Hydrogen circulation built-in system for CO2 recycling, methane production, and carbon capture

Advantages

• Enables methane production at 1/2 the amount of H₂ used in the standard process
• A process that promotes “methane production from CO₂” and “solid carbon capture” at a higher conversion rate
• Equipment incorporating H₂ and CO₂ recycling process through membrane separation

Background & Technology

The increasing atmospheric carbon dioxide (CO₂) levels are becoming a global concern, which has prompted researchers to advance the technologies for CO₂ reduction to meet Japan’s 46 % CO₂ reduction target for FY2030 and net-zero CO₂ emissions by FY2050. Against this backdrop, the development of technologies for “zero-emission thermal power generation” with no CO₂ emissions and “CO₂ recycling” has been gaining momentum. One strategy for “CO₂ conversion to resources” is to convert CO₂ into methane, which can be used as a fuel. However, the methanation process has challenges in terms of procurement volume and cost because of the large amount of hydrogen used, which is in increasing demand as a next-generation energy source.　Furthermore, CO₂ generation is observed upon the consumption of produced methane hence, innovative process engineering is required to avoid the re-generation of CO₂.

The research group found that when the amount of hydrogen used for methane conversion was reduced to half of its original concentration, the amount of remaining CO₂ was increased, and methane gas in this excess CO₂ state significantly improved the dry reforming efficiency in comparison　to the conventional method. Based on the aforementioned key principle, the technology was developed: “methane conversion with half the amount of hydrogen and solid carbon conversion from the produced methane” and “hydrogen and CO₂ recycling equipment through membrane separation”.

The illustration shown below is a conceptual chart of this technology. The 19047 invented by the same researcher shows a continuous treatment system of “methane conversion and dry reforming” and “continuous carbon capture” with almost no catalyst degradation, and the present technology is an improvement of the 19047.

Data

Relationship between CH₄ conversion, emissions H₂/CO ratio and reaction time

It was confirmed that the CH₄ conversion rates at higher CO₂/CH₄ ratios of 1.2, 1.5, and 2.0 were higher than the CH₄ conversion rate with CO₂/CH₄ ratio equivalent to 1.0, the amphoteric ratio of the dry reforming reaction.

This confirms that the dry reforming reaction can proceed efficiently and for a long time by using a gas with a relatively higher CO₂ ratio discharged from the methanation reactor.

Patent

Pending

Publication

Fukuhara et al.; J. of CO₂ Utilization, 22 (2017) 91/ Chemical Engineering Journal Advantages, 5(2021) 100057
https://www.sciencedirect.com/science/article/abs/pii/S2212982017304912

Fukuhara et al.; Applied Catalysis A: General 492 (2015) 190-200
https://www.sciencedirect.com/science/article/abs/pii/S0926860X14007467

_Researcher

Professor Choji Fukuhara

National University Corporation Shizuoka University, Graduate school of Science and Technology

Expectations

We are looking for companies interested in developing practical applications for this methane production and solid carbon recovery equipment, or for partners interested in developing the CCU and CCUS processes.

Project No. ON-04195