Dehydrogenation of Methylcyclohexane To Produce High-Purity Hydrogen Using Membrane Reactors with Amorphous Silica Membranes

Abstract

We developed a membrane reactor that can produce high-purity hydrogen in one step from methylcyclohexane. This membrane reactor combined a hydrogen-selective amorphous silica membrane prepared with dimethoxydiphenylsilane and oxygen and employing counter-diffusion chemical vapor deposition, and Pt/Al 2 O 3 catalyst. The silica membrane showed excellent hydrogen permeance at 573 K of the order of 10 -6 mol m -2 s -1 Pa -1 and high hydrogen/sulfur hexafluoride permselectivity of around 10 4 . The membrane reactor exhibited equilibrium shifts as expected under reaction temperatures ranging from 473 to 553 K and reaction pressures ranging from 0.1 to 0.25 MPa, and these performances were successfully predicted using a simulation model, which was also developed in this study. Finally, we demonstrated that hydrogen with purity as high as 99.95% was produced from methylcyclohexane in the membrane reactor without using carrier gas or sweep gas.

Development of Membrane Reactors for Dehydrogenating Organic Chemical Hydrides to Supply High-purity Hydrogen

“…The extent of the equilibrium shift was greater when a membrane with higher hydrogen permeance was used. Furthermore, it is noteworthy that we have successfully operated these membrane reactors Production Rate and Hydrogen Permeance through the DMDPS-derived Membrane during the Operation of the Membrane Reactor with no Carrier Gas or Sweep Gas 51) with no carrier gas or sweep gas, for the first time in the world. This means that high-purity hydrogen at atmospheric pressure can be obtained in a one-step procedure, and the produced hydrogen can then be directly supplied to a fuel cell.…”

“…Figure 3 shows the permeances of H2, N2 and SF6 at 573, 473 and 373 K, respectively 51) . The permeance of H2 was around 10 Figs.…”

“…9 R e l a t i o n s h i p b e t w e e n t h e R e a c t i o n P r e s s u r e a n d Methylcyclohexane Conversion for the Packed Bed Reactor and the DMDPS-derived Membrane Reactor (Each line corresponds to the prediction by the model.) 51) ness of this membrane reactor for hydrogen production by dehydrogenating organic chemical hydrides.…”

In situ synthesis of highly-active Pt nanoclusters via thermal decomposition for high-temperature catalytic reactions

“…4c, nearly 100% of MCH are converted into hydrogen and toluene over the 0.45 wt% catalyst at 340 C. However, as the reaction temperature drops, the conversion of MCH decreases signicantly and reaches $50% at 280 C. The temperature-dependent conversion (Fig. [27][28][29] Meanwhile, it is very important for practical applications to obtain a high conversion at a high gas hourly space velocity (GHSV). 27 It was found that E a ¼ 47.1 kJ mol À1 for the in situ prepared Pt/CS, which is much lower than most of the catalysts synthesized by conventional methods.…”

Butene oligomerization, phenol synthesis from benzene, butane partial oxidation, and other reactions carried out in membrane reactors

“…From among these methods, organic chemical hydrides (hydrogenated aromatic compounds such as cyclohexane, methylcyclohexane, and decaline) have attracted researchers' attention because of their advantages, including (Itoh, Watanabe, Kawasoe, Sato, & Tsuji, 2008;Oda et al, 2010). Considering the fact that hydrogen has an explosive combustion rate and very high combustion temperature, special attention has been focused on establishing a low potential risk hydrogen storage and transportation system.…”