Affiliation:
1. Laboratory of Plant and Process Design, TU Dortmund University, 44227 Dortmund, Germany
2. Laboratory of Industrial Chemistry, TU Dortmund University, 44227 Dortmund, Germany
Abstract
The homogeneously catalyzed methoxycarbonylation of bio-based methyl 10-undecenoate (C11-DME) produces linear 1,12-dimethyl dodecanedioate (l-C12-DME). Subsequent selective product crystallization from the reaction mixture with downstream filtration and washing allows for the generation of the bio-monomer in polymer grade quality (>99.9%). This effective purification enables its direct use, e.g., for bio-based polyamides, without further purification. It separates the expensive homogeneous catalyst dissolved in the liquid phase in its active state for efficient catalyst recycling. We present the complex interactions of process parameters regarding reaction and crystallization-based purification in an integrated catalyst recycling process. Furthermore, we demonstrate that purification of l-C12-DME with >99.9% purity over multiple consecutive recycling runs is possible. However, as the crystallization is highly sensitive towards changing concentrations of by-products and particularly unreacted substrates, this high purity is only achieved by maintaining a stable composition in the reaction mixture using a newly developed system for precise conversion control in the reaction step.
Funder
German Research Foundation
Deutsche Forschungsgemeinschaft and Technische Universität Dortmund/TU Dortmund University
Subject
Process Chemistry and Technology,Chemical Engineering (miscellaneous),Bioengineering