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

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.

2017 ◽  
Vol 68 (4) ◽  
pp. 732-736
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Casen Panaitescu ◽  
Raluca Dragomir

Desulphurization by reactive adsorption was studied on sand abrasive blasting grit/ bentonite. The adsorbent was characterized by determining the composition, adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments were performed in continuous system at 260�300oC, 25 atm and volume hourly space velocities of 1-2 h-1. The efficiency of adsorption was evaluated at desulphurization of a synthetic reaction mixture and a catalytic cracking gas oil.


2018 ◽  
Vol 37 (1) ◽  
pp. 251-272 ◽  
Author(s):  
Junjian Zhang ◽  
Chongtao Wei ◽  
Gaoyuan Yan ◽  
Guanwen Lu

To better understand the structural characteristic of adsorption pores (pore diameter < 100 nm) of coal reservoirs around the coalbed methane production areas of western Yunnan and eastern Guizhou, we analyzed the structural and fractal characteristics of pore size range of 0.40–2.0 nm and 2–100 nm in middle–high rank coals ( Ro,max = 0.93–3.20%) by combining low-temperature N2/CO2 adsorption tests and surface/volume fractal theory. The results show that the coal reservoirs can be divided into three categories: type A ( Ro,max < 2.15%), type B (2.15% <  Ro,max <2.50%), and type C ( Ro,max > 2.15%). The structural parameters of pores in the range from 2 to 100 nm are influenced by the degree of coal metamorphism and the compositional parameters (e.g., ash and volatile matter). The dominant diameters of the specific surface areas are 10–50 nm, 2–50 nm, and 2–10 nm, respectively. The pores in the range from <2 nm provide the largest proportion of total specific surface area (97.22%–99.96%) of the coal reservoir, and the CO2-specific surface area and CO2-total pore volume relationships show a positive linear correlation. The metamorphic degree has a much greater control on the pores (pore diameter less than 2 nm) structural parameters than those of the pore diameter ranges from 2 to 100 nm. Dv1 and Dv2 can characterize the structure of 2–100 nm adsorption pores, and Dv1 (volume heterogeneity) has a positive correlation with the pore structural parameters such as N2-specific surface area and N2-total pore volume. This parameter can be used to characterize volume heterogeneity of 2–10 nm pores. Dv2 (surface heterogeneity) showed type A > type B > type C and was mainly affected by the metamorphism degree. Ds2 can be used to characterize the pore surface heterogeneity of micropores in the range of 0.62–1.50 nm. This parameter has a good correlation with the pore parameters (CO2-total pore volume, CO2-specific surface area, and average pore size) and is expressed as type C < type B < type A. In conclusion, the heterogeneity of the micropores is less than that of the meso- and macropores (2–100 nm). Dv1, Dv2, and Ds2 can be used as effective parameters to characterize the pore structure of adsorption pores. This result can provide a theoretical basis for studying the pore structure compatibility of coal reservoirs in the region.


2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao

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.


Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840016 ◽  
Author(s):  
JUN LIU ◽  
YANBIN YAO ◽  
DAMENG LIU ◽  
YIDONG CAI ◽  
JIANCHAO CAI

