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Energy Storage Systems in View of Nanotechnology towards Wind Energy Penetration in Distribution Generation Environment
Published in Shilpi Birla, Neha Singh, Neeraj Kumar Shukla, Nanotechnology, 2022
Dimpy Sood, Ritesh Tirole, Sujit Kumar
Use of nanotechnology is recommended when you need a small, controllable, porous or hierarchical structure that has a nanostructure in it. An article authored by Vu et al. used the colloidal crystal technique to manufacture a 3D, hierarchically porous LiFePO4–carbon (LFP/C) composite cathode material [16]. To get both meso- and macropores in the structure, they utilized a dual templating process, poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) triblock copolymer from BASF (PEO106PPO70PEO106). They have utilized poly (methyl methacrylate) (PMMA) for macropores, as well as colloidal crystals. LFP and carbon as well as phenol-formaldehyde sol and a nonionic surfactant are all mixed together using a multiconstituent synthesis technique, which uses a colloidal crystal template. An LFP/C monolithic composite is obtained when several heat treatments are performed at low ramp rates, followed by a final pyrolysis at high temperature (600, 700 or 800°C) that provides a three-dimensional LFP/C macroporous and meso-/microporous (3DOM/m) structure.
Requirements for the Metallurgical Properties of Briquettes
Published in Aitber Bizhanov, Briquetting in Metallurgy, 2022
Porosity can be measured in a number of ways. We will not go into detail on the description of traditional methods for determining porosity, which are described in sufficient detail in the reference literature. To identify macropores and determine the number, volume and distribution of pores, methods of direct visual-optical observation and observation using light and electron microscopy can be used. Visual-optical observation allows to determine porosity in the range of macropore sizes from 10 to 75 microns. Light microscopy is applicable for pore sizes in the range of 0.5–100 microns, and electron microscopy allows the study of pores ranging in size from 0.002 to 0.5 microns. Capillary methods for determining porosity (capillary permeability) are used to study porosity with pore sizes from 0.01 to 100 microns. Mercury porosimetry methods are used to determine pore sizes, pore size distribution and specific surface area in a wide range of pore sizes from 0.0015 to 800 microns. The methods for determining porosity by this method are described in the standards ISO 15901–1: 2006, ISO/NP 15901–2 and ISO 15901–1: 2016. Pycnometric methods (gas and liquid pycnometry) allow the determination of the total porosity, size and distribution of submicropores with sizes from 0.002 to 0.001 microns. In this way, the porosity is determined in accordance with the standards of GOST ISO 5017–2014. Open porosity is measured pycnometrically based on liquid saturation under vacuum in accordance with DIN 51056.
Adsorption
Published in Willy J. Masschelein, Unit Processes in Drinking Water Treatment, 2020
A typical pore volume distribution as measured through the adsorption of benzene is given in Fig. 1 according to (3) as well as the saturation volume Vs for different grades. The transitional pores and micropores constitute the most important part of the internal surface (∼95%). The macropores can be observed with a scanning electron microscope and evaluated by the penetration of mercury while the total volume is measured by helium or nitrogen penetration. The structure of the micropores is deduced from the adsorption characteristics of water according to the Kelvin equation, given below. The macropores are relatively unimportant where adsorption is concerned but are necessary as conduits for rapid diffusion to the micropores.
Calcium phosphate cements comprising spherical porous calcium phosphate granules: synthesis, structure, and properties
Published in Journal of Asian Ceramic Societies, 2022
Masanobu Kamitakahara, Kanau Asahara, Hideaki Matsubara
Recently, CPCs with macropores and micropores have been prepared by combining porous granules [23,24]. Porosity can be increased by controlling spaces between the granules and by using granules with high porosity. Macropores are formed because the spaces between the granules and micropores can be modified by controlling the microstructure of the granules. Porous spherical granules of Ca-deficient HA (CDHA) [25,26] and OCP/HA [27–29] have been prepared in earlier studies. Previous studies have found that CDHA composed of rod-shaped particles exhibits high osteoconductivity with mild biodegradability [30] because of specific protein adsorption [31]. The CDHA also has the potential to serve as a drug delivery carrier [32]. OCP and OCP/HA were also found to support bone regeneration [11,12,33].
Study on the effect of chemical inhibitors on CO2 adsorption in coal
Published in International Journal of Coal Preparation and Utilization, 2022
Fei Gao, Zhe Jia, Ya-Fei Shan, Rui-Jie Sun, Xiao-Gang Mu
Coal is a porous material. The pores can be divided into: micropores (<2 nm), mesopores (2–50 nm) and macropores (>50 nm) according to their size. The micropores are adsorption pores, which can store the highest quantity of gas. The pore characteristics are usually determined via mercury intrusion and low-temperature nitrogen experiments. The macropores with a size >100 nm are usually determined via the mercury intrusion method, whereas pores below 100 nm are suitable for gas adsorption experiments, which can be used to determine the pore characteristics. However, due to the activated diffusion effect, nitrogen cannot enter the micropores with a pore diameter lower than 2 nm. However, carbon dioxide molecules are smaller and have a faster diffusion rate than nitrogen. Moreover, carbon dioxide has a higher saturation pressure (P0 = 3485.266 kPa) at 273 K, which allows one to collect experimental data at a lower relative pressure. In addition, the filling of the micropores is mainly carried out at a low pressure. For this reason, the carbon dioxide adsorption curve at 273 K can provide information on the micropore volume, specific surface area, and pore size distribution of the coal.
Accumulation and combination characteristics of unconventional natural gas in Carboniferous coal-bearing strata: case study in the Central Hunan Province, South China
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Zhaodong Xi, Shuheng Tang, Songhang Zhang
The integration of porosity data (free gas potential) with methane isothermal adsorption data (adsorbed gas potential) provides a measure of the potential shale gas capacity and was used to evaluate the economic feasibility of the shale gas reservoir. Porosity ranges between 0.78% and 4.25% for the 10 samples with a mean value of 2.42%, and the Langmuir volume of the samples varies from 0.34 m3/t and 3.23 m3/t with an average of 1.40 m3/t (Table 2). Although the lower limits of porosity for shale gas reservoirs are approximately 1% (Nie, Tang, and Bian 2009), the measured porosity of the shale in the study area was lower than that of the Qinshui and Ordos Basins (Xi et al. 2017). In general, macropores contribute most to pore volume and porosity. However, the target shales contain large amounts of micropores and mesopores. Pores 3–4 nm in size are the most developed (Figure 6a). Moreover, the shale permeability ranges from 0.28 μD to 0.78 μD. The limit of permeability is 0.001 mD for a shale gas reservoir, which means the permeability of the target shale is quite low. Pore shape is one of the factors that affect shale permeability. The primary pore shape is ink-bottled according to the shape of N2 absorption-desorption isotherms (Figure 6b), which is adverse to gas diffusion and seepage. Therefore, low porosity and poor permeability may be a significant issue for developing shale gas.