UTILIZATION OF MANGOSTEEN PEEL WASTE AS ADSORBENT FOR NH3 AND H2S GASES REMOVAL

• Main Author: Arwieny Hanami, Zarah
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/46671
• Institution: Institut Teknologi Bandung

Odor pollution control from various activities that produce ammonia gas (NH3) and hydrogen sulfide gas (H2S) can be done by the adsorption process using activated carbon. This process is increasingly developed by the use of green adsorbents (low-cost materials derived from natural sources, agricultural residues and waste), one of which is mangosteen peel. Mangosteen peel waste has potential as raw material for activated carbon because of its high lignin content (48%) and hardness of the skin. This study aims to analyze the ability of mangosteen peel as an adsorbent in adsorbing H2S and NH3 odor gases, determine the breakthrough curve, kinetics and adsorption isotherm. This research is a laboratory scale which procedure starting from the preparation and manufacture of 10-20 mesh mangosteen peel derived activated carbon by carbonization and activation processes using tube furnace. The carbonization process is carried out at 700oC for 3 hours under N2 atmospheric condition, then physically activated at 850oC with CO2 for 2 hours also under N2 atmospheric conditions. The NH3 and H2S gas that will be use for adsorption test in this study is a synthesis gas made in the laboratory with variations in the concentration of NH3 gas inlet that will be used in the adsorption process is 10, 20, and 40 ppm, and for H2S gas is 20 ppm. In addition to variations in inlet concentrations, the mass of the mangosteen peel waste activated carbon also varied for adsorption test. The variations of adsorbent mass used for NH3 adsorption were 1 gram, 3 gram and 5 gram, while for H2S adsorption were 0.2 gram, 0.3 gram, and 0.5 gram. The adsorption test was carried out using an adsorption column with continuous NH3 and H2S gas flowing until breakthrough using a flow rate of 1.1 L / min at room temperature, where outlet concentration measurements were carried out at 1 minute intervals using H2S and NH3 gas sensors SKY2000-M2. The Brunauer-Emmett-Teller (BET) test results showed the specific surface area of mangosteen peel activated carbon was 588.407 m2/g. Morphological and elemental analysis with SEM-EDS was carried out on the activated carbon of mangosteen peel waste before and after the adsorption process. The value of moisture content, ash content, and iodine number obtained were 6.07%, 9.8%, and 1153.69 mg/g, respectively. The average adsorption capacity obtained for NH3 is 0.41 mg/g and H2S is 563.726 mg/g, which shows that the activated carbon of mangosteen peel waste is more effective at adsorbing H2S gas than NH3. The results show that the higher the inlet concentration, the faster the breakthrough time is reached, while the greater the mass of the adsorbent used, the longer the breakthrough time is reached. The suitable kinetics model for NH3 adsorption based on the highest coefficient of determination (R2) obtained is the second-order Pseudo Ho kinetics model which shows that adsorption tends to occur chemically, although the kinetics results also indicate conformity to the first-order pseudo Lagergren kinetics model so that the adsorption process also controlled by physics. Meanwhile, a suitable kinetics model that describes H2S adsorption is Pseudo Ho second-order kinetics model which indicates that the adsorption process occurs chemically. This result is also supported by SEM-EDS results which show that the element S (Sulfur) which was not previously present in the activated carbon of mangosteen peel waste, but after the adsorption process was found with a mass% of 8.91% due to desulphurization process occurred which indicated the occurrence of chemical adsorption. Then, the equilibrium isotherm results show that Langmuir isotherm is more suitable to describe the adsorption process than the Freundlich isotherm which shows that for both the NH3 and H2S gas adsorption process using mangosteen peel activated carbon are monolayer.