Production of Activated Carbon From Grape Stems After Tannin Extraction: An Integrated Valorization Approach

Synthesis of high surface area activated carbon derived from cocoa pods husk by hydrothermal carbonization and chemical activation using zinc chloride as activating agent

Activated carbon (AC) is becoming the limelight due to its widespread application as an adsorbent for wastewater treatment, gases, and catalysis. However, its high consumption and price have drawn more attention to the sustainable use of natural resources as precursor for AC production. This study focuses on synthesising AC from two types of oil palm trunk (OPT) fibres, a significant agricultural waste products produced by Malaysia's thriving palm oil industries. The BET surface area of about 2057.9 m2 g−1 was achieved by chemical activation with phosphoric acid (H3PO4). The efficiency of the synthesised AC was critically analysed based on the adsorption experiments with methylene blue (MB) by varying several parameters (dosage of adsorbent, pH, initial dye concentration, and temperature of the solution) to elucidate the adsorption mechanism(s). A maximum adsorption capacity of 320.4 mg g−1 at 50 °C was achieved, and the Temkin (r2 = 0.98, 0.95, 0.95) and Langmuir (r2 = 0.94, 0.93, 0.95) isotherm models fitted the adsorption process better than the Freundlich (r2 = 0.95, 0.90, 0.86) model. Besides, the pseudo-second-order model (r2 > 0.90) best described the adsorption process, favouring chemisorption over physisorption. Thermodynamics showed MB adsorption on AC was spontaneous except at the highest dye concentration. It was exothermic at lower dye concentrations (50 and 100 mg L−1) and endothermic at higher ones (300, 500, and 700 mg L−1). In a nutshell, this study reveals that OPT fibre is a promising precursor for synthesising highly porous AC for the adsorption of MB dye.

Purpose – In this research, we have prepared activated carbon (AC) from the waste of banana peels (Musa acuminate L.) using potassium hydroxide (KOH) for carbon monoxide (CO) adsorption from motorcycle gas emission. Design/Methodology/Approach – The activation was conducted using a chemical activator (KOH) at various concentrations of 1, 2, and 3 N for 1, 2, and 3 h, respectively. Characteristics of banana peels AC (BPAC) produced were analyzed using the Fourier-transform infra-red spectroscopy and scanning electron microscopy. Findings – Results showed that KOH concentration and activation time strongly affected the CO adsorption and opening of the AC surface pore. There was an increase in the CO sorption when the KOH concentration was increased up to 3 N concentration. The highest CO adsorption from the emission occurred at 70.95% under KOH concentration of 3 N during the 3-h preparation. Research Limitations/Implications – BPAC has been used as an adsorbent for only CO from motorcycle gas emission but not as an adsorbent for HC, NO, NOx, or H2S. Practical Implications – BPAC can be used as the potential adsorbent for the removal of CO from motorcycle gas emission, and it is an environmental friendly, low cost, and easy to make adsorbent. Originality/Value – In this study, the AC is made from biomass and is used in wastewater treatment, but limited studies are found on the removal of CO from motorcycle gas emission.

The application of carbon as an adsorbent is a well-known method of removal of chemical pollutants, including dyes, from waste waters. However, a lot of attention is now being paid to improving the adsorbent efficiency and searching for cheap precursors for activated carbon (AC) production. In this work, AC is obtained from flax shive by its physical and chemical activation with KOH. The pyrolysis process and mechanism of KOH activation are studied using thermogravimetric analysis. The methods of X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and low-temperature nitrogen adsorption are used to determine the AC characteristics. The AC ability to adsorb the methylene blue (MB) dye is studied. The effect of the properties of the synthesized AC on the MB equilibrium adsorption capacity is analyzed. The maximum BET surface area of the AC is equal to 1832.2 m2/g, which means its values lie in the range typical of industrial activated carbons. The maximum equilibrium adsorption capacity of MB is 464.2 mg/g. The AC adsorption capacity depends on the cellulose content in the flax shive and pore size distribution over the carbon matrix. The use of lignocellulosic biomass, namely flax shive, in the AC production is associated with solving environmental problems, such as agricultural waste recycling and disposal.

