Why is this research needed?

Hydrogen (H₂) and gas-to-liquid (GTL) products are among the most relevant chemicals products in the market and, more than 60% of global demand is satisfied by natural gas and oil/naphtha reforming [1]. However, conventional reforming technology is responsible of large quantity of CO₂ emissions from chemical industries [2]. Lack of CCS in industry (including via hydrogen production) means emissions of 68Mt in 2030 (vs 58Mt in baseline) [3]. In recent years, different options have been proposed to separate CO₂ which are hampered by high capital and/or operating costs [4]. Instead, chemical looping combustion (CLC) is an emerging CO₂ capture technology with low energy and economic penalties. CLC is based on a metal oxide, also called oxygen carrier (OC) which is alternately reduced in presence of fuel and oxidized with air generating heat and resulting in an unmixed combustion. Similar concepts can be employed in order to convert fuels into syngas through partial oxidation called chemical looping reforming (CLR).

[1] N. Z. Muradov and T. N. Veziroglu, Int. J. Hydrogen Energy, 2005, 30, 225-237.
[2] IEA, Technology Roadmap: Energy and GHG Reductions in the Chemical Industry via Catalytic Processes, 2015.
[3] UKCCSRC, Delivering Cost Effective CCS in the 2020s – a new start, 2016.
[4] J. C. Abanades, B. Arias, A. Lyngfelt, T. Mattisson, D. E. Wiley, H. Li, M. T. Ho, E. Mangano and S. Brandani, Int. J.
Greenh. Gas Control, 2015, 40, 126-166.

What is this research investigating?

Most of the research in chemical looping has been addressed in interconnected fluidised bed reactors at atmospheric pressure since solid recirculation is extremely challenging at high pressure. However, high pressure chemical looping integrated with chemical processes such as H₂ and GTL production would make results very cost-effective reducing the cost of syngas compression. Therefore, recently, dynamically operated packed bed reactors (PBRs) have been tested at lab scale up to 7 bar.

The use of PBR poses several research questions in terms of reactor and process design because of the challenge in the reactor heat management and the integration with other units which are still unclear. Moreover, no systematic approach and benchmark comparison exists yet in high pressure chemical looping using different oxygen carrier/catalyst and its stability under prominent thermal and chemical cycling. Therefore a lot of research is currently ongoing for new generation of oxygen carrier; however, several formulations have already demonstrated to be stable after thousand cycles and therefore sufficiently promising to be tested in larger batches.

This one-year project comprises two interlinked work packages (WPs):

1. Experimental campaign (WP1) will first test two developed OCs based respectively on Ni and Fe oxide from Johnson Matthey to derive the kinetics and perform the characterisation of the material. The two materials will be tested under different reactive conditions in a packed bed reactor hot rig to achieve the complete proof of concept.
2. Process modelling (WP2) will integrate the kinetics of the material in a 1D phenomenological reactor model and validate it in order to design the large scale reactor and perform the mechanical design of the reactor and full assessment of the integrated process for reforming.

What does the research expect to find?

In CLYCHING, we propose to demonstrate the feasibility of chemical looping process for the production of H₂ and GTL at high pressure (up to 10 bar) and perform the preliminary design and cost assessment of the reactor and process. This will be achieved by combining experimental activity and modelling in cooperation with industrial partners, which are world leaders in the field of material development and process engineering.

The knowledge gained both from the experimental and numerical activities will be used as guidance for future pilot-scale demonstration of the technology together with the industrial partners.