Johnson Matthey - Johnson Matthey Process Technologies
The Fluid Catalytic Cracking Unit has a long history of changing and adapting to new market conditions and environmental regulations. The FCCU was originally designed to convert low-value feedstocks into gasoline and other blending components; however, demand for propylene and diesel has caused process licensors to adopt the FCC process to satisfy the demand of such products.
Through hardware innovation and advances in catalyst technology, the FCCU has now been turned into a “Flexible” Catalytic Cracking Unit capable of handling almost any set of market conditions. Traditionally, FCCU’s were equipped with just one catalyst addition system. More recently, most new FCCU’s have been equipped with two or more additional systems to allow yield targets or environmental constraints to be met using catalyst additives.
In an RFCC unit, catalyst management is more complex than in a traditional vacuum gas oil feed FCC. These units usually require a higher catalyst addition rates, normally of more than one catalyst, and more frequent catalyst withdrawals.
This paper will outline current best practices in all areas of catalyst handling for today’s’ RFCC unit. Examples will be given of the technology which allows refiners to:
- Receive, store and move sufficient quantities of purchased catalyst – especially at remote locations, where logistics can be very challenging.
- Precisely control additions of multiple catalysts and additives to the RFCC unit.
- Safely withdraw catalyst from the RFCC unit on a continuous basis.
- Handle the transportation and disposal of spent catalyst, after it has been withdrawn.
Examples will also be given of the process and operational benefits of using these technologies.