465743 Allothermal Gasification of Lignite and Biomass with Integrated Syngas Cleaning and CO2 Removal
Within the European research project CO2freeSNG2.0 funded by the Research Fund for Coal and Steel (RFCS) the research efforts concerning allothermal steam gasification and methanation of the chair of energy process engineering, Friedrich-Alexander-University Erlangen-Nuremberg, are intensified. In addition to the formerly proposed hot gas cleaning a gas scrubbing unit based on the Benfield process is integrated in the process chain to provide the removal of heavy tars, sulphur components and surplus CO2 before the methanation process step. By implementing said gas scrubbing unit the integrated removal of undesirable components within the raw syngas with less thermodynamic losses can be accomplished.
The comparison between the carbonate scrubbing and cold scrubbing processes like methanol scrubbing in prior simulations showed that for small and medium-scale plants the Benfield process can reach higher coal-to-SNG efficiencies. Based on these simulations the complete process chain is demonstrated on two levels within the research project CO2freeSNG2.0. The bench scale process line is based on an allothermal lab scale gasifier (5 kW) and the pre-pilot process chain on the 100 kW EVT Heatpipe-Reformer (HPR). Prior tests with the lab scale gasifier and methanation reactor proofed the possibility of a tar tolerant methanation allowing a temperature peak at the inlet of the methanation reactor to reform light tar components and make them available for methanation. Within the current research project both process lines include a hot potassium carbonate scrubbing gas cleaning unit. The focus of research is set on the raw syngas cleaning evaluated on the basis of removal efficiency of CO2, sulphur components as well as heavy tars.
The commissioned bench scale process line for the production of SNG from biomass or coal introduced and the results of the 5 kW gasifier and scrubber will be presented proving the feasibility of the proposed syngas cleaning process with integrated removal of surplus CO2. In addition the influence of different process parameters of the gasification process on gas composition, tar and sulfur loading is investigated.
See more of this Group/Topical: Topical Conference: Innovations of Green Process Engineering for Sustainable Energy and Environment