Technology

Process Summary

The CATOFIN^® technology is a unique process for the production of olefins, such as propylene (from propane) and iso-butylene (from iso-butane)^[1].

Reaction Section

Lummus CATOFIN Technology uses fixed-bed reactors and a Chromium-based catalyst^[2].

In the reaction and regeneration section fresh propane feed is mixed with recycled propane from a propylene-propane splitter. This stream goes to a de-oiler for impurities removal and then is carried to the reaction step, which is continuous and operates in cycles. In this step, multiple parallel reactors undergo a controlled sequence of reaction, catalyst reduction and catalyst regeneration^[2].

Recovery Section

In the product recovery section there is a low-temperature separation unit, the objective of which is to separate hydrogen and light byproducts generated in the reaction step from the main product^[2].

The hydrogen-rich stream is then sent to a Pressure-Swing Adsorption (PSA) unit^[2].

The liquid stream generated in the low-temperature separation is fed to distillation facilities consisting of a fe-Ethanizer and a propylene-propane splitter for product recovery^[2].

Process Yield and Selectivity

According to the technology provider, the per pass conversion is >45% for propane and >53% for iso-butane, and selectivity is >88% wt/wt for propane and >89% wt/wt for iso-butane)^[2], meaning that it requires 1,135 metric tonnes of propane to produce 1,000 metric tonnes of propylene, and 1,115 metric tonnes of iso-butane to produce 1,000 metric tonnes of iso-butylene.

Installed Capacities

By May 2024, Lummus claims that there are^[1]:

• nine CATOFIN^® propane dehydrogenation plants operating worldwide, producing more than 5.0 million tonnes of propylene per year.
• six CATOFIN^® iso-butane dehydrogenation plants operating worldwide, producing close to 3.0 million tons of iso-butylene per year. 
• Two units are simultaneously producing propylene and isobutylene in the same reactor system.

References

1. LUMMUS Technology,Propylene Production -CATOFIN^® Propane/Butane Dehydrogenation.
2. Amir Razmi, May 2019, Propylene Production by Propane Dehydrogenation (PDH), (Process Review), Uploaded on Slideshare on 17^th Jun 2019.