Drying has been widely studied as a necessary process in biomass utilization. The steam diffusion law plays an important role in drying kinetics. The drying kinetics of a single biomass particle using Fick’s second law of diffusion was studied in this paper. A parabolic relationship appeared between the critical moisture content and temperature. The critical moisture content decreased with the increase in drying temperature and the initial moisture content. The drying temperature had a significant effect on the effective diffusivity and coefficient of mass transfer during the dramatically falling period of the biomass drying process. However, it was affected by the effective diffusivity and coefficient of mass transfer during the slowly falling period. The initial moisture caused the opposite effect during the different periods. The normalized biomass moisture content generally increased with the increase in drying temperature, and decreased with the increase in initial moisture content. The initial moisture content had an effect on the normalized biomass moisture during the slowly rising period. Meanwhile, the drying temperature had an effect on the normalized biomass moisture during the whole period. The critical moisture content and the normalized biomass moisture content had negative relevant relationship. This study provides some valuable conclusions regarding the biomass drying process.

Due to their low concentration and complex nature, the low-cost online and real-time monitoring of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) is a challenge. In this paper, based on a coupling adsorption model of activated carbon and the relationship of PCDD/Fs and flue gas, an online monitoring system with real-time control of final PCDD/F emissions was built for the tracing and control of PCDD/F emissions in municipal solid waste incinerators (MSWIs). According to the online monitoring system, the effects of activated carbon concentration, the specific surface area of activated carbon (AC), operating temperature, contact time, fly ash concentration, residence carbon concentration of fly ash, and the lime concentration of final PCDD/F emissions were discussed. These MSWI operating parameters for reaching standards of 0.1 ng international toxic equivalents (TEQ)/Nm3 and 0.05 ng TEQ/Nm3 were summarized by the predicting model based on several published models.