Paddy Drying in Chitosan Membrane Dryer

Abstract

Chitosan membrane equipped in an apparatus was used to separate water vapor evaporated from moist paddy out of the apparatus. The said apparatus was called “membrane dryer”. This study aimed at developing an alternative approach of paddy drying instead of the traditional open air technique which commonly encounter rainy or flooding problems. The prototype of membrane dryer was designed from mathematical air flow pattern analysis results. It was found that the airflow in overflow mode with triangular air flow path was the desired feature of the dryer. The performance results showed that the dryer using uncrosslinked dense and compositeon-spunbond chitosan membranes presented the highest drying rate in the first hour at 0.0464±0.0004 and 0.0578±0.0009 kg water/kg wet mass, respectively. As compared the drying rate by an open air technique and a hot air oven at 40°C of 0.0527±0.0011 and 0.0402±0.0007 kg water/kg wet mass respectively, the chitosan membrane dryer could be used as an alternative in drying biomass such as paddy. It was found that the uncrosslinked composite chitosan membrane dryer could reduce the moist paddy from 22–23% to 14–15% within 2 hours.