scholarly journals Structural and adsorption characteristics of potassium carbonate activated biochar

RSC Advances ◽  
2018 ◽  
Vol 8 (37) ◽  
pp. 21012-21019 ◽  
Author(s):  
Ling Zhu ◽  
Nan Zhao ◽  
Lihong Tong ◽  
Yizhong Lv
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Surface Properties ◽  
Specific Surface Area ◽  
Potassium Carbonate ◽  
Adsorption Process ◽  
Adsorption Characteristics ◽  
Activated Biochar ◽  
Surface Pores

The structure activation of K2CO3 enriches the surface pores of biochar and increases the specific surface area nearly 10 times. The changes of pore structure and surface properties significantly affect the adsorption process of naphthalene.

scholarly journals Adsorption of Ammonium Nitrogen from Aqueous Solution on Chemically Activated Biochar Prepared from Sorghum Distillers Grain

2019 ◽  
Vol 9 (23) ◽  
pp. 5249 ◽  
Author(s):  
Derlin Hsu ◽  
Changyi Lu ◽  
Tairan Pang ◽  
Yuanpeng Wang ◽  
Guanhua Wang
Keyword(s):  
Aqueous Solution ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Adsorption Process ◽  
Ammonium Nitrogen ◽  
Activated Biochar ◽  
Distillers Grain ◽  
Kinetics And Isotherms

Chemically activated biochars prepared from sorghum distillers grain using two base activators (NaOH and KOH) were investigated for their adsorption properties with respect to ammonium nitrogen from aqueous solution. Detailed characterizations, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and specific surface area analyses, were carried out to offer a broad evaluation of the prepared biochars. The results showed that the NaOH- and KOH-activated biochars exhibited significantly enhanced adsorption capacity, by 2.93 and 4.74 times, respectively, in comparison with the pristine biochar. Although the NaOH-activated biochar possessed larger specific surface area (132.8 and 117.7 m2/g for the NaOH- and KOH-activated biochars, respectively), the KOH-activated biochar had higher adsorption capacity owing to its much higher content of functional groups. The adsorption kinetics and isotherms of the KOH-activated biochar at different temperatures were further studied. The biochar had a maximum adsorption capacity of 14.34 mg/g at 45 °C, which was satisfactory compared with other biochars prepared using different feedstocks. The adsorption process followed pseudo-second-order kinetics, and chemical adsorption was the rate-controlling step. The equilibrium data were consistent with the Freundlich isotherm, and the thermodynamic parameters suggested that the adsorption process was endothermic and spontaneous. Consequently, this work demonstrates that chemically activated biochar from sorghum distillers grain is effective for ammonium nitrogen removal.

Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Adsorption Process ◽  
Continuous System ◽  
Gas Oil ◽  
Average Pore ◽  
Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

scholarly journals Nanometer Pore Structure Characterization of Taiyuan Formation Shale in the Lin-Xing Area Based on Nitrogen Adsorption Experiments

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Chenlong Ding ◽  
Jinxian He ◽  
Hongchen Wu ◽  
Xiaoli Zhang
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Shale Gas ◽  
Pore Volume ◽  
Ordos Basin ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Taiyuan Formation

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.

The whole-aperture pore-structure characteristics of marine-continental transitional shale facies of the Taiyuan and Shanxi Formations in the Qinshui Basin, North China

2019 ◽  
Vol 7 (2) ◽  
pp. T547-T563 ◽  
Author(s):  
Jiyuan Wang ◽  
Shaobin Guo
Keyword(s):  
High Pressure ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Gas Adsorption ◽  
Pore Morphology ◽  
Qinshui Basin ◽  
Mercury Intrusion ◽  
Structure Characteristics

