Session: 09-02-01 Repurposing pipelines for H2 transportation

Paper Number: 132090

132090 - Hydrogen Impurities and Their Potential Impact on Retrofitting Plans When Transitioning to Hydrogen – Natural Gas Blends 

Abstract: 

Hydrogen is being considered as one of the key options toward decarbonizing the existing energy system, as transformation and decarbonization of existing energy systems are a key part of global energy transition efforts to meet targets set in the COP21 Paris Agreement. As part of such transitions, existing natural gas networks are being evaluated for compatibility with transporting hydrogen – natural gas (H₂ – NG) blends. Utilizing the existing networks provides opportunities for time and cost-efficient transitions overcoming the high cost of, and public resistance to, building new infrastructures. However, hydrogen production, which is a key part of hydrogen value chain, has remained a challenge as producing enough hydrogen for an impactful decarbonization plan is an energy and resource intense process. There are several pathways to produce hydrogen, some of which are less energy intense with a larger carbon footprint considering that they are produced from fossil fuel. Different colors such as grey, brown, blue, turquoise, and green have been designated to different hydrogens based on their production methods. For example, blue hydrogen is produced from steam methane reforming (SMR) process that includes carbon capture and storage (CCS) technology, whereas green hydrogen is produced via water (H₂O) electrolysis using renewable energy sources. While green hydrogen does not contain many impurities, hydrogen produced from fossil fuels may contain impurities such as carbon monoxide (CO), H₂O, hydrogen sulfide (H₂S), etc., that could jeopardize the integrity of the gas grid upon blending. Additionally, stored hydrogen including green hydrogen could get contaminated while being stored, e.g., stored hydrogen in depleted gas reservoirs could be contaminant with biological contaminants. The current paper examines different hydrogen impurities based on their production or storage paths and their potential adverse impact on the existing natural gas grid. Additionally, potential approaches are discussed to mitigate the negative impact of impurities on the overall grid’s integrity and continuity of operation.

Presenting Author: Saba Esmaeely DNV

Presenting Author Biography: ....

Authors:

Saba Esmaeely DNV
Hans Sonke Shell
Martin Brown DNV
Shane Finneran DNV