (i-BDF) is used in several trucks in Wakayama City.
In the experiments, the engine performance and exhaust emissions were investigated in a single-cylinder, direct injection diesel engine. As a result, NO_x emissions are similar for both fuels. PM emissions are lower for waste cooking oil methyl esters than for other fuel at a wide range of engine loads. The combustion characteristics in the cylinder were investigated by an optical method. The luminous intensity, which might correspond to soot, near the injection nozzle was reduced for the waste cooking oil methyl esters operation.

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The combustion and emission characteristics for two waste cooking oils were investigated in detail. One fuel was the methyl esters in waste cooking oil. This fuel is in routine use in Kyoto City for a garbage collection vehicle with DI diesel engine (B100) and a city bus (B20; 80% by volume gas oil is mixed into B100) as an alternative fuel for gas oil. The other is fuel created by removing impurities from raw waste cooking oils. In order to improve the fuel properties, kerosene is mixed 70% by volume in this fuel. The mixed fuel (i-BDF) is used in several trucks in Wakayama City.
In the experiments, spray and combustion characteristics were investigated inside a rapid compression and expansion machine (RCEM) . The spray characteristics were measured by shadow-photography. We found that the spray tip penetration is greater and the spray angle is smaller for waste cooking oils than for gas oil. The combustion characteristics were measured by direct photography and imaging of OH chemiluminescence. As a result, flame luminosities in waste cooking oils are relatively low; in particular, soot formation in the combustion flame was found to be decreased in the case of B 100.

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The combustion and emission characteristics for two waste cooking oils were investigated in detail. One fuel was the methyl esters in waste cooking oil. This fuel is in routine use in Kyoto City for a garbage collection vehicle with DI diesel engine (B100) and a city bus (B20; 80% by volume gas oil is mixed into B100) as an altemative fuel for gas oil. The other is fuel created by removing impurities from raw waste cooking oils. In order to improve the fuel properties, kerosene is mixed 70% by volume in this fuel. The mixed fuel (i-BDF) is used in several trucks in Wakayama City.
In the experiments, the soot formation process inside the flame was focused using an optical measurement method. A rapid compression and expansion machine (RCEM) was used to simulate the DI diesel engine combustion process. Flame characteristics were investigated by the two-color method, and details of the soot formation process were detected using laser-induced incandescence (LII) . Results showed that the high flame temperature region in the BDF case existed throughout the whole flame, but existed only in the central part of the flame in the gas oil case. The gas oil case showed a high level of LII signal intensity, but when the combustion process progressed, the LII signal intensity of biodiesel fuels noticeably decreased.

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In previous paper, we improved the diesel engine system to use DME (Di-Methyl Ether) as fuel oil. The engine performance using the mixed fuel comprised of DME and Marine diesel oil was reported. In this report, further investigation was carried out in varying mixing ratio of DME and Marine diesel oil. In the experiments, combustion pressure, rate of heat release, pollutant emissions and injection condition were measured using a small high-speed single-acting 4 stroke diesel engine. A high-speed video camera was used to investigate the fuel spray pattern. As a result, it is shown that the ignition delay becomes shorter by increasing the mixing ratio of DME to Marine diesel oil. Fuel spray spreads wider in radial direction in case of higher mixing ratio of DME. Due to the changes in combustion history and spray pattern, concentration of soot and CO emission become smaller by increasing the mixing ratio of DME to Marine diesel oil.

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DME (Dimethyl Ether) is a clean fuel, which does not produce toxic gases or particulate matters after burning process. JFE group develops a direct synthesis process of DME, which has advantage in economics. Construction of demonstration plant with 100t/day capacity had been finished in November 2003 and total trial operation was completed successfully during December 2003. JFE group has also been developing MW-class diesel generating system since 2002 as an application of DME fuel. This paper describes about the characteristic of NOx emissions by a large amount of cooled EGR of 50kW DME diesel engine bench.

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In spite of new regulations the condition of the global environment has raised social problems all over the world. The coming into force of the Kyoto Protocol on Feb. 16, 2005 has created a need for private companies to grapple with environmental protection as their social responsibility by reducing emissions. The same can be said about shipping companies which as a result of the coming into force of MARPOL 73178 ANNEX VI on May 19, 2005 has to cany out various countermeasures for the reduction of pollutant emissions. Many of these countermeasures are introduced in this paper.

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In order to realize the energy-reused, the compound cycle is used in exhaust heat-reused plant on board ship based on the performance analysis of compound cycle and ammonia-water composite. The Kalina cycle, in which ammonia-water composite is used as the working fluid, is being researched for using in the electrical power plant on board ship in future. It is very important to fmd out the relationships between the properties and the concentration of ammonia-water composite. In this research, the properties of ammonia-water composite are obtained by using the general-purpose computer program “PROPATH” when the concentration is varied from 0 to 90%.
According to the calculated result, the condensing pressure is decreased if a separator is used in the condensing system. At the same time, the exergy efficiency of the steam turbine is raised, especially, when ammonia concentration is more than 30%. If the high-pressure and high-concentration ammonia is sent to turbine directly from separator, the exergy efficiency of the turbine could be increased up to 15%.

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An on-boardmeasuring system for diesel particulate matter (PM) is proposed. The systemuses β-ray attenuation to measure PM weight and incorporates a partial flow dilution unit. We compared results of the new system with those of the conventional method on a research engine. Both sets of results agreed when those of the new system were corrected for the filter efficiency of PM collection. In addition, we measured PM for an on-board generator and a main engine using the new system. The PM emission (g/kWh) from the generator did not depend on the engine load and varied widely at 25% load. The PM concentration (mg/m³N) from the generator was proportional to the engine load On the main engine, a few data for PM emissionwere observed at around 20% load.

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