Performance and emission evaluation of pure biodiesel from non-edible feedstock and waste oil in a diesel engine

Abstract

Biodiesel prepared from Jatropha, Moringa and restaurant waste oil were evaluated in a 3.5 kw diesel engine to determine their performance and pollutant emission. The brake specific (BS) emissions across the full load spectrum were benchmarked against the United States Environmental Protection Agency (US, EPA) and the European Union (EU) emission caps. Results showed that the brake specific fuel consumption (BSFC) and brake thermal efficiencies gave marginal differences between conventional diesel fuel (ndiesel) and the biodiesel fuel samples (±4% and ±5 respectively at peak load). Carbon monoxide (CO), unburnt hydrocarbon (UHC) and particulate matter (PM) emissions (in parts per million) showed a decreasing trend with load increase and were lower than those of ndiesel fuel samples. Oxides of nitrogen (NO_X) emission for the biodiesel were observed to be lower than those of ndiesel. This was because the 1650 k peak temperature to activate thermal NO_X was sparingly breached for the biodiesels. BSHC for all fuel types failed the EPA as well as the EU emission caps under all loading conditions. All tested fuel samples met the regulatory standards at load conditions exceeding 65%. Brake specific particulate matter (BSPM) for all fuel type fell short of the EPA and EU standard, except those of waste oil and jatropha biodiesel, with BSPM below the EU upper limit of 0.85 g/Kwh.

Keywords:

• pure biodiesel
• performance
• brake specific emission
• EPA & EU standard
• zeldovich mechanism

ORCiD

E. I. Onuh http://orcid.org/0000-0002-3891-222X

Additional information

Funding

This work was supported by the University of KwaZulu-Natal.