Werner's Blog — Opinion, Analysis, Commentary
The commercialization potential of turquoise hydrogen

Hydrogen (H2) is considered an important energy carrier of the near future. Hydrogen complements the increasing electrification of many sectors of our economy. Importantly, hydrogen can be stored for when it is needed, and it can be transported and traded globally. Converting solar power or wind power into hydrogen will allow our electric grids to rely more on such intermittent sources. Hydrogen can also help decarbonize applications that are otherwise difficult to move away from fossil fuels, such as aviation and making steel. In addition to generating electricity from hydrogen through the use of fuel cells, hydrogen can be combusted directly in turbines and can be used in a number of industrial application. The main benefit of hydrogen is the ability to store and transport it. Hydrogen can be shipped through dedicated pipelines, it can be liquefied, and it can also be converted into ammonia (which is much easier to liquefy than hydrogen). Hydrogen is an important part of Canada's energy policy. The Government of Canada has an explicit hydrogen strategy to develop hydrogen supply, and BC's provincial gobernment has a local B.C. hydrogen strategy.

Hydrogen production is colour-coded. Currently, about 95% of hydrogen is produced through steam-methane reformation (SMR) that generates carbon dioxide. This process is called grey hydrogen. Hydrogen can also be produced from coal through gasification as a precursor step; that is called brown (or black) hydrogen. If carbon dioxide emissions from these processes are captured and stored (CCS), then the resulting hydrogen is considered blue hydrogen. Green hydrogen is made from renewable energy sources through electrolysis. Green hydrogen is currently still expensive to produce, but production costs are expected to come down significantly through innovation both into electrolyzers and into renewable power production. And there is also pink hydrogen when electrolyzers are powered by nuclear power instead of renewable energy sources. Which of the clean hydrogen production methods succeeds commercially depends much on innovation, carbon pricing, and developing economies of scale.

‘Methane pyrolysis creates two useful products: hydrogen and carbon black. With turquoise hydrogen, natural gas has a sustainable future.’

Between blue and green hydrogen lies turquoise hydrogen. This is a novel technology where methane (CH4) is converted into solid carbon black (C) and gaseous hydrogen (H2) through an endothermic reaction: methane pyrolysis. Many firms around the globe are working on commercializing this idea because it is economically and environmentally attractive. Economically, methane pyrolysis could become cheaper than blue hydrogen because the latter still generates some emissions that are subject to a carbon price. Carbon dioxide emissions from blue hydrogen production are a waste product that needs to be sequestered at some expense; it's a cost factor unless it can be utilized for enhanced oil recovery. Carbon black from turquoise hydrogen production is a useful byproduct: it can be sold and used. For example, carbon black can be turned into graphite and graphene. As The Economist reported in May 2022, graphene may have found its killer app: adding graphene to cement makes it stronger, requiring less cement, whose production generates a large amount of carbon dioxide emissions. Thus carbon black could become a valuable byproduct of producing hydrogen through methane pyrolysis. I had previously written about methane cracking in 2016; "methane cracking" is a colloquial term for methane pyrolysis.

In Burnaby, start-up company Ekona Power Inc. is pioneering turquoise hydrogen production. In early 2022, Ekona received an infusion of $79mio of venture capital from Baker Hughes with participation from several other energy firms and investment firms. Ekona uses a technology called pulse combustion for pyrolysis. The process is typically referred to as pulsed methane pyrolysis (PMP). The reactor produces a partial combustion of methane to heat the vessel to about 1,200°C–1,500°C, with pressure cycles up to 20 bars and one pulse per second. The process produces hydrogen, solid carbon, unreacted methane, and a small amount of carbon dioxide, as well as combustion flue gases. However, the process does not require a catalyst.

In Port Moody, Fortis BC and Suncor are partnering with Australian technology firm Hazer Group Ltd. on building a turquoise hydrogen plant, starting with construction of a prototype facility in 2023. The new plant is expected to produce 2,500 tonnes of hydrogen per year along with 9,000 tonnes of synthetic graphite as a by-product. Hazar's particular patented process uses an iron-oxide (Fe2O3, Fe3O4) catalyst in a fluidized bed reaction vessel.

‘Turquoise hydrogen will very likely have a cost advantage over green hydrogen for some time.’

There are a number of different and competing methane pyrolysis methods. Some (like Hazer's approach) involve a catalyst, but the solid carbon produced by the process often leads to fouling of the catalyst and thus decreases efficiency. Much work has gone into finding suitable chemistries that maintain production efficiency over long times. There are alternative processes to Hazer's catalyst approach or Ekona's PMP approach. Methane can also be cracked in a microwave plasma and through a metal electrode plasma arc (known as "Hüls plasma-reforming"). French company Plenesys uses another plasma arc technology with an AC graphite electrode. With a reactor temperature between 1,500°C–1,800°C, a recycling loop can achieve a high hydrogen level (about 98% compared to 70-80% for PMP). Which of these technologies succeeds commercially will depend on cost. Thermal pyrolysis of the type developed by Ekona has the prospect of lower production cost than plasma pyrolysis. Over the next decade,h hydrogen production costs below $2/kg are fefasible. Rapid innovation into commercial-scale turquoise hydrogen production appears very promising and will have a commercial edge over green hydrogen for some time.

Turquoise hydrogen gives countries with large natural gas reserves a new market, superior environmentally to blue hydrogen, and to exporting LNG. Of course, there are important concerns that remain to be addressed environmentally. The largest concerns are about upstream emissions from methane production and through methane leakage. For turquoise hydrogen to have an environmentally sustainable future, these upstream emissions need to be tackled effectively. Emission intensities vary greatly across production sites in Canada. Sourcing natural gas from low-leakage sites is therefore crucial for maintaining the green credentials of turquoise hydrogen plants. Yet, turquoise hydrogen offers a bright future for British Colubmia's natural gas industry. Unlike oil and coal, natural gas has the potential of remaining a valuable natural resource that is compatible with climate action goals if methane cracking can be made commercially successful.

Further readings and sources:

Posted on Thursday, July 7, 2022 at 07:07 — #Energy | #Technology
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© 2022  Prof. Werner Antweiler, University of British Columbia.
[Sauder School of Business] [The University of British Columbia]