{"id":285,"date":"2025-04-06T10:32:35","date_gmt":"2025-04-06T08:32:35","guid":{"rendered":"https:\/\/sites.unica.it\/hydrochar\/?page_id=285"},"modified":"2026-03-26T16:26:19","modified_gmt":"2026-03-26T15:26:19","slug":"hydrothermal-processes-htp","status":"publish","type":"page","link":"https:\/\/sites.unica.it\/hydrochar\/wikichar\/hydrothermal-processes-htp\/","title":{"rendered":"Hydrothermal Processes (HTP)"},"content":{"rendered":"\n
\n
\n
\n<\/div>\n<\/div>\n\n\n\n

Hydrothermal processes use water at high temperature and pressure to convert organic materials \u2014 such as biomass and waste \u2014 into valuable products like fuels, chemicals, and materials (Libra et al., 2011). These technologies are based on unique properties of water under subcritical and supercritical conditions, which enable selective chemical reactions, decomposition, and transformation of biomolecules. Hydrothermal systems are studied for their efficiency, reaction kinetics, thermodynamics, and their role in sustainable energy and resource recovery.

In subcritical water (100\u2013374 \u00b0C, up to 22 MPa), the dielectric constant decreases, leading to enhanced solubility of organic compounds, accelerated hydrolysis, and repolymerization reactions. In supercritical water (>374 \u00b0C, >22 MPa), water behaves as a non-polar solvent, drastically changing chemical equilibria and facilitating gasification and synthesis reactions. Reaction pathways, catalyst effects, and reactor design are essential in optimizing product distributions and process sustainability.<\/p>\n\n\n\n

Table 1 summarizes the main hydrothermal processes, including their typical operating temperatures, products, and applications.<\/p>\n\n\n\n

<\/div>\n\n\n\n
Process<\/strong><\/th>Temperature Range<\/strong><\/th>Products<\/strong><\/th>Typical Application<\/strong>s<\/th><\/tr><\/thead>
HTC<\/strong>\u00a0(Hydrothermal Carbonization<\/a>)<\/td>180\u2013250 \u00b0C<\/td>Hydrochar, process water<\/td>Soil improvement, solid fuel, carbon sequestration<\/td><\/tr>
HTL<\/strong>\u00a0(Hydrothermal Liquefaction<\/a>)<\/td>280\u2013374 \u00b0C<\/td>Bio-crude, aqueous fraction<\/td>Renewable fuels, chemical synthesis<\/td><\/tr>
HTG<\/strong>\u00a0(Hydrothermal Gasification<\/a>)<\/td>>374 \u00b0C (supercritical)<\/td>Syngas, hydrogen<\/td>Gas fuel production, hydrogen economy<\/td><\/tr>
HTH<\/strong>\u00a0(Hydrothermal Humification<\/a>)<\/td>150\u2013220 \u00b0C<\/td>Humic substances, process water<\/td>Soil amendment, organic fertilizer<\/td><\/tr>
HTF<\/strong>\u00a0(Hydrothermal Fulvification<\/a>)<\/td>150\u2013220 \u00b0C<\/td>Fulvic acids, hydrochar<\/td>Agriculture, soil conditioner<\/td><\/tr>
VTP<\/strong> (Vapothermal Processes)<\/td>110\u2013350 \u00b0C (steam)<\/td>Dry products, vapothermal char<\/td>Material processing, environmental remediation<\/td><\/tr><\/tbody><\/table><\/div>
Table 1 – Hydrothermal processes and key features<\/em><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\ud83d\udcd6 References<\/h2>\n\n\n\n

<\/p>\n\n\n\n

\"Hydrochar<\/a><\/div>\n\n\n

Follow us:<\/p>\n\n\n\n