Periodic Reporting for period 2 - 112CO2 (Low temperature catalytic methane decomposition for COx-free hydrogen production)
Berichtszeitraum: 2021-09-01 bis 2023-02-28
The world needs a disruptive technology to very quickly decarbonize energy; the success of this technology depends heavily on its social acceptance, sustainability, and fast and easy implementation. 112CO2 aims at developing this technology: the low-temperature catalytic methane decomposition (MD). This reaction would allow in a very short time to produce COx-free hydrogen from natural gas or biogas. This technology enables using the present storage and distribution infrastructure for natural gas and produces hydrogen to be used locally as a fuel for electricity/heat or as feedstock for chemical industries. Apart from allowing the swift decarbonization of the energy, when biomethane is used, this reaction has the power to remove CO2 from the atmosphere as it produces hydrogen at very competitive costs.
The industrialization of MD has been hindered so far by the extremely fast catalyst deactivation, which is caused by the inevitable coverage of catalytic sites by the formed solid carbon. Competing institutions/companies are developing high temperature processes involving either metal liquid reactors or reactors using carbon catalyst particles; however, these approaches are energy-intensive, dangerous to operate, and display low catalytic activity. The 112CO2 designed reactor uses Ni-based catalysts, which are very active but need to be cyclically regenerated. Catalytic regeneration is achieved using hydrogen and selectively flipping the reaction direction, promoting carbon detachment that enables cyclic removal of commercially valuable carbon from the reactor.
The industrialization of MD has been hindered so far by the extremely fast catalyst deactivation, which is caused by the inevitable coverage of catalytic sites by the formed solid carbon. Competing institutions/companies are developing high temperature processes involving either metal liquid reactors or reactors using carbon catalyst particles; however, these approaches are energy-intensive, dangerous to operate, and display low catalytic activity. The 112CO2 designed reactor uses Ni-based catalysts, which are very active but need to be cyclically regenerated. Catalytic regeneration is achieved using hydrogen and selectively flipping the reaction direction, promoting carbon detachment that enables cyclic removal of commercially valuable carbon from the reactor.
During the 30-months period of 112CO2, the expected goals were successfully addressed. CSIC was responsible to synthesize the Ni-based catalysts; activities > 0.45 gH2 gcat-1 h-1 target productivity could be sustained for several hundreds of hours on stream. Research efforts aimed at fundamental knowledge for understanding the reaction mechanisms and the chemical processes involved in Ni-based catalysts, combining in-situ synchrotron spectroscopy and DFT. DLR developed proton conducting ceramic (PCC) half-cells in metal-supported architecture (MS-PCC), aiming to achieve 1 μm-thick gas-tight PCC electrolyte in button-sized cells. Hydrogen pump test stand is ready for operation and the optimization of hydrogen splitting electrode is on-going. A planar catalytic reactor was selected by UPORTO as the optimum design, which allowed to reach >3000 h of reactor operation at 550 ºC, and employing cyclic regeneration. CFD modeling was an important tool to simulate and optimize a wide set of reactor and process parameters.
An up-scaled reactor was designed and is currently under construction by Pixel Voltaic. Two new and large-scale experimental set-ups were designed to test multiple reactors at the same time. One of the new set-ups will also allow for the prototype demonstration. The preliminary results of the life cycle assessment showed that the production of 1 kgH2 emits less CO2-eq than competing hydrogen production technologies. In terms of economic impacts, the levelized cost of hydrogen (LCOH) by MD for various scenarios was estimated considering the CAPEX and OPEX of a MD process. The valorization of different carbon products for different types of applications is also being considered in the economic study. Pixel Voltaic prepared a first business plan, as the main end-user and potential exploiter of this technology.
An up-scaled reactor was designed and is currently under construction by Pixel Voltaic. Two new and large-scale experimental set-ups were designed to test multiple reactors at the same time. One of the new set-ups will also allow for the prototype demonstration. The preliminary results of the life cycle assessment showed that the production of 1 kgH2 emits less CO2-eq than competing hydrogen production technologies. In terms of economic impacts, the levelized cost of hydrogen (LCOH) by MD for various scenarios was estimated considering the CAPEX and OPEX of a MD process. The valorization of different carbon products for different types of applications is also being considered in the economic study. Pixel Voltaic prepared a first business plan, as the main end-user and potential exploiter of this technology.
Low temperature (500-650 ºC) catalytic MD has been only used in industry to produce solid carbon structures because, after short operation times, these completely block the catalyst and shut-down the reactor. This has been hindering a continuous H2 production that is much cheaper than electrolysis and that can replace the reforming of hydrocarbons, which requires expensive carbon capture and sequestration systems.
