Dehydrogenation of methanol to anhydrous formaldehyde in a microstructured reactor system

An integrated microreactor system for the direct dehydrogenation of methanol to water-free formaldehyde was developed. The endothermic reaction can be homogeneously catalyzed with evapd. sodium. At reaction temps. of up to 1100 K nearly complete conversion of methanol can be achieved. Undesired consecutive reactions can be minimized, if the reaction products are rapidly cooled and if the residence time at reaction temp. is precisely controlled. Fast heating and cooling of the gases in the order of a few milliseconds is desired, specifications that can be met by microreactors. Several tests were carried out using conventional and microscaled systems. The results are compared and served as a base for the development of an integrated microsystem for the dehydrogenation of methanol. First, two different kind of mixers were tested. The results clearly showed that fast and homogeneous mixing of the gaseous sodium catalyst and the methanol is indispensable. Second, in order to improve the temp. profile in the reactor a cross flow micro heat exchanger was employed. A special adaptor with internal heater was developed, allowing to keep the gases at reaction temp. close up to the micro heat exchanger. The final setup allowed to obtain a formaldehyde selectivity of 80.3% at methanol conversion higher than 97%. [on SciFinder (R)]

Published in:
Chemical Engineering Research and Design, 81, A7, 730-734
CAN 140:199787 35-2 Chemistry of Synthetic High Polymers Laboratory of Chemical Reaction Engineering,Swiss Federal Institute of Technology (EPFL),Lausanne,Switz. Journal 0263-8762 written in English. 7440-23-5 (Sodium) Role: CAT (Catalyst use), USES (Uses) (catalyst; dehydrogenation of methanol to anhyd. formaldehyde in microstructured reactor system); 50-00-0P (Formaldehyde) Role: IMF (Industrial manufacture), PREP (Preparation) (dehydrogenation of methanol to anhyd. formaldehyde in microstructured reactor system); 67-56-1 (Methanol) Role: RCT (Reactant), RACT (Reactant or reagent) (dehydrogenation of methanol to anhyd. formaldehyde in microstructured reactor system)
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 Record created 2006-04-18, last modified 2018-03-17

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