Shape-selective zeolite process patent granted
This work was published in Science back in 2015
Shape-selective BEA zeolites translated from petrochemistry to biobased plastic processing
Recently, the patent was granted to Bert Sels and Michiel Dusselier.
Biodegradable and renewable polymers, such as polylactic acid, are benign alternatives for petrochemical-based plastics. Current production of polylactic acid via its key building block lactide, the cyclic dimer of lactic acid, is inefficient in terms of energy, time, and feedstock use. We present a direct zeolite-based catalytic process, which converts lactic acid into lactide. The shape-selective properties of zeolites are essential to attain record lactide yields, outperforming those of the current multistep process by avoiding both racemization and side-product formation. The highly productive process is strengthened by facile recovery and practical reactivation of the catalyst, which remains structurally fit during at least six consecutive reactions, and by the ease of solvent and side-product recycling.
Dusselier et al. Science 2015, 349 78-80,
Old versus new
The current process consists of two steps, time and energy intensive reactor needs, and intermediate selectivity due to side-product formation.
Now, a new 1-step zeolite process was developed.