The effect of degrading agents and diluents on oil recovery from lithium based waste lubricating grease
- Authors: Diphare, Motshumi J. , Pilusa, Jefrey , Muzenda, Edison
- Date: 2013
- Subjects: Oil recovery , Waste lubricating grease , Waste lithium based lubricating grease
- Type: Article
- Identifier: uj:4931 , http://hdl.handle.net/10210/13031
- Description: In this study, the recovery of base oils from waste lithium based lubricating grease was investigated using a novel combination of thermal degradation in an aqueous caustic solution and solvent extraction. Lubricating grease is an important resource that cannot be disposed of randomly due to the presence of pollutants. In response to economic challenges and environmental protection, there is a growing trend to regenerate and reuse waste lubricant. Waste grease was initially dissolved in a 20 w/w% KOH solution at 80oC while being agitated for a period of 15 min. Two distinct layers were observed after 10 min of settling time. The top layer being of dark brown oil and the bottom layer was a heterogeneous mixture. The two layers were separated by decantation. The bottom layer was cooled to 45oC followed by slow addition of n-hexane while agitating to prevent the settling of solids. Two distinct layers were also formed, the top homogeneous mixture of light brown oil–toluene mixture and the bottom sludge layer. This research has further optimized the process by studying the effect of KOH concentration to enhance flocculation and recovery of oil. Oil recovery increased from 5% to 30%. The recovery also increased with an increase of solvent-togrease ratio up to 1:6. A solvent recovery of 82.6% to 88% by mass was obtained through fractional distillation. The overall oil recovery from waste grease using the combined extraction processes was 75 w/w% .
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A review of waste lubricating grease management
- Authors: Diphare, Motshumi J. , Pilusa, Jefrey , Muzenda, Edison , Mollagee, Mansoor
- Date: 2014
- Subjects: Waste lubricating grease , Waste management
- Type: Article
- Identifier: uj:4930 , http://hdl.handle.net/10210/13030
- Description: This paper reviews the handling, disposal, treatment of waste lubricating grease as well as its environmental impact. Lubricants require careful disposal as they contain pollutants. In response to economic considerations and environmental protection, there is a growing trend of regeneration and reuse of waste lubricants. Accordingly, this work provides an overview on various ways of handling, disposal, treatment of waste grease and its associated environmental impacts. In addition to the fact that petroleum and crude oil are not inexhaustible resources, waste products from these resources present a hazard to human health and the environment. As such, proper management of waste lubricants is necessary to prevent the adverse environmental impacts. Efficient recycling of waste lubricants could help reduce environmental pollution.
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