IDTechEx: Methane pyrolysis and turquoise H2 should not be overlooked

In its market report “Blue Hydrogen Production and Markets 2023-2033: Technologies, Forecasts, Players,” technology company IDTechEx explores the topic of turquoise hydrogen and delves into the various methane pyrolysis technologies, their benefits, drawbacks and the key commercial activities shaping this industry.

In the hydrogen production spectrum, blue and green hydrogen have emerged as key solutions to a low-carbon future, IDTechEx said, noting that blue hydrogen is produced by reforming natural gas with steam or partially oxidising it with oxygen while capturing and storing the CO2 emissions from the process, while green hydrogen is generated through the electrolysis of water powered by renewable energy sources such as wind or solar, rendering it carbon-free in terms of Scope 1 and 2 emissions.

When it comes to turquoise hydrogen, the approach is different. IDTechEx pointed out that turquoise hydrogen is generated via methane pyrolysis, a process where methane is decomposed into hydrogen and solid carbon at high temperatures without releasing any direct CO2, making turquoise hydrogen a more environmentally friendly option than blue hydrogen as it avoids the need for carbon capture and storage (CCS).

“Compared to green hydrogen, the production of turquoise hydrogen is typically more cost-effective and easier to scale due to its reliance on the abundant and currently more affordable natural gas as a feedstock. In addition, the process is thermodynamically much less energy intensive than water electrolysis, requiring around seven times less energy per mole of H2 produced. This is especially advantageous, considering that many methane pyrolysis process variations can be fully electrified, thus removing Scope 2 emissions. The use of biogas as a feedstock could potentially make the process carbon negative,” IDTechEx reported. To note, research on other uses of turquoise hydrogen is also underway.

IDTechEx identified three broad types of methane pyrolysis processes, and all are quite different in terms of their working principles, pros and cons, stages of development and the relative number of players developing them. There are also more variations of these.

Three broad types of processes are:

• Thermal: non-catalytic thermal decomposition using very high temperatures (1000-1400°C). Heating is supplied via the reactor walls or heat exchange tubes (if combustion is used). Companies developing this process include BASF (resistive heating of reactor walls) and Ekona Power (heating by combustion of tail gases).
• Catalytic: thermocatalytic process that employs either a molten catalyst in a bubble column or catalyst particles in a fluidised bed reactor. Companies developing this process include C-Zero (molten salt catalyst) and Hazer Group (solid iron ore catalyst).
• Plasma: methane molecules are split by high-temperature plasma (via plasma torches) or microwave-generated low-temperature plasma. Companies developing this process include Monolith (high temperature) and Transform Materials (low temperature).

IDTechEx said it believes that plasma pyrolysis processes are by far the most advanced in terms of the stage of technological development and the number of players, and they are also the most energy-efficient processes.

In regard to the commercial interest and activity in methane pyrolysis, IDTechEx noted that the companies developing methane pyrolysis span across multiple regions, with North America (primarily the US) and Europe (primarily the UK, France and Germany) dominating development in terms of the number of players and their technological readiness levels (TRL).

Aside from the many benefits of methane pyrolysis, IDTechEx claimed that the technology comes with some drawbacks as well:

“The need for methane (natural gas) is a shared challenge with blue hydrogen as it means hydrogen production will rely on natural gas. Additionally, the hydrogen yield per mole of natural gas used is lower than that of blue hydrogen processes, such as steam-methane or auto-thermal reforming (SMR & ATR). There are also some challenges associated with the carbon by-product. Off-take agreements can only be established for a quality carbon product. Otherwise, the carbon would have to be sequestered underground.”

“In addition, methane pyrolysis generates 3 kg of carbon black for every kg of hydrogen. Therefore, pyrolysis plants would only be able to scale to very large scales (in the millions of tonnes of hydrogen) if suitable markets for the by-product are available. Otherwise, the process economics may be prohibitive.”

Overall, IDTechEx said it believes that the use of methane pyrolysis will be rather limited in the hydrogen industry compared to blue and green hydrogen as the technologies still need to develop and be demonstrated at commercial scales. However, it noted: “That does not mean that methane pyrolysis and turquoise hydrogen should be overlooked since various industries could benefit from such technologies.”