Valorization of waste vegetable oil-based blend fuels as sustainable diesel replacement: comparison between blending with diesel versus kerosene

A valorization strategy of waste vegetable oil (WVO) as an alternative fraction in blend fuels is proposed in this study. The effect of blending WVO with diesel and kerosene is investigated by formulating three blends comprising of 0.20, 0.35, and 0.50 fraction as WVO. Upon characterization, the blend fuels are found to be within the standards for diesel, except for the viscosity of fraction containing diesel-WVO (D-WVO) blend. The kerosene-WVO (K-WVO) blends demonstrated fuel properties close to diesel. K-WVO blends showed better engine performance, with lower fuel consumption and elevated thermal efficiency relative to diesel. Lower density and viscosity, higher calorific value and superior volatility of kerosene is the probable reason. K-WVO blends resulted in lower CO, but higher HC emissions than diesel and D-WVO. However, a slight rise in NOx, particulate matter and soot emissions were observed with the addition of WVO in diesel and kerosene. Blending WVO with fossil fuels has reduced the overall price of the fuel. The engine running cost of K-WVO blends recorded a 52-61% reduction as compared to similar D-WVO blends. Also, the potential environmental impacts associated with WVO blends are much lower compared to pure diesel. Moreover, the K-WVO_0.50 blend showed maximized reduction in PEIs as compared to its diesel counterpart. Thus, the direct blending of WVO as an alternative fraction in fossil fuels can be considered as an economic and superior route for valorizing a common liquid waste.

Automated summary

This study proposes a valorization strategy of blending waste vegetable oil (WVO) with diesel and kerosene as an alternative fraction in blend fuels. The blend fuels showed good performance and lower environmental impacts compared to pure diesel. Blending WVO with kerosene resulted in improved engine performance and reduced overall fuel price.