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Presidential Green Chemistry Challenge: 2016 Greener Synthetic Pathways Award




AlkyClean® Technology:  An Inherently Safer Technology for the Production of Gasoline Alkylate

  • Developed and commercialized an inherently safer technology to produce alkylate, a clean gasoline component.
  • Replaced the traditional toxic and corrosive liquid acid catalysts with an inherently safer technology that also has a lower environmental impact.

Summary of Technology: 

Alkylate is a highly valued “clean fuels” blending component for motor gasoline. It consists of clean-combusting isoparaffins that have low vapor pressures and high octane values. Alkylate also does not contain toxic components such as aromatics, olefins, or sulfur compounds. Alkylate is the preferred gasoline blending component for compliance with relevant environmental regulations.

Alkylate is produced from the reaction of isobutane and light olefins (C3-C5). Alkylate production is currently about 30 billion gallons/year worldwide, of which 60% is located in North America. A challenge facing refineries today is that alkylate production requires the use of liquid acid catalyzed processes, typically hydrofluoric acid or sulfuric acid. Hydrofluoric acid, in particular, is extremely toxic and, upon release, forms clouds that can be lethal for up to five miles.

For more than 40 years, scientists have been trying to replace liquid acid technologies with a greener solid acid catalyst technology. Prior approaches failed because of poor product selectivity and/or excessively rapid catalyst deactivation, coupled with the lack of an acceptable catalyst regeneration procedure. In some cases, these catalysts used leachable corrosive components such as halogens, triflic acid, and boron trifluoride, which could migrate into product streams.

Albemarle and CB&I developed a catalyst-process combination technology, the AlkyClean® solid acid alkylation process, which coupled with CB&I’s novel reactor scheme, produces high quality alkylate without the use of liquid acid catalysts. Additionally, neither acid-soluble oils nor spent acids are produced, and there is no need for product post-treatment of any kind.

Albemarle’s AlkyStarTM catalyst was designed for use exclusively with the AlkyClean® alkylation process. It uses a type of zeolite catalyst that is well-proven in the industry. The strength and the number of acid sites on the catalyst have been optimized to enhance hydrogen transfer reactions over multiple alkylation reactions. The catalyst particle size and porosity were also optimized using a pilot plant and a demo unit that allowed the investigation of regeneration procedures as well.

The world’s first commercial-scale, solid catalyst alkylation unit was started up in August, 2015. The unit employs the AlkyClean® technology and has a capacity of 2,700 BPD alkylate production. The plant has met or exceeded all performance expectations and is producing an alkylate product of quality that is on par with existing technologies.

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