Hydrogen dissociative adsorption on pipeline steels in high-pressure gaseous environments

Hydrogen is acknowledged as a key player in energy transition and the pursuit of achieving the net-zero target. Pipeline can serve as an ideal transportation method for H2 due to its high efficiency, large capacity, and relatively low cost. However, H2 pipelines are facing the problem of Hydrogen Embrittlement (HE), which might cause catastrophic failure. However, due to the size limitation, only atomic H can enter the pipeline steel and lead into HE. Thus, research on atomic H generation on steel surface, i.e., dissociative adsorption, is essential to H2 pipelines application. Up to date, there have been limited investigations on hydrogen dissociative adsorption at irregularities on pipeline steel. In this work, hydrogen dissociative adsorption on steel crystalline plane is studied to verify the feasibility of simulation methodology. Models of typical irregularities on pipeline steel surface, i.e., grain boundary, dislocation, non-metallic inclusion are constructed. To the authors’ best knowledge, it is the first time to develop microstructure models considering surface effect. It is found that interior high angle grain boundary, edge dislocation core and the sites under tensile strain, Fe side of Al2O3 interface, are preferential sites for hydrogen adsorption. The bonding mechanism for hydrogen adsorption is determined to be orbital hybridization. Electrons will shift to adsorbed H atoms from nearby Fe atoms and Al/O atoms. Partition function is applied to indicate that high pressure and low temperature are favorable for hydrogen dissociative adsorption. Oxygen included gas impurities can inhibit hydrogen adsorption by competitive attraction of electrons, while CH4 can also slightly inhibit hydrogen dissociative adsorption. Based on literature review and conducted investigations, perspectives on atomic H generation and HE under gaseous environment, and inhibiting effect of certain impurity gases on hydrogen dissociative adsorption are provided.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Engineering – Mechanical & Manufacturing

Grantor dc:publisher.institution

Schulich School of Engineering

Year dc:date.issued

2024

Author dc:creator

• Sun, Yinghao

Advisor dc:contributor.advisor

• Cheng, Frank

Committee members dc:contributor.committeemember

• Egberts, Philip
• Hugo, Ronald

• Hydrogen embrittlement
• Pipelines
• Density functional theory

Statement dc:rights

• University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

en

DOI

https://dx.doi.org/10.11575/PRISM/47364

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:1880/119753