Waste lubricant

There are many companies offering a collection service for the disposal of waste lubricating oil. The three main methods employed are ... 

M. L. Whismann, J. W. Goetzinger, and F. O. Cotton, Waste Lubricating Oil Research, Bardesville Energy Research Center, Bardesville, Okla., 1974—1977. 

T. Kuokkanen, P. Peramaki, 1. Valimaki and H. Ronkkomaki, Determination of heavy metals in waste lubricating oils by inductively coupled plasma-optical emission spectrometry, Int. J. Environ. Anal. Chem., 81(2), 2001, 89-100. 

Higgins, RJ., B.A. Bishop and RL. Goldsmith, 1994, Reclamation of waste lubricating oil using ceramic membranes, presented at 3rd Int. Conf. Inorg. Membr., Worcester, MA,USA. 

In terms of the lubricant, (i) is largely a matter for the equipment designer and builder. The specialist lubricant company is affected by (iii) and can affect (ii). The collection and treatment of waste lubricants will now be described and followed by consideration of the environmental impact of lubricants. Einally, the results of recent research into the impact of lost or consumed automotive engine oils will be described. 

The EU legislation, as The Waste Oil Directive [4], requires that the use of collected waste lubricants should be reclaimed as the major priority, rather than be burned as fuel. The withdrawal of the 40/tonne subsidy changed the emphasis towards reclamation and recycling. With modern reclamation plants and a shortage of base stocks as crude oil and fuel prices continue their inexorable rise due to increasing demands this requirement continues to meet commercial demands. There is however a strong possibility that the Waste Oil Directive may be repealed, and the choice of whether to reclaim the oil is expected to revert to individual... 

Complex processes are required to deal with the wide range of contaminants and additives present in waste lubricants from multiple sources. The objective is to recycle waste lubricants to produce base oils that can then be used as substitutes or alternatives to virgin mineral base oils. The main re-refining processes are summarised in the sub-sections below most are continuous rather than batch processes and rely on receiving a reasonably homogenous used lubricant feedstock if the products are to be consistent. 

Environmental Considerations of Waste Lubricant 15.6.1 Disposal of Waste Lubricant as a Fuel... 

Of the three basic methods of disposal of used lubricants, the most efficient in terms of energy conservation, in that it displaces an equivalent amount of oil, is the use of the material as a fuel or a fuel supplement. In heating processes where the fuel is supplied through a burner, some limited pre-treatment of the waste lubricants and blending with conventional fuels is necessary. 

One of the most satisfactory uses of waste lubricants is as a fuel extender in cement production, subject to control over metal content. The advantages of this disposal route are the low-cost, or free, calorific value of the waste as a fuel to the cement manufacturer and the wastes which might otherwise be vented to the atmosphere with the flue gases are retained within the cement product with no adverse environmental consequences. There are, of course, limits to the cement production capacity which can use this waste as a fuel, particularly as cement kilns are seen as the ideal disposal route for other hazardous wastes such as contaminated solvents. The capacity of cement plants to dispose of combustible wastes is also dependent upon the level of demand for cement, which reduces when the building industry is in recession. 

Disposal of waste lubricant classified as a hazardous waste requires that it is burned in a suitably authorised incinerator at high temperatures to complete oxidation of the PAHs, PCBs and PCT (polychlorinated terphenyls). The expense of this disposal... 

The environmental degradation of lubricating oils is less easily demonstrated. One of the problems is the complex and varied nature of the used material. Materials other than hydrocarbons can inhibit or influence the rate of degradation, which is of greatest interest. Once released into the environment, there is a finite time before the waste lubricant is bound up in sediments or soils. Once there, due to the hydrophobic nature of the material, water is excluded and conditions are essentially anoxic. Anaerobic degradation of oils does not readily occur in nature - much to the relief of the oil exploration and refining industry. However, waste lubricant on the road or in soil or sediments is not locked in place in the same way as crude oil in rock formations. Heavy rain can wash surfaces, churn up river beds and release sediments, whilst the action of animals and plant can oxygenate soils. One means of... 

Huggins FE, Zhao J, Huffman GP, Kuo C-H, Tarter AR (1996) Investigation of zinc additives in coliquefaction of waste lubricating oil and a bituminous coal. J Environ Sci Health, Part A Environ Sci Eng Toxic Hazard Subst Control A31 1755-1766... 

The other major sources of metals in waste lubricants are those resulting from wear or use. The disposal of waste lube oils has been recognized as a potential pollution problem for many years. However, not until 1966 was the first attempt made to bring the problem into focus service stations throughout the United States were surveyed to determine how they disposed of their waste automotive oils. The results of that survey led to a better awareness of the pollution potential of used lubricants and to the eventual formation of an American Petroleum Institute Task Force on Used Oil Disposal. 

Only one comprehensive study of waste lubricant disposal has apparently been done. This study, by Arthur D. Little, Inc., showed the ultimate fate of used automobile oil in the State of Massachusetts (Table 7.9). 

If waste-lubricant disposal is subdivided into two general categories—dumping and reprocessing—it appears that as much as three-fourths of the nation s used automotive oils may be disposed of by dumping. 

Table 7.10 shows the typical metal content of used automobile engine oil. On the basis of an estimate of 1.1 billion gallons of lubricant used for this purpose, we have calculated the quantity of metals entering the environment from waste automotive oil. The 29,000 tons of lead calculated to be found in waste lubricants amounts to only 10% of the lead added to gasoline each year. ... 

Higgins, R., Bishop, B., and Goldsmith, R. (1993). Reclamation of waste lubricating oil using ceramic membranes, Proceedings of Third International Conference on Inorganic Membranes, pp. 447-456. 

Waste lubricating oils from vehicles can be processed to produce an acceptable recycled lubricating oil. Normally, this involves distillation and vacuum distillation to remove water and lighter hydrocarbon impurities, leaving some heavy residue that can be burned, purification by treatment with solvents such as methylethyl ketone, and hydrotreatment with H2 to eliminate unsaturated hydrocarbons and compounds containing O, N, or S. 

Solids other an activated carbon can be used for sorption of contaminants from liquid wastes. These include synthetic resins composed of organic polymers and mineral substances. Of the latter, clay is employed to remove impurities from waste lubricating oils in some oil recycling processes. 

Other synthetic waste oils such as waste lubrication oil or tire pyrolysis oil, as well as bio-based municipal waste, olive mill, or kapok waste oils, have also been proposed for biofuel production (Yadav et al., 2015). 

---