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Fang S, Zhao L, Rong G, Chen B, Xu X, Qiu H, Cao X. Converting coastal silt into subgrade soil with biochar as reinforcing agent, CO 2 adsorbent, and carbon sequestrating material. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118394. [PMID: 37354594 DOI: 10.1016/j.jenvman.2023.118394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/01/2023] [Accepted: 06/11/2023] [Indexed: 06/26/2023]
Abstract
Large amounts of coastal silt produced annually is urgent to be treated with a feasible strategy. This study converted it into subgrade soil by cement solidification for resource utilization. Biochar was used as exogenous additive for enhancing compressive strength of the product, simultaneously achieving carbon sequestration. Three biochars derived from peanut shells (PSBC), cow dung (CDBC) and sewage sludge (SSBC) at 300 °C, 500 °C and 700 °C pyrolysis, were added into raw materials with 1%, 2% and 5%, respectively. All biochars significantly improved the compressive strength of the subgrade soil by 20-110%. Biochar catalyzed cement hydration reactions to produce more Ca(OH)2, CaCO3 and calcium silicate hydrates (C-S-H gel). The catalytic capacity of different biochars followed the order of SSBC > PSBC > CDBC. Addition of 2% SSBC500 induced the greatest increase in 28 d-strength from only 1.0 MPa-2.1 MPa, which was due to that 500 °C biochar had a suitable specific surface area and porosity. Biochar facilitated CO2 capture (absorption) during the hydration reactions at the initial 48 h with 55-70 mg g-1. The high alkalinity and water holding capacity of biochar contributed to the absorption of CO2; the high content of minerals in SSBC compared to CDBC and PSBC promoted chemical conversion of CO2 to carbonate. Besides, the biochar itself as carbon rich material was encapsulated in the subgrade soil, which can be regarded as a long-term carbon sequestration strategy. Carbon budget analysis demonstrated that converting one ton dry silt into subgrade soil with addition of 2% biochar could increase CO2 sequestration from 11 kg to 36-94 kg. This study proposes a novel strategy of using biochar to strengthen the subgrade soil simultaneously achieve long-term carbon sequestration.
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Affiliation(s)
- Shuwei Fang
- China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 201306, China
| | - Ling Zhao
- China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 201306, China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Guoqiang Rong
- Baowu Group Environmental Resources Technology Co., Ltd., Shanghai, 201999, China
| | - Bing Chen
- Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaoyun Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hao Qiu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xinde Cao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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David E. Production of Activated Biochar Derived from Residual Biomass for Adsorption of Volatile Organic Compounds. MATERIALS (BASEL, SWITZERLAND) 2022; 16:389. [PMID: 36614729 PMCID: PMC9822064 DOI: 10.3390/ma16010389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
Volatile organic compounds (VOCs) released in air represent a major potential for environmental pollution. Capture methods based on activated biochar have attracted attention because of their low cost and for the high removal capacity of the material due to its physical and chemical properties. In this paper, activated biochars were developed and their adsorption performance for VOC capture was evaluated. In the first step, biochars derived from rapeseed cake (RSC) and walnut shells (WSC) were obtained through a carbonization process and then were activated using basic/acid agents (KOH/H2SO4) to increase their performance as adsorbents. Acetone and toluene were used as the VOC templates. The adsorption capacities of toluene and acetone for non-activated biochars were reduced (26.65 mg/g), while that of activated biochars increased quite significantly, up to 166.72 mg/g, and the biochars activated with H2SO4 presented a higher adsorption capacity of VOCs than the biochars activated with KOH. The higher adsorption capacity of biochars activated with H2SO4 can be attributed to their large surface area, and also to their larger pore volume. This activated biochar adsorbent could be used with good results to equip air purification filters to capture and remove VOCs.
