Poly(oxymethylene) dimethyl ethers (OME, H 3 C−O−(CH 2 O) n −CH 3 ) are promising synthetic diesel fuels. For designing OME production processes, a model for describing the vapor-liquid equilibrium (VLE) in mixtures of (formaldehyde + water + methanol + methylal + OME + trioxane) is needed. Building on previous work of our group, a phyisco-chemical model for the VLE in these mixtures is developed in the present work. For the development and the testing of the model, experiments of different types were carried out: VLE measurements in a thin film evaporator, batch evaporation experiments in an open still, and continuous distillation experiments in a laboratory column. The model predicts the results of the distillation experiments well. It is shown that OME with n ≥ 3 can be separated as bottom product from mixtures of formaldehyde, water, methanol, methylal,

Poly(oxymethylene) dimethyl ethers (OME) are promising synthetic fuels. When compared to fossil diesel fuel, OME reduce the soot formation in diesel engines. OME can be produced from the C1 platform syngas via different routes. This work investigates an OME production process via dimethyl ether and trioxane. The process is simulated and optimized using process simulation with varying model depth. As no experimental data are available on the chemical equilibrium of the reaction of dimethyl ether and trioxane, chemical equilibrium constants are partly estimated from formation data of the reactants.

In this work, pervaporation experiments were carried out, in which water was separated from mixtures containing formaldehyde, water, methanol, methylal, and poly(oxymethylene) dimethyl ethers (OME). This separation is interesting for new production processes for the synthetic fuel OME. Five commercial membranes were studied: two zeolite membranes (Type NaA

Poly(oxymethylene) dimethyl ethers (OME) are interesting synthetic fuels that could replace fossil diesel fuel. Therefore, economic routes for OME production have to be developed. One particularly interesting route is the synthesis of OME from dimethyl ether (DME) and formaldehyde. The principal feasibility of this route is established, but the physicochemical information on essential steps is still lacking. In particular, there is no data on the first step in this synthesis, which is the formation of methylal (MAL) from DME and formaldehyde. Kinetic batch experiments were carried out in a stirred batch autoclave with a commercially available acidic ion-exchange resin as a catalyst in the temperature range of 353−373 K for up to 200 h. Trioxane was used as a water-free source of formaldehyde. Due to the volatility of DME, the experiments were carried out under pressure; high-pressure magnetic resonance (NMR) spectroscopy was applied for the analysis. During the reaction, not only MAL but also OME are formed, as well as a side product, methyl formate (MeFo). Therefore, the equilibrium constant of the MAL formation had to be determined based on a reaction kinetic model of the entire reaction network. The formation of MAL was found to have a larger equilibrium constant than the subsequent oligomerization reactions leading to OME, but it is also much slower than these reactions.

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