Electric field effects on gasification/combustion at thermo-chemical conversion of biomass mixtures

A series of experimental studies and mathematical simulations of the electric field influence on the thermal decomposition of mixtures of wheat straw with wood and peat pellets and on the development of volatile combustion downstream the swirling flame flow was carried out. The main aim of these studies is to provide more efficient use of straw for cleaner and more efficient energy production by improving the gasification/combustion characteristics of the mixture and the composition of emission. The electric field influence on the combustion dynamics was studied experimentally using a pilot device, which combines a biomass gasifier and a combustor. An electric field was applied to the flame base using an axially inserted electrode. The electric field effect on the main gasification/combustion characteristics of a biomass mixture was estimated through complex measurements of the field-induced variations of the flow velocity, flame temperature, composition and heat output by varying the positive bias voltage of the axially inserted electrode. The mathematical model of the combustion process considers the electric field influence on the combustion characteristics using the approach of single chemical reaction. Simulations were performed for the opposite field configuration, when the negative bias voltage was applied to the axially inserted electrode by varying its length.