Experimental investigations of inorganic membrane reactors: A distributed feed approach for partial oxidation reactions

Packed‐Bed Membrane Reactors

“…The shell side outlet was closed so that all dosed air was pressed through the membrane into the catalyst bed (see Figure 5.1 ). This confi guration is similar to that reported most often in the recent literature, for example, by (Mallada, Men é ndez, and Santamar í a, 2000a ;Ramos, Menendez, and Santamaria, 2000 ;Tonkovich et al , 1996b ). However, it differs from those studies, where the shell side outlet was open, in that oxidant transfer over the membrane is infl uenced by diffusion (Farrusseng, Julbe, and Guizard, 2001 ;K ö lsch et al , 2002 ).…”

“…Reactants fed via the shell side have a different residence time distribution. Due to the fact that reactants entering the reaction zone next to the inlet pass a longer reactor distance than molecules entering close to the outlet, the average residence time of the reactants dosed in a PBMR through the membrane is higher compared to a PBR (Tonkovich et al , 1996b ). Thus, a higher conversion can be expected in a PBMR.…”

The influence of distributed reactant injection along the height of a fluidized bed reactor

“…These trends are consistent with other predictions (e.g. Tonkovich et al, 1996;Cavani and Trifirò, 1995;Moghaddam et al, 1994), where the ethane conversion increases with increasing ethane-to-oxygen molar feed ratio until the amount of oxygen becomes insufficient to react with the extra ethane. On the other hand, oxygen conversion increases rapidly with increasing ethane-to-oxygen molar feed ratio, then almost levels off.…”

“…Oxygen-lean feeds lead to high product selectivities, but low per pass conversion. Distributing the oxygen along the height of the reactor lowers the in situ oxygen partial pressure, thus promoting the desired reaction, while at the same time maintaining higher conversion (Tonkovich et al, 1996).…”

“…Few investigations have used reactors other than conventional fixed bed reactors. Among these are fluidized bed reactors, membrane reactors, and fixed beds with distributed oxygen feed (Choudhary et al, 1989;Santamaria et al, 1992;Schmidt et al, 1994;Tonkovich et al, 1996;Al-Sherehy, 1997, 2002. Several studies have treated delayed addition of reactants (Aris, 1961;Van de Vusse and Voetter, 1961;Jackson and Senior, 1968;Sheintuch et al, 1986;El-Halwagi, 1990), focusing on the advantages of delayed addition, modeling and optimization for tubular reactors and bubble-column slurry reactors.…”