Comparative study on supercritical carbon dioxide dewatering and conventional kiln drying of bamboo strips

The aim of this study was to compare the dewatering rate, timing, moisture transfer and distribution, shrinkage, and stress characteristics of bamboo strips using supercritical carbon dioxide dewatering (SCD) and conventional kiln drying (CKD) at a temperature of 55 °C. SCD showed a faster dewatering rate than CKD, which increased with decreasing moisture content (MC) of the bamboo strip. During a dewatering cycle, approximately 82% of the water was removed during CO2 decompression and within the initial five minutes of CO2 emission. Comparison of MC showed that SCD did not exhibit any significant differences in the longitudinal direction, while CKD showed lower MC at the end locations of the bamboo strips. Additionally, SCD significantly decreased shrinkage in both the tangential (71%) and radial (52%) directions compared to CKD. However, SCD was less effective in reducing drying stress in bamboo.