Petroleum recycling

Polymerization in Hquid monomer was pioneered by RexaH Dmg and Chemical and Phillips Petroleum (United States). In the RexaH process, Hquid propylene is polymerized in a stirred reactor to form a polymer slurry. This suspension is transferred to a cyclone to separate the polymer from gaseous monomer under atmospheric pressure. The gaseous monomer is then compressed, condensed, and recycled to the polymerizer (123). In the Phillips process, polymerization occurs in loop reactors, increasing the ratio of available heat-transfer surface to reactor volume (124). In both of these processes, high catalyst residues necessitate post-reactor treatment of the polymer. 

The distillation system is designed to recover a high purity cumene product. The unconverted benzene and polyisopropylbenzenes are separated and recycled to the reaction system. Propane ia the propyleae feed is recovered as fiquid petroleum gas (LPG). 

The term oil includes a variety of liquid or easily liquefiable, unctuous, combustible substances that are soluble in ether but not in water and that leave a greasy stain on paper and cloth. These substances can include animal, vegetable, and synthetic oils, but usually the word oil refers to a mineral oil produced from petroleum (qv). An oil that has been used or contaminated, or both, but not consumed, can often be recycled to regain a useful material, regardless of its origin. For the purposes of this article, only the recycling of used petroleum oils is considered. 

A significant source of concern for potential users of recycled petroleum products has been the lack of specifications or certifications related to the quaUty of the material and the consistency in producing oil of high quaUty. This perception of possible inferiority has been exacerbated by the reluctance of some equipment manufacturers to state whether they would honor warranties if recycled lubricants were used. 

The hterature is hiU of detailed evaluations of recycled petroleum products (2,6,17,18,23,28) and investigations into the environmental ramifications of the recycling processes themselves (30). 

In addition, specifications have been produced by such organizations as the Canadian General Standards Board (31) and Green Seal (32) further activities ate also occurring within the ASTM. The thmst of these actions is to requite the recycled petroleum products to meet the same requirements as placed on their virgin equivalent, as well as to demonstrate that contaminants have been reduced to insignificant levels. 

Based on the evidence that acceptable recycled petroleum products can be produced, there is a considerable legislative record encouraging the recycling of used oil. Starting with the Resource Conservation and Recovery Act in 1976 (20), used oil was held apart from the normal hazardous waste system because the oil was viewed as a valuable commodity. This was followed by the Used Oil Recycling Act in 1980 (33), which removed any federal requirement that lubricants containing re-refined base oil carry special labeling. 

The Federal Trade Commission has aimounced a rule, effective November 30, 1995, that sets test procedures and labeling standards for recycled oil used as engine lubricating oil (35). The test procedures used are those contained in the Engine Oil Licensing and Certification System of the American Petroleum Institute (API) (36). The rule states in effect that if recycled oils meet the requirements of the API Certification System, such oils ate substantially equivalent to new oil for use as engine oil. This federal rule preempts certain state recycled oil rules (35). 

Although 600 m of water is used to make a metric ton of fertilizer, 150—240 m to make a tonne of steel, 480 m to make a tonne of gasoline, and 1000 m to make a tonne of acetate fiber, Htde if any is required chemically in any of these processes. Recycling can reduce industrial requirements by a factor of 10—50. Much of this water, particularly that for cooling, and often that for washing, can be saline. Some petroleum refiners have used salt water to remove heat (water s principal role in gasoline production), and some have actually produced table salt by evaporation in cooling towers. 

A second route based on olefin disproportionation was developed by Phillips Petroleum (131). Here isobutylene reacts with propylene to form isoamylenes, which are dehydrogenated to isoprene. 2-Butene can be used in place of propylene since it also yields isoamylene and the coproduct propylene can be recycled. Use of mixed butylenes causes the formation of pentenes, giving piperjlene, which contaminates isoprene. 

The use of methane, ethane, ethylene, propylene, and propane pure light hydrocarbons as refrigerants is quite common, practical, and economical for many hydrocarbon processing plants. Examples include ethylene manufacture from cracking some feedstock, ethylene or other hydrocarbon recycle purification plants, gas-treating plants, and petroleum refineries. 

Figure 8-7. The Phillips Petroleum Co. process for producing 2-butene and ethylene from propylene (1) metathesis reactor, (2) fractionator (to separate propylene recycle from propane), (3, 4) fractionator for separating ethylene, butylenes, and Cg. ...

High Performance Polymers 13, No.2, June 2001, p.S365-71 SURFACTANTS BASED ON RECYCLED POLYETHYLENE TEREPHTHALATE FOR BREAKING WATER-IN-OIL EMULSIONS Abdel-Azim A-AA El-Sukkary M M A Egyptian Petroleum Researeh Institute... 

Polymer Recycling 3,No.3, 1997/98, p.173-80 UNSATURATED POLYESTER RESINS FROM POLY(ETHYLENE TEREPHTHALATE) WASTE SYNTHESIS AND CHARACTERISATION Abdel-Azim AA Mekewi M A Gouda S R Egyptian Petroleum Research Institute Ain Shams,University Egypt,Military Technical College... 

Techniques for the chemical recycling of plastics into monomers and petrochemical feedstocks are described, including chemical and thermal depolymerisation, pyrolytic liquefaction, pyrolytic gasification and partial oxidation. BRITISH PETROLEUM CO.PLC... 

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