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Affiliation(s)
- Elena David
- National Research Institute for Cryogenic & Isotopic Technologies, Street Uzinei no. 4, P.O. Râureni, P.O. Box 7, 240050 Râmnicu Vâlcea, Romania
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Guo T, Zhang R, Wang X, Kong L, Xu J, Xiao H, Bedane AH. Porous Structure of β-Cyclodextrin for CO 2 Capture: Structural Remodeling by Thermal Activation. Molecules 2022; 27:7375. [PMID: 36364201 PMCID: PMC9657893 DOI: 10.3390/molecules27217375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 10/22/2022] [Accepted: 10/26/2022] [Indexed: 11/07/2023] Open
Abstract
With a purpose of extending the application of β-cyclodextrin (β-CD) for gas adsorption, this paper aims to reveal the pore formation mechanism of a promising adsorbent for CO2 capture which was derived from the structural remodeling of β-CD by thermal activation. The pore structure and performance of the adsorbent were characterized by means of SEM, BET and CO2 adsorption. Then, the thermochemical characteristics during pore formation were systematically investigated by means of TG-DSC, in situ TG-FTIR/FTIR, in situ TG-MS/MS, EDS, XPS and DFT. The results show that the derived adsorbent exhibits an excellent porous structure for CO2 capture accompanied by an adsorption capacity of 4.2 mmol/g at 0 °C and 100 kPa. The porous structure is obtained by the structural remodeling such as dehydration polymerization with the prior locations such as hydroxyl bonded to C6 and ring-opening polymerization with the main locations (C4, C1, C5), accompanied by the release of those small molecules such as H2O, CO2 and C3H4. A large amount of new fine pores is formed at the third and fourth stage of the four-stage activation process. Particularly, more micropores are created at the fourth stage. This revealed that pore formation mechanism is beneficial to structural design of further thermal-treated graft/functionalization polymer derived from β-CD, potentially applicable for gas adsorption such as CO2 capture.
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Affiliation(s)
- Tianxiang Guo
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Runan Zhang
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Xilai Wang
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Lingfeng Kong
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Junpeng Xu
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Huining Xiao
- Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Alemayehu Hailu Bedane
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Power University, Baoding 071003, China
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
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Effect of Pore Structure on CO2 Adsorption Performance for ZnCl2/FeCl3/H2O(g) Co-Activated Walnut Shell-Based Biochar. ATMOSPHERE 2022. [DOI: 10.3390/atmos13071110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Walnut shell is a very potential biochar precursor because of its wide source, low cost, and easy structure modification. In this paper, the co-activation method of FeCl3, ZnCl2 and H2O(g) was adopted to prepare walnut shell-based biochar with high microporosity and the effect of pore structure on CO2 adsorption performance at different temperatures was investigated. The prepared biochar had a larger specific surface area (2647.8 m2 g−1), satisfactory micropore area (2008.7 m2 g−1) and high total pore volume (2.58 cm3 g−1). At 273 K and 298 K, its CO2 adsorption capacity was 4.79 mmol g−1 and 3.20 mmol g−1, respectively. Particularly, CO2 adsorbed uptake on biochar was strongly sensitive to their narrow micropore volume, instead of the total specific surface area, total pore volume, and micropore specific surface area. The optimal pore size beneficial for CO2 adsorption was 0.33–0.82 nm at 273 K, but the optimal pore size was 0.33–0.39 nm at 298 K. It provides theoretical guidance for future material preparation and selection, and FeCl3, ZnCl2 and H2O(g) may be effective biochar activators.
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Guo T, Fan Z, Du Y, Xu J, Kong L, Pan Y, Xiao H, Xie Q. Thermodynamics of
CO
2
adsorption on cellulose‐derived biochar prepared in ionic liquid. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.23940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tianxiang Guo
- Hebei Key Lab of Power Plant Flue Gas Multi‐Pollutants Control, Department of Environmental Science and Engineering North China Power University Baoding PR China
- MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering, North China Electric Power University Beijing PR China
| | - Zeng Fan
- Hebei Key Lab of Power Plant Flue Gas Multi‐Pollutants Control, Department of Environmental Science and Engineering North China Power University Baoding PR China
- MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering, North China Electric Power University Beijing PR China
| | - Yarong Du
- Department of Power Engineering North China Electric Power University Baoding PR China
| | - Junpeng Xu
- Hebei Key Lab of Power Plant Flue Gas Multi‐Pollutants Control, Department of Environmental Science and Engineering North China Power University Baoding PR China
- MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering, North China Electric Power University Beijing PR China
| | - Lingfeng Kong
- Hebei Key Lab of Power Plant Flue Gas Multi‐Pollutants Control, Department of Environmental Science and Engineering North China Power University Baoding PR China
- MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering, North China Electric Power University Beijing PR China
| | - Yuanfeng Pan
- School of Chemistry and Chemical Engineering Guangxi University Nanning PR China
| | - Huining Xiao
- Department of Chemical Engineering University of New Brunswick Fredericton New Brunswick Canada
| | - Qing Xie
- Department of Electrical Engineering North China Electric Power University Baoding PR China
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