Main group catalysis for H2 purification based on liquid organic hydrogen carriers
Taiki Hashimoto1, Takahiro Asada1, Sensuke Ogoshi1
1Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Science Advances
|October 26, 2022
Summary
This study shows N-heterocyclic compounds, known as liquid organic hydrogen carriers (LOHCs), can purify and store hydrogen gas (H2) from mixtures with CO and CO2. This bypasses costly traditional purification methods.
Area of Science:
- Energy storage and conversion
- Chemical engineering
- Materials science
Background:
- Molecular hydrogen (H2) is a key energy carrier, but its production often involves energy-intensive purification steps to remove contaminants like CO and CO2.
- Current methods for H2 purification increase production costs and environmental impact.
- Liquid organic hydrogen carriers (LOHCs) are established for H2 storage and release via dehydrogenation.
Purpose of the Study:
- To investigate the potential of N-heterocyclic compounds as liquid organic hydrogen carriers (LOHCs) for simultaneous H2 purification and storage.
- To develop a cost-effective and environmentally friendly alternative to conventional H2 purification processes.
- To demonstrate the separation of H2 from a complex gaseous mixture containing CO and CO2.
Main Methods:
- Utilizing N-heterocyclic compounds as LOHCs to capture H2 from a gaseous mixture.
- Simultaneously storing the purified H2 within the LOHC structure.
- Analyzing the composition of the gaseous mixture before and after the H2 separation process.
- Evaluating the feasibility of subsequent H2 release through dehydrogenation.
Main Results:
- Demonstrated successful separation of H2 from a mixture containing excess CO and CO2, along with CH4.
- Showcased the capacity of LOHCs to store purified H2.
- Indicated that LOHCs can effectively remove CO and CO2 contaminants from crude H2 streams.
- Confirmed the potential for H2 recovery via dehydrogenation from the H2-loaded LOHCs.
Conclusions:
- N-heterocyclic compounds acting as LOHCs offer a viable dual-functionality for H2 purification and storage.
- This approach presents a promising strategy to reduce the cost and environmental footprint of H2 production.
- LOHCs can be integrated into H2 production pathways to handle crude H2 streams, complementing their established storage applications.
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