On the gasification of wet biomass in supercritical water: Over de vergassing van natte biomassa in superkritiek water

Supercritical water gasification (SCWG) is a challenging thermo-chemical conversion route for wet biomass and waste streams into hydrogen and/or methane. At temperatures and pressures above the critical point the physical properties of water differ strongly from liquid water or steam. Because of the physical properties of supercritical water, SCWG is considered to be a promising technology for the thermo chemical conversion of wet biomass. Anticipated applications for supercritical gasification of wet biomass are for example: • The on-site production of a fuel gas in industry, vehicles, buildings. • The production of pure hydrogen for the process industry. • The production of a hydrogen or methane rich gas from manure or sewage sludge. • The production of syngas, mainly consisting of CO and H2, at high pressure. Although the results on a laboratory scale show that SCWG is a very promising technique, the process is still in an early stage of development. A lot of work remains to be done to get a full understanding of the complex process and to bridge the gap between small-scale testing in laboratories to demonstration on full-scale. For this purpose, adequate design rules for SCWG need to be developed. The primary objective of this thesis is to study the mechanisms and key param- eters of SCWG and to develop design rules for adequate reactor and process design. The following approach is chosen to meet these objectives: 1. Investigation of the influence of key process parameters on the thermal efficiency of supercritical gasification of wet biomass. 2. The development of heat transfer models for water at supercritical pressures. 3. The development of a new high throughput batch reactor for conversion rate measurements of supercritical gasification of wet biomass. 4. The evaluation and experimental validation of sorption enhanced supercritical gasification of wet biomass.