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.