Reforming reactions for H2 production

The majority of the dense Pd or its alloy membrane is used in hydrogen production because of its infinite perm-selectivity. It has been demonstrated that the Fl2 recovery and purity levels in Pd-MRs can reach as high as 99% and 99.9999%, respectively without the use of a sweep gas. Table 4.4 summarizes the reactions for H2 production in the Pd-MRs. 

MRs have been utilized to increase CO conversion by shifting the equilibrium conversion toward the products (CO2 and H2). In order to reduce the reactor volume, the WGS reaction is usually conducted under high 

Reaction Membrane Catalyst Reactor configuration Operation Ref. 

HJ R steam reforming of liquid hydrocarbons 4.5 pm Pd on a-Al203 tube N 1-La203-Al203 PBMR T=723-823 K P = 2-9 bar Ar as sweep gas [49] 

The use of Pd-MRs for MDR helps to reduce the operating temperature, leading to suppression of catalyst deactivation due to coke deposition. By adding H2O vapor in the reactant feed, MSR will take place together with MDR. As a result, carbon formation can be reduced due to the oxidation of the carbon precursors - such as partially hydrogenated CH species - leading to improved catalyst stability. A desirable H2/CO ratio can be obtained conveniently via adjustment of the CH4/H2O ratio in the feed [67]. Furthermore, methane conversion and hydrogen yield can be increased, whereas CO2 conversion and CO yield will be decreased. 

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