진공 막증류 공정을 활용한 리튬브로마이드 수용액(LiBr-water)의 재농축에 관한 연구

Abstract

The conventional absorption system which uses various absorbents, is widely applied during different process stages, such as with the dehumidification and cooling system etc., due to the possibility that the application will waste heat or other sustainable energy resources. However, the conventional absorption system requires the external heating process which is highly depending on the use of fossil fuels, to evaporate the water vapor from a diluted absorbent. Therefore, the membrane distillation process which can separate the water vapor from the solution from below boiling temperatures, is attracting attention as an advantageous and eco-friendly process with many applications to industries. In this study, we suggested the membrane distillation system is useful as the alternative re-concentration process of various absorbents. The performance evaluation and application feasibility test were conducted with experimentally and theoretically. The simulation results were well validated with the experimental results, and the maximum difference was noted as 5%. In addition, the investigation of the rejection rate and permeate flux of water vapor were conducted and measured at the various operating conditions. As a result, the permeate flux was 7.84 ㎏/.,h at the inlet feed temperature of 64.5℃, vacuum level of 4400 Pa, and the inlet volume flow rate of 0.9 L/min; and thus we proved with lab-scale experiment that the diluted LiBr solution can be concentrated from 53 wt% to 54 wt%. The possibility of the reverse flux which can be issued during the process was discussed in terms of the various solution concentrations and the operating conditions.