Methyl formate is a key component for both defossilized industry and mobility. The current industrial production via carbonylation of methanol has various disadvantages such as high requirements on reactant purity and low methanol conversion rates. In addition, there is a great interest in replacing the conventional homogeneous catalyst with a heterogeneous one, among other things to improve the downstream processing. This is why new approaches for methyl formate are sought. This review summarizes promising approaches for methyl formate production using methanol as a reactant.

A packed‐bed membrane reactor in a distributor configuration is studied theoretically for the oxidative propane dehydrogenation and compared with a fixed‐bed reactor. Based on detailed 2D models considering two different heat and mass transport models the reactor scale‐up including various reactor‐to‐particle diameter ratios (D/dP) is analyzed with respect to reactor performance, heat transfer and hot spot formation. Higher selectivities at lower hot spot temperatures occur in the packed‐bed membrane reactor for the same reaction conditions.

der Zuckerphosphat-Region sind zusatzlich zu den Peaks der bekannten Entner-Doudoroff-Intermediate mehrere Peaks erkennbar, die moglicherweise zu Zuckerphosphaten gehoren, die in der Biosynthese eine Rolle spielen. Die Zuordnung und Quantifizierung der Resonanzen in den Extraktspektren erfolgt durch Zugabe von Reinsubstanzen. Bei erstenversuchen rnit einem neu gebauten Bioreaktor-Prototyp fur 3'P-NMR-Messungen im DurchfluBbetrieb konnten die Resonanzen intrazellularer Metaboliten in einer Zellsuspension von (2,6 . lo9 Zellen/ml) von 2. mobilis mit etwa gleichem S/N wie in Proben rnit dichten Zellsuspensionen (1,6 . 10") in 30 min gemessen werden. Da die erforderliche NMR-MeBzeit fur gleiches S M mit abnehmender Konzentration quadratisch zunimmt, ergibt sich nach Berechnung durch das DurchfluB-Verfahren ein MeBzeitGewinn um einen Faktor 126 (Empfindlichkeitssteigerung um etwa einen Faktor 11). Es zeigte sich zudem eineverbesserung der spektralen Auflosung. Die beobachtete Verschiebung der Resonanz in der linken Z-P-Region konnte durch einen vergroBerten pH-Gradienten undloder eine Veranderung des Stoffwechselflusses im Vergleich zur dichten Zellsuspensionen erklart werden.

A heat-integrated packed-bed membrane reactor is studied based on detailed, transient 2D models for coupling oxidative and thermal propane dehydrogenation in one apparatus. The reactor is structured in two telescoped reaction zones to figure out the potential of mass and heat integration between the exothermic oxidative propane dehydrogenation (ODH) in the shell side, including membrane-assisted oxygen dosing and the endothermic, high selective thermal propane dehydrogenation (TDH) in the inner core. The developing complex concentration, temperature and velocity fields are studied, taking into account simultaneous coke growth corresponding with a loss of catalyst activity. Furthermore, the catalyst regeneration was included in the simulation in order to perform an analysis of a periodic operating system of deactivation and regeneration periods. The coupling of the two reaction chambers in a new type of membrane reactor offers potential at oxygen shortage and significantly improves the achievable propene yield in comparison with fixed bed and well-established membrane reactors in the distributor configuration without inner mass and heat integration. The methods developed allow an overall process optimization with respect to maximum spacetime yield as a function of production and regeneration times.

The further optimization of 3-ketodisaccharide formation with sucrose, leucrose and iso maltulose was studied with special regard to pH and oxygen concentration in the reaction mixture with resting cells of Agrobacterium tumefaciens. It was found that the optimal pH values for the highest reaction rate and highest yield were different as the pH affected the stability of the 3-keto derivatives formed. A pH shift to 5.0 clearly reduced the enzymatic degradation of the 3-keto derivatives thus stabilizing them. The influence of constant oxygen concentrations on 3-ketosucrose formation was tested showing results not explicable with normal Michaelis-Menten kinetics. For each substrate a maximum of reaction rate and yield were obtained at very low oxygen concentrations.