Is Polyethylene PE100 Pipe Really the Best Pipe for Hydrogen Transport?

By PPN Editor

‍With the global push for clean and renewable energy sources, hydrogen has emerged as a promising candidate to replace traditional fossil fuels. It offers numerous advantages, including zero greenhouse gas emissions upon combustion, sustainability, and abundant availability.

As a result, many countries are investing heavily in hydrogen research and development. Efficient transportation of hydrogen through pipelines is a critical component of the emerging hydrogen economy. However, the choice of pipeline material is crucial, as the properties of the material can significantly impact hydrogen transport efficiency and safety. One of the materials gaining attention for this purpose is Polyethylene PE100.

The Challenge of Hydrogen Transport

The transportation of hydrogen gas poses unique challenges. Hydrogen molecules are small and have a high tendency to permeate through nonmetallic materials, leading to potential energy waste and safety concerns. Traditional metal pipes used for hydrogen transport can be prone to hydrogen embrittlement, blistering, and cracking, making them less than ideal for this application. This has led to a growing preference for nonmetallic pipes, but their higher gas permeation rates need to be addressed to ensure efficient and safe hydrogen transportation.

Research on Nonmetallic Pipe Materials

Recent research has focused on understanding the permeation characteristics of hydrogen in nonmetallic materials and selecting suitable materials to minimize hydrogen permeation. Among the nonmetallic materials considered, polyvinyl chloride (PVC), polyethylene (PE), and polyvinylidene fluoride (PVDF) have garnered significant attention due to their corrosion resistance, lightweight properties, low friction, and ease of installation. These materials are commonly used in various industries, including food packaging, construction materials, membrane separation, and medicine.

Permeation Studies on Various Materials

Several studies have investigated the permeation of hydrogen and other gases in these materials to gain insights into their material properties:

1. Polyvinyl Chloride (PVC): Research by Mao et al. demonstrated that PVC pipes effectively prevent the permeation of organic pollutants like benzene, toluene, and trichloroethylene under different environmental conditions. The findings highlight PVC's utility in resisting the permeation of certain substances.
2. Polyethylene (PE): Dutta et al. conducted molecular dynamics simulations to examine the dissolution and diffusion of nitrogen, carbon dioxide, and methane in polyethylene. They found that the solubility coefficient of nitrogen increases with rising temperature, while those of methane and carbon dioxide decrease. These insights into gas behavior in PE can guide material selection.
3. Polyvinylidene Fluoride (PVDF): PVDF has shown promise in resisting gas permeation. Studies by Flaconnèche et al. and Qi et al. revealed that PVDF exhibits superior resistance to gases such as hydrogen sulfide. The polarity of PVDF molecules, with two fluorine atoms, increases molecular forces, contributing to its enhanced resistance.

Polyethylene PE100: A Potential Contender

While PE is considered a viable nonmetallic material for hydrogen transport, its performance is influenced by various factors, including temperature.   On the other hand, PVDF emerges as a strong contender due to its superior resistance to hydrogen permeation. Its larger polarity, resulting from two fluorine atoms in each monomer unit, leads to increased molecular forces, making it an attractive choice for hydrogen transport.

Conclusions

Efficient and safe hydrogen transportation is crucial for the development of a sustainable hydrogen economy. While nonmetallic materials like PVC, PE, and PVDF offer advantages such as corrosion resistance and ease of installation, their permeation properties must be carefully considered. Recent research suggests that Polyethylene PE100, while suitable for hydrogen transport in certain conditions, may not be the best choice in all scenarios due to its temperature-dependent properties. In contrast, Polyvinylidene Fluoride (PVDF) demonstrates superior resistance to hydrogen permeation and appears to be a more reliable material for this critical application. As the hydrogen industry continues to evolve, the choice of pipeline material will play a pivotal role in ensuring the efficient and safe transport of this clean energy source.