{
  "abstract": "Hydrogen storage in geologic reservoirs is a promising technology for storing surplus renewable energy, but the H2 gas quality may be compromised by fluid-rock-gas interactions. Using redox-decoupled, kinetically-controlled, abiotic 0D batch models, this study simulates the 30-year geochemical evolution of a sandstone reservoir (117 °C, 150 bar Ptotal, 98 mol% H2) and quantifies the temporal evolution of gas concentrations (H2, CO2, H2S). The models reveal two concurrent reaction regimes: initial perturbation of the pre-existing carbonate-fluid-gas equilibrium, causing CO2 degassing (∼4.2 mol%) and siderite dissolution, and long-term pyrite reductive dissolution with secondary pyrrhotite precipitation. Leaching of Fe2+ from Fe-chlorite enhances sulfide scavenging via pyrrhotite formation, stabilizing H2S(gas) at 26-28 ppm. Sensitivity analyses (40-140 °C, 5-250 bar Ptotal, 0.001-2.0 vol% pyrite) demonstrate that the reservoir geochemistry is governed by a reaction feedback loop involving: i) sulfide release from reductive pyrite dissolution, ii) aqueous sulfide removal by pyrrhotite precipitation, and iii) secondary Fe2+-mobilization from ferrous minerals. An Fe-mineral buffer sequence (Fe-chlorite → siderite → ankerite) determines the geochemical impact on the reservoir. Siderite alteration notably increases dilution of the H2 storage gas mixture by CO2. Under storage-relevant conditions (T ≤ 120 °C, Ptotal ≥ 50 bar), our batch models indicate H2S(gas) concentrations ranging from 0.5 to 80 ppm at H2(gas) concentrations from 85 to 98 mol%. At temperatures ≤ 80 °C, the mineral reaction kinetics are slow enough to significantly reduce gas contamination, with abiotically-derived concentrations > 97 mol% H2. Our gas estimates are conditional, but stress the importance of non-sulfide Fe-minerals to prevent excessive H2S accumulation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "Robin Hintzen"
    },
    {
      "name": "Jeroen Snippe"
    },
    {
      "name": "Tim Tambach"
    },
    {
      "name": "Roland Hellmann"
    },
    {
      "name": "Laurent Truche"
    },
    {
      "name": "Kevins Rhino"
    },
    {
      "name": "Julia van Winden"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4gwpjryge8zk2.bib",
  "cited_by": 0,
  "doi": "10.1016/j.apgeochem.2026.107098",
  "fulltext_url": null,
  "id": "4gwpjryge8zk2",
  "issns": [
    "0883-2927"
  ],
  "landing_url": "https://brgm.hal.science/hal-05799930v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.sdu.stu"
    ],
    [
      "openalex",
      "2305|CO2 Sequestration and Geologic Interactions"
    ]
  ],
  "openalex": "W7214359855",
  "pdf_url": "https://brgm.hal.science/hal-05799930/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/4gwpjryge8zk2.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:00Z",
      "native_id": "hal-05799930",
      "source": "hal",
      "url": "https://brgm.hal.science/hal-05799930v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "openalex:2305|CO2 Sequestration and Geologic Interactions",
      "subfield": "environmental-science"
    }
  ],
  "title": "Geochemical modeling of H2 storage in a sandstone reservoir: Sensitivity analysis of abiotic H2S and CO2 gas formation",
  "title_text": "Geochemical modeling of H2 storage in a sandstone reservoir: Sensitivity analysis of abiotic H2S and CO2 gas formation",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:00Z",
  "url": "https://research.draconitic.com/paper/4gwpjryge8zk2",
  "venue": "Applied Geochemistry",
  "versions": []
}