Work

Microfluidic study of evaporation-driven crystallization of saline and ammonia brines under hydrogen flow

Year: 2026

Type: article

Abstract: Underground hydrogen storage in geological formations is critical for renewable energy integration, but salt precipitation during gas injection can impair storage performance. While well studied for CO 2 systems, precipitation mechanisms in hydrogen–brine and ammonia–brine systems remain poorly understood. This study presents a systematic microfluidic investigation of salt crystallization during hydrogen injection into saline and ammonia-containing brine aquifers under high pressure with varying compositions (1–5 mol/kg NaCl), chemical additives (surfactants, alcohols, ammonia), and hydrogen flow rates (200–1300 mL/min). Quantitative imaging shows hydrogen induces physical precipitation through evaporation and capillary trapping, resulting in discrete deposits, whereas CO 2 -ammonia systems produce interconnected ammonium bicarbonate networks. Interfacial tension controls brine distribution and crystal coverage: high-IFT fluids form large pools promoting crystallization, low-IFT fluids form isolated pools reducing coverage by 50%. Alcohols and surfactants suppress precipitation, while ammonia increases crystal fraction. Higher flow rates accelerate crystallization, highlighting gas-specific mitigation strategies for underground hydrogen storage. • H 2 injection triggers salt precipitation via evaporation and capillary trapping. • Ammonia-rich brines accelerate precipitation on secondary substrates. • Post-breakthrough water saturation is spatially variable due to high H 2 mobility. • Crystal shape and distribution follow residual brine size and connectivity. • Additives change surface tension, shifting brine flow and growth sites.

Source: International Journal of Hydrogen Energy

DOI: 10.1016/j.ijhydene.2026.154090

Authors: K.M. Dąbrowski, Mohammad Nooraiepour, Mohammad Masoudi

Institutions: AGH University of Krakow, University of Oslo, SINTEF, SINTEF Industry

Language: English

Topic: CO2 Sequestration and Geologic Interactions

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $3,730