Ethylene
Last month, Linde GmbH (Pullach, Germany; www.linde.com) and Shell (den Hague, the Netherlands; www.shell.com) announced an exclusive collaboration agreement on ethane-oxidative dehydrogenation (E-ODH) technology for ethylene production. The catalytic process is an alternative route to ethane steam cracking, offering the potential of economic advantages, acetic acid co-production and significantly lower overall carbon footprint. The two companies have been developing E-ODH independently for many years and this new collaboration brings together their complementary patent positions, expert know-how and common commitment to a lower-carbon future. The agreement will enable accelerated deployment of this novel technology across the wider chemicals sector, with Linde marketing the process under the tradename EDHOX.
Today, ethylene is mainly obtained by steam-cracking technology, which takes place in furnaces operating at temperatures over 900°C. In contrast, Linde’s EDHOX technology operates at moderate temperatures (below 400°C), with the corresponding reduction in CO2 emissions. This catalytic on-purpose ethylene technology takes place in a fixed-bed reactor, where ethane and oxygen react to form ethylene, acetic acid and CO2. After separation and purification, the pure CO2 can be stored or used for downstream processing, and the acetic acid co-product can be used for making vinyl acetate monomer, ethylene-vinyl acetate copolymer and polyvinyl alcohol products.
The EDHOX technology was successfully validated for commercial use in a demonstration plant operating since 2017 at Pullach. The plant achieved a high yield of combined ethylene and acetic acid, with an overall selectivity of greater than 93%, according to Linde.