scholarly journals Valorization of Waste Tires by Pyrolysis and Activation Processes

2021 ◽  
Vol 11 (14) ◽  
pp. 6342
Author(s):  
Reyna Berenice González-González ◽  
Nadia Ruiz-Gómez ◽  
Gloria Gea ◽  
Matias Vazquez-Pinon ◽  
Sergio O. Martinez-Chapa ◽  
...  
Keyword(s):  
Energy Storage ◽  
Pore Size ◽  
Surface Area ◽  
Liquid Fraction ◽  
Average Pore Size ◽  
Chemical Activation ◽  
Partial Substitution ◽  
Physical Activation ◽  
Waste Tires ◽  
Energy Storage Applications

The problems related to the increase in the generation of discarded tires demonstrate the need for profitable, efficient, cost-effective, and sustainable processes for their waste management. In particular, the valorization of pyrolytic solids for energy storage applications is of interest. In this study, four processes were performed: (1) pyrolysis; (2) chemical activation and pyrolysis; (3) pyrolysis and physical activation; and (4) chemical activation, pyrolysis, and physical activation. The process consisting of chemical activation, pyrolysis, and physical activation yielded 52% solid material with the highest electrical conductivity (2.43 Ω–1 cm–1) and a surface area of 339 m2/g with an average pore size of 3.6 nm. In addition, it was found that pore size had a greater effect on the conductivity than surface area. Liquid and gas fraction compositions were modified by the presence of chemical activation: aromatization reactions were favored, and limonene was not observed in the liquid fraction, while an increase on the CH4 concentration caused an increment in the heating value of the gas fraction. It was demonstrated that chemical and physical activation enhance the properties of the pyrolytic solid product derived from waste tires that make it suitable for the partial substitution of materials for electric energy storage applications.

scholarly journals Enhancement of the Thermal Energy Storage Using Heat-Pipe-Assisted Phase Change Material

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6176 ◽  
Author(s):  
Hamidreza Behi ◽  
Mohammadreza Behi ◽  
Ali Ghanbarpour ◽  
Danial Karimi ◽  
Aryan Azad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Heat Pipe ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Liquid Fraction ◽  
Energy Storage Applications ◽  
Change Material

Usage of phase change materials’ (PCMs) latent heat has been investigated as a promising method for thermal energy storage applications. However, one of the most common disadvantages of using latent heat thermal energy storage (LHTES) is the low thermal conductivity of PCMs. This issue affects the rate of energy storage (charging/discharging) in PCMs. Many researchers have proposed different methods to cope with this problem in thermal energy storage. In this paper, a tubular heat pipe as a super heat conductor to increase the charging/discharging rate was investigated. The temperature of PCM, liquid fraction observations, and charging and discharging rates are reported. Heat pipe effectiveness was defined and used to quantify the relative performance of heat pipe-assisted PCM storage systems. Both experimental and numerical investigations were performed to determine the efficiency of the system in thermal storage enhancement. The proposed system in the charging/discharging process significantly improved the energy transfer between a water bath and the PCM in the working temperature range of 50 °C to 70 °C.

Characterisation of Low-K Dielectric Films by Ellipsometric Porosimetry

2000 ◽  
Vol 612 ◽  
Author(s):  
M.R. Baklanov ◽  
K.P. Mogilnikov
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Average Pore Size ◽  
Dielectric Films ◽  
Swelling Properties ◽  
Small Surface ◽  
Ellipsometric Porosimetry ◽  
Low K

AbstractEllipsometric porosimetry (EP) is a simple and effective method for the characterization of the porosity (volume of both open and close pores), average pore size, specific surface area and pore size distribution (PSD) in thin porous films deposited on top of any smooth solid substrat e. Because a laser probe is used, small surface area can be analyzed. Therefore, EP can be used on patterned wafers and it is compatible with microelectronic technology. This method is a new version of adsorption (BET) porosimetry. In situ ellipsometry is used to determine the amount of adsorptive which adsorbed/condensed in the film. Change in refractive index is used to calculate of the quantity of adsorptive present in the film. EP also allows the study of thermal stability, adsorption and swelling properties of low-K dielectric films. Room temperature EP based on the adsorption of vapor of some suitable organic solvents and method of calculation of porosity and PSD is discussed. Examination of the validity of Gurvitsch rule for various organic adsorptives (toluene, heptane, carbon tetrachloride and isopropyl alcohol) has been carried out to assess the reliability of measurements of pore size distribution by the ellipsometric porosimetry.

