Characterization and combustion of olive pomace in a fixed bed boiler: Effects of particle sizes

Abstract

The aim of this study is to characterize and burn out three olive pomace samples in a fixed bed boiler. These products are: Raw olive pomace (R.O.P), exhausted olive pomace (E.O.P), and deoiled olive pomace (D.O.P). Before their combustion, they have been characterized using different analyses: Proximate, ultimate, and thermogravimetric. So, proximate analysis illustrated that raw olive pomace contains volatile matter (74.2%), fixed carbon (20.2%), moisture (7.51%) and ash (2.8%). Next, ultimate analysis showed that R.O.P has important content percentages of carbon and oxygen (48.2% and 44.3% respectively). Furthermore, thermogravimetric analysis proved that the weight loss corresponding to the burnt volatile matter (VM) is ranging between 65% and 75% for all these biomasses. During the combustion of (R.O.P) and (E.O.P) samples, which is compared to that of wood sawdust, ignition propagation and char oxidation were observed. Moreover, effects of olive pomace particle size on temperature distributions at different combustor device positions were highlighted. The maximum temporal average temperature was reached with the smaller particles. Finally, the flue gas composition (O2, CO, CO2, NOx, SOx) has been measured and it has shown that the emissions of nitrogen oxides (NOx) are very low and sulphur oxides (SOx) are negligible.