Waste oils processing/ recycling

Consider the oil-recycling plant shown in Fig. 3.16. In this plant, two types of waste oil are handled gas oil and lube oil. The two streams are first deashed and demetallized. Next, atmospheric distillation is used to obtain light gases, gas oil, and a heavy product. The heavy product is distilled under vacuum to yield lube oil. Both the gas oil and the lube oil should be further processed to attain desired properties. The gas oil is steam stripped to remove light and sulfur impurities, then hydrotreated. The lube oil is dewaxed/deasphalted using solvent extraction followed by steam stripping. 

An account is given of the chemical recycling activities of BASF in a pilot plant at Ludwigshafen in Germany, where mixed plastics waste is processed to obtain hydrochloric acid, oil, gas, naphtha, aromatics and alpha-olefins. 

The average waste oil generation from the colorant and additive process is approximately 200gal (4 drums) per year per facility. This material is sent to a qualified recycling facility where it is blended into fuel for energy recovery. 

Mohammad Fabhat Ah, Ph.D., is Professor of Industrial and Petroleum Chemistry at King Fahd University of Petroleum Minerals in Saudi Arabia. An expert in characterization studies of heavy ends, residues, and asphalt, he is also knowledgeable about crude oils and products, refining process technology, waste oil recycling, and stabihty characteristics of jet fuels. 

A considerable number of reports regarding the formation of compounds that may represent a health hazard are related to the formation of polycyclic aromatic hydrocarbons (PAHs) during industrial pyrolysis processes (recycling of waste, incineration, etc.). This interest is particularly geared toward the study of polyolefins pyrolysis and synthetic and natural rubber pyrolysis. The formation of PAHs during polyethylene pyrolysis has been reported frequently in literature [6, 12] and is further discussed in Section 6.1. The formation of PAHs during tire pyrolysis is also of considerable concern. The concentrations of some components in the oils generated from the pyrolysis of used tires as a function of temperature are indicated in Table 5.3 1 [13]. 

This process will allow the recycling of solid waste to produce a useful product. High pressure and temperature combined with hydrogen can convert most types of domestic and industrial wastes back into products that are currently obtained from fossil coal and oil. No volatile polluting chemicals will be vented into the atmosphere. The metals can be recovered for further use and the ceramic materials will be converted into a product difficult to distinguish from natural rocks. This type of process will not solve all the solid waste disposal problems, but will provide a potential method for recovery of valuable products from waste. When implemented, it will dramatically reduce the amount of solid waste placed in landfills. This process also has the potential to reduce the amount of oil and coal mined to provide the carbon compounds needed to manufacture all petrochemical derived materials. This waste reduction process is a variation on the Fischer-Tropsch process, mentioned on page 101, in use commercially to produce hydrocarbon materials from coal. 

Flow diagram of the Fuji Recycle-Mohil Oil process for the conversion of plastic wastes by thermal-catalytic treatments. 

ASTM technical committees have pubhshed hundreds of standards about environmental safety. The aim of these efforts is to obtain cleaner air and water, eco-friendly homes and office buildings enhanced waste management and recycling programmes new innovations in oil spill response, and improved environmental assessment processes (Url-7). 

Equipment has been developed for the recycling of HDPE containers, waste oil and detergent bottles into saleable flakes at rates of 1000 to 5000 lbs per hour. The most used system is based on hydrocyclone separation, a process... 

The recycle of waste oils (as opposed to their treatment prior to disposal) is becoming an important process for the decanter, as the cost of all kinds of oils has started once again to rise. The recycling of plastics is of rapidly growing concern, and the double beach (one at each end) decanter is used to separate plastic granules into two fractions by density. 

Several wastes important to DOE are excluded from the RCRA definition of solid wastes (40 CFR 261.2). They include source, special nuclear, or byproduct material as defined by the AEA [Section 11(e), (z), (aa)] waste from extraction, beneficiation, and processing of ores and minerals, including overburden from mining uranium ores utility wastes oil and gas drilling muds and brines and some wastes that are reused or recycled. 

The recovery and recycling of waste solvents has some similarities to the recycling of waste oil and is also an important enterprise. Among the many solvents listed as hazardous wastes and recoverable from wastes are dichloromethane, tetra-chloroethylene, trichloroethylene, 1,1,1-trichloroethane, benzene, liquid alkanes, 2-nitropropane, methylisobutyl ketone, and cyclohexanone. For reasons of both economics and pollution control, many industrial processes that use solvents are equipped for solvent recycle. The basic scheme for solvent reclamation and reuse is shown in Figure 22.4. 

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