Evonik AG is developing new process for producing methyl methacrylate (MMA), an important precursor for acrylic and for specialty applications such as contact lenses and adhesives. Evonik engineers have named the technology LiMA, an acronym that reflects their ambitions: LiMA stands for Leading in Methacrylates.
The process is currently being tested at a pilot plant in Darmstadt, Germany.
Intelligent process set-up and control and a highly efficient new catalyst result in final product yields exceeding 90 percent. Because it uses considerably less energy, the process also reduces carbon dioxide emissions by up to 40 percent.
LiMA begins with ethylene and methanol. These then undergo multiple reaction steps to produce methacrolein. Evonik has developed a new catalyst system that can convert the methacrolein to methyl methacrylate in a single step. The new system is efficient and stable, with very little 'bleeding', where individual components of the catalyst are gradually lost from the carrier with reaction time. By-products and catalyst toxins are removed during preliminary process stages.
The overall favorable process design as well as moderate reaction conditions minimize wastewater streams, engineering work, and maintenance needs. Another advantage of the technology is its use of petrochemical raw materials, which are readily available throughout the world.