Pore Volume Values Research Articles

Shale pore structure characteristics of the high and low productivity wells, Jiaoshiba shale gas field, Sichuan Basin, China: Dominated by lithofacies or preservation condition?

Abstract Both the characteristics of lithofacies and tectonic movements are important factors in controlling the development, destruction, and preservation of pores in shale reservoirs. However, the main factors that control the structure of shale pores are complex and highly disputed, restricting the understanding of the mechanisms that lead to the accumulation of shale gas. In this study, mineral composition and geochemical analyses, high resolution field emission scanning electron microscopy (FE-SEM), and low-pressure gas adsorption (N2 and CO2) were conducted to evaluate the pore systems of different types shale in the Jiaoshiba area, Sichuan Basin. A total of three shale groups, including silica-rich high production shales, clay-rich low production shales, and silica-rich low production shales were identified on the basis of lithofacies and gas-bearing characteristics. The highest values of TOC, pore volume, and specific surface area are found in the silica-rich high production shales, with an average of 4.182%, 33.04 × 10−3 cm3/g, and 38.71 m2/g, respectively. The total pore volume and specific surface area in the clay-rich low production shales are 19.85% and 28.62% lower than that of silica-rich high production shales. This suggests that the types of lithofacies have a more prominent influence on the specific surface area of the shales, while the pore volume plays a smaller role. However, the pressure in silica-rich low production shales is often released due to strong tectonic deformation. The OM pores in the silica-rich low production shales therefore tend to be both compressed and closed, with low surface porosity and of round shape. The total pore volume and specific surface area of silica-rich low production shales are 34.63% and 22.0% lower than that of the silica-rich high production shales. This indicates that tectonic movement has a significant influence on the shale pore volume, while specific surface area has a smaller influence.

Laboratory study influence pore volume in compressive strength foam cement

Pore volume of foam cement is a main factor affected compressive strength in the addition axial load design. Foam agent material used in this research is Sika-aer as a replace the nitrogen gasses. This research study used mix composition cement 1 : silica sand 0.25 : water 0.5and foam agent 0.03% - 0.15% BWOC. The purpose of this study is providing alternative cementing product beside lightweight cement in oil and gas industry with foam cement to mitigate loss circulations. Compressive strength testing was carried out with different time periods and pore volume testing were carried out on each addition/change in foam agent concentrations every cement slurry mixture. Characteristics of bubbles on cement slurry is one of many factors that influences compressive strength parameters. Compressive strength foam cement depends on size, diameters and relationship between bubbles on the cement slurry. This laboratory study produced compressive strength values between 1078 psia – 3745 psia and pore volume values between 15 cc – 17 cc in 5 samples core foam cement with different foam agent concentrations Sika-aer.

Effect of pyrolysis temperature on characteristics, chemical speciation and environmental risk of Cr, Mn, Cu, and Zn in biochars derived from pig manure

The comprehensive analysis of environmental risk for heavy metals in pig manure was essential for optimization of pyrolysis conditions and scientific utilization of pig manure biochars as soil amendment. However, in previous studies, the selected pyrolysis temperature points were limited and temperature interval was large, it’s was difficult to accurately verify the effect of pyrolysis temperature on chemical speciation and environmental risk of heavy metals. Therefore, in this study, pig manure was pyrolyzed at 300–700 °C with a small interval of 50 °C to study the effect of pyrolysis temperature on characteristics and environmental risk of Cr, Mn, Cu and Zn in pig manure biochar. Results indicated that the characteristics of biochars (>500 °C) were relatively stable. The biochar obtained at 700 °C exhibited the largest surface area (8.28 m2 g−1) and pore volume (25.17 m3 kg−1), secondly is the biochar derived at 500 °C. The total percentages of exchangeable and acid fraction and reducible fraction decreased from 16.98% to 9.43% for Cr, 85.60% to 65.55% for Mn, 57.26% to 10.61% for Cu, 37.90% to 13.78% for Zn, respectively, suggesting that exchangeable and acid fraction and reducible fraction of Cr, Mn, Cu and Zn in pig manure were transformed into oxidizable and residual fractions after pyrolysis. The leaching rates, risk assessment code and potential ecological risk index values significantly decreased after pyrolysis and presented lower value at 500 and 700 °C. Biochars derived at 300–700 °C conditions posed no phytotoxicity with germination index >80%. Correlation analyses revealed that larger surface area, pore volume and pH values of biochars may help to immobilize heavy metals and reduce bioavailability. These findings demonstrated that bioavailability and toxicity of Cr, Mn, Cu and Zn in pig manure biochar were greatly reduced after pyrolysis and the optimum temperature was 500 °C considering energy cost.

