Study On Drying Characteristics And Kinetics Of Moso Bamboo

The utilization rate of bamboo is low and the waste production is huge,but the initial water content is high,which greatly limits the comprehensive utilization of bamboo waste so that the drying of bamboo waste is obviously important.In this paper,the drying characteristics and kinetics of bamboo waste are studied,which can optimize the drying process and improve drying equipment.Based on the thermogravimetric analysis of the isothermal drying characteristics and kinetics of bamboo waste?initial moisture content 41.82%?,the effect of drying temperature on drying characteristics is investigated.It is found that increasing the drying temperature can increase the drying rate of bamboo waste.The kinetic analysis of the obtained experimental data is carried out by using nonlinear regression fitting between the water ratio MR and time t,which is based on the determination coefficient?R²?,root mean square?RMSE?and chi-square??²?.Midilli and Kucuk can describe the law of water migration well during the isothermal drying of bamboo,and we can obtain D_eff by fitting ln MR and t,,the value of which varies from 2.9007 to 3.8744?10^-10,and the activation energy?E_a?is 22.54 kJ/mol.Based on the thermogravimetric analysis of the non-isothermal drying characteristics of bamboo waste,the effects of different moisture content materials on the drying process at different heating rates are investigated.The higher the water content,the lower the heating rate and the longer the drying time required.The nonlinear regression analysis is carried out on MR and four non-isothermal drying models.The comprehensive analysis and evaluation parameters are available.The Henderson model can describe the internal water migration of bamboo waste well,and whose R² is higher than 0.9990,and E_a varies from 24.3524 kJ/mol to 31.7496 kJ/mol.The non-isothermal method is used to obtain the effective water diffusion coefficient.The non-isothermal calculation results at the heating rate of 5,10,and 15 K/min are included in the calculation results in Chapter 2.The results show that the non-isothermal method is feasible and stable.On the self-built fluidized bed hot air drying device,the drying characteristics of bamboo waste are studied in depth,and the effects of hot air temperature,hot wind speed,bed thickness and initial moisture content on drying characteristics are analyzed.The higher the temperature,the higher the drying rate.The higher the initial moisture content,the smaller the drying rate;the thicker the bed thickness,the smaller the drying rate.At last,the experimental datas are analyzed by four isothermal models of Midiliil and Kucuk,Page,Loganthmic,Henderson and Pabis.The results show that the Midilli and Kucuk models have the best fitting effects.The comprehensive evaluation parameters R² are all higher than 0.9930.The analytical isothermal drying kinetics results are consistent and have guiding significance for future large-scale industrial applications.