Experimental studies on combustion, performance and emission characteristics of diesel engine using different biodiesel bio oil emulsions

Preliminary investigations on characterisation and utilisation of emulsions obtained from Wood pyrolysis oil (WPO) and Jatropha methyl ester (JME) revealed that up to 15% of WPO can be emulsified with the JME and used as a fuel in a DI diesel engine. From the experimental results in terms of emulsion stability, combustion, performance and emission parameters, the emulsion prepared from 81% by volume of JME, 15% by volume of WPO with the help of a mixed surfactant 4% by volume (Z2JOE15) was found to be a better emulsion for further investigation. However, it was found that the Z2JOE15 emulsion was acidic in nature, due to the addition of WPO. In this investigation, the acid quality of the Z2JOE15 emulsion was reduced by acid treatment, and the emulsion was denoted as ATJOE15. The acid treated emulsion was tested as a fuel in the same engine. The combustion, performance and emission behaviour of the diesel engine fuelled with the ATJOE15 in comparison with those of diesel and JME operations are presented in this paper. The results indicated that the higher brake thermal efficiencies in the order of 11.3% and 8.2% are noticed with the Z2JOE15 and ATJOE15 emulsions compared to that of diesel operation. The NO emissions are found to decrease with the addition of WPO in JME.