Microwave-assisted pyrolysis with chemical activation, an innovative method to convert orange peel into activated carbon with improved properties as dye adsorbent

This study investigates the effectiveness of activated carbon (AC) produced from Brazil nut shells, using chemical activation with H3PO4, in the removal of ibuprofen sodium (IBU) and diclofenac sodium (DIC) from aqueous solutions, both single (AC_IBU and AC_DIC) and in mixtures [AC_IBU(+ DIC)] and [AC_DIC(+ IBU)]. AC was characterized using X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM)/ Energy Dispersive X-ray Spectroscopy (EDS), Nitrogen (N2) adsorption/desorption at 77K (SBET = 1,383.624 m2/g and micropore volume VMIC = 77.88%), surface pH (2.9) and pH of point zero charge (pHPZC = 3.1). A RCCD was applied to assess the effects of varying pH, C0 (mg/L), and AD (g/L) on single adsorption. Based on these results, kinetics and equilibrium were performed for single and mixture adsorption. For single adsorption, the pseudo-first order (PFO) for (AC_IBU) and pseudo-second order (PSO) for (AC_DIC) models resulted in the best fits. Sips model fitted the experimental data well, with maximum adsorption capacity (qmS) at 26°C (i) AC_IBU (150.00mg/g) and (ii) AC_DIC (116.23mg/g). The negative values of ΔG° and ΔH° indicated that the single adsorption processes are spontaneous and exothermic, while the isosteric heat values, ΔHst (from - 23.76 to - 5.00kJ/mol) suggest predominance of physical interactions. For mixture adsorption, the PFO and Extended Langmuir (EL) models were considered the best fit tothe kinetics and equilibrium experimental data, respectively. Antagonistic interactions were observed in binary adsorption. The loss of adsorption performance after three cycles of use (adsorption/ desorption) for single and binary adsorption was (3-5%). The synthesis of AC was effective, resulting in a microporous and reusable material. AC can be assessed as a promising material for the removal of NSAIDs (IBU and DIC) from aqueous medium.

Activated carbon (AC) has been utilized for various applications including as an electrode for supercapacitor, i.e., electric double-layer capacitor (EDLC) as well as hybrid capacitor such as lithium ion capacitor. In this research, salacca peel was used as a raw material for AC. It was chosen among other biomass wastes because it is abundant and is still considered as a waste. The hydrothermal carbonization was conducted at 5 MPa, temperature of 200–250 °C, and 5 h in subcritical water, which is a green dehydrating agent. The effect of parameters (temperature and addition of citric acid as a catalyst) on the hydrochar and AC product was investigated. The hydrochar from hydrothermal carbonization was activated by chemical activation using potassium hydroxide (KOH) as an activated agent to enhance the surface area and porosity. The morphology of both hydrochar and AC was measured by scanning electron microscopy (SEM), its chemical transformation was measured by Fourier transform infrared spectroscopy (FTIR) while the surface area and pore size distribution were measured by nitrogen adsorption at 77.35 K. The electrochemical performance of activated carbon from salacca peel as well as commercial activated carbon using a coin cell in a Li half-cell system was evaluated by CV, GCD, and EIS. The results show that the presence of citric acid contributes to higher specific capacitance in the rate performance test of LIC at different current density as well as in long rate stability test.

Textile dyes are organic compounds that can pose an environmental threat if not properly treated. They can cause many problems ranging from human health, ecosystem disturbances, and the reduction of the esthetic value of water bodies. The adsorption process using activated carbon (AC) has been proven to be effective in treating dyes in wastewater. However, the production of AC is limited by the non-renewables and relatively expensive precursor of coal. Date palm residues (DPRs) provide a good alternative for AC’s precursor due to their continuous supply, availability in a large amount, and having good physiochemical properties such as high oxygen element and fixed carbon. This study provides a review of the potential of date palm residues (DPRs) as AC in adsorbing textile dyes and the recent technological advances adopted by researchers in producing DPR-based AC. This review article focuses solely on DPR and not on other biomass waste. This study presents a background review on date palms, textile dyes, biochar, and AC, followed by production methods of AC. In the literature, DPR was carbonized between 250 and 400°C. The conventional heating process employed an activation temperature of 576.85–900°C for physical activation and a maximum of 800°C for physicochemical activation. Chemical agents used in the chemical activation of DPR included NaOH, KOH, ZnCl2, H3PO4, and CaCl2. The maximum surface area obtained for DPR-AC was 1,092.34 and 950 m2/g for physical and chemical activation, respectively. On the other hand, conditions used in microwave heating were between 540 and 700 W, which resulted in a surface area of 1,123 m2/g. Hydrothermal carbonization (HTC) utilized carbonization temperatures between 150 and 250°C with pressure between 1 and 5 MPa, thus resulting in a surface area between 125.50 and 139.50 m2/g. Isotherm and kinetic models employed in the literature are also discussed, together with the explanation of parameters accompanied by these models. The conversion of DPR into AC was noticed to be more efficient with the advancement of activation methods over the years.

