Hybrid reactor for production of power, hydrogen and valuable chemical compounds from natural gas with integrated CO2 capture
2016 – 2018
Goal of the Project: Develop a hybrid reactor for simultaneous carbon-neutral generation of hydrogen, electricity and solid carbon
Technical content: In the near- to medium term future the production/co-production of electricity, hydrogen and solid carbon will continue to rely on the use of fossil fuels. These technologies currently remain a source of significant greenhouse gases (GHG) emissions. For example, most of the hydrogen (about 95%) is being produced by steam methane reforming (SMR) process. A typical SMR plant produces about 0,3-0,4 standard cubic meters of CO2 per one standard cubic meter of hydrogen, or 13,7 kg CO2 per 1 kg of H2. We propose a new concept – a hybrid pyrolysis / gasification reactor operating on natural gas (NG) or biogas. It allows both power production with integrated CO2 capture or stand-alone hydrogen production with carbon storage.
Technical advantages: The main purpose of the proposed innovation - a hybrid pyrolysis / gasification reactor - is to utilize NG for power production and co-production of hydrogen in a highly efficient process while capturing the NG carbon content. To achieve this, two technologies are tightly integrated. The first is the use of pyrolysis (thermal decomposition) of NG. The production of hydrogen by pyrolysis of methane (main component of the NG) can be described (simplified) as CH4Cs+2H2, ΔH = 75,6 kJ/mol. The second is the use of a high temperature solid oxide fuel cell (SOFC). By utilizing the excess heat of the SOFC as input to the pyrolysis reaction and alternating between carbon production and carbon gasification, a very high overall efficiency (>90%) is achieved. The theoretical efficiency greatly exceeds that of even combined cycle gas turbines (around 60%). This combination allows highly efficient production of power from fossil or bio-derived hydrocarbons while at the same time either eliminating production of CO2, (carbon is deposited as a solid), or creating a stream of pure CO2 for storage.
R&D challenges: The goal of the project is to collect the necessary knowledge and expertise that will allow later to build and demonstrate the technology in a pilot plant of a commercial scale. Technically this will be achieved by designing, building and testing a new hybrid pyrolysis – gasification reactor, finding and optimising the operating conditions (temperature, pressure, flow rates, gas composition, reactor shape) and investigating the over-time effects on the process efficiency and reactor materials. Solid oxide fuel cell will not be integrated or tested at this stage. The main R&D challenges lie in combining the reactor design and operating conditions to create a continuous pyrolysis-gasification process with stable high efficiency and scalability in a multi-variable engineering and testing campaign.
Results to date: To date, an analysis of the super-alloys for highly carbonizing conditions has been performed, the most promising materials identified, and the search for available shapes have been initiated. The work on the hybrid reactor design has started, and the conceptual design phase performed