Determinación del riesgo de incendio en una instalación de secado de alperujo

Abstract

For the energy valorization of “alperujo”, by-product of the olive  oil two phases extraction process, it is necessary to perform  a drying process to reduce moisture content from over 60 %  to less than 10 % m/m w.b. In order to reduce primary energy  consumption and get an economic return, usually in this kind of  drying facilities Gas Turbine Cogeneration (GT-CHP) is used as a  heat source. In Spain, there have been recently some fires in this kind of  GT-CHP facilities, which have caused big material losses.  Therefore, the aim of this study is to determine experimentally  and analytically under which operational conditions could occur  self-ignition of alperujo in the drying process, and determine the  actual fire hazard in this type of GT-CHP system. For analytical study, it was raised and validated a mathematical  model to calculate the temperature and composition of the  flue gases into and out of the dryer, depending on the technical  characteristics of the GT, atmospheric conditions, and the flow  and moisture content of the treated biomass. The model also  calculates the wet bulb temperature, which sets the maximum  temperature reached by the biomass during the drying process  and determine the amount of biomass that can be completely dry  depending on the flow and the conditions of inlet combustion gas. With these results and the minimum auto-ignition temperature of  alperujo, experimentally determined according to EN 50281-2-1:  2000, it shows that there is no risk of ignition of alperujo under  normal operating conditions in a rotary drying process.