Investigation on activated carbon derived from biomass Butnea monosperma and its application as a high performance supercapacitor electrode

Abstract In the present work, Butnea monsperma flower pollens (BMPs) were used to synthesize high surface area activated carbons (ACs). ACs were prepared employing one-step thermal activation process, by varying the ZnCl2 impregnation ratio. Optimization was done to ensure suitable porosity parameters and better electrochemical performance. Optimization succeeded in achievement of large values of total pore volume (~0.77 cm3 g−1) and specific surface area (~1422 m2 g−1). Electrochemical characteristics of optimized AC were compared in aqueous and ionic liquid based electrolyte. The value of capacitance of AC electrode was observed to be large ~130 F g−1) in aqueous electrolyte. Large magnitudes of specific energy (~42 Wh kg−1) and specific power (~19 kW kg−1) were observed in ionic liquid based electrolyte. Further, it has been observed that AC provided capacitance retention of more than ~99% (for more than 10,000 cycles). Synthesized AC is thus believed, profitable for energy storage devices.

Shrinkage curves of monoliths from genetic horizons of Vertic Solonetz

Statistical cumulative distributions of indices for shrinkage curve of 324 monoliths from Vertisols and Vertic Solonetzes are created. Natric and vertic horizons have similar range of shrinkage indices, with that natric ones have higher values of pore volume weakly changed during water evaporation and lower bulk density at shrinkage limit.

Enhancing catalytic CH4 oxidation over Co3O4/SiO2 core–shell catalyst by substituting Co2+ with Mn2+

Co3O4, a transition metal oxide with spinel structure, has attracted wide attention due to its high catalytic activity in the field of catalytic oxidation of low concentration methane. However, due to the harsh conditions of methane catalytic reaction on catalysts, of which the high reaction temperature and complex reaction environment often lead to the deactivation and sintering of Co3O4 catalyst, improving the comprehensive performance of Co3O4 catalyst has become the current research hotspot and urgent demand. Core-shell flower-spheroidal cobalt-manganese composite catalyst was prepared in this paper by hydrothermal method, which gave full play to the advantages of carrier, special morphology and doping modification, reduced the risk of sintering and deactivation of Co3O4, and showed higher catalytic activity. Through SEM, EDS, and BET test and analysis, Mn1/Co/SiO2 has better microstructure and structure than Co3O4/SiO2. For example, the dispersion of Mn1/Co/SiO2 and the uniform distribution of elements are higher, and the values of surface area and pore volume are larger (129.956 m2/g → 180.639 m2/g, 0.333363 cm3/g → 0.398030 cm3/g). Combined with XRD and XPS analysis, it is concluded that Mn2+ manganese ion replaces Co2+ and causes lattice distortion of Co3O4, which promotes the production and mobility of reactive oxygen species, further increasing catalytic activity. Compared with Co3O4/SiO2, methane conversion at 350 °C and 450 °C increased by 10% and 6%, respectively.

Systematic structural characterization of high‐density porous silicon anodes in lithium‐ion batteries

AbstractLithium‐ion batteries lead to high energy density, especially desired for portable electronic device applications. Advanced electrode structures for high energy density lithium‐ion batteries make the technological breakthrough by improving performance. In the focus of this study, a simple, low cost, scalable, and a versatile way is chosen to obtain high‐density SiO‐based electrodes with high porosity for lithium‐ion batteries. SiO anode is fabricated in a conventional doctor blade system with the addition and removal of the NaCl to get a desired porous anode structure. Porosity and porous structure were characterized by various techniques such as atomic force microscopy, scanning electron microscope, mercury porosimetry, and pycnometry. The results showed that the porosities can be formed successfully after salt addition and removal method by providing the values of pore volumes and porosities of the electrodes before and after the salt‐washing process. According to NaCl salt content, the level of porosities was changed and it affected the electrochemical cycling performance of the lithium‐ion cells.