scholarly journals Insights into the influence of the pore size and surface area of activated carbons on the energy storage of electric double layer capacitors with a new potentially universally applicable capacitor model

2019 ◽  
Vol 21 (6) ◽  
pp. 3122-3133 ◽  
Author(s):  
Ruben Heimböckel ◽  
Frank Hoffmann ◽  
Michael Fröba
Keyword(s):  
Energy Storage ◽  
Pore Size ◽  
Surface Area ◽  
Double Layer ◽  
Electric Double Layer ◽  
Activated Carbons ◽  
Porous Carbons ◽  
Pore Sizes ◽  
Double Layer Capacitors ◽  
Electric Double Layer Capacitors

A new capacitor model that confirms the non-constant capacitive contribution of different pore sizes and provides the possibility of simulating the capacitance values of porous carbons.

scholarly journals Preparation of Composite Monolith Supercapacitor Electrode Made from Textile-Grade Polyacrylonitrile Fibers and Phenolic Resin

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 655
Author(s):  
Karim Nabil ◽  
Nabil Abdelmonem ◽  
Masanobu Nogami ◽  
Ibrahim Ismail
Keyword(s):  
Electrical Resistivity ◽  
Surface Area ◽  
Phenolic Resin ◽  
Physical Adsorption ◽  
Chemical Activation ◽  
Specific Capacity ◽  
Physical Activation ◽  
Gravimetric Analysis ◽  
Capacitive Properties

In this work a composite monolith was prepared from widely available and cost effective raw materials, textile-grade polyacrylonitrile (PAN) fibers and phenolic resin. Two activation procedures (physical and chemical) were used to increase the surface area of the produced carbon electrode. Characterization of the thermally stabilized fibers produced was made using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and Carbon-Hydrogen-Nitrogen(CHN) elemental analysis, in order to choose the optimum conditions of producing the stabilized fibers. Characterization of the produced composite monolith electrode was performed using physical adsorption of nitrogen at 77 °K, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrical resistivity in order to evaluate its performance. All the electrodes prepared had a mixture of micropores and mesopores. Pressing the green monolith during the curing process was found to reduce largely the specific surface area and to some degree the electrical resistivity of the chemically activated composite electrode. Physical activation was more suitable than chemical activation, where it resulted in an electrode with specific capacity 29 F/g, good capacitive behavior and the stability of the electrical resistivity over the temperature range −130 to 80 °C. Chemical activation resulted in a very poor electrode with resistive rather than capacitive properties.

AKTIVASI KIMIA-FISIK LIMBAH SERUTAN ROTAN MENJADI KARBON AKTIF

2014 ◽  
Vol 14 (1) ◽  
pp. 82-98
Author(s):  
Andy Mizwar
Keyword(s):  
Activated Carbon ◽  
Water Content ◽  
Iodine Number ◽  
Surface Area ◽  
Chemical Activation ◽  
Raw Material ◽  
Physical Activation ◽  
Fixed Carbon ◽  
Impregnation Time ◽  
Physical And Chemical

