Low-temperature dehydrogenation reaction-separation membranes using zeolite 13X polyethylacrylate

We prepared blend and pseudo-interpenetrating network (PIPN) membranes cont aining zeolite 13X with the dehydrogenation catalyst (Ti or Ni) and polyeth ylacrylate (PEA). Membranes were tested by a single cell reactor using the dehydrogenation reaction of cyclohexane to benzene at low temperatures (323 -360 K). Proton nuclear magnetic resonance (NMR) was used to analyze the co mposition of the throughput and the feed in our experiments. Using 2 wt% of Ti or Ni on 40 wt% of zeolite with 60 wt% PEA the conversion ratio of benz ene to cyclohexane was about 4-8%. The feed did not contain measurable amou nts of benzene, hence the separation was complete. Scanning electron micros copy (SEM) results showed that the blend membrane developed cracks consider ably earlier than the PIPN membrane. We also find the pseudo-first-order ra te constant and its activation energy for the dehydrogenation reaction in t he membrane by using a phenomenological diffusion-reaction model. The latte r values are consistent with surface diffusion control of the kinetics. (C) 1999 Elsevier Science B.V. All rights reserved.