Effect of desilication on the textural properties, acidity and catalytic activity of zeolite ZSM-23 synthesized with different structure-directing agents

Abstract The synthesis of ZSM-23 zeolite was studied using isopropylamine, ethylene glycol, pyrrolidine and N,N-dimethylformamide as structure-directing agents, followed by post-synthesis treatment. The samples were characterized by X-ray diffraction (XRD), dispersive energy X-ray spectroscopy (EDX), thermal analysis, adsorption-desorption of nitrogen, temperature programmed desorption of ammonia (TPD-NH3) and scanning electron microscopy (SEM). ZSM-23 was obtained with all organic molecules tested, and the sample synthesized with isopropylamine presented a higher crystallinity. EDX measurements indicated parent zeolites with SiO2/Al2O3 ratio ≥66. Thermal analysis curves showed that the parent sample prepared with isopropylamine presented lower mass loss, corroborating the crystallinity results and indicating a greater efficiency of this compound in the ZSM-23 synthesis. Micrographs of the parent samples synthesized with isopropylamine, ethylene glycol and N,N-dimethylformamide illustrated the characteristic morphology of ZSM-23 as “needles”, whereas the sample obtained with pyrrolidine showed the coexistence of ZSM-23 and ZSM-5 phases. TPD-NH3 results demonstrated that the post-synthesis treatment promoted, in all cases, a decrease in the weak acid sites and an increase in the strong and total acid sites densities for the samples from the isopropylamine and N,N-dimethylformamide series. Adsorption-desorption of nitrogen showed an increase in pore volume and specific surface area values for the modified samples compared to the parent materials. Modified zeolites presented higher catalytic activity and better deactivation resistance in n-heptane catalytic cracking in comparison to the precursor samples, with all catalysts showing excellent selectivity for propene and ethene.

Upcycling of polyurethane waste by mechanochemistry: synthesis of N-doped porous carbon materials for supercapacitor applications.

We developed an upcycling process of polyurethane obtaining porous nitrogen-doped carbon materials that were applied in supercapacitor electrodes. In detail, a mechanochemical solvent-free one-pot synthesis is used and combined with a thermal treatment. Polyurethane is an ideal precursor already containing nitrogen in its backbone, yielding nitrogen-doped porous carbon materials with N content values of 1–8 wt %, high specific surface area values of up to 2150 m2·g−1 (at a N content of 1.6 wt %) and large pore volume values of up to 0.9 cm3·g−1. The materials were tested as electrodes for supercapacitors in aqueous 1 M Li2SO4 electrolyte (100 F·g−1), organic 1 M TEA-BF4 (ACN, 83 F·g−1) and EMIM-BF4 (70 F·g−1).

Norfloxacin delivery systems based on MCM-type silica carriers designed for the treatment of severe infections

Mesoporous MCM-type silica (pristine and vinyl functionalized MCM-41, as well as MCM-48) materials were employed as carriers for norfloxacin, a poorly-water soluble antibiotic from the fluroquinolones class. Small MCM-41 nanoparticles were obtained by a new synthesis procedure that afforded the formation of spherical particles of around 60 nm diameter with large specific surface area and total pore volume values, features that synergistically contribute to the improvement of the drug release profile. The antibiotic-loaded materials were obtained through incipient wetness impregnation method having 20%(wt) drug content. Because of small pores diameter, all employed carriers favored the encapsulation of norfloxacin in amorphous state, which was proved by wide-angle X-ray diffraction (XRD). The carriers and drug-loaded samples were characterized by various techniques: FTIR spectroscopy, small- and wide-angle XRD, TEM analysis and N2 adsorption-desorption isotherms. The in vitro release experiments were performed at 37 °C in saline phosphate buffer solution pH 7.4 and showed an enhanced antibiotic solubility. The antimicrobial activity against E. coli ATCC 25922 of developed norfloxacin delivery systems preserved the antibiotic bactericidal activity after the drug encapsulation. Hence, these norfloxacin delivery systems could be suitable for applications, such as severe infections, where high initial drug concentration is desired immediately after administration.