Limbah rotan dari industri kerajinan dan mebel berpotensi untuk dijadikan sebagai bahan baku pembuatan karbon aktif karena memiliki kandungan holoselulosa dan kadar karbon yang tinggi. Penelitian ini bertujuan untuk menganalisis efektifitas dari aktivasi kimia menggunakan larutan natrium klorida (NaCl) yang dilanjutkan dengan aktivasi fisik dalam pembuatan karbon aktif berbahan dasar  limbah serutan rotan. Pembuatan karbon aktif diawali dengan proses karbonisasi pada suhu 250°C selama 1 jam. Selanjutnya aktivasi kimia menggunakan larutan NaCl dengan variasi konsentrasi 10%, 15% dan 20% serta waktu perendaman selama 10, 15 dan 20 jam. Aktivasi fisik dilakukan dengan pembakaran pada suhu 700°C selama 30 menit. Analisis karakteristik fisik-kimia karbon aktif mengacu pada SNI 06-3730-95, meliputi kadar air, fixed carbon, dan iodine number, sedangkan perhitungan luas permukaan spesifik karbon aktif dilakukan dengan Metode Sears. Hasil penelitian ini menunjukkan bahwa kondisi optimum aktivasi kimia terjadi pada konsentrasi NaCl 10% dan lama perendaman 10 jam dengan hasil analisis kadar air 2.90%, fixed carbon 72.70%, iodine number 994.59 mg/g dan luas permukaan 1587.67 m²/g. Peningkatan fixed carbon, iodine number dan luas permukaan karbon aktif berbanding terbalik dengan peningkatan konsentrasi NaCl dan lama waktu perendaman, sedangkan peningkatan kadar air pada karbon aktif berlaku sebaliknya. Rattan waste from handicraft and furniture industry could potentially be used as raw material of activated carbon due to high content of holoselulosa and carbon. This paper investigates the effectiveness of chemical activation using sodium chloride (NaCl) followed by physical activation in the making of activated carbon-based on rattan shavings waste. Preparation of the activated carbon began with the carbonization process at 250°C for 1 hour. Furthermore chemical activation using a variation of NaCl concentrations 10%, 15% and 20% as well as the time of immersion 10, 15 and 20 hours. Physical activation was done by burning at 700°C for 30 minutes. Analysis of the physical and chemical characteristics of the activated carbon was referred to the SNI 06-3730-95, including of moisture content, fixed carbon and iodine number, while the calculation of the specific surface area was done by the Sears’s method. The results of this study showed that the optimum conditions of chemical activation occurred in impregnation by NaCl 10% for 10 hours. The water content, fixed carbon, iodine number and surface area of activated carbon was 2.90%, 72.70%, 994.59 mg/g and 1587.67 m²/g  respectively. The increase values of fixed carbon, iodine number, and surface area was inversely proportional to the increase of NaCl concentration and the length of impregnation time, while the increase of water content applied vice versa.

Comparison on the Characteristics of Bio-Based Porous Carbons by Physical and Novel Chemical Activation

2014 ◽  
Vol 554 ◽  
pp. 22-26 ◽  
Author(s):  
Jibril Mohammed ◽  
Noor Shawal Nasri ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Hamza Dadum ◽  
Murtala Musa Ahmed
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Chemical Activation ◽  
Value Added ◽  
Potassium Acetate ◽  
Lower Surface ◽  
Physical Activation ◽  
Porous Carbons ◽  
Surface Areas ◽  
Agricultural Materials

There is significantly abundant portion of waste agricultural materials in the world serving as environmental challenge, however, they could be converted into useful value added products like activated carbon. Coconut shell based carbons were synthesized using physical activation by CO2 and chemical activation with potassium hydroxide and potassium acetate. The BET surface areas and pore volumes are 361m2/g and 0.19cm3/g for physical activation, 1353m2/g and 0.61cm3/g for activation with KOH and 622m2/g and 0.31cm3/g for potassium acetate activated carbon. From the Fourier Transform Infrared Spectroscopy analysis, hydroxyls, alkenes and carbonyl functional groups were identified with more prominence on the chemically activated porous carbons. Thermogravimetric analysis (TGA) results showed occurrence of moisture pyrolysis at 105°C, the pyrolysis of hemicellulose and cellulose occurred at 160–390°C and lignin at (390-650°C). Carbonization at 700°C and 2hrs had highest yield of 32%. Physical activation yielded lower surface area with approximately 88% micropores. On the other hand, chemically activation yielded higher surface area with elevated mesopores. The porous carbons can be applied to salvage pollution challenges.

scholarly journals Preparation of Activated Carbons from Waste External Thermal-Insulating Phenolic Foam Boards

2018 ◽  
Vol 142 ◽  
pp. 01005
Author(s):  
Lijuan Gao ◽  
Xiaojun Zheng ◽  
Yaming Zhu ◽  
Xuefei Zhao ◽  
Junxia Cheng
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Iodine Value ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Specific Area ◽  
Physical Activation ◽  
Thermal Insulating ◽  
Phenolic Foam

Activated carbons (ACs) were prepared by steam physical activation or KOH chemical activation with the waste external thermal-insulating phenolic foam board as the raw material. The Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) specific area, pore-size distribution and iodine value were used to characterize the properties of ACs. AC-1(with the method of KOH chemical activation) has the iodine value of 2300mg/g, BET specific area of 1293 m2g-1, average pore-size of 2.4 nm, and mainly composed of micropore and relatively small mesopore. AC-2(with the method of steam physical activation) has the iodine value of 1665mg/g. Compared with AC-2, AC-1 had a pore-size distribution with more evenly and relative concentrated, it’s belonging to the high microporosity materials. Actually, chemical activation had more significant influence on destruction of the pore wall than physical activation.

