Scale-up of the Continuous Production of Poly(oxymethylene) Dimethyl Ethers from Methanol and Formaldehyde in Tubular Reactors

Poly(oxymethylene) dimethyl ethers (OME) are discussed as a neat alternative or blend component to diesel fuel offering soot-free combustion and sustainable production pathways. This work investigates the continuous production of OME from methanol and formaldehyde in tubular reactors filled with the ion-exchange resin Amberlyst 46 as heterogeneous catalyst. Reaction experiments with varying feed composition and operating conditions are carried out. OME are successfully produced in the reactor. Catalyst stability experiments are performed, and catalyst deactivation is detected. The deactivation originates from ion exchange with cations present in feed solutions and is fully reversible by acid treatment. A pseudo-homogeneous model from the literature is adjusted to experimental data and is able to reliably describe the reaction progress throughout the reactor. The adjusted model is used to design the reactor of an industrial-scale process with a product capacity of 100 kt/a OME3-5. The space-time yield is selected to be 10 kg/(kgcat·h), and feasible reactor geometries are discussed for multitube reactors.