No abstract

With the extensive use of internal combustion engines, the large volume of lubricant consumption has become an urgent problem. In this study, a new adsorbent of modified sawdust (MS) was used to clean the waste diesel engine lubricant and prepared into a pure biomass oil filter (PBF) for the actual operation of buses. The characterization results of sawdust showed that the crystallinity index of MS enhanced 19.26%, and MS had smoother morphology, obvious pores than raw sawdust (RS). In on‐road tests, both total acid number (1 mg KOH·g−1) and total base number (9 mg KOH·g−1) were within the permitted range of the standard, and the kinematic viscosity showed a decreasing trend. In addition, the concentration of metals and insoluble colloids (<0.2%) in the lubricant was far below the oil change limit, which made the oil drain interval of the two vehicles extended from 15 000 km (recommended by manufacture) to 60 500 and 71 500 km, respectively. Conclusively, it is believed that PBF is efficient to alleviate lubricant deterioration and prolong the oil drain interval.