Fractal characterization offers a quantitative evaluation on the heterogeneity of pore structure which greatly affects gas adsorption and transportation in shales. To compare the fractal characteristics between marine and continental shales, nine samples from the Lower Silurian Longmaxi formation in the Sichuan basin and nine from the Middle Jurassic Dameigou formation in the Qaidam basin were collected. Reservoir properties and fractal dimensions were characterized for all the collected samples. In this study, fractal dimensions were originated from the Frenkel–Halsey–Hill (FHH) model with N[Formula: see text] adsorption data. Compared to continental shale, marine shale has greater values of quartz content, porosity, specific surface area and total pore volume but lower level of clay minerals content, permeability, average pore diameter and methane adsorption capacity. The quartz in marine shale is mostly associated with biogenic origin, while that in continental shale is mainly due to terrigenous debris. The N[Formula: see text] adsorption–desorption isotherms exhibit that marine shale has fewer inkbottle-shaped pores but more plate-like and slit-shaped pores than continental shale. Two fractal dimensions ([Formula: see text] and [Formula: see text] were obtained at [Formula: see text] of 0–0.5 and 0.5–1. The dimension [Formula: see text] is commonly greater than [Formula: see text], suggesting that larger pores (diameter [Formula: see text][Formula: see text]nm) have more complex structures than small pores (diameter [Formula: see text][Formula: see text]nm). The fractal dimensions (both [Formula: see text] and [Formula: see text]) positively correlate to clay minerals content, specific surface area and methane adsorption capacity, but have negative relationships with porosity, permeability and average pore diameter. The fractal dimensions increase proportionally with the increasing quartz content in marine shale but have no obvious correlation with that in continental shale. The dimension [Formula: see text] is correlative to the TOC content and permeability of marine shale at a similar degree with dimension [Formula: see text], while the dimension [Formula: see text] is more sensitive to those of continental shale than dimension [Formula: see text]. Compared with dimension [Formula: see text], for two shales, dimension [Formula: see text] is better associated with the content of clay minerals but has worse correlations with the specific surface area and average pore diameter.


2014 ◽  
Vol 513-517 ◽  
pp. 82-85
Author(s):  
Rui Rui Li ◽  
Yue Shi ◽  
Lei Zu ◽  
Hui Qin Lian ◽  
Yang Liu ◽  
...  

The mesoporous polycarbonate-silica nanocomposite materials were synthesized through the modified sol-gel approach under acidic condition. The specific surface area, pore diameter and pore volume of polycarbonate-silica could be controlled by changing the acidity of the synthesis system. The polycarbonate-silica possess an irregular block morphology according to the scanning electron microscopy observations. With decreasing the pH value of the synthesis system, the specific surface area and pore diameter of polycarbonate-silica were raised but the pore volume was reduced. The maximum specific surface area of polycarbonate-silica was 701.71m2/g which presented by the results of Nitrogen adsorptiondesorption isotherms.


2015 ◽  
Vol 1090 ◽  
pp. 154-159
Author(s):  
Sheng Zhou Zhang ◽  
Hong Ying Xia ◽  
Li Bo Zhang ◽  
Jin Hui Peng ◽  
Jian Wu ◽  
...  

Bamboo as the raw material is carbonized to prepare high specific surface area activated carbon by microwave heating under nitrogen atmosphere in our present work. Influences of activation agents on the preparation of activated carbon are studied. The results show that activation agents have a significant influence on the preparation of activated carbon. Under the heating time of 15 min, the adsorption capacity of the activated carbon prepared utilizing KOH as activation agent is the best. When the KOH/C ratio is 4, the iodine number and yield of activated carbon are 2298 mg/g and 39.82%, respectively. The BET specific surface area, total pore volume and average pore diameter of activated carbon are 3441 m2/g, 2.093 ml/g and 2.434 nm, respectively. The micropore volume of 1.304 ml/g is 62.30% of total pore volume, indicating that the activated carbon is microporous activated carbon.


Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Huiqun Niu ◽  
Hongying Yang ◽  
Linlin Tong

In this paper, the structures of element carbon and humic acid extracted from carbonaceous gold concentrate were characterized employing a variety of analytical methods. The extracted amounts of ECE (elemental carbon extract) and HAE (humic acid extract) were 14.84–38.50 and 11.55–28.05 mg g−1, respectively. SEM and porosity analysis indicated that ECE occurred mostly as irregular blocky particles with a mesoporous surface with the average pore diameter being 31.42 nm. The particle size of ECE was mainly ranged from 5.5 to 42 μm and the specific surface area was 20.35 m2 g−1. The physicochemical features and structure of ECE were close to activated carbon, and the crystallinity was slightly lower than graphite. The particle size distribution of HAE varied from 40 to 400 nm with the specific surface area of 42.84 m2 g−1, whereas the average pore diameter of HAE was 2.97 nm. FTIR and UV–VIS analyses indicated that HAE was a complex organic compound containing the enrichment of oxygen-containing structure. The results showed that the adsorption amounts of ECE and HAE under the acidic conditions were 470.46 and 357.60 mg g−1, respectively. In an alkaline environment, the amount of ECE was 449.02 mg g−1 and the value of HAE was 294.72 mg g−1. ECE mainly utilized the outer surface and mesoporous structure to adsorb gold, while the functional groups’ complexation or surface site adsorption was the leading approach for HAE to adsorb gold.


