In this study, we developed novel phosphoric acid crosslinked blend membranes for the pervaporation separation of tetrahydrofu-ran/water mixtures. Sodium alginate and chitosan blend membranes were prepared by solution casting and solvent evaporation technique. These blend membranes were crosslinked with phosphoric acid in isopropanol/water baths and used for pervaporation separation of feed mixtures ranging from 6 to 43 wt.% water in tetrahydrofuran (THF)/water mixtures at 30 °C. Crosslinking was confirmed by Fourier transform infrared (FTIR) and Ion Exchange Capacity (IEC) study. Thermal stability and crystallinity of the membranes were determined from thermogravimetric analysis (TGA) and X-ray diffraction (XRD) studies respectively. The surface morphology of the membranes was observed using Scanning electron microscopy (SEM). Sorption studies were carried out to evaluate the extent of interaction and degree of swelling of the membranes in THF, water and binary mixtures. The effect of experimental parameters such as feed composition, membrane thickness, and permeate pressure on separation performance of the phosphorylated membranes were determined. These membranes were found to have good potential for breaking the azeotrope of 94 wt.% THF with a selectivity of 459 and normalized flux of 0.25 kg m−2 h−1 10 µm. The membrane performance exhibited a reduction in selectivity and an improvement in flux with increasing feed water compositions. Selectivity improved and flux decreased with increasing membrane thickness. Both flux and selectivity decreased with increasing permeate pressure.
在这项研究中，我们开发了新型磷酸交联混合膜，用于四氢呋喃/水混合物的蒸发分离。通过溶液浇铸和溶剂蒸发技术制备了海藻酸钠和壳聚糖混合膜。这些混合膜在异丙醇/水浴中与磷酸交联，并在 30 °C 下用于四氢呋喃（THF）/水混合物中 6 至 43 wt.% 水的进料混合物的渗透分离。傅立叶变换红外光谱（FTIR）和离子交换容量（IEC）研究证实了交联情况。热重分析 (TGA) 和 X 射线衍射 (XRD) 研究分别确定了膜的热稳定性和结晶度。使用扫描电子显微镜（SEM）观察了膜的表面形态。进行了吸附研究，以评估膜在四氢呋喃、水和二元混合物中的相互作用程度和溶胀程度。确定了进料成分、膜厚度和渗透压力等实验参数对磷化膜分离性能的影响。研究发现，这些膜具有很好的潜力来分离 94 wt.% THF 的共沸物，其选择性为 459，归一化通量为 0.25 kg m-2 h-1 10 µm。随着进水成分的增加，膜性能表现出选择性降低和通量提高。随着膜厚度的增加，选择性提高，通量降低。随着渗透压力的增加，通量和选择性都有所下降。
{"title":"Pervaporation Separation of Tetrahydrofuran/Water Azeotropic Mixtures using Phosphorylated Blend Membranes","authors":"Subba Reddy Alla, Venkata Subbaiah Munagapati, Nadavala Siva Kumar, Suguna Madala, Vijaya Yarramuthi","doi":"10.3311/ppch.22461","DOIUrl":"https://doi.org/10.3311/ppch.22461","url":null,"abstract":"In this study, we developed novel phosphoric acid crosslinked blend membranes for the pervaporation separation of tetrahydrofu-ran/water mixtures. Sodium alginate and chitosan blend membranes were prepared by solution casting and solvent evaporation technique. These blend membranes were crosslinked with phosphoric acid in isopropanol/water baths and used for pervaporation separation of feed mixtures ranging from 6 to 43 wt.% water in tetrahydrofuran (THF)/water mixtures at 30 °C. Crosslinking was confirmed by Fourier transform infrared (FTIR) and Ion Exchange Capacity (IEC) study. Thermal stability and crystallinity of the membranes were determined from thermogravimetric analysis (TGA) and X-ray diffraction (XRD) studies respectively. The surface morphology of the membranes was observed using Scanning electron microscopy (SEM). Sorption studies were carried out to evaluate the extent of interaction and degree of swelling of the membranes in THF, water and binary mixtures. The effect of experimental parameters such as feed composition, membrane thickness, and permeate pressure on separation performance of the phosphorylated membranes were determined. These membranes were found to have good potential for breaking the azeotrope of 94 wt.% THF with a selectivity of 459 and normalized flux of 0.25 kg m−2 h−1 10 µm. The membrane performance exhibited a reduction in selectivity and an improvement in flux with increasing feed water compositions. Selectivity improved and flux decreased with increasing membrane thickness. Both flux and selectivity decreased with increasing permeate pressure.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140258517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inès Jallali, M. A. Benabderrahim, F. Medini, Hela Ben Ahmed, C. Abdelly, R. Ksouri
