Petroleum alkylation

The reduction ia tetraethyl lead for gasoline production is expected to iacrease the demand for petroleum alkylate both ia the U.S. and abroad. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used. However, concerns over the safety or potential regulation of hydrofluoric acid seem likely to convince more refiners to use the sulfuric acid process for future alkylate capacity. 

The primar> uses for hydrogen fluoride in the United States arc in the manufacture of chlorofluorocarbons, aluminum fluoride, sodium aluminum fluoride (ciyolitc). md uranium tetrafluoride, and in petroleum alkylation. 

Sulphuric acid is the largest volume chemical in the world with an annual production of about 180 mill, t/year which is used primarily for phosphate fertilizers, petroleum alkylation, copper ore leaching and in smaller quantities for a number of other purposes (pulp and paper, other acids, aluminium, titanium dioxide, plastics, synthetic fibres, dyestuffs, sulphonation etc.). The major sulphur sources for sulphuric acid production are sulphur recovered from hydrocarbon processing in the refineries and from desulphurisation of natural gas, SO2 from metallurgical smelter operations, spent alkylation acid, and to a minor extent mined elemental sulphur and pyrites. A simplified flow sheet of a modem double-absorption plant for sulphuric acid production from sulphur is shown in Fig. 1. 

Uses are for fluorocarbons (66%), alumina (14%), petroleum alkylation catalysis (4%), stainless steel pickling (4%), and uranium chemical production (2%). 

Hydrofluoric acid is used for manufacture of fluorocarbons, including fluoropolymers, chlorofluorocarbons chemical intermediates including fluoroborates, surfactants, herbicides, and electronic chemicals aqueous hydrofluoric acid petroleum alkylation and uranium processing. 

Anhydrous hydrogen fluoride and sulfuric acid are the two most common catalysts used by refineries in petroleum alkylation processes to produce a very high octane and low volatility gasoline. 

Distillates (petroleum), alkylate. See Petroleum distillates, alkylate... 

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