ENEOS invests A$200 million in Australian green hydrogen demonstration plant; methylcyclohexane
29 January 2025
Japanese energy company ENEOS is building a A$200-million green hydrogen demonstration plant in Brisbane, Queensland. The plant will produce up to 680 kilograms of green hydrogen per day from 2026.
The green hydrogen will be in the form of methylcyclohexane (MCH). MCH can be transported at room temperature and normal pressure, making it easy to store and transport. ENEOS will ship a portion to Japan.
Methylcyclohexane (MCH) is a liquid hydrogen carrier made by the chemical reaction of hydrogen with toluene. MCH contains more than 500 times more hydrogen per unit volume than hydrogen gas. MCH is a liquid with petroleum-like characteristics that can be transported at ambient temperature and pressure, and can be used in existing petroleum infrastructure. After dehydrogenation, the toluene can be reused to create MCH again. Both toluene and MCH are toxic substances.
Eneos’ Direct MCH uses an electrolyzer to produce MCH directly from water. Water is oxidized on the anode catalyst to produce oxygen, protons, and electrons. The resulting protons flow to the cathode through the ion exchange membrane, where they react with toluene and electrons from the external circuit on the cathode catalyst to produce MCH.
ENEOS will start building the plant in 2025. Production is expected to start by the middle of the following year. The project will run for two years and create 100 jobs. The new plant builds on an earlier investment in a smaller demonstration plant at the same site. (Earlier post.)
ENEOS is partnering with Japanese companies such as Chiyoda Corporation, Sumitomo Electric Industries, TOPPAN and AGC on the project. It is also working with Australian companies such as GPA and GRPS.
The demonstration project was commissioned by the New Energy and Industrial Technology Development Organization (NEDO). NEDO is Japan’s national research and development agency.
The project was also supported by the Green Innovation (GI) Fund established by the Japanese Ministry of Economy, Trade and Industry. The GI Fund is an approximately A$28 billion fund aimed at helping Japan achieve carbon neutrality by 2050.
Australia is set to become a major producer of green hydrogen. There are currently more ethan 100 hydrogen projects (Source: Department of Climate Change, Energy, the Environment and Water, National Hydrogen Strategy 2024) under development in the country. Of these, 31 are operating or under construction (CSIRO, HyResource Database).
Australia is also close to economies such as Japan and Korea that want to decarbonise their heavy industries. These economies have expressed a significant interest in importing renewable hydrogen and its derivatives.
Eneos scheme for using MCH as a hydrogen carriers involves two processes.
1. Electrolysis of water and toluene to MCH.
2. Dehydrogenation of MCH and utilization of the H2 in a fuel cell.
Here is some verbiage about these two processes from their web site (https://www.eneos.co.jp/english/rd/research/carbon-neutral/https://www.eneos.co.jp/english/rd/research/carbon-neutral/):
"A schematic diagram of the Direct MCH process is shown in Fig. 1. Oxygen is generated at the anode (left side) by electrolysis of water and toluene is converted to methylcyclohexane (MCH) at the cathode (right side). Although a complex process up to now, Direct MCH® enables MCH to be produced by a simple process with only an electrolyzer.
The key performance indicators in this process are current density (reaction rate) and Faraday efficiency (reaction selectivity). Improving these indicators can reduce facility costs in MCH production and lower hydrogen costs.
At ENEOS, we are working to improve these performance indicators by developing electrode catalysts, controlling the macro and micro structures of the catalyst layer and diffusion layer, enhancing the design of the electrolyzer structure, etc.
MCH-FCTM consists of a methylcyclohexane (MCH) dehydrogenation process, hydrogen-separation process and hydrogen-utilized power-generation process (fuel cell). By performing these three processes in a single system, the heat required for the dehydrogenation process can be provided by the waste heat generated by the power-generation.
In order to properly perform this thermal management and achieve high energy efficiency, it is necessary to have advanced technological capabilities to assemble the system as intended. We are working with world-leading companies in each of these technologies to develop such systems."
It is pretty clear that in spite of the demos they are doing that this is still very much a research a development process, and it remains to be seen whether an economically practical process will emerge from this effort.
It is also clear that they are not planning to use the hydrogen in automobiles or airplanes. Integrating dehydrogenation and H2 separation with the fuel cell imply a relatively bulky plant which would be more appropriate for stationary generation than for mobility applications.
Posted by: Roger Brown | 29 January 2025 at 08:01 PM