Sea fennel (Crithmum maritimum L.) is a facultative halophyte from the Apiaceae family. The variation of phenolic compounds, the antioxidant and antibacterial activities of different extracts of different organs of sea fennel were investigated. The roots, stems, leaves and seeds were collected from three bioclimatic stages of Tunisia. Solvent fractionation method (using aqueous acetone, petroleum ether and ethyl acetate) was adopted to separate the extract ingredient and to concentrate phenolics. Total phenolics, total flavonoids, and condensed tannins significantly varied between organs and localities. In leaves, the highest level of phenols was detected in the upper and sub-humid zones. However, in stems the high amounts of phenols were observed in semiarid climate. The antioxidant activity was evaluated through four different methods and the antimicrobial activity was assessed against five human pathogenic bacteria and a fungal strain. Multivariate analysis showed significant effect of organ and locality on the antioxidant properties. Results of the antibacterial activities showed significant differences among extracts and was reflected by a large spectrum of activity ranging from totally not active (Zones of inhibition (zi) < 1 mm) to very high activity (zi >16 mm). Combined statistical results allowed to select the more potent fraction to be analyzed using reversed-phase HPLC (RP-HPLC). The flavanol epigallocatechin was identified as a major phenolic compound which contributed greatly to the antioxidant capacity. The results established in this study highlighted the importance of this halophyte cash crop in the human diet as natural source of active components.
{"title":"Phytochemical Diversity and Related Bioactivity of Ethyl Acetate Fraction from Different Organs and Provenances of the Edible Halophyte Crithmum Maritimum L.","authors":"Inès Jallali, M. A. Benabderrahim, F. Medini, Hela Ben Ahmed, C. Abdelly, R. Ksouri","doi":"10.3311/ppch.22715","DOIUrl":"https://doi.org/10.3311/ppch.22715","url":null,"abstract":"Sea fennel (Crithmum maritimum L.) is a facultative halophyte from the Apiaceae family. The variation of phenolic compounds, the antioxidant and antibacterial activities of different extracts of different organs of sea fennel were investigated. The roots, stems, leaves and seeds were collected from three bioclimatic stages of Tunisia. Solvent fractionation method (using aqueous acetone, petroleum ether and ethyl acetate) was adopted to separate the extract ingredient and to concentrate phenolics. Total phenolics, total flavonoids, and condensed tannins significantly varied between organs and localities. In leaves, the highest level of phenols was detected in the upper and sub-humid zones. However, in stems the high amounts of phenols were observed in semiarid climate. The antioxidant activity was evaluated through four different methods and the antimicrobial activity was assessed against five human pathogenic bacteria and a fungal strain. Multivariate analysis showed significant effect of organ and locality on the antioxidant properties. Results of the antibacterial activities showed significant differences among extracts and was reflected by a large spectrum of activity ranging from totally not active (Zones of inhibition (zi) < 1 mm) to very high activity (zi >16 mm). Combined statistical results allowed to select the more potent fraction to be analyzed using reversed-phase HPLC (RP-HPLC). The flavanol epigallocatechin was identified as a major phenolic compound which contributed greatly to the antioxidant capacity. The results established in this study highlighted the importance of this halophyte cash crop in the human diet as natural source of active components.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140260105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Supercapacitors are the energy storage devices that have gained increased attention due to high charge storage capacity, fast charge-discharge rate, high specific power and excellent cycle stability. Recently, research on supercapacitors is focused on the development of new electrode materials prepared by surface engineering to obtain superior electrochemical performance. Carbonaceous materials (CM) such as graphene, graphene oxide (GO), reduced graphene oxide (rGO) and carbon nanotubes (CNTs) etc. and conducting polymer (CP) based composite materials have gained increased attention for their use in supercapacitors. The nanocomposites obtained by merely mixing these two components pose some serious drawbacks such as low conductivity or poor film forming ability. The conjugation of CPs to CMs through covalent bonds is able to address these drawbacks. This review mainly provide collective information about various synthetic strategies to obtain CP grafted CMs for supercapacitor application. Herein, we provide information on different CP-CM conjugation reactions for obtaining the composites and their effects on electrochemical performances. The analysis revealed the importance of CP-CM grafting is important for tuning the electrochemical properties of the materials.
