An integration recycling process for cascade utilization of waste engine oil by distillation and microwave-assisted pyrolysis

The feasibility of integrated recycling process by vacuum distillation (VD) and microwave-assisted pyrolysis (MAP) is demonstrated. This study also extends existing findings on the effects of pyrolysis process conditions (absorbents spatial distribution, final temperature, and nitrogen flow rate) on the yield and composition of the pyrolysis products. Cascade utilization of waste engine oil (WEO) produced a 72 wt% yield of re-refined engine oil (REO) and a 26 wt% yield of pyrolysis products. Almost the whole WEO was converted into valuable products after integrated recycling process, thus enhanced the production value as well as avoiding the secondary pollution. The oil product showed significantly high recovery (94.848%) of the energy present in WEO. With the comparison of various traditional methods, this integrated process shows a significant enhancement in the aspects of environmental and tech-economical performances. The results indicate that the integrated process shows exceptional promise as a means for recycling and treating WEO.