Correlation Between Fractal Dimension of Matrix and Extraction Behavior of Plant Materials

2010 ◽  
Author(s):  
Junhong Yang ◽  
Qianqian Di ◽  
Jun Zhao ◽  
Liqiu Wang
Keyword(s):  
Fractal Dimension ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Fractal Dimensions ◽  
Sem Images ◽  
Plant Materials ◽  
Matrix Microstructure ◽  
Extraction Behavior ◽  
Mercury Injection

This paper studies the correlation between fractal dimension of matrix microstructure of plant materials and extraction behavior using Astragalus root slices as examples. This work compared the yield of extracts on the conventional solvent soaking extraction of samples irradiated 3min by microwave 600W and 900W, respectively. Regarding to microwave treated samples, the area fractal dimensions (DL) of aperture in shape were estimated by using the slit island method on the basis of SEM images analysis, the volume fractal dimensions (DV) of pore size distribution inside matrix were also determined by the mercury injection method on the basis of measured results (6nm–40×105nm) by automatic mercury injection apparatus. Our findings are that, 900W treated sample behaves higher yield of extracts than 600W. The values of DL and DV both increase with increasing of microwave power. The higher values of DL correspond to the much irregular and deformed shape of aperture, which seems un-benefit for the extraction of component inside matrix. However, the higher values of DV correspond to the less concentration of pore size distribution, implying better connectivity of pore or channel at multi-scale (including trachea 20μm–50μm, aperture 0.1μm–1μm and plasmodesma 1nm–10nm in size) and permeability inside matrix during extraction, higher yield of extracts. It demonstrates that combining the two fractal dimensions can present much more information for better understanding of mass transfer behavior and the knowledge of material properties.

Depth and composition dependent nanopore structures of Indian shale gas reservoirs: An implication on storage potential

2021 ◽  
Author(s):  
Abinash Bal ◽  
Santanu Misra ◽  
Manab Mukherjee
Keyword(s):  
Fractal Dimension ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Negative Correlation ◽  
Fractal Dimensions ◽  
Clay Content ◽  
Pore Network Model ◽  
Cambay Basin ◽  
Gas Reservoirs

<p>We investigated the nanopore structures of shale samples obtained from Cambay and Krishna-Godavari (KG) basins in India using low-pressure N<sub>2</sub> sorption method. The samples occurred at variable depths (1403-2574m and 2599-2987m for Cambay and KG basins, respectively) and have wide ranges of clay contents (56-90%) both in volume and mineralogy. The results of this study indicate the specific surface area (SSA) and pore diameters of the samples share a non-linear negative correlation. The SSA is a strong function of the clay content over the samples’ depth. The specific micropore volumes of the KG basin have relatively higher (8.29-24.4%) than the Cambay basin (0.1-3.6%), which leads to higher SSA in the KG basin. From different statistical thickness equations, the Harkins Jura equation was found to be most suitable for the computation of BJH pore size distribution and t-plot inversion in shale. Shale samples from Cambay basin show unimodal pore size distribution, with a modal diameter of 4-5nm, while in the KG basin, show bi-modal to multimodal pore size distribution, mostly ranges from 3-12 nm. In the fractal FHH method, fractal exponent D<sub>f</sub>-3 provides a better realistic result than fractal dimensions calculated from (D<sub>f</sub>-3)/3. In our samples, pore surface fractal dimension (D<sub>f1</sub>) show a positive correlation with SSA and a negative correlation with pore diameter, and pore structure fractal dimension (D<sub>f2</sub>) shows a negative correlation both with clay(%) and depth. The experimental data obtained in this study are instrumental in developing the pore-network model to assess the hydrocarbon reserve and recovery in shale.</p>

Fractal Dimension of Pore Size Distribution Inside Matrix of Plant Materials and Drying Behavior

2010 ◽  
Author(s):  
Junhong Yang ◽  
Qianqian Di ◽  
Jun Zhao ◽  
Liqiu Wang
Keyword(s):  
Fractal Dimension ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Drying Time ◽  
Plant Materials ◽  
Hot Air ◽  
Drying Behavior

This paper studied the relationship between matrix microstructure of plant materials and drying behavior using Astragalus and Chinese Angelica root slices as examples. Astragalus and Chinese Angelica, two kinds of traditional Chinese Medicine Herb (CMH), are species of stem and root medicinal herb with the widely curative effects. Based on the measured results by using automatic surface area-porosity analyzer (at smaller scale ≤ 100nm), the volume fractal dimensions (DV) were estimated to characterize the pore size distribution inside matrix of samples dried by different drying technologies, including microwave drying at 200W and conventional hot air drying at 60 °C. In cases studied in this paper, the values of DV are well related with drying time. As compared to hot air dried sample, DV of microwave dried sample increases by 5.9% for Astragalus, while 7.7% for Chinese Angelica. In comparison with hot air drying, the microwave drying time is reduced to 1/6 (30min/180 min) for Astragalus, while 1/16 (50min/810min) for Chinese Angelica. Combined the observation of SEM images of sample, our findings is that, higher fractal dimension, less concentration of pore size distribution, better connectivity of pore or channel with multi-scale characteristics (aperture about 0.1μm–1μm, plasmodesma about 1nm–10nm, or 10Å–100Å), much loose distribution of cytoplasm inside parenchyma cells, better permeability of moisture transfer path during drying process, shorter drying time. Our results demonstrate that the volume fractal dimension (DV) of pore size distribution at smaller scale (≤ 100nm) could give a better understanding the mass transfer behavior of plant materials.

