The MACH-2 project was a KSP project in the CLIMIT program and had a project period between 2019 and 2024. The MACH-2 project aimed to develop and demonstrate the potential of an innovative hybrid technology for H2 production with CO2 capture enabling high carbon capture rates with high purity CO2 and H2 and a hydrogen cost comparable to conventional technologies without capture. The MACH-2 project was a collaboration between SINTEF Industry, SINTEF Energy AS, and the Norwegian University of Science and Technology. The project was spun off from the NCCS FME centre and executed as a task under this centre. The project has combined H2 production from methane by protonic membrane reformer (PMR) technology with subsequent low-temperature CO2 capture in one novel integrated process. By exploiting the advantages of both technologies and applying them in their preferred window of operation, significant cost and efficiency gains are expected. The project consisted of three main activities.
The process and system design has focused on the optimization of the hybrid system which has many degrees of freedom that require to be further analysed, both individually and how they interact. A governing criterion is the hydrogen recovery factor (HRF) in the membrane unit, which is a function of the applied membrane area and current density. It is found that in order to maximize the energy efficiency, optimal integration of the PMR and the CO2 separation processes are desired, including recycling from the CO2 capture process and a water-gas shift (WGS) reactor for the retentate gas from the PMR to convert the CO in the feed gas to the liquefaction process. Also, the developed process is benchmarked against state-of-the-art technology H2 production processes through a detailed techno-economic evaluation. This analysis reveals that the PMR-based hybrid concept appears a promising option to generate hydrogen with a low carbon intensity.
In close cooperation with FME NCCS Task 3 the potential gains in membrane robustness under MACH-2 operating conditions were investigated applying single PMR cell tests for nearly 1800 h. The gas composition and flow rate on the feed side were varied to simulate different rates of hydrogen recovery and to assess the impact of CO and CO2 on degradation. The results show that the area specific resistance of the cell increased with increased H2 recovery while the degradation rate, notably, decreased. Adding small amounts of CO or CO2 to H2-H2O had similar impact on increasing the immediate cell resistance, but CO led to almost twice the degradation rate compared to CO2. WP2 has made use of the ECCSEL infrastructure, TA 4.4, SINTEF MLab.
Low-temperature CO2 separation experimental campaigns, under conditions relevant for the MACH-2 process, were also conducted. For this, the Cold Carbon Capture Pilot rig (ECCSEL NO2.4) has been upgraded for the use of relatively high concentrations of flammable and poisonous gases (H2, CH4 and CO) relevant for the membrane-retentate gas. After the upgrade, successful measurement campaigns have been conducted with feed gas rates up 7.4 ton per day at CO2 feed fractions between 56 and 82 mol % to cover the range relevant for retentate gas. CO2 was separated by liquefaction and phase separation at pressures between 40 bar and 70 bar. The corresponding separator temperatures were between -55 °C and -45 °C. CO2 purities up to 99.90 mol % were achieved. The experiments showed that this purity can be controlled through the pressure level in the flash purification separator, as well as through regulating the temperature upstream of the inlet throttling valve. Results from the experiments and corresponding predictions based on GERG-2008 and Peng–Robinson are generally consistent. In MACH-2, the low-temperature CO2 capture process has thus been proven at TRL 4–5. The technology is ready for further advancement since the results were in accordance with expectations.
Where possible the MACH-2 project has laid emphasis on communicating the goal as well as the results of this project, both through scientific and more popular scientific channels. This has enabled exchanging information with other scientists in relevant fields and promoting the results to industry and end-users. The project has so far resulted in 3 journal articles in peer-reviewed journals and various conference and/or seminar contributions. The competence and results obtained in the MACH-2 project have also already been exploited in other ongoing projects and/or accepted project proposals. It is furthermore expected that the outcome of MACH-2 will be central for the establishment of a new project that will demonstrate 50 kg/day of hydrogen production with integrated CO2 liquefaction. Further exploitation will be considered in the upcoming RCN and EU calls.
De potensielle virkningene til MACH-2-resultatene påvirker flere nivåer. Fra et overordnet perspektiv har avkarbonisering av naturgass gjennom H2-produksjon kombinert med CCS et stort potensial for utslippsreduksjoner og dermed miljøgevinster. I denne forbindelsen leverer prosjektet reduserte CO2-utslipp knyttet til H2-produksjon med en karbonfangstrate på opptil 99 %. Hybridprosessen som ble utviklet har vist seg å ha høyere energikonverteringseffektivitet enn konvensjonelle blått H2 produksjonsprosesser. Andre forventede fordeler er mer på komponent- eller systemnivå; PMR-celleeksperimentene har gitt innsikt i effekten av prosessparametere på ytelse og stabilitet til PMR-kjerneteknologien. Dette resulterer i lavere CAPEX for hele prosessen, noe som også gjør hybridkonseptet mer attraktivt fra et økonomisk perspektiv. Resultatene oppnådd i lavtemperatur CO2-separasjonseksperimentene samsvarer med prediksjoner i simuleringsmodeller med konvensjonelle termofysiske egenskapsmodeller. Denne bekreftelsen er avgjørende for videreutviklingen og TRL-utviklingen av teknologien, fra TRL 4–5 til høyere TRL i fremtidige demonstrasjonsprosjekter. Prosessmodellen som har blitt utviklet som integrerer PMR-teknologi med lavtemperatur-CO2 flytendegjøring har vært svært nyttig for design av H2-produksjonsenheter som skal demonstreres i fremtidige prosjekter, hvor CoorsTek deltar.
The MACH-2 project will develop and demonstrate the potential of an innovative hybrid technology for H2 production with CO2 capture enabling high carbon capture rates with high purity CO2 and H2 and a hydrogen cost comparable to conventional technologies without capture. The project will combine H2 extraction from syngas by membrane technology with subsequent low-temperature CO2 capture in one integrated novel process. The low carbon residual fuel produced as the off-gas from the liquefaction process is aimed to provide sufficient heat input to the reforming stage.
By exploiting the advantages of both technologies and applying them in their preferred window of operation, significant cost and efficiency gains are obtained. Based on the concept, a targeted carbon capture rate of over 95% is projected with a specific energy penalty of less than 2 MJ/kg CO2. The H2 cost is expected to be less than 2 euro/kg. This H2 production cost is comparable to conventional technologies without carbon capture, which emit almost 10 kg CO2/kg H2.
The MACH-2 project is a collaboration between SINTEF Industry, SINTEF Energy AS, and the Norwegian University of Science and Technology, and involves international cooperation with West Virginia University in the US. They are chosen based on their world leading expertise in high-temperature membranes (SINTEF Industry), large-scale hydrogen production and liquefaction from renewable power as well as natural gas reforming with CO2 capture (SINTEF Energy AS), and process systems engineering (NTNU). Furthermore, international collaboration between SINTEF/NTNU and Prof. D. Bhattacharyya's "Advanced Process and Energy Systems Engineering" group at West Virginia University, will strongly contribute to expand knowledge and skills. By leveraging on activities in previous EU and national projects, MACH-2 represents thus a compact consortium that allows integrating knowledge from several partners.
