In one of our FCCU’s we have an automatic pneumatic fresh catalyst injector to load the catalyst from the catalyst tank to the regenerator. Some weeks ago we start having problems with the fresh cat injection. After inspection of the pneumatic injector, we could see that a very hard deposit on catalyst in the injector valve. We found some other catalyst agglomerates in the tank. We believe it could be formed due to a leak in a steam line in the fresh catalyst vessel.
After several weeks and trials we have not achieved to run again with the pneumatic injector and we must load the catalyst manually, straight from the tank, through the by-pass line of the pneumatic injector. After a very exhaustive inspection, everything seems to be OK mechanically in the all the system (vessels, pipes, etc). The catalysts deposits in the tank have disappeared. We are also having several fluidization problems in the loading pipe to the regenerator, either using the pneumatic or the manual loading.
Have anyone experienced similar problems? Could the properties of the fresh catalyst be related with the problem (losses on ignition, humidity, attrition, PSD)?
Could also a high catalyst level in the regenerator have some effect?