Abstract: Based on the analysis of the first cycle operation of a SINOALKY sulfuric acid alkylation unit, some problems affecting the smooth operation of the plant were found. The problem of unstable pressure difference in the vaporizing section was eliminated by optimizing the packing for acid-hydrocarbon coalescence separation in the self-vaporizing acid-hydrocarbon separation tank. The acid carrying capacity of circulating hydrocarbon was greatly reduced by raising the position of the hydrocarbon extraction outlet of the self-vaporized acid hydrocarbon separation tank and increasing coarse packing, and the load of acid recovery pump was further reduced. The vibration of the acid circulating pump was effectively alleviated by adding the vortex breaker at the bottom of the self-vaporizing acid-hydrocarbon separation tank. By optimizing the heat exchange process to recover the heat of by-product condensed water, the 1.0 MPa steam consumption of the deisobutanizer was reduced by 1.5 t/h, and the circulating water consumption was reduced by 200 t/h. Through the process modification, the sulfur-containing gas in the fractionation unit was recovered for alkali washing treatment, which effectively eliminated the corrosion risk. By adding 1.0 MPa steam outlet pressure control valve, the steam pressure could be controlled smoothly, and the anti-interference ability of the device could be improved. By optimizing the regeneration process of the pre-hydrogenation catalyst, the online regeneration of the pre-hydrogenation catalyst could be ensured, and the long-term operation capacity of the unit could be improved.

Key words: alkylation, self-vaporizing acid-hydrocarbon separation tank, sulfuric acid