EFFECTS OF OXIDATION TREATMENT ON THE CHARACTERISTICS OF COAL-BASED ACTIVATED CARBON AND ITS ADSORPTION CAPACITY OF CO2

• Main Author: Mevia, Axl
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78418
• Institution: Institut Teknologi Bandung

Significant reductions in atmospheric carbon dioxide (CO2) emissions need to be achieved to support the Net Zero Emission (NZE) target. Carbon Capture and Storage (CCS) is one of technology that has the potential to capture CO2 gas emissions through adsorption methods, one of which uses activated carbon (AC) from coal. In its application, the performance of AC is strongly influenced by the physical and chemical properties of its surface, so many efforts have been made to modify AC. One of the most common modifications is oxidation which can increase the number of carbon-oxygen surface groups on the surface of activated carbon. In addition, calcination of AC under inert conditions (N2) also has the potential to increase its adsorption power on CO2 gas. Although many efforts have been made, it is necessary to study the effect of a combination of oxidation and calcination treatments on coal AC, especially on CO2 gas adsorption capacity. The AC used as the starting material in this study is made from coal, hereafter referred to as the RAW sample. The RAW samples were then heated in a rotary kiln in an inert atmosphere from room temperature to oxidation temperature at 100, 200, 300, 400, or 500 oC, and then air flowed for 2 hours to obtain O100, O200, O300, O400, and O500 samples, according to the oxidation temperature. The oxidation samples were then calcined at 900 oC with nitrogen gas flow in a rotary kiln for 2 hours, resulting in samples C-O100, C-O200, C-O300, C-O400, and C-O500. The RAW, oxidation, and calcined samples were characterized for their functional groups by Fourier-Transform Infrared (FTIR) Spectroscopy; Iodine and BET (Brunauer-Emmet-Teller) tests to measure surface area; and adsorption tests to determine their adsorption capacity, including activated carbon fiber (ACF) samples from Coal tar Pitch (CTP); OG 5A and OG 10A, and Polyacrylonitrile (PAN); FE200 and FE300 for comparison. The analysis results on the oxidation sample showed an increase in the intensity of carbonyl functional groups in the form of carboxylic acids (-COOH) which can make the AC surface more acidic, where this correlates with a decrease in iodine number and BET surface area which causes a decrease in adsorption capacity. Meanwhile, in the calcined sample there is a decrease in the intensity of hydroxyl (OH) and carbonyl functional groups in the form of carboxylic acids (-COOH) which can make the AC surface more basic, where this correlates with an increase in iodine number and BET surface area which causes an increase in adsorption capacity. This combination of AC modification has an adsorption capacity of up to 1.013 mmol/g on sample C-O100 which is higher than CTP ACF OG 5A and PAN ACF, but lower than CTP ACF 10A. This shows that AC from coal has potential in the CO2 gas adsorption process.