{"title":"Synthesis Processes of Carbonaceous Material/Conducting Polymer Nanocomposites in Relation to Grafting and Electrochemical Properties for Supercapacitor Application: A Review","authors":"Vidya V. Kulkarni, Pranoti H. Patil, S. Jadhav","doi":"10.3311/ppch.22730","DOIUrl":"https://doi.org/10.3311/ppch.22730","url":null,"abstract":"Supercapacitors are the energy storage devices that have gained increased attention due to high charge storage capacity, fast charge-discharge rate, high specific power and excellent cycle stability. Recently, research on supercapacitors is focused on the development of new electrode materials prepared by surface engineering to obtain superior electrochemical performance. Carbonaceous materials (CM) such as graphene, graphene oxide (GO), reduced graphene oxide (rGO) and carbon nanotubes (CNTs) etc. and conducting polymer (CP) based composite materials have gained increased attention for their use in supercapacitors. The nanocomposites obtained by merely mixing these two components pose some serious drawbacks such as low conductivity or poor film forming ability. The conjugation of CPs to CMs through covalent bonds is able to address these drawbacks. This review mainly provide collective information about various synthetic strategies to obtain CP grafted CMs for supercapacitor application. Herein, we provide information on different CP-CM conjugation reactions for obtaining the composites and their effects on electrochemical performances. The analysis revealed the importance of CP-CM grafting is important for tuning the electrochemical properties of the materials.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140262148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ouarda Ben Messaoud, A. Ouahab, S. Rahmane, Souheila Hettal, Aicha Kater, Moustefa Sayad, Hafida Attouche, Noureddine Gherraf
The work in hand presents the elaboration of CuO thin films using a home-made spray pyrolysis technique at room atmosphere. The films were synthesized on preheated glass substrate at 450 °C. The source solution molarity was varied from 0.025 to 0.1 mol/L. The films were characterized by employing X-Ray Diffraction technique, UV-Vis-NIR spectrophotometry, Scanning Electron Microscope imagery, Energy Dispersive Spectroscopy, and four-points probe techniques. The X-ray diffraction analysis confirmed that all films are polycrystalline with a preferred orientation along the plane (−111) of the monoclinic crystal structure phase of tenorite (CuO). The SEM images showed a homogeneous and smooth surface. Crystallinity and grain size were improved. The rise of solution concentration induced a reduction of transmittance and reflectance in the visible region. The energy gap, the absorption coefficient, the extinction coefficient, refractive index, dielectric constant (ԑr and ԑi) and loss energy were estimated from transmittance and reflectance data. The gap energy decreases from 2.72 to 2.56 eV. The film deposited for 0.025 mol/L exhibits the highest real part of the dielectric constant (ԑr ~ 17). The film resistivity which is in order of 102 Ω cm decreases with the increase of molar concentration. The estimated dielectric constant indicated that the resulting CuO thin films could be used as dielectric layers for optoelectronic devices working in Vis-NIR region of radiation. Furthermore, the relatively high band gap, high absorption coefficient and high conductivity of the film obtained at 0.075 mol/L, make them good candidates as absorption layers in solar cells applications.