Parameters controlling the scale-up of CoMoP/γ-Al2O3 and NiMoP/γ-Al2O3 catalysts for the hydrotreating and mild-hydrocracking of heavy gasoil

Abstract This contribution deals about the more relevant technical aspects to be considered when scaling hydrotreating catalysts based on CoMoP/γ-Al2O3 and NiMoP/γ-Al2O3. The effect of porous structure of the alumina support, the impregnating solution properties, the aging time and drying conditions on the texture, surface dispersion of the active phase, elemental radial distribution profile and catalytic activity properties were investigated. When using high CoMoP solution concentration, the rate of diffusion intra- and extra-granules were influenced by the high density, viscosity and liquid-solid contact angle and the pore structure of the catalyst support. Under this catalyst preparation conditions, lower capillary pressure and longer impregnation time values were obtained. This solution was unstable over time which represent a limitation for the catalyst commercial production. The catalyst also showed lower surface area and pore volume values and a non-uniform elemental radial distribution profile. The co-impregnation with diluted metal solutions in two successive steps was found to be the best procedure to prepare CoMoP/γ-Al2O3 and NiMoP/γ-Al2O3 catalysts at large scale when using the pore filling method. The catalysts showed higher surface area and pore volume and uniform elemental radial distribution profile. The aging time resulted as a key controlling parameter, thus the material obtained without aging showed a non-uniform Mo and P radial distribution profile and resulted in a less active catalyst. The drying step was also a critical preparation parameter to control; when the impregnated material was submitted to a fast drying, a metal composition loss was observed. The control of uniform metal deposition profile and the adequate alumina support selection were key factors for the successful scaling-up preparation process of highly active and selective CoMoP/γ-Al2O3 and NiMoP/γ-Al2O3 hydrotreating and mild-hydrocracking catalysts.

Study of different geostatistical methods to model formation porosity (Cast study of Zubair formation in Luhais oil field)

This study is concerned with making comparison in using different geostatistical methods for porosity distribution of upper shale member - Zubair formation in Luhais oil field which was chosen to study.Kriging, Gaussian random function simulation and sequential Gaussian simulation geostatistical methods were adopted in this study. After preparing all needed data which are contour map, well heads of 12 wells, well tops and porosity from CPI log. Petrel software 2009 was used for porosity distribution of mentioned formation in methods that are showed above. Comparisons were made among these three methods in order to choose the best one, the comparing criteria was according to different statistical information and variograms analysis of entered porosity which was scaled up and modeled. The best method gave porosity distribution in model closest to enter porosity that represent real porosity of Zubair formation.The comparison proved that sequential Gaussian simulation is the best model of porosity distribution followed by Gaussian random function simulation and kriging methods respectively. Based on the results obtained, it was concluded that the distribution accuracy of the porosity or other petrophysics properties is one of the main factors that affect building correct geological model that represents the base of reservoir model and also pore volume (Oil reserve) value was affected by geostatistical methods variation.

Pore connectivity and water accessibility in Upper Permian transitional shales, southern China

Abstract Pore connectivity of shale controls shale gas migration and production behavior. The pore connectivity and water accessibility in clay-rich Upper Permian transitional shales remain unclear. Contrast matching small-angle neutron scattering (CM-SANS) tests were used to determine the accessibility of water to pores in the transitional shales. Complementary analyses with SANS, gas (CO2 and N2) physisorption isotherm, mercury intrusion capillary pressure (MICP), helium ion microscopy (HIM), as well as field emission-scanning electron microscopy (FE-SEM) were conducted to study the pore connectivity and distribution characteristics of closed pores. The results show that closed pores (inaccessible to nitrogen molecules and mercury) are mainly distributed in pore diameters ＜10 nm and associated with organic pores and interlayer spaces of illite-smectite mixed-layer mineral. The pore volume values obtained from MICP and N2 adsorption underestimate the large pores (pore diameters ＞100 nm) in shales. Based on deuterated water CM-SANS tests, 87–98% of the pores (2–200 nm diameters) are water-connected in transitional samples. The low accessibility to water is at pore-sizes of 5–10 nm and 20–30 nm. Results from in-situ gas contents show that closed pores have a certain gas bearing capacity, but micropores (pore diameters ＜2 nm) control the gas occurrence in transitional samples. The connectivity of the organic pore network and between organic pores and surrounding interparticle pores is directly supported by FE-SEM and HIM imaging. Overall, improving pore-fracture connectivity through effective fracturing techniques is a means of mitigating the rapid decline in shale gas production.

