Dimethyl ether (DME) is a new generation fuel produced from natural gas and coal. This fuel can be used directly to a conventional internal combustion (IC) engine without any significant modifications. The main advantage of DME combustion in IC engines is the low NO_x and particulate emissions compared with the fossil liquid fuel. Thus, the usage of DME in IC engines is potentially to improve engine efficiency and reduce emissions in the future with minimum attempts. This paper offers a comprehensive review of some topics related to DME as an alternative fuel for IC engines and efforts to increase its utilization to meet high efficiency and low emissions regulations in the future.

Fossil fuels as the main energy source of every country now predicted will be ended no more than 40 years. Therefore, alternative fuel such as biofuel has been developed by many countries including Indonesia. Indonesia as one of the highest populated country and has wide areas of agriculture, forest and crop field is potential to be the highest biofuel production in the world. However, after one decade since the Government of Indonesia launched the energy Policy in 2006, appears to be interesting that the biofuels progress in Indonesia seen not well developed. One of the basic weaknesses is the program only applied to the specific area with a high biofuel resource by central government without support by local government. Furthermore, the target of biofuel programs seems to be very high or too ambitious, while the condition of the people still very traditional which can be seen from the lifestyle and their energy consumption. This paper provides in detail a review of several topics related to resource, energy consumption, policy and the research and development activities of biofuel in Indonesia. As a discussion, some recommendation provided to encourage the biofuel development in the near future

Exhaust emission is one of the kind emission have contribute to the greenhouse effect in the world. Ethanol is one of the best tools to fight air pollution from vehicles. From its biodegradable nature to reductions in greenhouse gas and tailpipe emissions, ethanol provides a tool to address environmental concerns without requiring an entirely new way for goods and people to get from one place to another. Ethanol contains 35% oxygen and with adding oxygen to fuel results in more complete fuel combustion, reducing harmful tailpipe emissions. This paper addresses the possibility study of ethanol percentage to changing of performance and exhaust emissions for Diesel Engine using Virtual Engine Simulation Tool AVL Boost. In this study the blend formulation between Ethanol and Diesel Fuel were E0, E2.5, E5, E7.5 and E 10. The performance of diesel engine simulated in 1,000-1,500rpm with 0, 10, 20, 30, 40, 50 and 60 Nm engine loads. The direct blending of ethanol and diesel fuel has advantages reducing exhaust emissions CO, Soot and NOx percentages. The engine power break of pure diesel is slightly lower than those of E2.5-E10, especially for speed above than 1400rpm. The simulation work with the same results compare to the experiments can reduce the cost of research

An experiment on the application of diesel and ethanol blends as fuel in diesel engine was carried out at various engine loads and ethanol percentages. The experiments were performed using solar, E2.5%, E5%, E7.5%, and E10% ethanol-diesel blends and 0, 10, 20, 30, 40, 50 and 60 Nm engine loads. Several engine parameters i.e. power, brake specific fuel consumption, brake thermal efficiency, the exhaust gas temperature, and lubricating oil temperature were investigated. As a complement of the experiment, the exhaust emission characteristic of CO, HC and smoke were also investigated. The results indicate that the engine power and the indicated mean effective pressure increase with increasing of ethanol percentage. The brake specific fuel consumption and exhaust gas temperature decrease, meanwhile the lubricating oil temperature increase with increasing the ethanol content. From the experiments, as the increase of ethanol percentage content, the emission of CO, HC and smoke decrease