本作品介绍了在室温下利用自制喷雾热解技术制备氧化铜薄膜的情况。薄膜是在 450 °C 的预热玻璃基底上合成的。源溶液摩尔浓度在 0.025 至 0.1 摩尔/升之间变化。利用 X 射线衍射技术、紫外-可见-近红外分光光度法、扫描电子显微镜图像、能量色散光谱法和四点探针技术对薄膜进行了表征。X 射线衍射分析证实，所有薄膜都是多晶体，其优先取向沿钛铁矿（CuO）单斜晶体结构相的平面（-111）。扫描电镜图像显示薄膜表面均匀光滑。结晶度和晶粒尺寸都得到了改善。溶液浓度的增加导致可见光区域的透射率和反射率降低。根据透射率和反射率数据估算了能隙、吸收系数、消光系数、折射率、介电常数（ԑr 和 ԑi）和损耗能。间隙能从 2.72 eV 下降到 2.56 eV。在 0.025 mol/L 下沉积的薄膜显示出最高的介电常数实部（ԑr ~ 17）。薄膜电阻率随着摩尔浓度的增加而降低，约为 102 Ω cm。估计的介电常数表明，所制备的氧化铜薄膜可用作在可见光-近红外辐射区域工作的光电器件的介电层。此外，在 0.075 摩尔/升浓度下获得的薄膜具有相对较高的带隙、高吸收系数和高电导率，使其成为太阳能电池应用中吸收层的良好候选材料。
{"title":"Optoelectronic and Dielectric Properties of Tenorite CuO Thin Films Sprayed at Various Molar Concentrations","authors":"Ouarda Ben Messaoud, A. Ouahab, S. Rahmane, Souheila Hettal, Aicha Kater, Moustefa Sayad, Hafida Attouche, Noureddine Gherraf","doi":"10.3311/ppch.22136","DOIUrl":"https://doi.org/10.3311/ppch.22136","url":null,"abstract":"The work in hand presents the elaboration of CuO thin films using a home-made spray pyrolysis technique at room atmosphere. The films were synthesized on preheated glass substrate at 450 °C. The source solution molarity was varied from 0.025 to 0.1 mol/L. The films were characterized by employing X-Ray Diffraction technique, UV-Vis-NIR spectrophotometry, Scanning Electron Microscope imagery, Energy Dispersive Spectroscopy, and four-points probe techniques. The X-ray diffraction analysis confirmed that all films are polycrystalline with a preferred orientation along the plane (−111) of the monoclinic crystal structure phase of tenorite (CuO). The SEM images showed a homogeneous and smooth surface. Crystallinity and grain size were improved. The rise of solution concentration induced a reduction of transmittance and reflectance in the visible region. The energy gap, the absorption coefficient, the extinction coefficient, refractive index, dielectric constant (ԑr and ԑi) and loss energy were estimated from transmittance and reflectance data. The gap energy decreases from 2.72 to 2.56 eV. The film deposited for 0.025 mol/L exhibits the highest real part of the dielectric constant (ԑr ~ 17). The film resistivity which is in order of 102 Ω cm decreases with the increase of molar concentration. The estimated dielectric constant indicated that the resulting CuO thin films could be used as dielectric layers for optoelectronic devices working in Vis-NIR region of radiation. Furthermore, the relatively high band gap, high absorption coefficient and high conductivity of the film obtained at 0.075 mol/L, make them good candidates as absorption layers in solar cells applications.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140262662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Vavasori, Beatrice Fantinel, L. Ronchin, Francesco Zanrosso, M. Bulybayev, N.J. Kudaibergenov, K. Shalmagambetov, G.J. Zhaksylykova
In order to increase the catalytic activity of the Pd(II)-complexes in the alcoxycarbonylation of 1-olefins, the presence in solution of a strong Brönsted acid together with a phosphine ligand is usually required. From an industrial point of view, such two additives, however, influenced the sustainability of the process mainly caused by the related corrosion of the reaction vessel and the toxicity of the phosphine ligand.In this paper, the methoxycarbonylation of 1-octene has been efficiently carried out by using the [Pd(TsO)2(PPh3)2]/FeCl3 catalyst system. The catalyst is very active also without addition of PPh3, reaching the TON of ca. 1300 (mol/mol) in 2 hours by using the Fe(III)/Pd(II) = 400/1 (mol/mol) system. Such value is higher than the values obtained by using the traditional strong Brönsted acid TsOH or other Lewis acid such as AlCl3, in the presence of PPh3. The reaction takes place with the formation of two isomeric products of linear and branched structures with a yield towards the linear isomer of ca. 80%.
