Maleic Anhydride - Process
Chemistry
The INEOS fluid-bed reactor technology utilizes the selective one-step vapour phase catalytic reaction of n-butane with air to yield maleic anhydride. This economical route to maleic anhydride is referred to as “oxidation of n-butane”. The chemical equation is as follows:
Feedstocks
The feedstocks for INEOS’ maleic anhydride reactor technology are n-butane and air, both of which are readily commercially available.
Reaction
INEOS’ maleic anhydride reactor technology utilizes its proven fluidized-bed reactor system. The feeds containing n-butane and air are introduced into the fluid-bed catalytic reactor which operates at 5-50 psig with a temperature range of 390 – 460 °C (730 – 860 °F). The exothermic reaction yields maleic anhydride and valuable high-pressure steam. This energy efficient process does not require the use of molten-salt heat transfer material.
The most important issues in a fluid-bed design are obtaining and maintaining good catalyst/gas contact to achieve high yields. INEOS has refined these areas of fluid-bed technology through proper internal mechanical designs which mix reactants and maintain catalyst particle size distribution in the reactor’s catalyst bed. INEOS has learned how to achieve and optimize these conditions through years of reactor design and catalyst development, as well as by operating commercial reactors for maleic anhydride production. INEOS’ extensive experience and understanding make INEOS the leader in designing reactor/catalyst systems with better yields, less shutdowns, and fewer environmental problems than any other technology supplier. INEOS’ designs, processes, and catalyst systems allow high on-stream reliability factors.
Recovery & Purification
The effluent vapour from the reactor is scrubbed or absorbed to recover the organics. Non-condensables may be vented or incinerated depending on local regulations. Water, light ends, and high-boiling impurities are separated from the crude maleic anhydride in a series of fractionation steps to produce maleic anhydride product.
Catalyst
INEOS developed and commercialized its first fluid-bed catalyst system for the manufacture of maleic anhydride in the 1980s. Since the introduction of this technology, INEOS has also developed and commercialized improved catalysts. Catalyst improvements have increased yields and efficiencies versus prior generations to lower the cost to manufacture maleic anhydride. INEOS continues to improve upon and benefit from its long and successful history of catalyst research and development. INEOS’ catalyst system does not require change out or regeneration over time, unless the licensee chooses to introduce one of INEOS’ newer, more economically attractive catalyst systems.
Energy Utilization
The INEOS Maleic Anhydride Technology is feedstock and energy efficient. It is a net exporter of steam, and the steam system (an integral part of the process) can be optimized to fit each individual plant. Instead of exporting steam, a turbo generator can be used to generate electricity. INEOS will work with the licensee to optimize the use of all the utilities based on the requirements and economics of the specific plant site.
Flexibility
The process technology allows for a wide variance in operation and/or design. Typical turndown capability is 60% of the design butane feed rate. Accordingly, it may be possible to stage capital investments to respond to expected market demand changes.
Safety
INEOS Technologies considers safety to be of the highest priority. As such, reactor system designs, operations, and related work are thoroughly scrutinized to assure their safety and reliability. For over 40 years INEOS-designed plants have operated safely worldwide in a variety of conditions and environments.
Licensee Support
INEOS Technologies is committed to the safe and successful transfer of our maleic anhydride reactor technology to licensees. INEOS is proud of its excellent reputation in the industry, and will always make itself available to support the questions and needs of its licensees.
Future Developments
As the world’s largest preeminent licensor of petrochemical fluid-bed reactor technology, INEOS maintains our world-class research and development efforts in the areas of catalysis, process chemistry, and engineering design. This research and development effort takes place primarily in Naperville, Illinois (USA) and is complemented by extensive pilot plant and demonstration facilities.
Safety, Health, and the Environment (SHE)
INEOS Technologies is committed to ensuring that best practices in health, safety and the environment continue to be a key part of everything we do. We are committed to open discussion on all SHE issues. In particular, we work with companies around the world to progress the chemical industry’s commitment to Responsible Care, which involves the continuous improvement of our SHE performance and the open communication of that performance. We give high priority to safety in manufacturing, storage and handling operations, and devote considerable effort to monitoring these activities and minimizing risks. INEOS intends, therefore, to continuously improve our SHE performance and will be guided by the principles to provide safe operations, produce and market products which can be safely used, progressively improve our environmental performance, and respect the interests of our neighbours and the world community.