Effects of a Cyclone Dimensions on Quality of Syngas Produced with a Wood-fired Biomass Gasifier

Abstract

Charcoal gasification was widely used during the second World War to deal with petroleum scarcity. When petroleum was again available after the war, gasification was neglected afterwards. However, fossils resources are know as non-renewable and there are several reseach carried out all over the world to develop renewable sources of energy. Under that scope gasifiers are of great interest in the developing countries for developing individual or decentralised sources of energy. Even in developed countries, several research and implementation of gasification units are in progress. In a previous work, we designed and fabricated a downdraft biomass gasifier with a relatively big cyclone and filtration units. Produced syngas was full of moisture and carbon dioxyde (CO2) when the gasifier was feed with wood, but moisture content was lesser with charcoal. Therefore further work should be carried out in order to use low density wood itself from agricultural, furniture makers or sawmill wastes. We compared different cyclone separator design methods, adopted the Lapple’s cutt of model and found that to obtain good removal efficiency of unwanted particles, it is better to work with small cyclones. The new cyclone that we built allowed us on the one hand to reduce the humidity of the synthesis gas obtained, and on the other hand to reduce the quantity of tars in the liquid collected at the bottom of the cyclone. These improvements have led to the production of cleaner and better fuel syngas.