Combustion Performance of Agropellets in an Experimental Fixed Bed Reactor versus a Commercial Grate Boiler. Validation of Ash Behavior

Abstract

Agrobiomass is presented as a suitable alternative to contribute to the fossil fuel decarbonization strategy at the European level. To achieve the ambitious objectives established in this regard: (i) new biomass resources need to be used and therefore initially tested in order to confirm its potential for different applications, such as energy production, and (ii) biomass supply capacity needs to be enlarged; therefore, agroindustries converted into Integrated Biomass Logistic Center (IBLC) can play a key role. In this research, eight different agropellets (blends of wheat straw and maize stalk with forestry wood) were produced in a IBLC and tested in a commercial boiler, comparing the results with previous ones obtained in a fixed bed reactor test campaign and to a base case (woody pellets). This paper includes both individual results in terms of bottom ash, deposition, and a final comparison of ash behavior in both facilities. All biofuels tested showed an adequate performance in terms of efficiency and emissions, being slightly better for the agropellets produced with wheat straw. Regarding sintering and deposition, the tendencies found in the reactor investigation were also observed in the commercial boiler. Moreover, the assessment of the results from the boiler and reactor’s tests proved that reactor experiments are representative and may be used to test new biofuels more efficiently in terms of effort and time allocated and could be used to predict sintering and deposition phenomenon occurrence.