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Choleva E, Mitsopoulos A, Dimitropoulou G, Romanos GE, Kouvelos E, Pilatos G, Beltsios K, Stefanidis S, Lappas A, Sfetsas T. Adsorption of Hydrogen Sulfide on Activated Carbon Materials Derived from the Solid Fibrous Digestate. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5119. [PMID: 37512393 PMCID: PMC10386193 DOI: 10.3390/ma16145119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
The goal of this work is to develop a sustainable value chain of carbonaceous adsorbents that can be produced from the solid fibrous digestate (SFD) of biogas plants and further applied in integrated desulfurization-upgrading (CO2/CH4 separation) processes of biogas to yield high-purity biomethane. For this purpose, physical and chemical activation of the SFD-derived BC was optimized to afford micro-mesoporous activated carbons (ACs) of high BET surface area (590-2300 m2g-1) and enhanced pore volume (0.57-1.0 cm3g-1). Gas breakthrough experiments from fixed bed columns of the obtained ACs, using real biogas mixture as feedstock, unveiled that the physical and chemical activation led to different types of ACs, which were sufficient for biogas upgrade and biogas desulfurization, respectively. Performing breakthrough experiments at three temperatures close to ambient, it was possible to define the optimum conditions for enhanced H2S/CO2 separation. It was also concluded that the H2S adsorption capacity was significantly affected by the restriction to gas diffusion. Hence, the best performance was obtained at 50 °C, and the maximum observed in the H2S adsorption capacity vs. the temperature was attributed to the counterbalance between adsorption and diffusion processes.
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Affiliation(s)
- Evangelia Choleva
- QLAB Private Company, Research & Development, Quality Control and Testing Services, 57008 Thessaloniki, Greece
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research "Demokritos", 15310 Athens, Greece
- Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece
| | - Anastasios Mitsopoulos
- QLAB Private Company, Research & Development, Quality Control and Testing Services, 57008 Thessaloniki, Greece
- Biogas Lagada SA, 677 Parcel, Kolchiko, 57200 Lagadas, Greece
| | - Georgia Dimitropoulou
- QLAB Private Company, Research & Development, Quality Control and Testing Services, 57008 Thessaloniki, Greece
| | - George Em Romanos
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research "Demokritos", 15310 Athens, Greece
| | - Evangelos Kouvelos
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research "Demokritos", 15310 Athens, Greece
| | - George Pilatos
- Institute of Nanoscience and Nanotechnology, National Center of Scientific Research "Demokritos", 15310 Athens, Greece
| | - Konstantinos Beltsios
- Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece
- School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 9, Iroon Polytechniou Str., Zografou, 15780 Athens, Greece
| | - Stylianos Stefanidis
- Laboratory of Environmental Fuels/Biofuels and Hydrocarbons, Chemical Process and Energy Resources Institute, CERTH, 57001 Thessaloniki, Greece
| | - Angelos Lappas
- Laboratory of Environmental Fuels/Biofuels and Hydrocarbons, Chemical Process and Energy Resources Institute, CERTH, 57001 Thessaloniki, Greece
| | - Themistoklis Sfetsas
- QLAB Private Company, Research & Development, Quality Control and Testing Services, 57008 Thessaloniki, Greece
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Inthawong S, Wongkoblap A, Intomya W, Tangsathitkulchai C. The Enhancement of CO 2 and CH 4 Capture on Activated Carbon with Different Degrees of Burn-Off and Surface Chemistry. Molecules 2023; 28:5433. [PMID: 37513306 PMCID: PMC10385875 DOI: 10.3390/molecules28145433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/05/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
Activated carbon derived from longan seeds in our laboratory and commercial activated carbon are used to investigate the adsorption of methane (CH4) and carbon dioxide (CO2). The adsorption capacity for activated carbon from longan seeds is greater than commercial activated carbon due to the greater BET area and micropore volume. Increasing the degree of burn-off can enhance the adsorption of CO2 at 273 K from 4 mmol/g to 4.2 and 4.8 mmol/g at 1000 mbar without burn-off, to 19 and 26% with burn-off, respectively. This is because an increase in the degree of burn-off increases the surface chemistry or concentration of functional groups. In the investigation of the effect of the hydroxyl group on the adsorption of CO2 and CH4 at 273 K, it is found that the maximum adsorption capacity of CO2 at 5000 mbar is about 6.4 and 8 mmol/g for cases without and with hydroxyl groups contained on the carbon surfaces. The opposite behavior can be observed in the case of methane, this is due to the stronger electrostatic interaction between the hydroxyl group and carbon dioxide. The simulation results obtained from a Monte Carlo simulation method can be used to support the mechanism in this investigation. Iron oxide is added on carbon surfaces with different concentrations to reveal the effects of ferric compounds on the adsorption of CO2. Iron at a concentration of about 1% on the surface can improve the adsorption capacity. However, excessive amounts of iron led to a limited adsorption capacity. The simulation result shows similar findings to the experimental data. The findings of this study will contribute to the progress of gas separation technologies, paving the way for long-term solutions to climate change and greenhouse gas emissions.
