Multi-criteria decision analysis of steam reforming for hydrogen production

Abstract

Modern sustainable process design necessitates the use of sophisticated analytical approach to determine feasibility of design alternatives considering multiple criteria. This paper presents novel methodology for multi-criteria decision analysis (MCDA) considering economics, material and energy utilisation, inherent safety, and environmental impact. Its basis is the analytic hierarchy process (AHP) algorithm that allows to study multiple decision scenarios with variable emphasis on considered criteria. As a case study, hydrogen production from natural gas and biogas via steam methane reforming was selected due to its increasing popularity associated with world’s attention on implementing hydrogen economy. Sixteen process configurations differing in operating parameters and employed unit operations were developed and simulated in commercial process simulator Aspen Plus. Simulated production routes were ranked according to their performance in each criterium individually and then ranked globally using AHP methodology.In total, 9027 decision scenarios with different importance of each criterion were generated. Hydrogen production from natural gas was found out to be the most suitable production route in 78.4 % of the scenarios. The results obtained indicate strong preference of fossil-based hydrogen production represented by natural gas if economics, and material and energy utilisation were dominant criteria. Increasing importance of inherent safety led to partial preference shift towards biogas-based production although natural gas-based production remained generally more preferred option. However, if environmental impact was considered the most important criterion, complete switch to biogas-based design alternatives as the most feasible hydrogen production routes was observed. The proposed MCDA technique based on AHP presents powerful tool for selection of the most suitable process route accounting for different societal needs and current industrial trends.