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Increased environmental awareness and depletion of resources are driving industry to develop alternative fuels that are environmentally more acceptable. Fatty acids esters (biodiesel) are known to be good alternative fuels. Due to economic reasons, the use of cheap raw materials for biodiesel production is preferred. In this case, ricebran oil, non-edible grade is used. Base catalyzed transesterification of ricebran oil is investigated and process parameters for ricebran biodiesel production are optimized. Various properties like viscosity, density, flash point, calorific value of biodiesel thus prepared are characterized as per ASTM D6751 and found comparable to mineral diesel. Steady state engine dynamometer test at 1800 rpm has been carried out to evaluate the performance and emission characteristics of a medium duty transportation DI diesel engine. Emission tests with all the fuel blends have also been carried out using European 13 MODE test (ECE R49).

Petroleum products are used to power internal combustion engines (ICEs). Emissions and depletion of petroleum reserves are important questions that need to be answered to ensure existence of ICEs. Indian Railways (IR) operates diesel locomotives, which emit large volume of pollutants into the environment. IR is looking for an alternative to diesel for powering the Locomotives. Methanol has emerged as a replacement for petroleum fuels because it can be produced from renewable resources as well as from non-renewable resources in large quantities on a commercially viable scale. It has similar/superior physico-chemical properties, which reduce tailpipe emissions significantly. It is therefore necessary to understand the in-cylinder phenomenon in methanol fueled engines before its implementation on a large-scale.

The homogeneous charge compression ignition (HCCI) combustion process is capable of providing both high ‘diesel-like’ efficiencies and very low NOx and particulate emissions. However, among several technical challenges, controlling the combustion phasing, particularly during transients is a major issue, which must be resolved to exploit its commercial applications. This study is focused on the experimental investigations of behavior of combustion timing and other combustion parameters during startup and load transients. The study is conducted on a gasoline fuelled HCCI engine by varying intake air temperature and air-fuel ratio at different engine speeds. Port fuel injection technique is used for preparing homogeneous mixture of gasoline and air. For fueling startup transient test, fuel injection was turned off, and the engine was motored for several minutes until the fire-deck, intake and exhaust temperatures stabilized.

Due to the increasingly stricter emission legislations and growing demand for lower fuel consumption, there have been significant efforts to improve combustion efficiency, while satisfying the emission requirements. Homogenous Charge Compression Ignition (HCCI) combustion offers significant efficiency improvements compared to conventional gasoline engines. However, due to the nature of HCCI, fully homogeneous charge HCCI combustion can be realized only in a limited operating range. Control of HCCI engines to obtain the desirable operation requires understanding of how different charge variables influence the cyclic variations in HCCI combustion. Under certain operating conditions, HCCI engines exhibit large cyclic variations in ignition timing. Cyclic variability ranging from stochastic to deterministic patterns can be observed. One important design goal for engine development is to minimize cyclic variability.

The Homogeneous charge compression ignition (HCCI) is the third alternative for the combustion in the reciprocating engine. HCCI a hybrid of well-known spark ignition (SI) and compression ignition (CI) engine concepts and has potential of combining the best features of both. A two cylinder, four stroke, direct injection diesel engine was modified to operate one cylinder on the compression ignition by detonation of homogeneous mixture of ethanol and air. The homogeneous mixture of the charge is prepared by port injection of ethanol in the preheated Intake air. This study presents results of experimental investigations of HCCI combustion of ethanol at intake air temperature of 120°C and at different air-fuel ratios. In this paper, the combustion parameters, pressure time history, rate of pressure rise, rate of heat release, mean temperature history in the combustion chamber is analyzed and discussed.