ABSTRACT
The present experiment deals with the study of the effect of addition of diethyl ether (DEE) on the performance and emission characteristics of a thermal-barrier-coated (TBC) engine run on papaw (Carica papaya) and eucalyptus oil blends. The fuels studied were test blends, CPME30Eu70 (papaw methyl ester 30% and eucalyptus oil 70%) and CPME30Eu70 + 10% DEE, and diesel. Optimum results were obtained for CPME30Eu70 with DEE in a TBC engine. The addition of DEE creates a lean mixture, and its low viscosity, high cetane number, and volatility improve the performance of biofuel-powered engines. The investigation shows that the addition of 10% DEE gives the best results in brake-specific energy consumption (BSEC), brake-specific fuel consumption (BSFC), and brake thermal efficiency (BTE). The BTE of the DEE-adapted CPME30Eu70 blend was 32.2%, whereas for diesel it was 31.8%, which was 1.2% higher than that of CPME30Eu70 at normal mode of operation. The addition of DEE to CPME30Eu70 reduced BSEC and BSFC by 8.9 and 7.2%, respectively, compared to a non-coated engine powered by CPME30Eu70. The combination of DEE and CPME30Eu70 nominally decreased nitrogen oxide emissions. The carbon monoxide and hydrocarbon emissions of CPME30Eu70 after DEE addition were 0.195% vol. and 38 ppm, respectively, which were 13.3 and 5.1% lower than those for CPME30Eu70 powered by a compression ignition engine. The experiment found that adding DEE to CPME30Eu70 could improve its atomization and spray characteristics. Moreover, the performance and emission characteristics of the CPME30Eu70-powered engine were enhanced.
