화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.49, No.8, 3544-3552, 2010
Model-Based Analysis of Reactor Feeding Policies for Methane Oxidative Coupling
In this work, a new feeding policy structure for an alternative operation mode of the packed bed membrane reactor (PBMR) is proposed in order to increase the efficiency of the OCM oxidative coupling of methane process. This structure has a high potential to improve the process performance in comparison to fixed bed reactors (PFRs) and even to a conventional PBMR design structure. The main drawbacks in operating PFR or PBMR have been to find suitable operation policies toward the enhancement of both yield and selectivity at the same time. In this work, a model-based comparative study of the OCM process performance for these three reactors types is presented. For this purpose, the effect of oxygen accessibility in the different design structures is investigated. Basically, the new proposed feeding policy structure combines the advantages of PFR and the conventional PBMR so as to get a high yield amount by cofeeding methane and oxygen into the reactor entrance while guaranteeing an acceptable level of selectivily by reducing the accessibility to ethylene and oxygen, in particular, at the reactor end. Moreover, using the potential of the proposed operation mode, it is now possible to build a reactor network consisting of the new proposed and the conventional PBMR in order to treat the shell side gas streams, which results from each PBMR structure. The analysis of the proposed reactor network shows a performance of 23.21% yield, 53.93% selectivity, and 42.66% methane conversion, respectively. Besides, a sensitivity analysis is performed in order to analyze the effect of reactant accessibility in the proposed feeding policy structure. The results are analyzed along with the study of the optimal operating range in order to conceptually design a membrane reactor network toward satisfying economical and industrial considerations in terms of selectivity, one-pass yield, and methane conversion.