To systematically study the whole-aperture pore-structure characteristics of the marine-continental transitional shale facies in the Upper Palaeozoic Taiyuan and Shanxi Formations of the Qinshui Basin, we have collected a total of 11 samples for high-pressure mercury intrusion, low-pressure gas adsorption ([Formula: see text] and [Formula: see text]), nuclear magnetic resonance (NMR), and field-emission scanning electron microscopy with argon-ion polishing experiments to determine the pore morphology and distribution characteristics of shale samples in detail and to perform quantitative analyses. Then compared the pore-development characteristics of the Taiyuan Formation samples with those of the Shanxi Formation to determine which is preferable. The experimental results indicate that the shale samples of the Qinshui Basin mainly develop three types of pores: organic pores, intergranular pores, and microfractures. High-pressure mercury intrusion and gas-adsorption experiments indicate that the pore-size distributions exhibit multiple peaks. The samples contained varying proportions of macropores, mesopores, and micropores, among which the former two are dominant, accounting for approximately 85% of the total pore volume, whereas micropores account for only 15%. However, mesopores and micropores dominate the specific surface area; between them, the micropores are much more prevalent, accounting for more than 99% of the total specific surface area. Macropores contribute less than 1% of the specific surface area and therefore can be neglected. The pore morphology resembles the slit type parallel platy pores with a ballpoint pen structure. The NMR [Formula: see text] spectra have multiple-peak values. In addition, the large difference between the curved areas before and after centrifugation indicates that the samples contain a large proportion of mesopores and macropores, which is consistent with the results presented above. The results demonstrate that the development of pores in the Taiyuan Formation is better than that in the Shanxi Formation.

scholarly journals Investigation on the adsorption of antibiotics from water by metal loaded sewage sludge biochar

2020 ◽  
Author(s):  
Xiulei Fan ◽  
Zheng Qian ◽  
Jiaqiang Liu ◽  
Nan Geng ◽  
Jun Hou ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Adsorption Process ◽  
Low Cost ◽  
Particle Diffusion ◽  
Surface Functionality ◽  
Intra Particle Diffusion ◽  
Adsorption Amount

Abstract Application of sewage sludge biochar as an adsorbent for antibiotics treatment has obtained special attention owning to their low cost and surface functionality. Three metal ions were selected to modify sewage sludge biochar through the pyrolysis with the metal loaded method. Fe loaded sewage sludge biochar (BC-Fe), Al loaded sewage sludge biochar (BC-Al) and Mn loaded sewage sludge biochar (BC-Mn) were characterized and used to explore the performance of adsorbing tetracycline (TC), sulfamethoxazole (SMZ) and amoxicillin (AMC). BC-Fe, BC-Al and BC-Mn possessed rougher surfaces, larger specific surface area and better pore structure. Intra-particle diffusion and Langmuir models were more suitable to describe the adsorption process. The maximum adsorption amount of TC, SMZ and AMC could reach 123.35, 99.01 and 109.89 mg/g by BC-Fe. Furthermore, the main mechanism of antibiotics adsorption by metal loaded sewage sludge biochars might be pores filling, Van der Waals forces and H-bonding. The study can not only solve the problems associated with the pollution of antibiotics from wastewater, but also reduced the treatment press of sewage sludge effectively.

scholarly journals Effect of peat mire evolution on pore structure characteristics in thick coal seam: Examples from Xishanyao Formation (Middle Jurassic), Yili Basin, China

2020 ◽  
Vol 38 (5) ◽  
pp. 1484-1514 ◽  
Author(s):  
Rongfang Qin ◽  
Anmin Wang ◽  
Daiyong Cao ◽  
Yingchun Wei ◽  
Liqi Ding ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Coal Seam ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Thick Coal Seam ◽  
Structure Characteristics ◽  
Cyclic Changes