{"title":"New Sustainable Pd(II)/Fe(III) Catalytic System Very Efficient in the Hydromethoxycarbonylation of 1-octene","authors":"A. Vavasori, Beatrice Fantinel, L. Ronchin, Francesco Zanrosso, M. Bulybayev, N.J. Kudaibergenov, K. Shalmagambetov, G.J. Zhaksylykova","doi":"10.3311/ppch.22887","DOIUrl":"https://doi.org/10.3311/ppch.22887","url":null,"abstract":"In order to increase the catalytic activity of the Pd(II)-complexes in the alcoxycarbonylation of 1-olefins, the presence in solution of a strong Brönsted acid together with a phosphine ligand is usually required. From an industrial point of view, such two additives, however, influenced the sustainability of the process mainly caused by the related corrosion of the reaction vessel and the toxicity of the phosphine ligand.In this paper, the methoxycarbonylation of 1-octene has been efficiently carried out by using the [Pd(TsO)2(PPh3)2]/FeCl3 catalyst system. The catalyst is very active also without addition of PPh3, reaching the TON of ca. 1300 (mol/mol) in 2 hours by using the Fe(III)/Pd(II) = 400/1 (mol/mol) system. Such value is higher than the values obtained by using the traditional strong Brönsted acid TsOH or other Lewis acid such as AlCl3, in the presence of PPh3. The reaction takes place with the formation of two isomeric products of linear and branched structures with a yield towards the linear isomer of ca. 80%.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140419172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NOx are harmful pollutants emitted by many industries and must be removed before the gases are released into the atmosphere. Among the various techniques used for NOx removal, reactive absorption by hydrogen peroxide in a packed column has the advantage of being able to transform NOx into nitric acid which can be recycled and reused in the plants. This work aimed at modeling the NOx absorption by means of aqueous solutions of hydrogen peroxide and nitric acid, applied in a packed column operating under different representative conditions. The model established using the Aspen software considers the equilibrium and the kinetics of the reactions taking place both in the gas phase and in the liquid phase as well as the thermodynamic properties of the chemical (molecular and ionic) components estimated using the Electrolyte NRTL model. It allows predicting NOx absorption performances in terms of efficiency and selectivity. The model was validated by comparing simulation results with experimental ones obtained in a pilot-scale absorption column and published previously. The predicted values are in satisfactory agreement with the experimental data showing a deviation between 5 and 8%. Therefore, the model developed in this work could be advantageously used to design industrial-scale reactive NOx absorption columns.
{"title":"Pilot-scale Validation of the Modeling of NOx Reactive Absorption Process Using Aqueous Solutions Containing Nitric Acid and Hydrogen Peroxide","authors":"Ons Ghriss, H. Ben Amor, M. Jeday, Diane Thomas","doi":"10.3311/ppch.22855","DOIUrl":"https://doi.org/10.3311/ppch.22855","url":null,"abstract":"NOx are harmful pollutants emitted by many industries and must be removed before the gases are released into the atmosphere. Among the various techniques used for NOx removal, reactive absorption by hydrogen peroxide in a packed column has the advantage of being able to transform NOx into nitric acid which can be recycled and reused in the plants. This work aimed at modeling the NOx absorption by means of aqueous solutions of hydrogen peroxide and nitric acid, applied in a packed column operating under different representative conditions. The model established using the Aspen software considers the equilibrium and the kinetics of the reactions taking place both in the gas phase and in the liquid phase as well as the thermodynamic properties of the chemical (molecular and ionic) components estimated using the Electrolyte NRTL model. It allows predicting NOx absorption performances in terms of efficiency and selectivity. The model was validated by comparing simulation results with experimental ones obtained in a pilot-scale absorption column and published previously. The predicted values are in satisfactory agreement with the experimental data showing a deviation between 5 and 8%. Therefore, the model developed in this work could be advantageously used to design industrial-scale reactive NOx absorption columns.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140424620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Susanti, Raden Gemelli Rachma Wiratmadja, Kevin Cleary Wanta, Arenst Andreas Arie, H. Kristianto
In this study, we have successfully synthesized a high surface area of activated carbons (ACs) from cocoa pod husk (CPH) by using a combination of hydrothermal carbonization (HTC) and chemical activation in the presence of ZnCl2 as both of catalyst as well as activating agent. During HTC, the effect of HTC temperature (200 and 225 °C) and ZnCl2 to biomass mass ratio (1:1, 2:1, 3:1) as a catalyst to the characteristics of the obtained hydrochar (HC) and ACs were investigated. The obtained hydrochar (HCs) was then processed by using ZnCl2 chemical activation with a fixed HC to ZnCl2 mass ratio of 1:4 and the mixture was pyrolyzed at 600 °C for 1 h under an inert atmosphere. The results showed that the addition of catalyst during HTC presented different AC morphology, where the carbon samples were decorated with carbon microspheres. An increase of surface area was observed, where the ACs synthesized from catalyzed HC at biomass to ZnCl2 ratio of 1:3 at temperature 200 °C gave a higher surface area of 1954 m2/g compared to that of without catalyst (1165 m2/g). The catalysis effect was more profound at the HTC temperature of 200 °C compared to 225 °C, as reflected in the significant increase of AC surface area. The addition of a catalyst creates ACs with narrow pore distribution compared to that of synthesized in the absence of a catalyst. It was also observed that the ACs from catalyzed hydrochar possessed higher oxygenated functional groups (OFG) than those without catalysts.
