scholarly journals Comparison of Surface and Structural Properties of Carbonaceous Materials Prepared by Chemical Activation of Tomato Paste Waste: The Effects of Activator Type and Impregnation Ratio

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.

2018 ◽  
Vol 20 (3) ◽  
pp. 75-80
Author(s):  
J. Serafin ◽  
A.K. Antosik ◽  
K. Wilpiszewska ◽  
Z. Czech

Abstract In this work for the fi rst time, activated carbons were prepared from carboxymethyl fi lm (low-cost carboxymethyl fi lm waste), using chemical activation with potassium hydroxide. The samples were characterized by nitrogen adsorption-desorption at 77 K, XRD, SEM methods. The high values of the specifi c surface area and total pore volume were achieved and were equal to 2064 m2/g and 1.188 cm3/g, respectively. Waste from the fi lm can be immediately utilized without CO2 production. This is the environmentally friendly way of waste utilization. Through this process, we can protect our environment. This study showed that the activated carbon obtained from carboxymethyl fi lm waste can be used as a good adsorbent for CO2 adsorption.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


Author(s):  
Nawwarah Mokti ◽  
Azry Borhan ◽  
Siti Nur Azella Zaine ◽  
Hayyiratul Fatimah Mohd Zaid

The use of an activating agent in chemical activation of activated carbon (AC) production is very important as it will help to open the pore structure of AC as adsorbents and could enhance its performance for adsorption capacity. In this study, a pyridinium-based ionic liquid (IL), 1-butylpyridinium bis(trifluoromethylsulfonyl) imide, [C4Py][Tf2N] has been synthesized by using anion exchange reaction and was characterized using few analyses such as 1H-NMR, 13C-NMR and FTIR. Low-cost AC was synthesized by chemical activation process in which rubber seed shell (RSS) and ionic liquid [C4Py][Tf2N] were employed as the precursor and activating agent, respectively. AC has been prepared with different IL concentration (1% and 10%) at 500°C and 800°C for 2 hours. Sample AC2 shows the highest SBET and VT which are 392.8927 m2/g and 0.2059 cm3/g respectively. The surface morphology of synthesized AC can be clearly seen through FESEM analysis. A high concentration of IL in sample AC10 contributed to blockage of pores by the IL. On the other hand, the performance of synthesized AC for CO2 adsorption capacity also studied by using static volumetric technique at 1 bar and 25°C. Sample AC2 contributed the highest CO2 uptakes which is 50.783 cm3/g. This current work shows that the use of low concentration IL as an activating agent has the potential to produce porous AC, which offers low-cost, green technology as well as promising application towards CO2 capture.


2021 ◽  
Vol 1162 ◽  
pp. 65-73
Author(s):  
Rakhmawati Farma ◽  
Ona Lestari ◽  
Erman Taer ◽  
Apriwandi ◽  
Minarni ◽  
...  

Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H3PO4, NaOH, ZnCl2 and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H3PO4 activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.


2014 ◽  
Vol 875-877 ◽  
pp. 196-201 ◽  
Author(s):  
Mohd Faisal Taha ◽  
Ahmad S. Rosman ◽  
Maizatul S. Shaharun

The potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Pb (II) ion from aqueous solution was investigated. Rice husk-based activated carbon was preparedviachemical activation process using NaOH followed by the carbonization process at 500°C. Morphological analysis was conducted using field-emission scanning electron microscope /energy dispersive X-ray (FESEM/EDX) on three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon. These three samples were also analyzed for their C, H, N, O and Si contents using CHN elemental analyzer and FESEM/EDX. The textural properties of rice husk-based activated carbon, i.e. surface area (253 m2/g) and pore volume (0.17 cm2/g), were determined by N2adsorption. The adsorption studies using rice husk-based activated carbon as an adsorbent to remove Pb (II) ion from aqueous solution were carried out at a fixed initial concentration of Pb (II) ion (150 ppm) with varying adsorbent dose as a function of contact time at room temperature. The concentration of Pb (II) ion was determined by atomic absorption spectrophotometer (AAS). The removal of Pb (II) ion from aqueous solution increased from 35 % to 82 % when the amount of rice husk-based activated carbon was increased from 0.05 g to 0.30 g. The equilibrium data obtained from adsorption studies was found to fit both Langmuir and Freundlich adsorption isotherms.


2000 ◽  
Vol 18 (4) ◽  
pp. 373-383 ◽  
Author(s):  
Laila B. Khalil ◽  
Badie S. Girgis ◽  
Tarek A.M. Tawfik

Locally discarded olive oil waste was tested as a potential raw material for the preparation of activated carbons. Chemical activation by impregnation with H3PO4 was employed using acid solutions of varying concentration in the range 30–70% followed by thermal treatment at 500–700°C. The development of porosity was followed from an analysis of the nitrogen adsorption isotherms obtained at 77 K by applying standard BET and t-plot methods. Carbons with low to moderate surface areas (273–827 m2/g) and total pore volumes (0.27–0.69 ml/g), containing essentially micropores with diameters of 8.2 Å up to 12.4 Å were obtained. Increasing the concentration of impregnant led to the development of porosity with the optimum being attained at 60% H3PO4. Phosphoric acid is visualized as acting both as an acid catalyst promoting bond-cleavage reactions and the formation of new crosslinks and also as a reactant which combines with organic species to form phosphate and polyphosphate bridges which connect and crosslink biopolymer fragments. The present study suggests many applications for environmental pollution control, firstly by utilizing accumulating low-cost agricultural by-products and secondly by producing a multi-purpose high-capacity adsorbent useful in the remediation of micropollutants in various water courses.


