Abstract: The qualitative and quantitative analysis and IR characterization were conducted for scales in several parts of the continuous catalytic reforming unit. The reason of scaling and its influence on the unit were analyzed. The scale analysis showed that the samples at the top of the pre-hydrogenation reactor composed of corrosion products and coke, while the deposits at the steam turbine were mainly carbon deposition and impurity in steam. Samples contained metals including Fe (69.78%), Ni (19.16%), Cu (4.67%) and Ca (4.18%). Corrosion products and ammonium chloride were the major constituents in the separation tank of reforming products and the outlet tank of membrane separation compressor. After the overhaul of the device, the water injection operation in the pre-hydrogenation reaction section was resumed to remove the ammonium chloride in the system to prevent ammonium salt from separating out and blocking the pipeline. A new liquid-phase dechlorination tank is added, and a set of dechlorinating agent with excellent performance is added to control the chlorine content in the system and slow down the trend of salt deposition.

Key words: Continuous Catalytic Reforming Unit, scale, corrosion, ammonium chloride