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Affiliation(s)
- Supawan Inthawong
- School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Atichat Wongkoblap
- School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Worapot Intomya
- School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Chaiyot Tangsathitkulchai
- School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
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Khan MH, Akash NM, Akter S, Rukh M, Nzediegwu C, Islam MS. A comprehensive review of coconut-based porous materials for wastewater treatment and CO 2 capture. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117825. [PMID: 37031519 DOI: 10.1016/j.jenvman.2023.117825] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 03/06/2023] [Accepted: 03/26/2023] [Indexed: 06/19/2023]
Abstract
For several decades, water pollution has become a major threat to aquatic and non-aquatic species, including humans. Different treatment techniques have already been proposed and implemented depending on wastewater characteristics. But many of these treatment techniques are expensive and inefficient. Adsorption-based techniques have shown impressive performances as an inexpensive treatment method previously. Coconut-based resources have been considered as adsorbents for wastewater treatment because of their abundance, low cost, and favorable surface properties. However, over the last decade, no comprehensive study has been published regarding biochar from coconut-based materials for wastewater treatment and CO2 capture. This review discusses biochar production technology for coconut-based materials, its modification and characterization, its utilization as an adsorbent for removing metals and organics from wastewater, and the associated removal mechanisms and the economic aspects of coconut-based biochar. Coconut-based materials are cheap and effective for removing various organic compounds such as pesticides, hormones, phenol, and phenolic compounds from solutions and capturing CO2 from air mainly through the pore-filling mechanism. Utilizing coconut-based biochars in a hybrid system that combines adsorption and other techniques, such as biotechnology or chemical coagulation is a promising way to increase their performance as an adsorbent in wastewater treatment.
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Affiliation(s)
- Mahmudul Hasan Khan
- Department of Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh; Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, 50011, United States
| | - Nasim Mahmud Akash
- Department of Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh
| | - Sonia Akter
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Mahe Rukh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, North Carolina, United States
| | - Christopher Nzediegwu
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Md Shahinoor Islam
- Department of Chemical Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh.
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Usmani A, Watthaisong P, Grisdanurak N, Suthirakun S. Insight into the effect of alkali treatment on enhancing adsorptivity of activated carbon for HCl removal in H2 feedstock. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-022-02111-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AbstractThe removal of contaminated HCl gas in the petrochemical plants is essential to prevent corrosion problems, catalysts poisoning, and downstream contamination. Alkali-treated activated carbon (AC) was proposed as an effective adsorbent for HCl removal. Understanding the underlying mechanism of HCl adsorption on modified AC is key to design promising strategies for removal of HCl and other chlorinated hydrocarbon gases in the H2 feedstock. Here, a combined experimental and computational approach was used to study the role of alkali treatment on the adsorption behavior of HCl on the AC surfaces. We find that an interplay between alkali ions and oxygen-containing functional groups on the AC surface plays a crucial role in stabilizing the adsorbed HCl. The origin of such stable adsorbed configurations can be attributed to the dissociative adsorption of HCl leading to a formation of low energy species such as water, OH– and Cl– anions. These anions are electrostatically stabilized by the alkali ions resulting in a strong adsorption of −3.61 eV and −3.69 eV for Na+ and K+, respectively. Close investigation on charge analysis reveals that the epoxy functional group facilitates adsorbent-surface charge transfer where O and Cl atoms gain more charges of 0.37 e and 0.58 e which is in good correlation with the improved adsorption strength. The calculated results are consistence with the experimental observations that the Langmuir adsorptivity has been enhanced upon alkali modification. The maximum adsorption capacity of AC has been improved approximately by 4 times from 78.9 to 188.9 mg/g upon treatment.
