Hydrothermal gasification is a promising technology for converting wet biomass and organic wastes into valuable gases and biofuels under high-temperature, high-pressure conditions. This process offers versatile applications in renewable energy production, waste treatment, carbon capture, and hydrogen generation, contributing to the development of sustainable and environmentally friendly energy solutions. Ongoing research and development efforts focus on optimizing hydrothermal gasification processes for broader commercial deployment and integration into the circular bioeconomy

1. Hydrothermal Gasification:
Overview, Operating Parameters,
and Applications
By
Er. T. AYISHA NAZIBA, Dr. D. RAMESH, Dr. S. PUGALENDHI

2. Hydrothermal gasification (HTG)
 Hydrothermal gasification (HTG) is a thermochemical process that converts
wet biomass or organic wastes into valuable gases such as hydrogen (H2)
and methane (CH4) using water under high temperature and pressure
conditions. This process typically occurs in the subcritical or supercritical
water phase, where water behaves differently compared to its normal state
at ambient conditions.

4. Operating Parameters

5. Temperature
 Hydrothermal gasification operates at elevated
temperatures ranging from 250°C to 600°C or
higher.
 Higher temperatures promote the breakdown of
biomass components into gases and enhance
gasification reactions.

6. Pressure
 Pressure plays a crucial role in hydrothermal gasification, typically ranging from 5 MPa to 25 MPa or
more.
 Higher pressure increases the solubility of reactants in water and shifts the phase behavior of water towards
supercritical conditions.

7. Residence Time
 The residence time of biomass in the reactor influences gasification efficiency and product yields.
 Longer residence times allow for more complete conversion of biomass into gases.

8. Catalysts
 Catalysts can be used to enhance gasification rates and selectivity towards desired gas products.
 Common catalysts include transition metals (e.g., Ni, Co), oxides (e.g., CeO2, ZrO2), and supported catalysts
(e.g., Ru/C).

9. Applications of HTG

10. Biomass Conversion
 Hydrothermal gasification offers a promising route for converting various biomass feedstocks (such
as wood residues, algae, food waste) into renewable gases.
 It enables the production of biofuels and bioenergy with reduced environmental impact.

11. Wastewater Treatment
 Hydrothermal gasification can be applied to treat organic-rich wastewater streams by converting
organic pollutants into valuable gases.
 The process reduces wastewater volumes and produces energy-rich gases.

12. Carbon Capture and Utilization (CCU)
 Hydrothermal gasification can be integrated with carbon capture technologies to convert
carbonaceous wastes (such as plastics or municipal solid waste) into syngas while capturing carbon
dioxide (CO2).

13. Hydrogen Production
 Hydrothermal gasification is a promising method for producing hydrogen (H2) from biomass-
derived feedstocks.
 The produced hydrogen can be used as a clean fuel for transportation or industrial applications.

14. THANK
YOU