{
  "abstract": "Cu-based catalysts can enhance bio-oil production during the hydrothermal liquefaction (HTL) of lignin; however, the influence of Cu incorporation strategy on individual reaction pathways remains insufficiently understood. In this study, experimental HTL of lignin under direct Cu-assisted and Cu-impregnated conditions was investigated over 200–320 °C and residence times of 5–25 min, together with a five-pathway lumped kinetic model. Apparent kinetic parameters were estimated by nonlinear regression of the experimental product yields. The model captured the principal evolution of residual solid, bio-oil, water-soluble fraction, and gas over the investigated conditions. The maximum bio-oil yield was obtained at 280 °C and 15 min, increasing from 24.87% for the direct process to 28.74% for Cu-impregnated lignin. Kinetic analysis revealed pathway-dependent effects of Cu impregnation. At 280 °C, the apparent residual-solid-to-bio-oil rate constant (k1) increased from 0.0211 to 0.0402 min-1, whereas the fitted contribution of the direct residual-solid-to-gas pathway (k3) was substantially lower following Cu impregnation. The apparent bio-oil-to-gas rate constant (k4) also increased at elevated temperatures, indicating stronger secondary conversion of bio-oil under more severe conditions. Arrhenius analysis further showed differences in the apparent activation energies and pre-exponential factors of the dominant pathways. Overall, the results demonstrate that Cu impregnation modifies the apparent distribution of reaction pathways rather than uniformly increasing all fitted rate constants, providing a quantitative kinetic framework for understanding the influence of Cu incorporation strategy on lignin HTL.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemical Engineering",
    "Indian Institute of Science",
    "Indian Institute of Technology Roorkee"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Ankit Kumar"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "Sivamohan N."
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/52a3bcb79jd2h.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009969/v1",
  "fulltext_url": null,
  "id": "52a3bcb79jd2h",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009969/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2204|Thermochemical Biomass Conversion Processes"
    ]
  ],
  "openalex": "W7220686050",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009969/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/52a3bcb79jd2h.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15009969",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009969/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Reaction-Network Kinetics of Lignin Hydrothermal Liquefaction: Effect of Cu Incorporation Strategy",
  "title_text": "Reaction-Network Kinetics of Lignin Hydrothermal Liquefaction: Effect of Cu Incorporation Strategy",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/52a3bcb79jd2h",
  "venue": "ChemRxiv",
  "versions": []
}