Techno-Economic Comparative Study on Hydrogen and Electricity Cogeneration Systems With CO2 Capture

Abstract

In order to achieve the international climate goals and to keep the global temperature increase below 2 °C, carbon capture and storage in large point sources of CO2 emissions has received considerable attention. In recent years, mitigation of CO2 emissions from the power sector has been studied extensively whereas other industrial point source emitters such as hydrogen industry have also great potential for CO2 abatement. This study aims to draw an updated comparison between different hydrogen and power cogeneration systems using natural gas and coal as feedstock. The goal is to show the relative advantage of cogeneration systems with respect to CO2 emission reduction costs. Accordingly, the Reference Case is selected as a large-scale H2 production system with CO2 venting using natural gas based on steam methane reforming. In this work, H2 and electricity cogeneration with CO2 capture based on auto-thermal reforming of natural gas has been simulated using ASPEN Plus™, while the cost and performance indicators for the plant based on steam methane reforming of natural gas and the coal-based plants have been adopted from the literature. Using a consistent approach, different plants are compared techno-economically. A sensitivity analysis has also been performed with variation in the most important input parameters including natural gas price (2–8 $/GJ), coal price (1–4 $/GJ), electricity price (30–90 $/MWh) and capacity factors (85–50%) and the results are presented here. The results demonstrate that the total efficiency of the system is slightly higher in natural gas-based systems than in coal-based systems. The results also indicate that although H2 production cost increases with power cogeneration and CO2 capture, cogeneration is a promising and attractive alternative for clean power generation. The highest sensitivity of the results has been observed for the fuel price.