Development of natural zeolites adsorbent: Chemical analysis and preliminary TPD adsorption study

Klaten indonesian natural zeolites had been modified to become a potential adsorbent for gas or liquid separation. to enhance the adsorption capacity and stability,a pre-treatment by acid (hcl dan h2so4) and ba-cation activation and modification were applied to the raw natural zeolite samples. the pre-treatment could increase the si/al ratio which correspond to the low-hydrophilic characteristic of the zeolites and increase the bronsted acid sites. this enhancement will improve the capability of the natural zeolites as adsorbents or catalysts. after the pretreatment,the adsorbent was characterized by aas,xrd analysis and tpd adsorption measurement. the result shows that higher si/al ratio was achieved when natural zeolites was activated by strong acid of hcl and h2so4 (0.1 m and 0.3 m). si/al ratio of the hcl-activated zeolite is 5.33 while si/al ratio of the h2so4 activated zeolite is 6.65. for the untreated zeolite,the si/al ratio is 5.14. the result of xrd analysis supports the aas analysis result in which the composition of mordenite and clinoptilolite increased after acid activation. the increase of mordenite and clinoptilolite composition related to the increase of si/al ratio. the tpd adsorption measurement of the ba(no3)2 activated zeolite gave results of co2 peak partial pressure of 4.4×10-7 torr,greater than the raw zeolite’s which is only 9.9×10-8 torr. by observing the adsorption time,the ba(no3)2-activated zeolite requires 137 minutes to reach it’s co2 peak partial pressure compared to the raw natural zeolites which requires 48 minutes. this indicated that the ba(no3)2 modification can improve the adsorption capacity of natural zeolites qualitatively. © school of engineering,taylor’s university.