Utveckling av en experimentell uppställning för studie av massöverföring genom membran

Sammanfattning: The primary goal of this project is to develop an experimental setup for testing membrane materials. The membranes tested are all porous, hydrophilic and non- selective. The secondary goal is that the module finds use as an educational tool for learning about diffusion on a university level. The final setup consisted of two modified 250 ml polyethylene bottles with a wide neck joined together with a flange pinning the test object in between. In the experiments one side is loaded with a sodium chloride solution, while the other is loaded with pure deionized water. The conductivity change is then monitored in the chamber loaded with deionized water using a conductivity probe. Two test subjects are tested, an alpha Cellulose filter and a polycarbonate membrane. The mass transfer coefficient are determined to be 8.99'10-6 ± 3.90'10-6 [cm/min] and 3.62'10-5 ± 1.49'10-6 [cm/min] respectively. The large inconsistencies in the alpha cellulose filters results in large standard deviations, whereas the polycarbonate is very consistent and therefore have very small error bars. Meaning that the largest error in this design originates from inconsistencies between samples of the test subject. The setup is suitable as an educational tool due to short run times of one hour, the generated data only requires simple linear regression to extract mass transfer coefficients from the slope. The experiment can be varied further by adjusting temperature and stirring.