The physical properties of thick coal seams show strong vertical heterogeneity; thus, an accurate characterization of their pore structure is essential for coalbed methane (CBM) exploration and production. A total of 18 coal samples, collected from a thick coal seam in the Yili Basin of NW China, were tested by a series of laboratory experiments to investigate the peat mire evolution and pore structure characteristics. The results show that the No. 4 coal seam has undergone multiple stages of evolution in the peatification stage, and was divided into four water-transgression/water-regression cycles according to the regular cyclic changes of the vitrinite/inertinite ratio, structure preservation index, gelification index, vegetation index, trace element ratios, and stable carbon isotopes of organic matter. The changes of pore structure characteristics with the changes of coal deposition cycles are also analyzed. It is concluded that pore structure characteristics of the four cycles are quite different. In each water-transgression cycle, the vitrinite gradually increased and the inertinite gradually decreased, resulting in a decrease of the porosity, pore volume, specific surface area, and fractal dimension. While in each water-regression cycle, the vitrinite gradually decreased and the inertinite gradually increased, leading to an increase of the porosity, pore volume, specific surface area, and fractal dimension. A strong relationship exists between the porosity, pore volume, specific surface area, fractal dimension, and submacerals, with fusinite and semifusinite which contained more pores having a positive correlation, desmocollinite and corpovitrinite which contained few pores having a negative correlation.

Nano/Micro Pore Structure and Fractal Characteristics of Baliancheng Coalfield in Hunchun Basin

2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Coal Reservoir

The pore structure characteristic is an important index to measure and evaluate the storage capacity and fracturing coal reservoir. The coal of Baliancheng coalfield in Hunchun Basin was selected for experiments including low temperature nitrogen adsorption method, Argon Ion milling Scanning Electron Microscopy (Ar-SEM), Nuclear Magnetic Resonance (NMR), X-ray diffraction method, quantitative mineral clay analysis method. The pore structure of coal was quantitatively characterized by means of fractal theory. Meanwhile, the influences of pores fractal dimension were discussed with experiment data. The results show that the organic pores in Baliancheng coalfield are mainly plant tissue pores, interparticle pores and gas pores, and the mineral pores are corrosion pores and clay mineral pores. There are mainly slit pore and wedge-shaped pore in curve I of Low temperature nitrogen adsorption. There are ink pores in curve II with characteristics of a large specific surface area and average pore diameter. The two peaks of NMR T2 spectrum indicate that the adsorption pores are relatively developed and their connectivity is poor. The three peaks show the seepage pores and cracks well developed, which are beneficial to improve the porosity and permeability of coal reservoir. When the pore diameter is 2–100 nm, the fractal dimensions D1 and D2 obtained by nitrogen adsorption experiment. there are positive correlations between water content and specific surface area and surface fractal dimension D1, The fractal dimension D2 was positively and negatively correlated with ash content and average pore diameters respectively. The fractal dimensions DN1 and DN2 were obtained by using the NMR in the range of 0.1 μm˜10 μm. DN1 are positively correlated with specific surface area of adsorption pores. DN2 are positively correlated volume of seepage pores. The fractal dimension DM and dissolution hole fractal dimension Dc were calculated by SEM image method, respectively controlled by clay mineral and feldspar content. There is a remarkable positive correlation between D1 and DN1 and Langmuir volume of coal, so fractal dimension can effectively quantify the adsorption capacity of coal.

scholarly journals Quantitative Characterization for the Micronanopore Structures of Terrestrial Shales with Different Lithofacies Types: A Case Study of the Jurassic Lianggaoshan Formation in the Southeastern Sichuan Basin of the Yangtze Region

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Weiwei Liu ◽  
Kun Zhang ◽  
Qianwen Li ◽  
Zhanhai Yu ◽  
Sihong Cheng ◽  
...  
Keyword(s):  
Organic Matter ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Sichuan Basin ◽  
Parallel Plate ◽  
Quantitative Characterization ◽  
Southeastern Sichuan Basin