2021 ◽  
Vol 2 (3) ◽  
pp. 324-343
Author(s):  
Viola Hoffmann ◽  
Catalina Rodriguez Correa ◽  
Saskia Sachs ◽  
Andrea del Pilar Sandoval-Rojas ◽  
Mo Qiao ◽  
...  

Bio-based activated carbons with very high specific surface area of >3.000 m² g−1 (based on CO2 adsorption isotherms) and a high proportion of micropores (87% of total SSA) are produced by corncobs via pyrolysis and chemical activation with KOH. The activated carbon is further doped with different proportions of the highly pseudocapacitive transition metal oxide RuO2 to obtain enhanced electrochemical properties and tune the materials for the application in electrochemical double-layer capacitors (EDLC) (supercapacitors). The activated carbon and composites are extensively studied regarding their physico-chemical and electrochemical properties. The results show that the composite containing 40 wt.% RuO2 has an electric conductivity of 408 S m−1 and a specific capacitance of 360 Fg−1. SEM-EDX, XPS, and XRD analysis confirm the homogenous distribution of partly crystalline RuO2 particles on the carbon surface, which leads to a biobased composite material with enhanced electrochemical properties.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 378 ◽  
Author(s):  
Manuel Peñas-Garzón ◽  
Almudena Gómez-Avilés ◽  
Jorge Bedia ◽  
Juan Rodriguez ◽  
Carolina Belver

Several activated carbons (ACs) were prepared by chemical activation of lignin with different activating agents (FeCl3, ZnCl2, H3PO4 and KOH) and used for synthesizing TiO2/activated carbon heterostructures. These heterostructures were obtained by the combination of the activated carbons with a titania precursor using a solvothermal treatment. The synthesized materials were fully characterized (Wavelength-dispersive X-ray fluorescence (WDXRF), X-ray diffraction (XRD), Scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier transform infrared (FTIR) and UV-visible diffuse reflectance spectra (UV-Vis DRS) and further used in the photodegradation of a target pharmaceutical compound (acetaminophen). All heterostructures were composed of anatase phase regardless of the activated carbon used, while the porous texture and surface chemistry depended on the chemical compound used to activate the lignin. Among all heterostructures studied, that obtained by FeCl3-activation yielded complete conversion of acetaminophen after 6 h of reaction under solar-simulated irradiation, also showing high conversion after successive cycles. Although the reaction rate was lower than the observed with bare TiO2, the heterostructure showed higher settling velocity, thus being considerably easier to recover from the reaction medium.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2047 ◽  
Author(s):  
Katarzyna Januszewicz ◽  
Paweł Kazimierski ◽  
Maciej Klein ◽  
Dariusz Kardaś ◽  
Justyna Łuczak

Pyrolysis of straw pellets and wood strips was performed in a fixed bed reactor. The chars, solid products of thermal degradation, were used as potential materials for activated carbon production. Chemical and physical activation processes were used to compare properties of the products. The chemical activation agent KOH was chosen and the physical activation was conducted with steam and carbon dioxide as oxidising gases. The effect of the activation process on the surface area, pore volume, structure and composition of the biochar was examined. The samples with the highest surface area (1349.6 and 1194.4 m2/g for straw and wood activated carbons, respectively) were obtained when the chemical activation with KOH solution was applied. The sample with the highest surface area was used as an adsorbent for model wastewater contamination removal.


2020 ◽  
Vol 15 (2) ◽  
pp. 79-89
Author(s):  
Sriatun Sriatun ◽  
Shabrina Herawati ◽  
Icha Aisyah

The starting material for activated carbon was biomass from teak woodcutting, which consists of 47.5% cellulose, 14.4% hemicellulose, and 29.9% lignin. The surface area and iodine number of activated carbons are the factors determining the adsorption ability. This study aims to determine the effect of the activator type on activated carbon characters and test the absorption ability for waste cooking oil. The synthesis stages include carbonization, chemical activation, and then physics activation. The activation process consists of two steps. Firstly, the chemical activation via adding H2SO4, and H3PO4 at room temperature for 24 hours, the second, physical activation by heating at various temperatures of 300, 400, and 500 °C for two hours. The characterizations of activated carbon include water content, ash content, iodine number, functional groups, and surface area. Furthermore, the activated carbon was used as an adsorbent for waste cooking oil for 60 minutes at 100 °C with a stirring of 500 rpm. The results were analyzed using UV-Vis spectrophotometry at a maximum wavelength of 403 nm. The iodine numbers of activated carbon ranged 481.1-1211.4 mg/g and 494.8-1204 mg/g for H3PO4 and H2SO4, respectively.Activated carbon with H3PO4 of 15% and an activation temperature of 400 °C has the highest surface area of 445.30 m2/g.  The H2SO4 dan H3PO4 activators can be used to improve the quality of activated carbon in absorbing dyes in waste cooking oil, where the optimum concentration is 10-15% (v/v). The H3PO4 activator tends to produce a higher bleaching percentage than H2SO4. 


Sign in / Sign up

Export Citation Format

Share Document