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.

中文翻译：

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改良纯生物质滤油器延长润滑油换油周期

随着内燃机的广泛使用，大量的润滑油消耗已成为亟待解决的问题。在这项研究中，一种新型的改性木屑 (MS) 吸附剂用于清洁废弃的柴油发动机润滑油，并制备成纯生物质滤油器 (PBF)，用于公交车的实际运行。锯末表征结果表明，MS的结晶度指数提高了19.26%，且MS的形态比生锯末(RS)更光滑，孔隙明显。在道路测试中，总酸值 (1 mg KOH·g ^-1 ) 和总碱值 (9 mg KOH·g ^-1)均在标准允许范围内，运动粘度呈下降趋势。此外，润滑油中金属和不溶性胶体（<0.2%）的浓度远低于换油限值，使得两款车的换油周期从15000公里（厂家推荐）延长至60500公里。分别为 71 500 公里。最后，相信 PBF 可有效减轻润滑油劣化并延长换油间隔。