Performance, emission and combustion characteristics of liquid fuel produced through catalytic co-pyrolysis of waste LDPE and Pongamia pinnata seeds: An experimental investigation in CI engine

As there is an urgent need to address the global problem of increasing plastic waste and decreasing petroleum-based fuels, it is possible to convert waste plastic and unused biomass seeds into fuels that can be utilized in transportation sector. The current study deals with blending pure diesel (D100) with the liquid fuel (PB2) obtained from the co-pyrolysis of Pongamia pinnata seeds and waste low-density polyethylene (LDPE) with Calcium oxide (CaO) as the catalyst. Three blends of D100, namely, PB2@10 (with 10 % blend), PB2@20 (with 20 % blend) and PB2@30 (with 30 % blend) were tested for performance, emission and combustion in an unmodified CI engine for an analytical comparative analysis using standard methods. The results showed that the BSFC was almost same (0.3 kg/kWh) at higher loads for all three blends, while the BTE was found to be equal or increased compared to D100 in the range of 27-30 % at higher loads for higher blends. NOx formation was found to decrease by 19.4 % and 13 % at the highest load for PB2@30 andPB2@30. The smoke formation also decreased for all blends (maximum 22.5 %) while the maximum difference of lambda was determined to have decreased in comparison to D100, close to 1 at higher loads. The maximum cylinder pressure and temperature were also found to have increased during combustion by approximately 1 % for PB2@10 while that of PB2@20 and PB2@30 remained quite close to D100. The obtained renewable liquid fuel could certainly be utilized in blends with pure diesel for use in vehicles.