Calorimetric study of activated carbons
impregnated with CaCl<sub>2</sub>

Vargas, Diana; Giraldo, Liliana; Moreno–Piraján, Juan Carlos

doi:10.1515/chem-2015-0075

Cited by 7 publications

(7 citation statements)

References 14 publications

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“…These can be industrial wastes, such as by-products of the petroleum industry [8], used tires [9] and polymer resins [10,11]; biomass waste, i.e. agricultural residues [13][14][15], cones [16,17], bamboo waste [18][19][20], saw dust [21]; or food-processing wastes, such as sugarcane bagasse [22]. Such approaches improve the utilization, recovery and reuse of waste and reduce the cost of the final product [23].…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

2015

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Activated carbons from biomass material of giant knotweed Reynoutria sachalinensis (F. Schmidt ex Maxim.) Nakai were obtained. Use of this plant for manufacturing activated carbon has not been studied yet. Therefore, the first activated carbons of giant knotweed origin are described. Both physicochemical (by steam and CO 2 ) and chemical (by KOH) activation methods were applied. Influences of temperature (500, 600, 700 and 800°C), burn-off [10, 25 and 50 wt. % (daf)] and KOH concentration on pores surface area and volume distribution of the obtained activated carbons were explored. Porosity of the elaborated sorbents was determined by benzene and carbon dioxide sorption measurements. Sorbents obtained by steam activation were micro-and mesoporous with surface area and volume of pores increasing with temperature and burn-off to V = 0.351 cm 3 g -1 and S = 768 m 2 g -1 at 800°C at 50% burn-off. Carbon dioxide activation resulted with notably microporous activated carbons with porous texture parameters also increasing with burn-off to V = 0.286 cm 3 g -1 and S = 724 m 2 g -1 at 50% burn-off. The highest BET surface area of 2541 m 2 g -1 was achieved when chemical (KOH) activation was performed using KOH to char ratio 4:1.

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Section: Introductionmentioning

confidence: 99%

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

2015

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“…behavior is adjusted as described and to that obtained in similar investigations that have prepared carbonaceous materials that have been characterized by benzene immersion calorimetry. 25,27,30,32,34 This correlation shows that the materials prepared under these conditions have an adequate interaction with benzene. It is possible to evaluate the adsorption of molecules with similar characteristics.…”

Section: ■ Results and Discussionmentioning

confidence: 69%

“…This type of material tends to have a hydrophobic character, which is indicative of the adsorption of nonpolar-type adsorbates as is the case with CO 2 into this type of material. 34 Figure 8 presents the calorimetric curves obtained by the immersion in benzene and dichloromethane of the carbons prepared, and it is noted that the magnitude of the peak in each sample is proportional to the enthalpy of immersion obtained in this analysis; the enthalpy with greater calculated value corresponds to ACCu5-1073 in both benzene and dichloromethane. There is a correlation between the enthalpies of immersion of the solids in benzene and dichloromethane.…”

Section: ■ Results and Discussionmentioning

confidence: 95%

Adsorption of CO₂ on Activated Carbons Prepared by Chemical Activation with Cupric Nitrate

2020

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Activated carbons were prepared from a lignocellulosic material, African palm shells (Elaeis guineensis), by chemical impregnation of the precursor with solutions of 1–7% w/v Cu(NO3)2 at five different concentrations. These were carbonized in a carbon dioxide atmosphere at 1073 K to obtain different carbons. Their textural properties were characterized by nitrogen and carbon dioxide adsorption isotherms in order to evaluate the pore-size distribution. The immersion enthalpies of the activated carbons in benzene, dichloromethane, and water were determined. The CO2 adsorption capacities of the materials at 273 K under low-pressure conditions were also determined. Chemical characterization was performed by mass spectrometry, Fourier transform infrared spectroscopy, and temperature-programmed reduction. With this method of preparation under the concentrations described, activated micro–mesoporous carbons were obtained, with the formation of highly mesoporous solids that favored the process of diffusion of molecules of CO2 into the material. Here, we show that activated carbons were obtained with different textural characteristics: surface Brunauer–Emmett–Teller areas varied between 473 and 1361 m2 g–1 and micropore volume between 0.18 and 0.51 cm3 g–1. The activated carbon with the highest values of textural parameters was ACCu5-1073. Micro–mesoporous solids were obtained with the methodology used. This is important as it may help the entry of CO2 molecules into the pores. The adsorption of CO2 in the materials prepared presented values between 103 and 217 mg CO2 g–1; the values of volume of narrow microporosity obtained were between 0.16 and 0.45 cm3 g–1. The solid with the greatest capacity for adsorption of CO2 and volume of narrow microporosity was ACCu3-1073. The use of these solids is of importance for future practical and industrial applications. The adsorption kinetic of CO2 in the activated carbons prepared with metallic salt of copper is in good accordance with the intraparticle diffusion model, for which diffusion is the rate-limiting step. The adsorption of CO2 in the prepared activated carbons is favorable from the energy and kinetic point of view, as these accompanied by the presence of wide micro–mesoporosity favor the entry of CO2 into the micropores.

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“…The change in the potential signal, product of the immersion, is captured by the computational system until the base line is re-obtained (this usually requires approximately 30 minutes), finally the electrical calibration of the calorimeter is carried out. The experiments were repeated four times for each solvent mentioned above [30, 31, 32, 33, 34, 35].…”

Section: Methodsmentioning

confidence: 99%

Thermodynamic study of adsorption of nickel ions onto carbon aerogels

Fonseca-Correa

Giraldo

Moreno–Piraján

2019

Heliyon

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In this work, 8 samples of carbon aerogels with different ratios of catalyst versus resorcinol (R/C) from 25 to 1500 were used. The textural properties were evaluated from N 2 adsorption isotherms in 77 K, as well as the chemical ones, where the surface chemistry was evaluated through the Boehm titrations. The results were analyzed and related to the adsorption of the nickel (II) ion from aqueous solution. The experimental results show that the aerogel samples can be divided into two series with different properties: Series I, mainly microporous (low ratio R/C) and Series II (high ratio R/C) mainly microporous but with a contribution of mesoporosity. The specific surface area varied between 64 and 990 m 2 g -1 . The experimental results show that prepared aerogels have an adequate adsorption capacity towards nickel (II) ions. The behavior of the kinetics of Ni(II) adsorption on carbon aerogels adjusts in a better way the kinetic model of pseudo-second order since it is the one that presents the value of the highest R 2 correlation coefficient. The calorimetric data shows that the greater the area developed in carbons aerogels the enthalpy increases.

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Calorimetric study of activated carbons impregnated with CaCl₂

Cited by 7 publications

References 14 publications

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

Adsorption of CO₂ on Activated Carbons Prepared by Chemical Activation with Cupric Nitrate

Thermodynamic study of adsorption of nickel ions onto carbon aerogels

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Calorimetric study of activated carbons impregnated with CaCl2

Cited by 7 publications

References 14 publications

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

Preparation and characterization of activated carbons from biomass material – giant knotweed (Reynoutria sachalinensis)

Adsorption of CO2 on Activated Carbons Prepared by Chemical Activation with Cupric Nitrate

Thermodynamic study of adsorption of nickel ions onto carbon aerogels

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Product

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Calorimetric study of activated carbons impregnated with CaCl₂

Adsorption of CO₂ on Activated Carbons Prepared by Chemical Activation with Cupric Nitrate