Wet impregnation of silver oxide on Lampung natural zeolite as an adsorbent to produce oxygen-enriched air using PSA technique

Chemical Engineering Department, Universitas Indonesia, Kampus Baru UI Depok, Depok 16424, Indonesia

^* Corresponding author: sbismo@che.ui.ac.id

Abstract

High purity oxygen can be used for various things. Oxygen purification method to be applied on this research is the Pressure Swing Adsorption (PSA) technique. The adsorbent that would be used is a natural zeolite, namely ZAL (Zeolite Alam Lampung). Natural zeolite has non-polar properties, so it will adsorb gas with high quadruple moment, which is nitrogen. The varied variable is the size of adsorbent and the concentration of H₂SO₄. The sizes are 18-35 mesh, 35-60 mesh, and 60-100 mesh. While the H₂SO₄ concentration are 1M, 2M and 3M. Size of ZAL, and the concentration of sulfuric acid (H₂SO₄) were varied to get the optimum value. The adsorbent will be activated in aqua demine, H₂SO₄, NaOH, and through a calcination process. The purpose of this pre-treatment was to remove the impurities and to increase the specific surface area of zeolite. Moreover, ZAL will also be modified by wet impregnation technique using AgNO₃ solution with 1%-wt loading nominal. The morphology, composition, and crystal phase were characterized by BET, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The result of the adsorption process was analyzed by using GC (Gas Chromatograph). ZAL 35-60 mesh 1M showed the best performance on adsorbing nitrogen, with its lowest peak at 60356 μV. The result of this research suggested that ZAL itself has the main role on adsorbing nitrogen, while Ag_xO did not give any significant effect