COMPUTER SIMULATION OF THE POROUS STRUCTURE OF HYDROLYSIS LIGNIN AND ITS HARD COMPO-SITES WITH COMPONENTS OF OIL FUELS AND WATER

A fragment of the supramolecular structure of lignin was simulated by cross-linking the C546H600O196 structural units along the corresponding CH–bonds followed by geometric optimization by the Polac-Ribier’s conjugate gradient method in the MNDO field of the HyperChem 8.0 software and ChemBio 13.0. The pore structure of lignin was simulated as well with optimization by the molecular mechanic’s method according to the MM2 Norman-Alinger’s algorithm taking into account the dipole-dipole interaction. Сoumaric alcohol molecule was a building block. The calculation of the energy parameters of lignin’s pore structure filling by the molecules of organic substances and water were carried out. It included a search for a global minimum of the potential energy by the molecular mechanic’s method according to the MM2 program and by the molecular dynamics method. The calculation had its basis in the “closed” pores existence in lignin. The calculated values of pore volume and specific surface area correlate with the experimental data. The way of prediction of organic substances sorption activity to lignin was proposed. This is evident from their calculated hydrophobicity parameter that correlates with the interaction energy of the molecules in the lignin pore.

Preparation of delafossite–type CuFeO2 powders by conventional and microwave–assisted hydrothermal routes for use as photo–Fenton catalysts

In this work, delafossite–type CuFeO2 powders were prepared by conventional hydrothermal and microwave–assisted hydrothermal routes and employed as potential catalysts in photo–Fenton reaction. The degradation efficiency of Reactive Red 141 dye under visible light was investigated. The solids were characterized by XRD, FTIR, N2 adsorption–desorption isotherms, SEM/EDX and diffuse reflectance spectroscopy. The sample prepared by microwave irradiation presented higher values of specific surface area and total pore volume as well as smaller band–gap energy. The synergistic effects of these properties favored the superior catalytic activity when compared to the material prepared by the conventional hydrothermal route. About 98% of dye degradation was obtained at 30 min for the CuFeO2 sample prepared by microwave irradiation against 84% at 150 min for that prepared by conventional method. In addition, the CuFeO2 catalyst prepared by microwave route showed high chemical stability and dye degradation efficiency after four cycles.

The effect of potassium modification on structural properties and catalytic activity of copper and iron containing SBA-16 catalysts for selective oxidation of ethanol

Abstract Copper and iron SBA-16 catalysts were synthesized using hydrothermal method and modified with potassium. XRD patterns showed that characteristic peaks of SBA-16 for all catalysts did not destroy with metal loading. The metal and potassium loading to SBA-16 structure led to generally the decreasing of specific surface area values. While total pore volume value of SBA-16 increased with copper loading, it decreased with iron loading. Pore diameter values of SBA-16 generally increased with metal loading. It was seen that from TEM images metals settled as nanoparticles to the SBA-16 structure. EDX results demonstrated that potassium modification treatment increased especially the success of metal loading. FTIR spectrums of all catalysts exhibited the characteristic structural bands of SBA-16. It was seen that the peak intensity of both Bronsted and Bronsted + Lewis acid sites of the SBA-16 increased by the metal loading. On the other hand potassium modification improved the acid sites. UV–Vis DR and XPS spectra showed that copper and iron species settled as Cu+2 and Fe+3 form, respectively. The potassium modified catalysts exhibited the highest conversion of 77% and acetaldehyde selectivity of 81% compared to catalysts without potassium modification at reaction temperature of 350 °C.

