Abstract:

To solve the ammonium salt deposition and corrosion problems caused by Cl- in high pressure heat exchanger of hydrogenation unit, the source of chloride and the causes of corrosion were investigated. Based on the analysis, a series of measures was adopted: (i) adding intermediate feed tank to reduce water content in feed, (ii) increasing system pressure, (iii) increasing circulating hydrogen flow, (iv) raising the outlet temperature of heat exchanger E2101B, (v) increasing the water injection amount before heat exchanger E2101A/B, and (vi) reducing the total amount of injection water to the design range. After the complementation of the measures, the problems were effectively controlled, and the energy consumption of hydrogenation unit reduces from 596.87 MJ/t to 451.44 MJ/t.

Key words: hydrogenation unit, high pressure heat exchanger, ammonium chloride, corrosion, anti-corrosion measure