INEOS is the recognized world leader in fluid-bed reactor technology for maleic anhydride production, which it licenses through INEOS Technologies. In addition to technology licensing, INEOS Technologies manufactures and markets the catalyst that is used in both the fixed-bed and fluid-bed reactor maleic anhydride processes.
INEOS’ maleic anhydride technology uses its proven fluidized bed reactor system. The feeds, containing n-butane and air, are introduced into the fluid-bed catalytic reactor, which operates at 5 psig to 50 psig with a temperature range of 730°F–860°F (390°C–460°C). This exothermic reaction yields maleic anhydride and valuable high-pressure (HP) steam. The energy-efficient process does not require using moltensalt heat transfer.
The reactor effluent may be either aqueous scrubbed or absorbed by an inorganic solvent. Through either process, essentially 100% recovery of maleic anhydride is achieved. Non-condensables may be vented or incinerated depending on local regulations. Water, light ends and high-boiling impurities are separated in a series of drying, dehydration and fractionation steps to produce maleic anhydride product.
n-Butane + Oxygen → Maleic Anhydride + Water
Products and economics: Products include maleic anhydride and HP steam. Instead of exporting steam, a turbo generator can be used to generate electricity. INEOS has applied more than 40 years of experience as an operator and licensor of fluid-bed technology to the INEOS maleic anhydride technology delivering high yields and efficiency with low
investment and operating costs, maximum safety and flexibility, exceptional process reliability with less shutdowns and environmentally acceptable effluents. INEOS has also drawn on its many decades of experience in oxidation catalysis in both the fluid-bed and fixed-bed forms to deliver catalysts that meet the needs of the maleic anhydride market.
Catalyst: INEOS developed and commercialized its first fixed-bed catalyst system for the manufacture of maleic anhydride in the 1970s and fluid-bed catalyst system in the 1980s. Since the introduction of this technology, INEOS has also developed and commercialized three generations of improved catalysts. Catalyst improvements have increased
yields and efficiencies vs. prior generations to lower manufacturing costs for maleic anhydride. INEOS continues to improve upon and benefit from its long and successful history of catalyst research and development. INEOS’ fluid-bed catalyst system does not require change out or regeneration over time, unless the licensee chooses to introduce one of INEOS’s newer, more economically attractive catalyst systems. Fixed-bed catalysts provide high yield, low pressure drop and long-term stability.
Maleic anhydride end uses: With three active sites (two carboxyl groups and one double bond), maleic anhydride is a preferred joining and crosslinking agent. Maleic anhydride is used as an additive in multiple applications, but also as an intermediate to several downstream products, the largest of which is unsaturated polyester resins (UPR) that is used in glass-fiber reinforced products (marine, automotive and construction applications) and castings and coatings (cultured marble and onyx manufacture). Another major use of maleic anhydride is as a feed to produce butanediol (BDO), which is used as an intermediate to tetrahydrofuran (THF) for spandex and solvents applications, polybutylene terephthalate (PBT) for engineered plastics and gamma-butyrolactone (GBL) for pharmaceutical and solvent applications.
Maleic anhydride is an important intermediate in the fine chemical industry, particularly in the manufacture of agricultural chemicals and lubricating oil additives. It is also a component of several copolymers in the engineering polymers sector as well as a raw material in the production of artificial sweeteners.
Licensor: INEOS Technologies. From SOHIO to its successor companies, BP Chemicals, BP Amoco Chemical, Innovene and now INEOS have delivered a successful licensing and technology transfer program with catalyst supply, training, plant start-up support and on-going technical assistance.