Abstract: The present situation of energy consumption of 0.20 Mt/a alkylation unit was introduced and the causes of high consumption of 1.0 MPa steam, circulating water and demineralized water were analyzed. Four measures were taken, such as cooling and decompressing operation in fractionators, stopping the acid, alkali and water washing process of reaction products, reduce anti-surge flow of refrigerating compressor, optimizing water service, resulting in reduction of 1.0 MPa steam consumption by 9 t/h, 3.5 MPa steam by 3 t/h, demineralized water by 7 t/h, electricity by 102.95 kW.h, and circulating wate by 340 t/h. According to the comprehensive calculation, comparing with the initial stage of operation, the energy consumption of unit reduced from 6 064.762 MJ/t to below 4 598 MJ/t. According to the actual situation of the unit, the measures, such as reusing of low temperature medium heat of process, and low temperature heat of condensate water, adding frequency conversion of machine pump, were put forward as the direction for further energy-saving of the unit.

Key words: SINOALKY sulfuric acid alkylation, energy consumption, optimization, measures