Activated carbon (AC) was recognized by many researchers as useful substance in adsorption of impurities. Several processes involved in the production of AC which were carbonization, crushing, and activation process. Carbonization of carbon required high temperature up to 900oC. Then the carbon will be crush to a desired size for activation process. Activation of carbon can be either chemical activation, physical activation or combination of chemical and physical activation which called physiochemical activation. The mechanism adsorption of AC commonly due to its micropore present in the carbon or the weak vander waals forces which can attract the impurities. Activated carbon have multiple function in human daily life. This study will be discuss the function of AC in the production face mask, water filtration and air filtration.

Objective: The objective of this study is to investigate the design process, economic evaluation, and sensitivity analysis for the construction of an activated carbon production plant from single-use plastic waste at the National University of Engineering. This project aims to transform plastic waste into a high-value-added product, thereby contributing to sustainability and aligning with circular economy principles. Theoretical Framework: The theoretical framework covers concepts related to the circular economy and sustainable waste management, emphasizing the need to reduce environmental impact through innovative alternatives such as recycling PET into activated carbon. Previous studies on pyrolysis and thermal or chemical activation of plastics for conversion into high-value materials are cited, establishing a solid foundation to contextualize the activated carbon production process. Method: The methodology adopted for this research includes a technical and economic study design based on the assessment of processes and equipment required for activated carbon production. An experimental approach is proposed, wherein plastic waste is collected, shredded, washed, dried, carbonized, activated, and finally packaged. Data collection involved detailed calculations of investment, energy consumption, and mass and energy balances for each stage of the production process. Results and Discussion: The results revealed that the project is economically viable, with a Net Present Value (NPV) of 59,733 USD and an Internal Rate of Return (IRR) of 13%. In the discussion, the project’s profitability is contextualized through a sensitivity analysis evaluating different scenarios of exchange rate and sale price. This analysis confirms that, in optimistic scenarios, the IRR can reach up to 341%, reducing the payback period to less than a year. Research Implications: The practical implications of this research include the potential to implement a circular economy model in educational institutions, promoting sustainability and efficient waste management. Theoretically, the study contributes to the field of plastic waste valorization through its transformation into activated carbon, which could positively impact sectors such as environmental management and industrial recycling. Originality/Value: This study contributes to the literature by presenting an innovative approach for plastic waste valorization into activated carbon within an educational institution, using pyrolysis and activation processes in a circular economy context. The relevance of this research lies in its practical applicability in academic settings and its potential impact on reducing plastic waste.

Evaluation of fast and slow pyrolysis methods for bio-oil and activated carbon production from eucalyptus wastes using a life cycle assessment approach

This work presents highly porous magnetic activated carbon nanoparticles (MPFRC-A) derived from pine fruit residue. The MPFRC-A were produced through a three-step process: physical activation (carbonization temperature: 110–550 °C), chemical activation (H2SO4 (0.1 N, 96%)), and co-precipitation. These nanoparticles were then used to remove tetracycline (TC) and paracetamol (PC) from water. Functionalization with Fe3O4 nanoparticles on the surface of the pine fruit residue-derived activated carbon (PFRC-A) resulted in high saturation magnetization, allowing for separation from aqueous solution using an external magnet. The MPFRC-A adsorbent was characterized by Brunauer–Emmett–Teller (BET) analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX) analyses, In the experimental section, the effects of various factors on the adsorption process were investigated, including pH, contact time, initial pollutant concentrations, adsorbent dosage, and temperature. Based on these investigations, adsorption isotherm models and kinetics were studied and determined. The results showed that MPFRC-A exhibited a large specific surface area (182.5 m2/g) and a high total pore volume (0.33 cm3/g). The maximum adsorption capacity was achieved at pH 6 and 5 for PC and TC drugs with an adsorbent dose of 400 mg and an initial concentration of 20 mg/L at 25 °C. The study revealed that the experimental data were well-fitted by the Langmuir isotherm model (R2 > 0.98), with maximum uptake capacities of 43.75 mg/g for TC and 41.7 mg/g for PC. Outcomes of the adsorption thermodynamics shows non-spontaneity of the reaction and the adsorption process by all adsorbents was endothermic.

Sustainable Activated Carbons from Agricultural Residues Dedicated to Antibiotic Removal by Adsorption

Efficient synthesis of bio-based activated carbon (AC) for catalytic systems: A green and sustainable approach

Removal of cephalexin from aqueous solutions by original and Cu(II)/Fe(III) impregnated activated carbons developed from lotus stalks Kinetics and equilibrium studies