Q & A > Question Details
We have a fixed bed reformer. During the last two regenerations of the catalyst, the vibrations of our recycle compressor have increased. is it possible that it is related to the fact that the catalyst has been regenerated more times than recommended by UOP?
16/03/2021 A: Peter Marsh, XBP Refining Consultants Ltd, peter.marsh@xbprefining.co.uk
Chloride retention reduces as the catalyst ages. Consequently, if organic nitrogen is present in the reformer feed, there may be increased ammonium chloride (NH4Cl) salt deposition at the cold end of the reactor effluent system (including in the demister of the recycle gas compressor suction drum) during the operating cycle. NH4Cl salts are hygroscopic and become corrosive when wetted with water. Damage to the demister combined with an increased tendency for the circulating soda ash solution used during regeneration to start foaming if it contains a relatively high concentration of corrosion product solids may result in increased liquid droplet carryover to the compressor and hence an increase in vibrations. Injecting an antifoam agent into the circulating soda ash solution may help control this. If you are carrying out maintenance on the compressor during the regen outage, you could analyse any fouling deposits found in the machine for presence of sodium chloride to prove or eliminate this possibility.