Application of pressure swing adsorption technology combined with 13X molecular sieves for the regenerative air cleaning systems with a dimethyl sulfide as a contaminant

Abstract

The use of pressure swing adsorption (PSA) system in the air cleaning technology for the application of regenerative air cleaning systems, which have wide applications in the defence sector has been reported. For this, a test procedure has been established and is elucidated for air purification using dimethyl sulfide (DMS) as a contaminant with 13X molecular sieves as the adsorbent at 4 kg/cm2. The dynamic adsorption capacities of 13X molecular sieves for DMS decreases from 14 to 0.3 wt% by increasing the flow rate from 3 to 15 lpm at 25°C, and at 4 kg/cm2. The flow rate and contact time are optimized as 6.5 lpm and 5.8 s, respectively for a selected PSA system. No DMS break through has been observed in 80 hr of continuous operation at an average feed concentration of 130 ppm. The 13X molecular sieves are further characterized by BET-SA, FT-IR, XRD and TPD. The TPD data reveal that the regeneration of 13X molecular sieves can be effectively achieved at ~180°C. The PSA system combined with 13X molecular sieves appears to be the promising technology for regenerative air purification applications and specific to the reduced sulfur compounds.