Combustion effect of jatropha producer gas fumigation in a stationary diesel genset


Monorom Rith

Date of Publication


Document Type

Master's Thesis

Degree Name

Master of Science in Mechanical Engineering


Gokongwei College of Engineering


Mechanical Engineering

Thesis Adviser

Jose Bienvenido Manuel M. Biona
Horizon Walker Gitano-Briggs
Masahiro ShiojI
Sambo Sar

Defense Panel Chair

Archie Maglaya

Defense Panel Member

Laurence A. Gan Lim
Neil Stephen Angosta Lopez


Jatropha has been considered as a promising energy crop because its oil content can be converted into biodiesel. However, the net energy ratio of Jatropha-based biodiesel production is low (1.40-1.85) for a number of years. Using gasification technology to convert the Jatropha seed into producer gas is another pathway. In this present work, the gas was inducted into a stationary diesel genset to partially replace diesel. The main objective of this study is to technically investigate the feasibility of gasified Jatropha seed to run the genset on dual fuel mode. The engine performance, combustion characteristics, exhaust emission, ANOVA analysis, and net energy analysis were included. The engine speed remained constant (3,000rpm).

Gas flow rate with 20kg/h could replace diesel up to 48% when the genset was operated at 2kWe load. However, the efficiency was considerably reduced from 20% on neat diesel mode to 7.5% on dual fuel mode. Also, it was found that the flue gases (HC, CO, CO2, and NOX) significantly increased for dual fuelling as compared to neat diesel fuelling for the corresponding operations. Poor and unstable combustion was observed when the engine ran on dual fuel mode, especially at 1kWeh load. The highest peak pressure for diesel alone and dual fuel mode were 57bar at about 7 ATDC (after top dead center), and 49bar at about 14 ATDC respectively at 2kWe load. Furthermore, the second peak pressure was seen for gas-diesel dual fuel mode operation. When the engine was operated at 2kWe, roughly 10J/CA higher NHRR for dual fuelling was obtained as compared with neat fossil diesel mode in other words, the maximum NHRR occurred slightly later for dual fuelling.

For the ANOVA analysis, three factors (injection timing, gas flow rate, and engine load) were pre-determined. Advanced injection timing, 2kWeh load operation, and gas flow rate range from 10 to 15kg/h were the best optimum for the diesel genset to run on producer gas-diesel dual fuel mode. The net energy analysis of Jatropha seed producer gas production was conducted for initial five years from one hectare iv plantation. The respective net energy balance and net energy ratio were calculated 38.57GJ and 1.91. However, these values are expected to be higher than 73.65GJ for NEB and 11.64 for NER for the next five years.

Abstract Format






Accession Number


Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall

Physical Description

computer optical disc.

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