Pyrolysis of waste lubricating oil/waste motor oil to generate high-grade fuel oil: A comprehensive review

The petroleum industry has developed rapidly since its inception and evolved into an irreplaceable society component, especially in the urban areas. Besides being a limited resource, lubricating oil generates waste oil, posing a threat to both human health and the environment. The sustainable management of waste lubricating oil (WLO) could be done by applying the pyrolysis technique to avoid its antagonistic impact on the ecology. Finding a robust design for WLO pyrolysis with a reliable range of operating paraments is challenging. Hence, the main objective of the review is to study the different parameters and reactor configurations affecting the sustainability of the pyrolysis of WLO to high-value fuels. For this study, many research articles from top-rated journals in scientific indexes, including recent publications, are reviewed. This article represents an extensive review of WLO pyrolysis, including (i) the reactor configuration, (ii) co-pyrolysis studies with other wastes, (iii) advantages of catalytic pyrolysis and (iv) the factors affecting the yield and productivity of pyro oil. The valuable byproduct produced can compensate for the energy obligation and increase the overall process's productivity. The mi-crowave pyrolysis oil was efficient in terms of the exergy analysis. However, the electric pyrolysis oil was more superior in terms of performance combustion and emission characteristics. It would be interesting to study the co-pyrolysis of the WLO process for a multi-component waste mixture rather than a binary blend. Yet more research is required to study the performance, combustion, and emission characteristics of pyro oil generated in both catalytic and non-catalytic pyrolysis processes to have a comparative analysis of the oil quality on the diesel engine.