Bioethanol-gasoline blends represent for Otto-cycle engines a consolidated alternative in the attempts to reduce GHG emissions and to limit the use of fossil fuels. However, the use of alternative fuels can strongly influence the performance of engines.
The purpose of this study is to analyse the output and the pollutant emissions of a four-stroke SI engine fuelled with 0%, 50% and 80% bioethanol-gasoline blends. Tests were performed on a 3-kW engine used in broad applications. No specific modifications were applied to the carburetion system in order to evaluate its fuel flexibility capabilities.
The tests evidenced that the mixture tends to get lean with alcoholic fuels; the brake specific fuel consumption increased due to the lower LHV of bioethanol, while the highest brake thermal efficiency was obtained with E50. Minor torque and power reductions were recorded with the ethanol blends. The concentration of UHC decreased with E50 and E80 while NOx emissions reduced because of the lower combustion temperature due to the bioethanol cooling effect and the leaner mixture. In contrast, the concentration of CO increased because a poor homogenization of the charge and a lower combustion temperature had facilitated the formation of partial oxidation products.

Internal combustion engines are well spread in traditional power-generation systems: given their reliability, lowcost and performance it is desirable to avoid their full substitution in the short term, but, rather, to rely on the reduction of their environmental impact. This can be achieved by implementing solutions that involve minor modifications on the devices, such as the use of different fuels. In this work, the fossil fuels replacement approach has been applied to a micro-cogeneration system based on a small water-cooled compression ignition engine.
The effect of bioethanol introduction as a diesel substitute in six diesel-biodiesel blends has been studied in terms of performances of the whole energy-conversion system and of the exhaust gas emissions. Positive results have been obtained showing that with a small amount (3%) of bioethanol, enhancements can be fulfilled both on performances (with approximately an average 13%-boost of the electrical and thermal efficiency) and emissions (reaching nearly a 80% of smoke opacity reduction).

In order to contribute positively to the environmental and human health sensitivity, it is necessary to fight to reduce emissions of the diesel-induced pollutant. Ethanol is providing the notable potential to reduce particulate emissions in diesel engines since ethanol has lower carbon content than diesel fuel and it is oxygenated. In the present study, the effects of ethanol fumigation on engine performance and combustion characteristics and pollution emissions were investigated experimentally at eleven different engine speed in a turbocharged three-cylinder tractor diesel engine. The injector placed for spraying on the intake manifold was controlled by the ECU board developed as Arduino-based and the engine was driven with dual fuel. It was detected that cylinder gas pressure increased at the beginning of the combustion process and decreased during the last phase of combustion. The experimental results of the engine performance indicated for the ethanol fuel are higher than that of diesel fuel. HC emissions have declined considerably, and NOx emissions have decreased compared to diesel fuel at high speed.

To prevent over emission & global warming (prevent also greenhouse generation & pollution) through vehicles with powered engine and we talk specially diesel engine with multi-cylinder system (such as more than one cylinder system) or four stroke multi-cylinder .In diesel engine high performance than petrol engine due heavy transportation purpose and heavy league system for long distance traveling and high revenue generation on it. In diesel engine with multi-cylinder system, problems are vapour lock, knocking of fuel, proper atomization, scavenge and need high performance etc. If such problems have to remove so that engine efficiency will improve that's what vehicle powered with engine may run smoothly with low emission and high fuel efficiency and low cost. Due to that reason will search for blend for diesel fuel; so we looked for methanol, petrol and karanja oil as blend of diesel fuel as proper proportion is required engine point of view. Here main blend is Karanja oil as abstracts from vegetable oil as non-edible. The mixing of petrol and methanol is to reduce viscosity with karanja oil. So mainly karanja oil is mixing with diesel fuel but to reduce viscosity level as vegetable oil to use as fuel mixing with methanol and petrol by process of distillation or new technique of chemical process. The aim is to do experimental analysis for performance of a diesel engine fuel with blend of karanja oil ;as composition of 2.0 vol%, 6.0 vol%, 8.0 vol% and 12 vol% blends with methanol , petrol and to improve it chemical behavior so that both the agents taken as equally proportions in karanja oil make as fuel. Therefore we see improve in calorific value for high performance of methanol, petrol and karanja oil blend of diesel engine. We see in result of better engine performance as in term of Indicated power more efficient as earlier as 10% of engine performance so improved in brake power that's what engine get excellent efficiency as in Mechanical, volumetric and thermal.