Development of integrated volatile organic compound purification system using tubular NaA zeolite membrane: Experimental and theoretical insights into vapor permeation and pervaporation process

Abstract

This study experimentally and theoretically investigated the dehydration performance of vapor permeation (VP) and pervaporation (PV) processes using tubular NaA zeolite membranes. The effects of the key operating conditions (e.g., feed flow rate, concentration, temperature, and permeate pressure) on the dehydration performance of each process were experimentally investigated using a binary mixture of isopropanol and water. In addition, detailed mathematical models were developed to investigate the separation behavior in the VP and PV processes. The prediction results were validated using experimental results from the VP and PV processes (relative error < 5%). Additionally, based on the developed VP and PV processes, an integrated system for the purification of volatile organic compounds (VOCs) was proposed and evaluated. The integrated VOCs purification system consisted of a two-stage VP process (once-through mode) and single-stage PV process (recycling mode). The isopropanol from the binary mixture (74 wt% isopropanol and 26 wt% water) was recovered at a rate of 99.9% via the two-stage VP process, with an isopropanol concentration of 96.67%. Moreover, the isopropanol recovered from the VP process was upgraded to 99.23 wt% via the PV process. The simulation results showed that the integrated system obtained isopropanol with a concentration of 99.97 wt% with a recovery of 97.10% from the binary VOCs mixture.; this was in good agreement with the experimental results (relative error < 3%).