Improved propane dehydrogenation

BASF SE (Ludwigshafen, Germany; www.basf.com) and thyssenkrupp Uhde GmbH (Dortmund, Germany; www.thyssenkrupp-industrial-solutions.com) achieved measurable improvements in the STAR process, a proprietary dehydrogenation process from thyssenkrupp Uhde that can produce propylene from propane feedstocks, or iso-butylene from iso-butane feedstocks. Beginning in 2020, thyssenkrupp Uhde focused on the optimization and further development of the STAR process, while BASF validated the targeted improvements through an extended test program. The technology has been optimized to reduce CO₂ emissions and operating costs through lower energy consumption by up to 30%, while also reducing investment costs and enabling additional feedstock savings.

ThyssenKrupp Uhde acquired the STAR process and STAR catalyst technology from Phillips Petroleum Co. in 1999. The company subsequently enhanced the process by adding an oxydehydrogenation section downstream from the conventional reactor. The STAR catalyst is based on a zinc and calcium aluminate support that, impregnated with various metals, has excellent dehydrogenation properties with high selectivity at near equilibrium conversion and is versatile in its application.

The STAR process (Chem. Eng., January 2014, p. 13) is said to have the highest space-time yields of all propane dehydrogenation technologies, and operates at a reactor exit pressure of approximately 5.8 bars (higher than competing technologies), thereby allowing higher compressor suction pressures, which significantly saves capital and operating expenses on raw-gas compression. Further, compared to other technologies, the STAR process operates at rather mild process temperatures (below 600°C), above which coke formation is more severe and leads to higher de-activation rates of the catalyst. Therefore, the formation of unwanted side products is minimized, says the company.