Selecting a catalyst for methanation process: Technical and economic performance based TOPSIS Analysis

Greenhouse gases are released during various industrial processes. Use of CO and CO₂ in methanation processes reduces the negative impact of greenhouse gases on the environment and promotes conversion of CO_x into added value products (such as methane). Performance of methanation processes largely depends on specific inlet gas parameters, operational process parameters and reactor parameters. Besides, selection of a catalyst is of special importance since the performance of various catalysts at constant process parameters differs. Process temperature, H₂/CO_x ratio and catalyst stability have the largest influence on catalyst efficiency in enhancing the CO_x conversion and CH₄ selectivity. The paper demonstrates application of technique for order preference by similarity to ideal solution (TOPSIS) in selection of preferred catalyst with respect to CH₄ selectivity. Technical and economic performance is evaluated. The results show that Ru-based catalysts are the preferred alternative for methanation processes, as they show the highest technical and economic performance. In addition, it is demonstrated that multi-criteria analysis can be used as a convenient approach for selecting the preferred catalyst, especially in cases when the research aim is to study the CO_x reduction via methanation processes and when the availability of resources for experiments is limited.