Congratulations, Ali, for successfully defending his thesis and receiving his Master's degree

08 May, 2024

Congratulations to Ali M. Alghamdi for successfully defending his thesis and receiving his Master's degree.

Thesis: Diffusion of CO2 in HDPE and Subsequent Rapid Gas Decompression Damage For Sustainable Energy Pipeline Materials


  • Prof. Carlos Grande 
  • Prof. Frédéric Laquai 
  • Prof. Gilles Lubineau (Supervisor)


In this master thesis, the diffusion behavior of carbon dioxide (CO2) in High-Density Polyethylene (HDPE) pipe materials and its impact on rapid gas decompression (RGD) damage was investigated. The suitability of HDPE for carrying CO2 containing medium is of particular interest to the energy industry as CO2 pipelines play a critical role in carbon capture and storage in sustainable blue hydrogen production, and enhanced oil recovery strategies. RGD damage is a concern for polymeric materials used to transport gasses under high pressures and temperatures. RGD damage can lead to deterioration of the lifetime of the pipes, and economically and environmentally damaging scenarios. To address this challenge, diffusion behavior was studied via gravimetric sorption analysis with magnetic suspension balance on samples extracted from extruded HDPE pipes. Data filtering techniques and numerical methods were used to estimate diffusion kinetics parameters for CO2 in HDPE liners. Additionally, a test method was devised for assessing RGD effect on HDPE and its dependency on the liner thickness.

The validity of the test methods for evaluating diffusion kinetics and RGD damage was reported. Most importantly, we hypothesized and attempted to experimentally show that RGD affects sorption of the liner material and its permeability after a single cycle, even if no visual damage is observed under optical microscopy. The aim was to contribute valuable insights for safer design and operation of polymer-based pipes for sustainable energy pipelines.