ABSTRACT
Biodiesels are mandatory due to the depletion of petroleum fuels and it also gives a relatively better performance and emissions except for NOx emission. The biodiesel-fuelled compression ignition (CI) engine reduces emissions of hydrocarbon (HC), carbon monoxide (CO) significantly. However, it increases the nitrogen oxides (NOx) emissions. It is the main concern in a diesel engine to meet stringent emission standards. The water injection (WI) and emulsification methods are considered as one of the cost-effective methods to reduce NOx emissions in CI engine. The emission characteristics of the diverse biodiesel–diesel blends have been summarised and discussed. NOx emissions can be reduced up to 37–50% by WI method in biodiesel engines. It is also observed that water–biodiesel emulsification reduces the NOx about 10–60% compared to conventional diesel. However, these technologies (WI and emulsification) reduce NOx and particulate matter emissions considerably but increases HC, CO emissions and increase specific fuel consumption.
Disclosure statement
No potential conflict of interest was reported by the authors.