Process heaters and heat exchangers preheat feedstock in distillation towers and in refinery processes to reaction temperatures. Isomerization is important for the conversion of n-butane into isobutane, to provide additional feedstock for alkylation units, and the conversion of normal pentanes and hexanes into higher branched isomers for gasoline blending. Salt corrosion is caused by the hydrolysis of some metal chlorides to hydrogen chloride (HCl) and the subsequent formation of hydrochloric acid when crude is heated. Following shutdown, where water has been used the unit should be thoroughly dried before hydrofluoric acid is introduced.Leaks, spills, or releases involving hydrofluoric acid or hydrocarbons containing hydrofluoric acid can be extremely hazardous.
Remote sensors, control valves, isolation valves, and fire valves may be provided at tanks for pump-out or closure in the event of a fire in the tank, or in the tank dike or storage area. Special antifoam additives may be used to prevent catalyst poisoning from silicone carryover in the coker feedstock. Reactor The vessel in which chemical reactions take place during a chemical conversion type of process. Crude oils range in consistency from water to tar-like solids, and in color from clear to black. An «average» crude oil contains about 84% carbon, 14% hydrogen, 1%-3% sulfur, and less than 1% each of nitrogen, oxygen, metals, and salts. Washington, D.C.: American Petroleum Institute. __________. 1973. Industrial Hygiene Monitoring Manual for Petroleum Refineries and Selected Petrochemical Operations. Deasphalting Process of removing asphaltic materials from reduced crude using liquid propane to dissolve nonasphaltic compounds.
The catalyst section contains the reactor and regenerator, which, with the standpipe and riser, forms the catalyst circulation unit. When coke is moved as a slurry, oxygen depletion may occur within confined spaces such as storage silos, since wet carbon will adsorb oxygen. Cracking The breaking up of heavy molecular weight hydrocarbons into lighter hydrocarbon molecules by the application of heat and pressure, with or without the use of catalysts. The combustion of petroleum products containing sulfur compounds produces undesirables such as sulfuric acid and sulfur dioxide. Feedwater must be free of contaminants that could affect operations.