Ethers, particularly methyl tertiary butyl ether (MTBE) and tertio amyl methyl ether (TAME), have long been used in reformulated gasoline owing to their attractive blending and engine burning characteristics.
In the 80s, Axens and IFP Energies nouvelles pioneered the development of the concept of reactive distillation for high conversion of isobutylene, and obtained the first reference of CatacolTM in 1996. Thanks to the successful start-up of this plant, since then several commercial successes were obtained with this technology.
Through an extensive R&D effort and by working closely with government agencies, agricultural organizations, petroleum refiners and automobile manufacturers, Axens and IFP Energies nouvelles licensed the first ETBE plant in the world.
Since 2000, new sulfur and olefins specifications have given rise to a renewed interest in ethers, and especially TAME/TAEE, as they allow the partial compensation of the octane loss in the FCC gasoline Desulfurization unit. In parallel, numerous polyolefin projects started-up with the objective of generating butene-1, which is a co-polymer of LLDPE, leading to more demand for ETBE and MTBE projects.
To respond to the market Axens has strengthened its offer in etherification solutions proposing several schemes that are very versatile and can be tuned to reach the following objectives:
- Moderate to very high conversion while minimizing the formation of by-products
- Staged investment
- Possible switches between methanol and ethanol
- Possible processing of C4s and C5s.
Further to the refining use of etherfication technologies, this process is a key one in the petrochemicals when it comes to recovering 1-butene from the crude C4 produced by the steam cracker.
In the crude C4 from steam cracker, 1-butene and isobutene are indeed present. And, due to their very close boiling points, these can not be separated by distillation: the etherification appears as the way to deeply and selectively remove isobutene from the mixture and therefore enables to match the necessary 1-butene purity.
For this petrochemical use, an extremely high conversion of isobutene is required, which is achieved thanks to the combined use of possibly several reactor and a finishing section of Catacol.