Patent name: METHOD FOR ALKYLATION OF C4-C5 ISO-PARAFINS WITH C3-C5 OLEFINS
Patent Number: Patent No. 2111201
Priority: October 07, 1994
May 20, 1998
In a method of sulfuric acid alkylation, in order to considerably increase selectivity of alkylation, lower sulfuric acid uptake, and eliminate induction period, composition of catalyst is changed by adding 5-30 wt.% of alifatic C1-C3-nitroalkane. Process is conducted in flow reactor under following conditions: temperature range 0 to 10 °C, pressure ensuring liquid state of reactants, catalyst to hydrocarbons ratio about 1: 1, and olefin space velocity 0.2-0.3 hr-1. For indicated temperature and concentration ranges, solubility of isobutane in catalyst ranges from 0.5 to 1.5 wt.%, i.e. 10-25-fold higher than in concentrated sulfuric acid. In this case, weight part of trimethylpentanes (most valuable component) in alkylate increases by a factor of 1.2 to 1.5 and hence octane number increases by 4-5 points. Simultaneously, duration of induction period of sulfuric acid development reduces by 50-100 times, and acid-hydrocarbon emulsion formed in reactor immediately and completely segregates. Sulfuric acid consumption to produce ton of alkylate is reduced by 30-40%. Invention can be used at petrochemical plants.