在本研究中，我们采用水热碳化（HTC）和化学活化相结合的方法，在同时使用氯化锌作为催化剂和活化剂的情况下，成功地从可可荚壳（CPH）中合成了高比表面积的活性碳（ACs）。在水热碳化过程中，研究了作为催化剂的水热碳化温度（200 和 225 °C）和氯化锌与生物质的质量比（1:1、2:1、3:1）对所获水炭（HC）和 AC 特性的影响。然后，使用 ZnCl2 化学活化法处理获得的氢碳 (HCs)，氢碳与 ZnCl2 的质量比固定为 1:4，并在 600 °C 的惰性气氛下热解混合物 1 小时。结果表明，在 HTC 过程中添加催化剂后，碳样品呈现出不同的 AC 形貌，碳样品上装饰有碳微球。在生物质与氯化锌的比例为 1:3 且温度为 200 ℃ 的条件下催化 HC 合成的 AC 比表面积有所增加，与无催化剂的 AC（1165 m2/g）相比，表面积增加了 1954 m2/g。HTC 温度为 200 ℃ 时的催化效果比 225 ℃ 时更明显，这反映在 AC 表面积的显著增加上。与不使用催化剂合成的 AC 相比，添加催化剂生成的 AC 孔分布更窄。此外还观察到，与未加催化剂的 AC 相比，加催化剂的水碳 AC 具有更高的含氧官能团 (OFG)。
{"title":"Zinc Chloride as a Catalyst in Hydrothermal Carbonization of Cocoa Pods Husk","authors":"R. Susanti, Raden Gemelli Rachma Wiratmadja, Kevin Cleary Wanta, Arenst Andreas Arie, H. Kristianto","doi":"10.3311/ppch.22328","DOIUrl":"https://doi.org/10.3311/ppch.22328","url":null,"abstract":"\u0000In this study, we have successfully synthesized a high surface area of activated carbons (ACs) from cocoa pod husk (CPH) by using a combination of hydrothermal carbonization (HTC) and chemical activation in the presence of ZnCl2 as both of catalyst as well as activating agent. During HTC, the effect of HTC temperature (200 and 225 °C) and ZnCl2 to biomass mass ratio (1:1, 2:1, 3:1) as a catalyst to the characteristics of the obtained hydrochar (HC) and ACs were investigated. The obtained hydrochar (HCs) was then processed by using ZnCl2 chemical activation with a fixed HC to ZnCl2 mass ratio of 1:4 and the mixture was pyrolyzed at 600 °C for 1 h under an inert atmosphere. The results showed that the addition of catalyst during HTC presented different AC morphology, where the carbon samples were decorated with carbon microspheres. An increase of surface area was observed, where the ACs synthesized from catalyzed HC at biomass to ZnCl2 ratio of 1:3 at temperature 200 °C gave a higher surface area of 1954 m2/g compared to that of without catalyst (1165 m2/g). The catalysis effect was more profound at the HTC temperature of 200 °C compared to 225 °C, as reflected in the significant increase of AC surface area. The addition of a catalyst creates ACs with narrow pore distribution compared to that of synthesized in the absence of a catalyst. It was also observed that the ACs from catalyzed hydrochar possessed higher oxygenated functional groups (OFG) than those without catalysts.\u0000","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140442190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Shevko, Baktygul Makhanbetova, D. Aitkulov, A. Badikova
The article presents the results of thermodynamic prediction and electric smelting of Shalkiya sulfide zinc-lead-bearing ore in the presence of magnetite and coke. Using the HSC-6.0 software package, it was found that under equilibrium conditions in the presence of Fe3O4 and carbon, the reduction and formation of gaseous zinc from ZnS (according to ∆G° = 0) occurs at a temperature of 1205.7 °C, and the formation of ferroalloy at the interaction of the sulfide ore with magnetite and carbon begins at 1200 °C. About 58% of silicon is extracted into the ferroalloy at 1800–1900 °C; almost all zinc and 83–88% of lead turns into a gaseous state. Electric smelting of the sulfide ore in the presence of magnetite concentrate and coke makes it possible to obtain the FS45 grade ferrosilicon (42–43% of Si); the silicon extraction degree was 84–88%. At the same time, 97.3% of lead and 99.2% of zinc are extracted into the sublimates. The developed method for processing zinc sulfide ores allows us to increase the degree of raw materials' comprehensive use due to the extraction of not only zinc and lead, but also silicon. The technology can be used to process raw materials containing zinc, lead and silica, such as zinc ore concentration tailings.
