Modeling and optimization of steady flow of natural gas and hydrogen mixtures in pipeline networks

Journal Article · 17 December 2023 · International Journal of Hydrogen Energy

DOI: https://doi.org/10.1016/j.ijhydene.2023.12.054 · OSTI ID:2329240

Kazi, Saif R.  ^[1]; Sundar, Kaarthik  ^[1]; Srinivasan, Shriram  ^[1]; Zlotnik, Anatoly  ^[1]

---

1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Here, we extend the canonical problems of simulation and optimization of steady-state gas flows in pipeline networks with compressors to the transport of mixtures of highly heterogeneous gases injected throughout a network. Our study is motivated by proposed projects to blend hydrogen generated using clean energy into existing natural gas pipeline systems as part of efforts to reduce the reliance of energy systems on fossil fuels. Flow in a pipe is related to endpoint pressures by a basic Weymouth equation model, with an ideal gas equation of state, where the wave speed depends on the hydrogen concentration. At vertices, in addition to mass balance, we also consider mixing of incoming flows of varying hydrogen concentrations. The problems of interest are the heterogeneous gas flow simulation (HGFS), which determines system pressures and flows given fixed boundary conditions and compressor settings, as well as the heterogeneous gas flow optimization (HGFO), which extremizes an objective by determining optimal boundary conditions and compressor settings. We examine conditions for uniqueness of solutions to the HGFS, as well as compare and contrast mixed-integer and continuous nonlinear programming formulations for the HGFO. We develop computational methods to solve both problems, and examine their performance using four test networks of increasing complexity.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 2329240
• Report Number(s): LA-UR--22-32518
• Journal Information: International Journal of Hydrogen Energy, Journal Name: International Journal of Hydrogen Energy Vol. 54; ISSN 0360-3199
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English