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Lawtae P, Tangsathitkulchai C. The Use of High Surface Area Mesoporous-Activated Carbon from Longan Seed Biomass for Increasing Capacity and Kinetics of Methylene Blue Adsorption from Aqueous Solution. Molecules 2021; 26:6521. [PMID: 34770928 PMCID: PMC8587158 DOI: 10.3390/molecules26216521] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 12/07/2022] Open
Abstract
Microporous- and mesoporous-activated carbons were produced from longan seed biomass through physical activation with CO2 under the same activation conditions of time and temperature. The specially prepared mesoporous carbon showed the maximum porous properties with the specific surface area of 1773 m2/g and mesopore volume of 0.474 cm3/g which accounts for 44.1% of the total pore volume. These activated carbons were utilized as porous adsorbents for the removal of methylene blue (MB) from an aqueous solution and their effectiveness was evaluated for both the adsorption kinetics and capacity. The adsorption kinetic data of MB were analyzed by the pseudo-first-order model, the pseudo-second-order model, and the pore-diffusion model equations. It was found that the adsorption kinetic behavior for all carbons tested was best described by the pseudo-second-order model. The effective pore diffusivity (De) derived from the pore-diffusion model had the values of 4.657 × 10-7-6.014 × 10-7 cm2/s and 4.668 × 10-7-19.920 × 10-7 cm2/s for the microporous- and mesoporous-activated carbons, respectively. Three well-known adsorption models, namely the Langmuir, Freundlich and Redlich-Peterson equations were tested with the experimental MB adsorption isotherms, and the results showed that the Redlich-Peterson model provided the overall best fitting of the isotherm data. In addition, the maximum capacity for MB adsorption of 1000 mg/g was achieved with the mesoporous carbon having the largest surface area and pore volume. The initial pH of MB solution had virtually no effect on the adsorption capacity and removal efficiency of the methylene blue dye. Increasing temperature over the range from 35 to 55 °C increased the adsorption of methylene blue, presumably caused by the increase in the diffusion rate of methylene blue to the adsorption sites that could promote the interaction frequency between the adsorbent surface and the adsorbate molecules. Overall, the high surface area mesoporous carbon was superior to the microporous carbon in view of the adsorption kinetics and capacity, when both carbons were used for the removal of MB from an aqueous solution.
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Affiliation(s)
| | - Chaiyot Tangsathitkulchai
- Institute of Engineering, School of Chemical Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand;
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Lawtae P, Tangsathitkulchai C. A New Approach for Controlling Mesoporosity in Activated Carbon by the Consecutive Process of Air Oxidation, Thermal Destruction of Surface Functional Groups, and Carbon Activation (the OTA Method). Molecules 2021; 26:2758. [PMID: 34067110 PMCID: PMC8125282 DOI: 10.3390/molecules26092758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
A new and simple method, based entirely on a physical approach, was proposed to produce activated carbon from longan fruit seed with controlled mesoporosity. This method, referred to as the OTA, consisted of three consecutive steps of (1) air oxidation of initial microporous activated carbon of about 30% char burn-off to introduce oxygen surface functional groups, (2) the thermal destruction of the functional groups by heating the oxidized carbon in a nitrogen atmosphere at a high temperature to increase the surface reactivity due to increased surface defects by bond disruption, and (3) the final reactivation of the resulting carbon in carbon dioxide. The formation of mesopores was achieved through the enlargement of the original micropores after heat treatment via the CO2 gasification, and at the same time new micropores were also produced, resulting in a larger increase in the percentage of mesopore volume and the total specific surface area, in comparison with the production of activated carbon by the conventional two-step activation method using the same activation time and temperature. For the activation temperatures of 850 and 900 °C and the activation time of up to 240 min, it was found that the porous properties of activated carbon increased with the increase in activation time and temperature for both preparation methods. A maximum volume of mesopores of 0.474 cm3/g, which accounts for 44.1% of the total pore volume, and a maximum BET surface area of 1773 m2/g was achieved using three cycles of the OTA method at the activation temperature of 850 °C and 60 min activation time for each preparation cycle. The two-step activation method yielded activated carbon with a maximum mesopore volume of 0.270 cm3/g (33.0% of total pore volume) and surface area of 1499 m2/g when the activation temperature of 900 °C and a comparable activation time of 240 min were employed. Production of activated carbon by the OTA method is superior to the two-step activation method for better and more precise control of mesopore development.
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Affiliation(s)
| | - Chaiyot Tangsathitkulchai
- School of Chemical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000, Thailand;
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