From the conventional to the intermittent biodrying of orange solid waste biomass

Abstract

Biodrying is an innovative solution in the search for ecologically viable and economically attractive drying processes. However, biodrying processes often have long operating times, which makes them unsuitable for some applications. Thus, the objective of this work was to evaluate the biodrying of orange solid waste biomass in three operation modes: conventional full load and long operation time (CFLT); conventional partial load and short operating time (CPST); and intermittent partial load biodrying with homogenization (IPST). The results showed that the oxidative biological activity promoted temperature peaks greater than 50 °C for the CFLT operation, and 45 °C for the CPST and IPST operations. Both, CFLT and CPST, presented irregular distribution of the gaseous phase in the bed and poor water removal. The IPST operation, however, promoted a significant improvement in the moisture transport mechanisms. Comparatively, orange solid waste with an initial moisture of (3.0 ± 0.1) db. had an average final moisture of (2.5 ± 0.1) db. for CFLT (t = 500 h), (2.2 ± 0.1) db. for CPST (t = 48 h), and (1.6 ± 0.1) db. for IPST (t = 48 h). We concluded that the IPST operation is advantageous over CFLT and CPST, presenting higher moisture reduction with a significant reduction in operating time from 500 h to 48h