The standard Johnson Matthey addition system consists of a storage vessel mounted on 3 load cells for continuous weight measurement. These load cells ensure the utmost accuracy of the system to allow the IMS controller to precisely regulate the catalyst or additive additions. The discharge line from the vessel to the FCC is equipped with a patented Everlasting valve, the only regularly moving part in the system. The Addition System also includes a Sintered Metal Filter for particulate emissions.
The INTERCAT Management System (IMS) controls the flow of the catalyst from the hopper to the FCC. The IMS is a self-contained, digital, electronic controller which controls and tracks the catalyst or additive loaded into the regenerator. The operator enters the amount of catalyst or additive to be added daily to the process as a set point. By reading the vessel load cell output directly, the IMS automatically adjusts the periods between fixed shot additions to control catalyst addition rates precisely to refinery requirements, automatically spreading the additions out over a full 24-hour period. The IMS has the ability to be controlled locally and can be interfaced with the plant's distributed control system (DCS). The DCS connection options include analog, digital and/or Modbus.
The hopper is mounted on three load cells. Any change in weight is detected by means of these load cells allowing the IMS to precisely monitor and control catalyst and additive additions.
The catalyst and additives flow through a patented control valve, the Everlasting Valve, located on the outlet of the vessel into the catalyst feed line. The Everlasting valve is the only moving part of the system in frequent contact with catalyst during normal operation. The everlasting valve is a main contributor to the high reliability of these systems.
To prevent any fines escaping during the refill process, the Johnson Matthey loader is fitted with a sintered metal filter (SMF). The filter element is a special alloy fiber compatible with high temperature and abrasive operation. As catalyst enters the hopper, it displaces air which exits via the filter unit before being discharged to the atmosphere. The filter cartridge media collects catalyst particulates preventing discharge to the atmosphere. The particulates build into a filter cake on the surface of the filter elements leading to increased filter element differential pressure. The SMF includes an air back pulse system that uses pulse jet air to release the filter cake from the SMF and it is controlled by the Intercat Management System.
These SMF's are also available for retrofitting to existing addition systems, and refinery main catalyst storage hoppers to eliminate dust emissions.