Gasoline treating

Thiophene-type sulfur is found in cracked naphthas and is not removed in most gasoline-treating processes, except with very high losses in liquid yield. 

Consequently, an exploratory program was undertaken to see if this specification could be met by addition of a simple gasoline treating step. In a short time, a heavy gasoline treating (HGT) technology evolved. With the HGT, durene levels even higher than 5 wt% could be treated down to the 2% level. 

Garg BD, Olson MJ, Demyan WF, et al. 1988. Rapid postexposure decay of alpha 2pi-globulin and hyaline droplets in the kidneys of gasoline-treated male rats. J Toxicol Environ Health 24 145-160. 

In the solutizer or gasoline-treating processes, bubble plates have been... 

Natural Gas Upgrading via Fischer-Tropsch. In the United States, as in other countries, scarcities from World War II revived interest in the synthesis of fuel substances. A study of the economics of Fischer synthesis led to the conclusion that the large-scale production of gasoline from natural gas offered hope for commercial utiHty. In the Hydrocol process (Hydrocarbon Research, Inc.) natural gas was treated with high purity oxygen to produce the synthesis gas which was converted in fluidized beds of kon catalysts (42). 

A modem petroleum refinery is a complex system of chemical and physical operations. The cmde oil is first separated by distillahon into fractions such as gasoline, kerosene, and fuel oil. Some of the distillate fractions are converted to more valuable products by cracking, polymerization, or reforming. The products are treated to remove undesirable components, such as sulfur, and then blended to meet the final product specifications. A detailed analysis of the entire petroleum production process, including emissions and controls, is obviously well beyond the scope of this text. 

Depending upon the refinery needs, the raw C5 plus steam cracked naphtha may be sent to isoprene extraction, treated to remove gum forming diolefins and sent to the refinery gasoline pool, or else completely hydrogenated and then fed to an aromatics extraction unit. 

This term is used to describe oils that have a flash point above ambient temperature. They will therefore not burn or explode at ambient temperature but will do so when hot. Unfortunately many people do not realize this and treat heavy oils with a disrespect that they would never apply to gasoline, as shown by the incidents described below. Another incident was described in Section 12.2 (c). Heavy oils are widely used as fuel oils, solvents, lubricants, and heat transfer oils, as well as process materials. 

Cj s and C s include propane, propylene, normal butane, isobutane, and butylene. Propylene and butylene are used to make ethers and alkylate, which are blended to produce high-octane gasoline. Most gas plants also include treating facilities to remove sulfur from these products. 

The debutanized gasoline is cooled, first by supplying heat to the stripper reboiler or preheating the debutanizer feed. This is followed by a set of air or water coolers. A portion of the debutanizer bottoms is pumped back to the presaturator or to the primary absorber as lean oil. The balance is treated for sulfur and blended into the refinery gasoline pool. 

The mixture of caustic and disulfides is transferred to a settler. From the settler, the treated gasoline flows to a coalescer, sand filter, or wash water tower, before going to storage. The caustic solution is recirculated to the mixing vessel/fiber film contactor. 

Products from the reactor are recovered in the main fractionator a J the gas plant. The main fractionator recovers the heaviest produc, such as light cycle and decanted oil, from the gasoline and ligh r products. The gas plant separates the main fractionator overhead vap< s into gasoline, Cj s, C4 s and fuel gas. The products contain sulfur compounds and need to be treated prior to being used. A combination of amine and caustic solutions are employed to sweeten these products... 

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