Author(s):  
M. Troubitsin ◽  
Viet Hung Hoang ◽  
L. Furda

The object of our investigation is a biomimetic calcium-phosphate nanocomposite doped by silicate and carbonate anions (BMHAP) synthesized by chemical deposition from aqueous solutions. The obtained samples are investigated using X-ray phase analysis (XRD), FTIR spectroscopy, and low-temperature nitrogen adsorption (BET method). The influence of the techno chemical synthesis parameters on the products characteristics (including phase composition, crystal lattice parameters, average crystallite size, specific surface area) is evaluated. The study on the effect of the synthesis temperature shows that with increasing in temperature from 22°C to 80°C, reveals a slight increase in the parameters of unit cells a and c, which leads to an increase in its volume. There is also a tendency towards a decrease in the average size of coherent scattering regions of crystallites (from 7,52 to 4,65 nm) and specific surface area (from 192,51 to 74,72 m2/g), but the pore volume and average pore diameter of the synthesized powders increases. The effect of the aging time of the sediment in the mother liquor is studied from 0,5 to 24 hours. It is found that with an increase in the maturation time of the sediment, the percent crystallinity of the powders improves by 1,7 times, an increase in the specific surface area from 163,43 to 192,51 m2/g and a slight decrease in the pore volume and average pore size of the samples are observed. The impact of the stirring rate of the reagents is investigated. An increase in speed from 300 to 1300 rpm has been shown to decrease the average crystallite size from 8,80 to 6,41 nm, and as a result, to increase the specific surface area of the synthesized samples from 178,58 to 192,51 m2/g, respectively.


2010 ◽  
Vol 4 (2) ◽  
pp. 110-116 ◽  
Author(s):  
Silvester Tursiloadi ◽  
Hiroshi Hirashima

Stable anatase is attractive to its notable functions for photo catalysis and photon-electron transfer.   Stable anatase TiO­2 containing amorphous SiO2 aerogel was prepared by hydrolysis of Ti (OC3H7)4 and Si (OC3H7)4 in a 2-propanol solution with acid catalyst. The solvent in wet gels was supercritically extracted in CO2 at 60 oC and 22 Mpa. Thermal evolutions of the microstructure of the gels were evaluated by TGA-DTA, N2 adsorption and XRD. A stable anatase TiO2 containing amorphous SiO2 aerogel with a BET specific surface area of 365 m2/g and a total pore volume of 0.20 cm3/g was obtained as prepared condition. The anatase phase was stable after calcination up to 1000 oC, and BET specific surface area, total pore volume and average pore diameter did not change significantly after calcination up to 900 oC.   Keywords: Supercritical extraction, sol-gel, aerogel, stable anatase structure


2019 ◽  
Vol 69 (12) ◽  
pp. 3439-3444
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Rami Doukeh ◽  
Gabriel Vasilievici ◽  
Vasile Matei

Desulfurisation of 1-dodecanethiol was performed by adsorption process on MgO adsorbent. The adsorbant was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments were performed in continuous system at 300-450�C, 5 atm and volume hourly space velocities of 1�2 h-1. Conversion of 1-dodecanetol increases with increasing temperature and decreasing volume hourly space velocities. It was identified the stage determinant of the process and a kinetic study of the desulfurization process was developed by reactive adsorption of 1-dodecanethiol on a magnesium oxide adsorbent.


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