Potential for re-refining of used lubricating oils for re-use using zinc dialkyl dithiosulphate as an additive

Mercy M. Manyuchi, T. Nengiwa, Charles Mbohwa, Edison Muzenda, M. Mpeta

Research output: Contribution to journalConference articlepeer-review

Abstract

Used lubricating oils generated from automotive and process industries pose environmental hazards if not properly managed. In this study, the potential to re-refine used lubricants for reuse was investigated. Used oil collected from a local garage was dehydrated at 240°C and varying pressure of 4-12bars under vacuum distillation. Solvent extraction was employed using Methyl Ethyl Ketone (MEK) as a solvent with varying ratios from 2:1 to 6:1 at a mixing temperature of 60°C. MEK and oils mixture underwent atmospheric distillation at 80 °C to allow separation of oils and MEK. During the re-refining process, the amount of water removed, ash content, sulphur content, viscosity, specific gravity, flash point and pour point were measured. Optimum oil yield of 94 (wt %) was achieved at a solvent to oil-ratio of 6:1. Re-refining of used oils resulted in a 73% reduction in sulphur content, 76% reduction in ash content and 64% water removal. The re-refined oil's viscosity of 90 cP, flash point of 160 °C, the specific gravity of 0.91 and pour point of -12°C. The re-refined used oils properties were almost similar to those of virgin oil using a combination of vacuum distillation and solvent extraction with an additive for maximum performance. Re-refined oils employing zinc dialkylProceedings of the International Conference on Industrial Engineering and Operations Management Pretoria / Johannesburg, South Africa, October 29 - November 1, 2018 dithiosulphate as an additive exhibited physicochemical characteristics similar to virgin lubricating oils and can be adopted for re-use.

Original languageEnglish
Pages (from-to)1357-1364
Number of pages8
JournalProceedings of the International Conference on Industrial Engineering and Operations Management
Volume2018
Issue numberNOV
Publication statusPublished - 2018
EventProceedings of the International Conference on Industrial Engineering and Operations Management Pretoria, IEOM 2018 -
Duration: Oct 29 2018Nov 1 2018

All Science Journal Classification (ASJC) codes

  • Strategy and Management
  • Management Science and Operations Research
  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering

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