Properties and effects of organic additives on performance and emission characteristics of diesel engine: a comprehensive review

Fast depletion of conventional automobile fuels and environmental pollution due to exhaust emission are the issues of great importance. Improvement in engine performance and emission control is quite difficult to handle simultaneously. The fuel properties can be improved substantially by incorporation of additives in different proportions to get better emission standard without deteriorating the engine performance. The aim of current study is to review/summarize the effects of various organic additives on the engine performance (i.e., brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, etc.) and emissions (i.e., carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, particulate matter, and other harmful compounds). The physico-chemical and combustion properties (i.e., density, latent heat, dynamic viscosity, flash point, boiling point, cetane number, oxygen content, lower heating value, auto-ignition temperature, etc.) of various additives were also discussed to check the suitability of additives with diesel. Finally, limitations and opportunities using organic additives with respect to engine performance and combustion were discussed to guide future research and improvement in this field.