Energetic and economic analysis of absorption-based CO2 capture integrated hydrogen production processes – Retrofit perspective

Abstract

Efforts made to integrate absorption-based CO2 capture technologies with the production of hydrogen have mostly focused on new-build cases. Our understanding on the most appropriate way of implementing CO2 capture for blue hydrogen processes and its economic impact under retrofit scenarios are rather limited. In this study, the capture-integrated hydrogen plant is modeled and simulated using Aspen Plus, with which technical feasibility is evaluated with three potential positions of CO2 capture for PSA inlet gas, PSA tail gas and reformer flue gas streams. Three retrofit strategies for CO2 capture are established, of which techno-economic impact on the design of utility systems and its site-wide management is systematically investigated. TEA (techno-economic analysis) is carried out to determine the Levelized cost of hydrogen (LCOH), CO2 capture cost, and CO2 avoidance cost for three retrofit strategies subject to three capture options. From the case study presented, CO2 capture and avoidance cost is strongly dependent on the selection of CO2 capture option and retrofitting design philosophy, and CO2 capture for PSA inlet gas with fully utilizing excess energy from hydrogen plant is the most cost-effective strategy.