A NEW METHOD FOR CALCULATING FRACTAL DIMENSIONS OF POROUS MEDIA BASED ON PORE SIZE DISTRIBUTION

Fractals ◽  
2018 ◽  
Vol 26 (01) ◽  
pp. 1850006 ◽  
Author(s):  
YUXUAN XIA ◽  
JIANCHAO CAI ◽  
WEI WEI ◽  
XIANGYUN HU ◽  
XIN WANG ◽  
...  
Keyword(s):  
Porous Media ◽  
Fractal Dimension ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Space ◽  
Fractal Theory ◽  
Fractal Dimensions ◽  
New Method ◽  
Distribution Data

Fractal theory has been widely used in petrophysical properties of porous rocks over several decades and determination of fractal dimensions is always the focus of researches and applications by means of fractal-based methods. In this work, a new method for calculating pore space fractal dimension and tortuosity fractal dimension of porous media is derived based on fractal capillary model assumption. The presented work establishes relationship between fractal dimensions and pore size distribution, which can be directly used to calculate the fractal dimensions. The published pore size distribution data for eight sandstone samples are used to calculate the fractal dimensions and simultaneously compared with prediction results from analytical expression. In addition, the proposed fractal dimension method is also tested through Micro-CT images of three sandstone cores, and are compared with fractal dimensions by box-counting algorithm. The test results also prove a self-similar fractal range in sandstone when excluding smaller pores.

NANOSCALE PORE SIZE DISTRIBUTION EFFECTS ON GAS PRODUCTION FROM FRACTAL SHALE ROCKS

Fractals ◽  
2019 ◽  
Vol 27 (08) ◽  
pp. 1950142
Author(s):  
JINZE XU ◽  
KELIU WU ◽  
RAN LI ◽  
ZANDONG LI ◽  
JING LI ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Gas Transport ◽  
Gas Production ◽  
Lower Sensitivity ◽  
Apparent Permeability ◽  
Transport Efficiency ◽  
Nanoscale Pore

Effect of nanoscale pore size distribution (PSD) on shale gas production is one of the challenges to be addressed by the industry. An improved approach to study multi-scale real gas transport in fractal shale rocks is proposed to bridge nanoscale PSD and gas filed production. This approach is well validated with field tests. Results indicate the gas production is underestimated without considering a nanoscale PSD. A PSD with a larger fractal dimension in pore size and variance yields a higher fraction of large pores; this leads to a better gas transport capacity; this is owing to a higher free gas transport ratio. A PSD with a smaller fractal dimension yields a lower cumulative gas production; this is because a smaller fractal dimension results in the reduction of gas transport efficiency. With an increase in the fractal dimension in pore size and variance, an apparent permeability-shifting effect is less obvious, and the sensitivity of this effect to a nanoscale PSD is also impaired. Higher fractal dimensions and variances result in higher cumulative gas production and a lower sensitivity of gas production to a nanoscale PSD, which is due to a better gas transport efficiency. The shale apparent permeability-shifting effect to nanoscale is more sensitive to a nanoscale PSD under a higher initial reservoir pressure, which makes gas production more sensitive to a nanoscale PSD. The findings of this study can help to better understand the influence of a nanoscale PSD on gas flow capacity and gas production.

scholarly journals Fabrication of PES/PVP Water Filtration Membranes Using Cyrene®, a Safer Bio-Based Polar Aprotic Solvent

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Roxana A. Milescu ◽  
C. Robert McElroy ◽  
Thomas J. Farmer ◽  
Paul M. Williams ◽  
Matthew J. Walters ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Filtration ◽  
Solubility Parameters ◽  
Coagulation Bath ◽  
Additive Concentration ◽  
Sem Images ◽  
Water Contact ◽  
Water Permeation

A more sustainable dialysis and water filtration membrane has been developed, by using the new, safer, bio-based solvent Cyrene® in place of N-methyl pyrrolidinone (NMP). The effects of solvent choice, solvent evaporation time, the temperature of casting gel, and coagulation bath together with the additive concentration on porosity and pore size distribution were studied. The results, combined with infrared spectra, SEM images, porosity results, water contact angle (WCA), and water permeation, confirm that Cyrene® is better media to produce polyethersulfone (PES) membranes. New methods, Mercury Intrusion Porosimetry (MIP) and NMR-based pore structure model, were applied to estimate the porosity and pore size distribution of the new membranes produced for the first time with Cyrene® and PVP as additive. Hansen Solubility Parameters in Practice (HSPiP) was used to predict polymer-solvent interactions. The use of Cyrene® resulted in reduced polyvinylpyrrolidone (PVP) loading than required when using NMP and gave materials with larger pores and overall porosity. Two different conditions of casting gel were applied in this study: a hot (70°C) and cold gel (17°C) were cast to obtain membranes with different morphologies and water filtration behaviours.

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