Supercritical Water Gasification of Biomass
Next to hydrothermal gasification, the research group has additionally been working on fermentation of synthesis gas at elevated pressure since 2016.
In hydrothermal conversion processes, biomass can be thermochemically converted without prior drying, using water at high temperature and pressure as reaction medium. The process can be realized in a single stage and is suitable for decentralized applications. Since a large part of the available biomass, especially residual materials and wastes, has a high water content, the development of efficient processes for the energetic utilization of wet biomass is of particular interest and has been an integral part of the research at IKFT for many years.
Pilot Plant VERENA
Supercritical Water Gasification (SCWG) utilizes the special properties of supercritical water (T > 374 °C, p > 221 bar) to produce an energy-rich gas mixture from biomass. Main components of the SCWG product gas are H2, CH4 and CO2, depending on the reaction conditions.
Gasification at the conditions of supercritical water is a promising process for the conversion of (residual) biomass with high water content and has already been realized on a pilot scale at IKFT (construction of the "VERENA" plant in the early 2000s). The main work in terms of process development is conducted in parallel at laboratory scale. The main challenges are thermal efficiency and economic viability, material durability at extreme reaction conditions and blockages in the plant due to salts or coke. At IKFT, particularly the efficient separation of salts is being investigated and continuously developed. Current research is conducted as part of the EU project "CERESiS", which has started in November 2020.