Due to the specificity of the geological background, terrestrial strata are widely distributed in the major hydrocarbon-bearing basins in China. In addition, terrestrial shales are generally featured with high thickness, multiple layers, high TOC content, ideal organic matter types, and moderate thermal evolution, laying a solid material foundation for hydrocarbon generation. However, the quantitative characterization study on their pore structure remains inadequate. In this study, core samples were selected from the Middle Jurassic Lianggaoshan Formation in the southeastern Sichuan Basin of the Upper Yangtze Region for analyses on its TOC content and mineral composition. Besides, experiments including oil washing, the adsorption/desorption of CO2 and nitrogen, and high-pressure mercury pressure experiments were carried out. The pore structure of different petrographic types of terrestrial shales can be accurately and quantitatively characterized with these works. The following conclusions were drawn: for organic-rich mixed shales and organic-rich clay shales, the TOC content is the highest; the pore volume, which is primarily provided by macropores and specific surface area, which is provided by mesopores, was the largest, thus providing more space for shale oil and gas reservation. The pores take on a shape either close to a parallel plate slit or close to or of an ink bottle. For organic-matter-bearing shales, both the pore volume and specific surface area are the second-largest and are provided by the same sized pores with organic-rich mixed shales. Its pores take on a shape approximating either a parallel plate slit or an ink bottle. Organic-matter-bearing mixed shales have the lowest pore volume and specific surface area; its pore volume is primarily provided by macropores, and the specific surface area by mesopores and the shape of the pores are close to an ink bottle.

scholarly journals Application of CoMn/CoFe layered double hydroxide based on metal-organic frameworks template to activate peroxymonosulfate for 2, 4-dichlorophenol degradation

2021 ◽  
Author(s):  
Chenyu Liu ◽  
Haitong Wei ◽  
Yanhui Gao ◽  
Ning Wang ◽  
Xiaoying Yuan ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
High Specific Surface Area ◽  
State Transformation ◽  
Alkaline Conditions ◽  
Metal Organic

Abstract Metal-Organic Frameworks (MOFs) have unique properties and stable structure, which have been widely used as templates/precursors to prepare well-developed pore structure and high specific surface area materials. In this article, an innovative and facile method of crystal reorganization was designed by using MOFs as sacrificial templates to prepare LDH nano-layer sheet structure through a pseudomorphic conversion process under alkaline conditions. The obtained CoMn-LDH and CoFe-LDH catalysts broke the ligand of MOFs and reorganized the structure on the basis of retaining a high specific surface area and a large number of pores, which have higher specific surface area and well-developed pore structure than LDH catalysts prepared by traditional methods, and thus provide more active sites to activate PMS. Due to the unique framework structure of MOFs, the MOF derived CoMn-LDH and CoFe-LDH catalysts could provide more active sites to activate PMS, and achieve a 2, 4-dichlorophenol (2, 4-DCP) degradation of 99.3% and 99.2% within 20 min, respectively. Besides, the two LDH catalysts displayed excellent degradation performance for bisphenol A (BPA), ciprofloxacin (CIP) and 2, 4-dichlorophenoxyacetic acid (2, 4-D). XPS indicated that the valence state transformation of metal elements participated in PMS activation. EPR manifested sulfate radical () and singlet oxygen (1O2) were the main species for degrading pollutants. In addition, after the three-cycle experiment, the CoMn-LDH and CoFe-LDH catalysts also showed long-term stability with a slight activity decrease in the third cycle. The phytotoxicity assessment determined by the germination of mung beans proved that PMS activation by MOFs-derived LDH catalyst can basically eliminate the phytotoxicity of 2, 4-D solution. This research not only developed high-activity LDH catalysts for PMS activation, but also expanded the environmental applications of MOFs derivants.

BCN nanosheets templated by g-C3N4 for high performance capacitive deionization

2018 ◽  
Vol 6 (30) ◽  
pp. 14644-14650 ◽  
Author(s):  
Shiyong Wang ◽  
Gang Wang ◽  
Tingting Wu ◽  
Yunqi Zhang ◽  
Fei Zhan ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Performance ◽  
Electrode Materials ◽  
High Specific Surface Area ◽  
Capacitive Deionization ◽  
First Time

BCN nanosheets show a pore structure with a high specific surface area and are investigated as CDI electrode materials for the first time.

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