Catalyst Innovation Improves Commercial Application of the OATS~(TM) Process

摘要

Many catalyzed reactions in the refinery are carried out in multi-phase reactors, for example in the most widely used technology for sulphur removal - the HDS (Hydrodesul-phurisaiion) process. Even if the reaction has been well known for over 40 years, the chemical process is still very complex. Temperature control as well as the scaling up of the reactor are important and problematic, e. g. leading to a complex reactor design requiring gas phase recycle with high costs for recompressing because the H2-supply needs to exceed significantly what is chemically consumed. The OATS~(TM) (= Olefin Alkylation of Thio-phenic Sulphur) process is an alternative route for sulfur removal and requires no hydrogen at all. In this non-HDS based desul-phurisation technology, organic sulphur compounds are shifted to higher boiling points and thus can be removed by distillation from the light fractions and concentrated in the heavy boiling part of the refinery streams. In 2002 the Bayernoil Refinery in Bavaria licensed OATS technical information and patents from BP Refining Technology, and built the very first two commercial OATS~(TM) plants in their Neustadt and Vohburg refineries. As with most new processes the units had some initial problems, but both units have now been successfully operated and are now producing continuously up to 200 m /h ofULSG (ultra low sulphur gasoline) with feed coming from all three of Bayernoil's FCC units. Working as a 2-phase system under mild conditions with low energy costs and without any use of metal compounds in the catalyst, ULSG with sulphur levels of < 30ppm can beproduced, allowing, the blended products to meet the most severe motor gasoline specifications (Euro 5). After the introduction of a new tailor-made catalyst provided by Axens, who are now exclusive licensors of the technology, and testing by the refinery, the process conditions, yield pattern and catalyst handling have been improved in such a way that OATS can now be considered as an excellent alternative route for the desulphurisation of mainly light fractions from FCC units without using hydrogen. In this article, the chemical fundamentals and the short history at Bayernoil are de-scribed where both the licensor and the refinery optimized the OATS~(TM)process.