Creating binder-free supercapacitor electrodes from biomass resources: a nitrogen-doped pomelo peel derived carbon foam

We conducted experiments in producing nitrogen-doped carbon foam using pomelo peels as a raw material. Pomelos are a citrus fruit similar in appearance to grapefruit, and native to South and Southeast Asia. Specifically, we fabricated nitrogen-doped pomelo peel derived carbon foam (N-PPCF) by using an ammonia gas treatment. The as-prepared N-PPCF had a high specific surface area of 1,218.5 m2 g−1, an average pore size of 1.36 nm, and a pore volume value of 0.50 cm3 g−1. Additionally, the N-PPCF had a nitrogen content of 8.1%, allowing for a high specific capacitance of 150.1 F g−1 at a density of 1.0 A g−1. Even at 4 A g−1, the N-PPCF still maintained an ideal capacitance of 115.6 F g−1. Ultimately, we believe that nitrogen doped carbon foam is a potential method for treating pomelo peels, and that N-PPCF can function as a potential binder-free supercapacitor electrode.

Creating binder-free supercapacitor electrodes from biomass resources: a nitrogen-doped pomelo peel derived carbon foam

We conducted experiments in producing nitrogen-doped carbon foam using pomelo peels as a raw material. Pomelos are a citrus fruit similar in appearance to grapefruit, and native to South and Southeast Asia. Specifically, we fabricated nitrogen-doped pomelo peel derived carbon foam (N-PPCF) by using an ammonia gas treatment. The as-prepared N-PPCF had a high specific surface area of 1,218.5 m2 g−1, an average pore size of 1.36 nm, and a pore volume value of 0.50 cm3 g−1. Additionally, the N-PPCF had a nitrogen content of 8.1%, allowing for a high specific capacitance of 150.1 F g−1 at a density of 1.0 A g−1. Even at 4 A g−1, the N-PPCF still maintained an ideal capacitance of 115.6 F g−1. Ultimately, we believe that nitrogen doped carbon foam is a potential method for treating pomelo peels, and that N-PPCF can function as a potential binder-free supercapacitor electrode.

Removal of of Pb(II), Cd(II), Cu(II) and Ni(II) Ions from Aqueous Solution Using Pentaclethra Macrophylla Stem Activated Carbon

Pentaclethra Macrophylla stem activated carbon (PMSAC) was utilized as biomass derived adsorbent for adsorption of Pb(II), Cd(II), Cu(II) and Ni(II) from aqueous solution. The activation was chemically carried out using ZnCl 2 solution. The Physicochemical analysis of PMSAC showed high fixed carbon and pore volume values. The Scanning Electron Microscope (SEM) and Energy Dispersive X-ray were used to characterize the PMSAC. Simultaneous batch adsorptions used to evaluate the optimal operational conditions for the adsorption showed initial metal ions concentration (5 mg/L), solution pH (6), contact time (90 min), adsorbent dose (3.0 g for Cd(II) and 4.0 g for Pb(II), Cu(II) and Ni(II), particle size (30 µm) and carbonization temperature (400 o C). The Langmuir isotherm model gave better fit for the adsorption process. Dubinin-Radushkevich isotherm indicates physical adsorption. The kinetics and thermodynamic parameters were studied.

Preparation of carbonaceous materials from pyrolysis of chicken bones and its application for fuchsine adsorption.

Activated carbon and biochar were obtained from chicken bone (CB), characterized, and applied to remove basic fuchsine from aqueous media. The adsorbent dosage and pH effects were studied, as well as kinetic, equilibrium, and thermodynamic curves were constructed. The values of BET surface area and total pore volume were 108.94m2g-1 and 0.219cm3g-1 for the activated carbon and, 18.72m2g-1 and 0.075cm3g-1 for the biochar. The dye removal percentages were 93.63 and 55.38% when 2.5gL-1 of activated carbon and biochar were used, respectively. The adsorption was favored using 0.5gL-1 of adsorbent and pH of 7.0. Adsorption kinetics was well represented by the pseudo-second-order model. Langmuir model was the best to represent the equilibrium. Maximum adsorption capacity was 260.8mgg-1, obtained using activated carbon. The process was endothermic, favorable, and spontaneous. Results showed that alternative carbonaceous materials can be obtained from chicken bones and used as adsorbents to treat colored effluents containing fuchsine.