Competing institutions/companies are developing high temperatures (> 1000 ºC) MD processes, involving either metal liquid reactors or using carbon catalysts; however, these approaches are energy-intensive, dangerous to operate, and display low catalytic activity. Though the promising advantages of fast reaction kinetics, high power density and lower costs, the low-temperature catalytic methane decomposition process has never been successfully demonstrated for periods longer than 200 h. The EU Project 112CO2 is overcoming the challenges that will make H2 easily available also for mobility applications, in compact and safe devices. It was developed a unique cyclic regeneration strategy, which combined with a disruptive reactor design and a nickel-based supported catalyst, makes the MD to be fully stable for thousands of hours. This idea was disclosed in a patent application (WO/2020/121287) by Pixel Voltaic. The reaction in these conditions is 100 % selective, allowing the hydrogenation of the catalyst/coke interface, making the produced carbon to detach periodically from the catalyst surface; this hydrogenation process uses ca. 6 % of the H2 produced. This reaction is equilibrium limited, where at 600 °C and 1 bar the equilibrium conversion is ca. 60 %. Very recently, the consortium proved >3000 h of continuous operation at 550 °C with a constant catalyst productivity of 0.64 gH2/gCat/h. But the experiment is going on, aiming at reaching over 6000 h of fully stable operation, by September 2023.
The 112CO2 team is continuing to improve the catalyst aiming at displaying higher catalytic activities. Also, the reactor is being optimized to reach even higher power densities – target power density of 10 kW/L, while the H2 permeable membranes are being improved to display higher permeabilities. 112CO2 consortium has an ambitious program for delivering a fully integrated lab low-temperature catalytic methane decomposition membrane reactor, while a pilot reactor is expected to be demonstrated by the end of 2024. This pilot will be tested under real conditions to reach TRL 4.
The carbon by-product is >90 % graphitic, which is a quite valorized carbon and especially suitable for making electric conductive carbon paints, electrodes for electrochemical devices, bipolar plates for PEMFC and redox flow batteries, anodes of sodium-ion batteries, among a variety of other high-value applications. However, these carbon particles of ca. 100 µm can also find use for making concrete, asphalt for streets and fertilizers for soil.
If the methane used comes from a renewable source such as biogas, this reaction not only would remove CO2 from the atmosphere, but it also would allow to produce graphitic renewable carbon and bright-H2 – the proposed color-code for this H2, produced from a renewable source, with negative CO2 emissions and low cost. Also, it can be made to react with CO2 from biogas to produce bright methanol, with an estimated cost of ca. 300 €/ton, which compares quite nicely with the present price from Methanex – 478 €/ton, and if the emitted CO2 is included in the methanol price, with the final value of 611 €/ton.
Competing institutions/companies are developing high temperatures (> 1000 ºC) MD processes, involving either metal liquid reactors or using carbon catalysts; however, these approaches are energy-intensive, dangerous to operate, and display low catalytic activity. Though the promising advantages of fast reaction kinetics, high power density and lower costs, the low-temperature catalytic methane decomposition process has never been successfully demonstrated for periods longer than 200 h. The EU Project 112CO2 is overcoming the challenges that will make H2 easily available also for mobility applications, in compact and safe devices. It was developed a unique cyclic regeneration strategy, which combined with a disruptive reactor design and a nickel-based supported catalyst, makes the MD to be fully stable for thousands of hours. This idea was disclosed in a patent application (WO/2020/121287) by Pixel Voltaic. The reaction in these conditions is 100 % selective, allowing the hydrogenation of the catalyst/coke interface, making the produced carbon to detach periodically from the catalyst surface; this hydrogenation process uses ca. 6 % of the H2 produced. This reaction is equilibrium limited, where at 600 °C and 1 bar the equilibrium conversion is ca. 60 %. Very recently, the consortium proved >3000 h of continuous operation at 550 °C with a constant catalyst productivity of 0.64 gH2/gCat/h. But the experiment is going on, aiming at reaching over 6000 h of fully stable operation, by September 2023.
The 112CO2 team is continuing to improve the catalyst aiming at displaying higher catalytic activities. Also, the reactor is being optimized to reach even higher power densities – target power density of 10 kW/L, while the H2 permeable membranes are being improved to display higher permeabilities. 112CO2 consortium has an ambitious program for delivering a fully integrated lab low-temperature catalytic methane decomposition membrane reactor, while a pilot reactor is expected to be demonstrated by the end of 2024. This pilot will be tested under real conditions to reach TRL 4.
The carbon by-product is >90 % graphitic, which is a quite valorized carbon and especially suitable for making electric conductive carbon paints, electrodes for electrochemical devices, bipolar plates for PEMFC and redox flow batteries, anodes of sodium-ion batteries, among a variety of other high-value applications. However, these carbon particles of ca. 100 µm can also find use for making concrete, asphalt for streets and fertilizers for soil.
If the methane used comes from a renewable source such as biogas, this reaction not only would remove CO2 from the atmosphere, but it also would allow to produce graphitic renewable carbon and bright-H2 – the proposed color-code for this H2, produced from a renewable source, with negative CO2 emissions and low cost. Also, it can be made to react with CO2 from biogas to produce bright methanol, with an estimated cost of ca. 300 €/ton, which compares quite nicely with the present price from Methanex – 478 €/ton, and if the emitted CO2 is included in the methanol price, with the final value of 611 €/ton.