{"title":"Smelting a Zn – Pb Sulfide Ore with Magnetite and Carbon for the Production of a Silicon Alloy and Extraction of Zinc and Lead into Sublimates","authors":"V. Shevko, Baktygul Makhanbetova, D. Aitkulov, A. Badikova","doi":"10.3311/ppch.22114","DOIUrl":"https://doi.org/10.3311/ppch.22114","url":null,"abstract":"The article presents the results of thermodynamic prediction and electric smelting of Shalkiya sulfide zinc-lead-bearing ore in the presence of magnetite and coke. Using the HSC-6.0 software package, it was found that under equilibrium conditions in the presence of Fe3O4 and carbon, the reduction and formation of gaseous zinc from ZnS (according to ∆G° = 0) occurs at a temperature of 1205.7 °C, and the formation of ferroalloy at the interaction of the sulfide ore with magnetite and carbon begins at 1200 °C. About 58% of silicon is extracted into the ferroalloy at 1800–1900 °C; almost all zinc and 83–88% of lead turns into a gaseous state. Electric smelting of the sulfide ore in the presence of magnetite concentrate and coke makes it possible to obtain the FS45 grade ferrosilicon (42–43% of Si); the silicon extraction degree was 84–88%. At the same time, 97.3% of lead and 99.2% of zinc are extracted into the sublimates. The developed method for processing zinc sulfide ores allows us to increase the degree of raw materials' comprehensive use due to the extraction of not only zinc and lead, but also silicon. The technology can be used to process raw materials containing zinc, lead and silica, such as zinc ore concentration tailings.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139957902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tam Thi Bang Dao, Loan Thi Thu Ha, Nhien Hon Le, Do Trung Nguyen, Truong Huu Nguyen, C. Ha-Thuc
This study aimed to modify montmorillonite (MMT) with titanium dioxide (TiO2) by wet stirring method combined with ultrasonic to form MMT/TiO2 nanocomposite and used as a photocatalyst in the removal of organic dye rhodamine B (RhB). The characteristics of the synthesized samples were analyzed by methods such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). The degradation of RhB was carried out for 210 min under UVC irradiation, and the decolorization efficiency of RhB was evaluated by UV-vis spectroscopy. The results show that the TiO2 anatase nanoparticles are randomly distributed on the surface or the space between the MMT sheets to form a house-of-card structure. After 210 min of exposure under a UVC light source, the decolorization efficiency reached 91.5% for the solution with pH = 6.8, photocatalyst content 0.1 g/L, initial concentration RhB 10 mg/L, and UVC power 15 W. Liquid chromatography–mass spectrometry (LCMS) identified the degradation intermediates that MMT/TiO2 successfully cleaved the chromophore structure and formed more minor broken-ring by-products. The influence of operating parameters on RhB removal efficiency, including solution pH, photocatalyst content, initial dye concentration, inorganic, and organic scavengers, was studied. In addition, the kinetic modeling study shows that the RhB photodegradation reaction is consistent with the Langmuir-Hinshelwood first-order kinetic model.
