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Activated carbon is synthesized from sugarcane bagasse through a pre-carbonization process in a muffle furnace at 400 °C, followed by carbonization and activation using the pyrolysis method at 800 °C. In the activation process, pre-carbonized SB is activated using 0.1 M NaOH. The activated carbon is then impregnated with cobalt oxide (CoO) using a hydrothermal method at 110 °C to improve its electrochemical performance. After impreg­nation, the presence of CoO is confirmed by X-ray diffraction patterns. Scanning electron microscopy suggests that the samples' morphology shows pore structures. Electrochemical properties are measured by cyclic voltammetry and galvanostatic charging-discharging techniques using a three-electrode system with 1 M Na2SO4 as an electrolyte. It is found that the specific capacitance of activated carbon from SB is 89.53 F/g, while after impreg­nation with CoO, it increases to 102.04 F/g at the same current density of 0.05 A/g.

In this study, saturated and superheated agents were used to produce activated carbon from red calliandra (Calliandra calothyrsus) hydrochar. Proximate, ultimate, XRD, FTIR, thermal gravity analyzer, and SEM were used to characterize the prepared activated carbon. Chemical pollutants, such as benzene, chloroform, methylene blue (MB), and iodine, were used to test the adsorption ability. The hydrothermal and activation procedures were conducted at 250 °C and 800 °C, respectively. The activation of superheated agents effectively increased the BET surface area compared to saturation and thermal methods alone. The BET surface areas were measured as 470, 759, and 766 m²/g for thermal, saturation, and superheated methods, respectively. The superheated method preserved tiny mesopores (2–10 nm), while saturation produced large mesopores (20–50 nm), and the thermal method was more favorable for macropore development (>50 nm). Analyses of the structure of superheated activated carbon (HC–SS) showed that the aromatic layer (Lc) was thinner, which led to pores that were smaller. The adsorption test confirmed the superiority of the superheated method. For the pollutant species benzene, chloroform, MB, and iodine, HC–SS exhibited adsorption abilities of 146, 240, 81, and 618 mg/g, respectively.

Beberapa tanaman seperti kakao (Theobroma cacao), alpukat (Persea americana), puspa (Schima wallichii), sengon (Falcataria mollucana) dan tarik angin (Usnea sp.) banyak ditanam di masyarakat untuk kebutuhan buah-buahan atau kayu. Secara periodik, masyarakat memanen jenis-jenis tersebut untuk dimanfaatkan kayunya atau peremajaan tanaman. Pada umumnya, sortimen kayu digunakan untuk konstruksi sederhana, atau dibakar. Selain teknik pembakaran konvensional untuk menghasilkan arang, ada produk lain yang dapat dihasilkan yaitu asap cair menggunakan teknik pembakaran dengan menambahkan kondensor untuk menghasilkan asap cair. Asap cair memiliki kandungan kimia organik dengan beragam manfaat. Studi ini bertujuan untuk menganalisis kandungan kimia organik jenis asap cair dari jenis kayu kakao, kayu alpukat, kayu puspa, kayu sengon dan kayu tarik angin. Kelima jenis material studi dikarbonisasi menggunakan reaktor pirolisis pada suhu 400°C. Asap cair didapat dengan cara kondensasi uap karbonisasi kelima jenis tersebut. Analisis kandungan kimia organik asap cair menggunakan kromatografi gas-spektrometer massa (Gas Chromatography Mass Spektophotometry, GCMS) Pirolisys Type QP2010 dan High Performance Liquid Chromatography (HPLC). Analisis GCMS menunjukkan bahwa asap cair kayu kakao memiliki konsentrasi kelompok asam tertinggi, yaitu 45,53%, sementara konsentrasi asam asetatnya adalah 31,81%. Kehadiran kelompok fenol tertinggi terdapat pada asap cair kayu alpukat sebanyak 56,86%, di mana konsentrasi senyawa fenol mencapai 41,92%. Kelompok asam dan fenol merupakan jenis senyawa yang terkandung pada asap cair dan memiliki manfaat yang luas.

In this work, both pyrochar and activated carbon were prepared by physical activation (i.e., saturation and superheated) by involving a thermal agent as a comparison. The effects of three agents on the pore development of activated carbon from a new material, Calliandra calothyrsus, were observed in detail. The BET surface area and the iodine index of the prepared activated carbon were used as pyrochar selection. Proximate, ultimate, XRD, FTIR, TGA, and SEM were used to characterize the physical and chemical properties of the product. Pyrochar pores were found to develop significantly at 350 °C, indicated by an increase in the BET surface area and iodine index. Pyrochar from a temperature of 350 °C was then selected as a precursor of activated carbon. S–SS and SS–S activated carbon samples were declared to have the highest iodine index (870 mg/g) and the highest BET surface area (642 m2/g), respectively. The pore distribution data showed that the superheated agent widened the pore and provided an active site for iodine adsorption, while the saturation agent resulted in a narrower pore for an increase in the BET surface area. S–SS has a lower C fraction and higher O fraction than SS–S. The SS–S samples have both Vol and Volmic for an increased BET surface area. The number of aromatic layers and –OH functional groups of the S–SS sample is more convenient for iodine enhancement than for increasing the BET surface area. Less water droplets and greater energy from superheated resulting pores widen, increasing the aromatic layer and providing additional functional groups.