Low temperature catalytic decomposition of methane for hydrogen production
Adélio Mendes, full professor at the University of Porto and coordinator of the 112CO2 project, describes the concept of the catalytic decomposition of methane at low temperature for the production of hydrogen without COx.
The world needs disruptive technology to rapidly decarbonize the energy sector; the success of this technology critically depends on its social acceptance, sustainability, low cost, and rapid implementation. The 112CO2 team believe they have this technology in place, the so-called decomposition of methane is necessary for the profitable production of CO.2-free hydrogen.
Decomposition of methane for the production of COx-free hydrogen
The methane decomposition reaction (MD) converts the methane in natural gas or biomethane to solid carbon and hydrogen. With the advantage of being 100% selective, this reaction has the power to produce clean hydrogen and remove atmospheric CO.2 at competitive costs. The advanced process for producing hydrogen from MD uses a moving bed reactor loaded with coal pellets, operating at ~ 1400 ° C. The main objectives in the context of 112CO2 are to lower the temperature to 550 ° C and to produce pure hydrogen in a compact, transportable, inexpensive and stable reactor; low stabilities are a problem in low temperature processes. The 112CO2 project started in September 2020 and brings together some of the most remarkable research laboratories and companies in the EU (UPORTO, CSIC, DLR, EPFL, Pixel Voltaic, Paul Wurth, Quantis).
“The main innovations discussed in 112CO2 are: i) making the MD catalyst very active, stable and regenerable; ii) pumping and electrochemical purification of hydrogen at high temperature; and iii) demonstrate a compact and efficient reactor capable of operating at low temperatures.
The development of the MD catalyst is a cooperative effort of CSIC, UPORTO and EPFL. The nanoscale control of composition and nanostructure is used as a driving force towards highly active catalysts, which further lend themselves to cyclic regeneration by hydrogenating gasification of a fraction of the deactivating carbon deposits on active surfaces, with minimal use of hydrogen. During the first year of the implementation of the project, precise methods of catalyst synthesis made it possible to understand the fundamental aspects of the course of this reaction on metallic nanocrystals, for example the phenomena of structural sensitivity. This information has led to the identification of optimal sizes of metal nanocrystals that result in very high hydrogen production rates (> 3 grams of hydrogen per gram of metal per hour) at remarkably mild operating temperatures (
Innovate in the field
DLR and UPORTO are working together to develop a device to purify the hydrogen obtained in the reactor. The device must be simple and able to be integrated into the reactor, and the process must be energy efficient. Our proposal is an electrochemical hydrogen pumping device based on proton conductive ceramics (PCC). PCCs show promise for electrochemical energy conversion devices, such as fuel cells, steam electrolysers, as well as hydrogen pumps. It can perform well at the operating temperature of the reactor which is ideal as no additional cooling / heating is required. In addition, electrochemical pumping makes it possible to pressurize the hydrogen up to several bars, and no pressurization condition is necessary in the reactor. Based on the successful demonstration of PCC at DLR, metal-supported PCCs are being developed for a cost-effective hydrogen pumping device, using inexpensive stainless steel porous metal substrates to make PCC cells by combining Wet chemical and physical processing routes for integration into single pumping units in the reactor.
UPORTO, the inventor of this new MD concept, is developing a new MD reactor approach for this process, allowing the cyclic regeneration of hydrogen. It should reach> 0.45 gH2 .g-1cat.h-1 and be stable for> 10000h. The production of carbon, a value-added by-product, not only covers the surface of the catalyst, but also clogs the reactor during operation. Therefore, the design of the reactor is optimized to improve hydrogen production, for easy catalyst regeneration and easy removal of produced carbon flakes. Preliminary results with a non-optimized commercial catalyst and with cyclic regeneration made it possible to maintain the activity for> 200h. Pixel Voltaic, a UPORTO spinoff company, is developing a prototype laboratory reactor. This demonstrative device, comprising the MD catalyst and the PCC membranes, will be tested in real conditions to push the technology from TRL1 to TRL4.
The life cycle assessment (LCA) of this revolutionary new technology is approached at Quantis, in accordance with international standards (ISO 14044), in order to identify the environmental performance and the main drivers of the technology compared to alternative solutions. In development, competing processes perform the MD reaction at high temperature and, namely, they use liquid metal reactors (~ 1000 ° C), iron ore (~ 900 ° C) or a carbon catalyst ( ~ 1400 ° C). These alternatives are however very energy intensive, dangerous to operate and use a very expensive reactor. The results will provide recommendations on the most promising configurations, thus guiding eco-design choices and the sustainable integration of 112CO2 technology.
In addition to the LCA, an economic evaluation will be carried out to determine the price of hydrogen produced by MD for different scenarios. Considering only the price of raw materials, hydrogen from natural gas and biomethane costs € 5.2 / kg and € 5.9 / kg (assuming € 83.9 / MWh for natural gas, € 95 / MWh for biomethane and 20 € / MWh for electricity). However, from these values, the selling price of the carbon produced (assumed 143 € / tonne) should be subtracted and, in the case of biomethane, the removal of CO should also be considered.2 of the atmosphere (assumed 88.9 € / tonne of CO2 deleted), which represent € 0.43 / kg and € 1.42 / kg, bringing the final price of hydrogen produced from natural gas to € 4.8 / kg and produced from biomethane to 4 , 5 € / kg. At the current price of CO2 (around 88.9 € / tonne), the hydrogen resulting from the steam reforming of methane costs 5.0 € / kg (just the cost of methane and CO2 quotas), being more expensive than the MD of natural gas. The carbon produced will be used in particular for civil engineering, soil amendment, road surfacing and electrodes in electrochemical systems.
112CO2 also offers an ambitious communication strategy, aiming to involve stakeholders, investors, researchers, young people and students for this emerging technology. UPORTO is responsible for the social impact analysis. Mapping of external stakeholders is currently underway; they were identified by sector of activity and classified according to four indicators: interest, urgency, risk and influence.
Visit the 112CO2 website to learn more about the project. The project includes two prizes (~ 140k €) related to the “constitution of an interdisciplinary community” and three grants (~ 65k €) concerning the creation of an innovative ecosystem around the DM.
Attention: This is a commercial profile
© 2019. This work is under license CC-BY-NC-ND.