(454c) A Process Integration Approach for a Sustainable Gtl Process Using Tri-Reforming of Methane

Reforming of methane to produce synthesis gas is one of the key components of a Gas to Liquid (GTL) process. This process can be carried out primarily using three technologies; namely the Steam reforming(SRM), Partial Oxidation (POX) and Dry reforming of methane(DRM). Each of the aforementioned processes have their advantages and limitations and differ in terms of oxidant used. Compared to SRM and POX reforming which utilize steam and oxygen, DRM uses carbon dioxide as oxidant. This capability of Dry reforming to utilize two greenhouse gases (methane and carbon dioxide) has therefore attracted due interest in many of the current research studies around the globe. Of the three aforementioned processes, SRM and POX are conventionally utilized processes, and have been implemented in industry since mid-20^th century. While DRM is a relatively new process, and has not been implemented commercially due to critical process limitations like high endothermicity and coke formation. As an extension to our previous work in Challiwala et al. (2017) and Gabriel et al. (2014), the present work is targeted to utilize DRM process through a combined DRM/SRM/POX tri-reforming reaction with an objective to improve CO₂ footprints and water/energy nexus potential in a typical GTL superstructure. Some of the preliminary optimization results show that 47% fixation of CO₂ can be achieved per pass through tri-reforming reaction with energy requirements much lower than the individual SRM and DRM processes. The combined model also aims to incorporate transport effects in the reformer reactor in a separate CFD study in COMSOL^® to make the process more realistic as opposed to thermodynamic equilibrium results. Therefore, a major effort of the current work is to combine the kinetics of the individual reforming reactions that could be compatible to accurately predict the behavior of a tri-reforming reaction. The developed combined tri-reforming based GTL superstructure is further targeted to compete with a base case scenario of Auto thermal reforming process (ATR, a combination of SRM and POX) in terms of water and energy requirements with overall optimization target to reduce CO₂ emissions. This work is a part of a broader CO₂ management project that aims for a multiscale experimental/simulation study from catalyst to reactor design in order to enhance CO₂ fixation in a reforming process.

References:

1. Challiwala, M. S., M. M. Ghouri, P. Linke, M. M. El-Halwagi, and N. O. Elbashir. 2017. 'A combined thermo-kinetic analysis of various methane reforming technologies: Comparison with dry reforming', Journal of CO₂ Utilization, 17: 99-111.
2. Gabriel, Kerron J, Patrick Linke, Arturo Jiménez-Gutiérrez, Diana Yered Martínez, Mohamed Noureldin, and Mahmoud M El-Halwagi. 2014. 'Targeting of the water-energy nexus in gas-to-liquid processes: A comparison of syngas technologies', Industrial & Engineering Chemistry Research, 53: 7087-102.