Open Access

ARTICLE

Performance Evaluation of Static Mixers for Hydrogen–Natural Gas Blending in Pipelines

Liang Hu, Fuyong Su^*, Cunwang Li, Shengnan Wei, Yunsheng Yang
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
* Corresponding Author: Fuyong Su. Email:

Energy Engineering https://doi.org/10.32604/ee.2026.086747

Received 04 June 2026; Accepted 05 August 2026; Published online 07 August 2026

Abstract

Hydrogen blending into natural gas pipelines is considered a promising approach for reducing carbon emissions in existing gas transmission systems. However, the differences in physical properties between hydrogen and natural gas may cause non-uniform mixing, hydrogen stratification, and local enrichment during transportation, affecting the safety and reliability of hydrogen-blended natural gas systems. This study establishes a CFD model of hydrogen–methane mixing using methane as a surrogate fuel to investigate the effects of static mixer configurations and installation positions on mixing performance and pressure loss. Three static mixers (SK, SS, and SX) are systematically evaluated under different hydrogen blending ratios. After grid independence analysis and numerical model verification, a coefficient of variation (COV) < 0.05 is adopted as the criterion for mixing uniformity. Results show that all three mixers achieve optimal performance when installed at the 0D position (near the hydrogen inlet), while the influence of hydrogen blending ratio on mixing performance depends on mixer configuration. A trade-off exists between mixing enhancement and pressure loss: the SX-type mixer provides the fastest mixing, the SK-type mixer exhibits the lowest pressure loss, and the SS-type mixer achieves the best overall performance, achieving uniform mixing within 13D with a pressure loss of 114.0–143.8 Pa. This study clarifies the relationship between mixer structure, installation position, and hydrogen mixing performance, providing theoretical guidance and engineering references for hydrogen-blended natural gas pipeline applications.

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Keywords

Hydrogen-blended natural gas; static mixer; installation layout; mixing uniformity; pressure drop

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