Design Optimization of Multi-stage Biomass Gasifier Generating Gas with Very Low Tar Content
The aim of this project is a full utilization of the main advantages of a multi-stage gasification concept using original know-how of unique multi-stage gasifier Tarpo. In order to achieve high efficiency in production of gas with very low tar content which is suitable for heat and power production with high efficiency (comparable to power plant) it is necessary to realize several adjustments and optimizations of existing technology and to determine the effect of fundamental technological and operational parameters. Key factors for successful achievement of project goals include: 1. To study the effect of woody biomass type (different types of wood chips, soft or hard wood) on process steps – drying, pyrolysis, partial oxidation, reduction, gas cleaning (de-dusting, cooling, absorption) and engine operation. 2. To study the effect of fuel properties, especially particle size distribution, moisture, ash and soil (inert) content on carbon conversion into primary pyrolysis gas and properties and quantity of pyrolysis residue. 3. Optimization of operation conditions (temperature, residence time) in pyrolysis zone of multi-stage gasifier for production of primary carbonate residue usable as a catalyser in reduction zone and for its high conversion into gas in reduction zone. 4. To study the effect of operating conditions (temperature, construction material, air pre-heating, moisture content) in partial-oxidation zone on tar content and gas composition. 5. To study the effect of water vapour content/addition into gasification agent in reduction zone of the generator on gas quality and unburned carbon in ash. 6. Optimization of gas cleaning technology – redesign of primary filters (ceramic or textile) and secondary (engine) filter, condenser, optimization of oil quench, or its elimination from the technology, optimization of gas temperature on engine inlet. 7. Optimization of safety equipment and procedures (start up and shut down of the generator, fire protection).