{"title":"Characterization and the Effect of Different Parameters on Photocatalytic Activity of Montmorillonite/TiO2 Nanocomposite under UVC Irradiation","authors":"Tam Thi Bang Dao, Loan Thi Thu Ha, Nhien Hon Le, Do Trung Nguyen, Truong Huu Nguyen, C. Ha-Thuc","doi":"10.3311/ppch.22065","DOIUrl":"https://doi.org/10.3311/ppch.22065","url":null,"abstract":"This study aimed to modify montmorillonite (MMT) with titanium dioxide (TiO2) by wet stirring method combined with ultrasonic to form MMT/TiO2 nanocomposite and used as a photocatalyst in the removal of organic dye rhodamine B (RhB). The characteristics of the synthesized samples were analyzed by methods such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). The degradation of RhB was carried out for 210 min under UVC irradiation, and the decolorization efficiency of RhB was evaluated by UV-vis spectroscopy. The results show that the TiO2 anatase nanoparticles are randomly distributed on the surface or the space between the MMT sheets to form a house-of-card structure. After 210 min of exposure under a UVC light source, the decolorization efficiency reached 91.5% for the solution with pH = 6.8, photocatalyst content 0.1 g/L, initial concentration RhB 10 mg/L, and UVC power 15 W. Liquid chromatography–mass spectrometry (LCMS) identified the degradation intermediates that MMT/TiO2 successfully cleaved the chromophore structure and formed more minor broken-ring by-products. The influence of operating parameters on RhB removal efficiency, including solution pH, photocatalyst content, initial dye concentration, inorganic, and organic scavengers, was studied. In addition, the kinetic modeling study shows that the RhB photodegradation reaction is consistent with the Langmuir-Hinshelwood first-order kinetic model.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140447127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erzsébet Varga, Noémi Birtalan, Abdulnabi Abushita, Ibolya Fülöp
Our phytochemical investigation defined the polyphenol, anthocyanin and flavonoid content from methanolic, ethanolic 50% and watery extracts from fresh pomegranate juice and seeds with a spectrophotometric method. The antioxidant capacity was defined with the ABTS and DPPH methods. We determined the polyphenols with the Folin-Ciocalteu method, the anthocyanins with the method in Hungarian Pharmacopoeia VIIIth edition at Myrtilli fructus monography and the flavonoids with a modified method of the Romanian Pharmacopeia Xth edition Cynarae folium monography. We expressed the concentration of polyphenols in gallic acids (GA). The values indicated the following: in fruit juice, 47.57 μg GA/ml, in methanol seed extract 7 μg GA/g, the ethanol 50% and in watery seed extracts 8 μg GA/g. The definition of flavonoids indicated the following values expressed in quercetin (QE): in fruit juice 706 μg QE/ml, in methanol seed extract 416 μg QE/g, in ethanol 50% seed extract 46 μg QE/g and in watery seed extract 57 μg QE/g. The anthocyans from juice 3.95 mg/100 ml and seed 6.47 mg/100 g expressed in cyanidin-3-0-glycoside. We determined the following values with the ABTS method: the antioxidant capacity of juice is 25.40 μg/ml, in methanol seed extract 2.87 μg/ml, in ethanol seed extract 2.52 μg/ml, in watery 9.15 μg/ml. With the DPPH method, we obtained the following values: from juice 54.2 μg/ml, from methanolic extract 14.7 μg/ml, from ethanolic extract 10.58 μg/ml and watery extract 18.22 μg/ml. The received data shows the importance of pomegranate, which can be a new phytotherapeutic potential resource.
{"title":"The Effects of Different Solvents on Phenolic, Flavonoid, Anthocyanin Contents and Free Radical Scavenging Activity on Pomegranate Juice and Seeds","authors":"Erzsébet Varga, Noémi Birtalan, Abdulnabi Abushita, Ibolya Fülöp","doi":"10.3311/ppch.21901","DOIUrl":"https://doi.org/10.3311/ppch.21901","url":null,"abstract":"Our phytochemical investigation defined the polyphenol, anthocyanin and flavonoid content from methanolic, ethanolic 50% and watery extracts from fresh pomegranate juice and seeds with a spectrophotometric method. The antioxidant capacity was defined with the ABTS and DPPH methods. We determined the polyphenols with the Folin-Ciocalteu method, the anthocyanins with the method in Hungarian Pharmacopoeia VIIIth edition at Myrtilli fructus monography and the flavonoids with a modified method of the Romanian Pharmacopeia Xth edition Cynarae folium monography. We expressed the concentration of polyphenols in gallic acids (GA). The values indicated the following: in fruit juice, 47.57 μg GA/ml, in methanol seed extract 7 μg GA/g, the ethanol 50% and in watery seed extracts 8 μg GA/g. The definition of flavonoids indicated the following values expressed in quercetin (QE): in fruit juice 706 μg QE/ml, in methanol seed extract 416 μg QE/g, in ethanol 50% seed extract 46 μg QE/g and in watery seed extract 57 μg QE/g. The anthocyans from juice 3.95 mg/100 ml and seed 6.47 mg/100 g expressed in cyanidin-3-0-glycoside. We determined the following values with the ABTS method: the antioxidant capacity of juice is 25.40 μg/ml, in methanol seed extract 2.87 μg/ml, in ethanol seed extract 2.52 μg/ml, in watery 9.15 μg/ml. With the DPPH method, we obtained the following values: from juice 54.2 μg/ml, from methanolic extract 14.7 μg/ml, from ethanolic extract 10.58 μg/ml and watery extract 18.22 μg/ml. The received data shows the importance of pomegranate, which can be a new phytotherapeutic potential resource.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139804774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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