A STUDY OF THE EFFECTS OF ASH CHEMICAL COMPOSITION AND ADDITIVES ON FUSION TEMPERATURE IN RELATION TO SLAG FORMATION DURING GASIFICATION OF BIOMASS

The elemental chemical composition of 26 biomass ashes are presented. The deformation and fusion temperatures of these ashes are determined. A rationale is developed to predict deformation and fusion temperatures of the ashes from phase diagrams. Regression models are developed to predict the deformation and fusion temperatures from the ashes chemical compositions.; The description of the downdraft laboratory gas producer and its operational procedure are given. The sources of the biomass materials used in the tests are tabulated. Corn stalks, cotton stalks, rice straw, corn cobs, wood, almond shells and walnut shells are tested for slag formation in the downdraft gas producer. The effect of the temperature below the choke plate and 2" above the tuyeres on slag formation is investigated. Water and steam injection through nozzles inside the firebox are tested as means of reducing slag formation. Also, water and steam are injected into the combustion air as an aid to minimize slag formation.