Effect of Sintering Temperature on the Structure and Properties of Attapulgite-Based Nanofibrous Membranes

2017 ◽  
Vol 898 ◽  
pp. 1929-1934
Author(s):  
Ye Kai Zhu ◽  
Da Jun Chen
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sintering Temperature ◽  
Average Pore Size ◽  
Pure Water ◽  
Water Fluxes ◽  
Structure And Properties ◽  
Nanofibrous Membranes

Attapulgite (AT)-based nanofibrous membranes (NFMs) were fabricated via a facile papermaking procedure, and the AT-based NFMs were sintered at three different temperatures (240 °C, 400 °C, and 600 °C). The effect of sintering temperature on the structure and properties, such as specific surface area, pore size distribution, porosity, mechanical property, pure water fluxes of AT-based NFMs, were investigated. The results showed that average pore size, total pore volume, and porosity of AT-based NFMs increased with increasing of the sintering temperature, while specific surface area and flexural strength of AT-based NFMs decreased. The optimal sintering temperature for AT-based NFMs was 400 °C. In addition, it was also found that the swelling degree of AT-based NFMs in aqueous solutions was suppressed and the pure water fluxes of AT-based NFMs were improved by sintering process.

scholarly journals Karakteristik luas permukaan karbon aktif dari ampas tebu dengan aktivasi kimia

2018 ◽  
Vol 10 (3) ◽  
pp. 149
Author(s):  
Mahmud Sudibandriyo ◽  
L Lydia
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Sugarcane Bagasse ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Physical Activation ◽  
Mass Ratio ◽  
Characterization Of Activated Carbon

Surface area characterization of activated carbon from sugarcane baggase by chemical activationAdsorption is one the process with many applications in the industries such as in a separation or in gas storage. In this adsorption, adsorbent selection is the most important thing. One of the adsorbent most suitable for this process is activated carbon. Previous studies show that high surface area of activated carbon can be produced from sugarcane bagasse using activator ZnCl2. The research’s goal is to produce activated carbon from sugarcane bagasse and determine the effects of activator on the surface area of activated carbon produced. Activators used in this research are KOH and ZnCl2 with the mass ratio of activator/carbon are 1/1, 2/1 and 3/1. The results show that The highest surface area, 938,2 m2/g, is obtained by activation using KOH with mass ratio of activator/carbon 3/1, whereas the highest surface area by activation using ZnCl2 is 632 m2/g with mass ratio of activator/carbon 2/1. For comparison, preparation of activated carbon by physical activation is also done and the surface area is 293 m2/g.Keywords: Activated carbon, chemical activation, sugarcane bagasse, KOH, ZnCl2 Abstrak Adsorpsi merupakan salah satu proses yang banyak digunakan dalam industri baik dalam pemisahan maupun untuk penyimpanan gas. Pada proses adsorpsi ini, pemilihan adsorben merupakan hal yang sangat penting. Salah satu jenis adsorben yang sangat cocok untuk proses ini adalah karbon aktif. Penelusuran studi sebelumnya menunjukkan bahwa karbon aktif dengan luas permukaan yang cukup tinggi dapat dibuat dari ampas tebu dengan menggunakan aktivator ZnCl2. Penelitian ini bertujuan untuk menghasilkan karbon aktif dari ampas tebu dengan aktivasi kimia serta mengetahui pengaruh aktivator terhadap luas permukaan karbon aktif yang dihasilkan. Aktivator yang digunakan dalam penelitian ini adalah KOH dan ZnCl2 dengan rasio massa aktivator/massa karbon 1/1, 2/1, dan 3/1. Aktivasi dilakukan pada temperatur 700 oC selama 1 jam. Hasil penelitian menunjukkan bahwa luas permukaan tertinggi sebesar 938,2 m2/g diperoleh dengan aktivasi menggunakan KOH dengan rasio massa aktivator/massa arang 3/1, sedangkan aktivasi dengan menggunakan ZnCl2 diperoleh luas permukaan tertinggi sebesar 632 m2/g dengan rasio massa aktivator/massa arang 2/1. Sebagai pembanding, pada penelitian ini juga dilakukan pembuatan karbon aktif dengan metode aktivasi fisika dan diperoleh luas permukaan karbon aktif sebesar 293 m2/g.Kata kunci: Aktivasi kimia, ampas tebu, karbon aktif, KOH, ZnCl2

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