Pub Date : 2022-01-01DOI: 10.2298/hemind210526003f
P. Felix, Velavan Rajagopal, Kannan Kumaresan
Low thermal conductivity of organic phase change materials (PCMs) for thermal energy storage systems induces the necessity to apply suitable heat transfer enhancement techniques for these materials. The purpose of this study was to improve thermal conductivity of a PCM erythritol by using sodium chloride as an additive, such that the material can be applied for steam cooking systems when integrated with solar parabolic trough collectors. In this study, erythritol-NaCl composites were synthesized by using the melting method, and the key physicochemical properties of the composites were estimated by using differential scanning calorimetry (DSC) coupled with thermo-gravimetric analysis (TGA). The observations indicate that there has been a significant improvement in the thermal conductivity of erythritol supplemented with NaCl. Further, thermal behaviour of the material indicates that it is suitable for steam cooking applications. Furthermore, mathematical models based on the experimental observations can be potentially utilized for further studies of erythritol-NaCl composites.
{"title":"Differential scanning calorimetry-based investigations of erythritol - sodium chloride phase change composites for thermal energy storage","authors":"P. Felix, Velavan Rajagopal, Kannan Kumaresan","doi":"10.2298/hemind210526003f","DOIUrl":"https://doi.org/10.2298/hemind210526003f","url":null,"abstract":"Low thermal conductivity of organic phase change materials (PCMs) for thermal energy storage systems induces the necessity to apply suitable heat transfer enhancement techniques for these materials. The purpose of this study was to improve thermal conductivity of a PCM erythritol by using sodium chloride as an additive, such that the material can be applied for steam cooking systems when integrated with solar parabolic trough collectors. In this study, erythritol-NaCl composites were synthesized by using the melting method, and the key physicochemical properties of the composites were estimated by using differential scanning calorimetry (DSC) coupled with thermo-gravimetric analysis (TGA). The observations indicate that there has been a significant improvement in the thermal conductivity of erythritol supplemented with NaCl. Further, thermal behaviour of the material indicates that it is suitable for steam cooking applications. Furthermore, mathematical models based on the experimental observations can be potentially utilized for further studies of erythritol-NaCl composites.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79209893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220214015s
M. Saldaña, E. Salinas-Rodríguez, Jonathan Castillo, F. Peña-Graf, Francisca Roldán
In multivariate analysis, a predictive model is a mathematical/statistical model that relates a set of independent variables to dependent or response variable(s). This work presents a descriptive model that explains copper recovery from secondary sulfide minerals (chalcocite) taking into account the effects of time, heap height, superficial velocity of leaching flow, chloride concentration, particle size, porosity, and effective diffusivity of the solute within particle pores. Copper recovery is then modelled by a system of first-order differential equations. The results indicated that the heap height and superficial velocity of leaching flow are the most critical independent variables while the others are less influential under operational conditions applied. In the present study representative adjustment parameters are obtained, so that the model could be used to explore copper recovery in chloride media as a part of the extended value chain of the copper sulfides processing.
{"title":"Development of an analytical model for copper heap leaching from secondary sulfides in chloride media in an industrial environment","authors":"M. Saldaña, E. Salinas-Rodríguez, Jonathan Castillo, F. Peña-Graf, Francisca Roldán","doi":"10.2298/hemind220214015s","DOIUrl":"https://doi.org/10.2298/hemind220214015s","url":null,"abstract":"In multivariate analysis, a predictive model is a mathematical/statistical model that relates a set of independent variables to dependent or response variable(s). This work presents a descriptive model that explains copper recovery from secondary sulfide minerals (chalcocite) taking into account the effects of time, heap height, superficial velocity of leaching flow, chloride concentration, particle size, porosity, and effective diffusivity of the solute within particle pores. Copper recovery is then modelled by a system of first-order differential equations. The results indicated that the heap height and superficial velocity of leaching flow are the most critical independent variables while the others are less influential under operational conditions applied. In the present study representative adjustment parameters are obtained, so that the model could be used to explore copper recovery in chloride media as a part of the extended value chain of the copper sulfides processing.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86406633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220609018t
V. Trifunovic, Snežana Milić, L. Avramović, R. Jonovic, V. Gardić, Stefan Djordjievski, S. Dimitrijević
Dust from an electric arc furnace is formed as the main by-product of the steel production process from the secondary iron-based raw materials. This dust has significant contents of Zn and Fe, as well as Pb, Cd, Ca, Mg, Cr, Mn, Si, Ni, Cu, F, Cl and other elements and is considered hazardous industrial solid waste since it contains heavy metals. In order to protect the environment and public health from the negative impact of this type of hazardous waste, it is necessary, even mandatory, to carry out its treatment in accordance with the legislation of the country where it is located. Before applying any treatment of the electric arc furnace (EAF) dust, it is necessary to perform its detailed characterization. In this paper, the following characterization of EAF dust originating in the Republic of Serbia was performed: physical-mechanical and chemical characterization, determination of granulometric composition, and mineralogical characterization. Also, the EAF dust impact on the environment and human health was assessed (Leachability and Toxicity Characteristic Leaching Procedure (TCLP) tests). The results have shown that the Zn content is in the range 32 to 35 % and that the main mineralogical phases of the dust are zincite, franklinite, magnetite, and magnesioferrite. Granulometric analysis has shown that 80 % of the sample consists of particles less than 26 ?m in size. According to the leaching test results, the EAF dust is characterized as a hazardous waste due to the increased chloride content, while the TCLP test indicated dust toxicity due to the increased contents of Zn, Cd, and Pb.
{"title":"Investigation of hazardous waste a case study of electric arc furnace dust characterization","authors":"V. Trifunovic, Snežana Milić, L. Avramović, R. Jonovic, V. Gardić, Stefan Djordjievski, S. Dimitrijević","doi":"10.2298/hemind220609018t","DOIUrl":"https://doi.org/10.2298/hemind220609018t","url":null,"abstract":"Dust from an electric arc furnace is formed as the main by-product of the steel production process from the secondary iron-based raw materials. This dust has significant contents of Zn and Fe, as well as Pb, Cd, Ca, Mg, Cr, Mn, Si, Ni, Cu, F, Cl and other elements and is considered hazardous industrial solid waste since it contains heavy metals. In order to protect the environment and public health from the negative impact of this type of hazardous waste, it is necessary, even mandatory, to carry out its treatment in accordance with the legislation of the country where it is located. Before applying any treatment of the electric arc furnace (EAF) dust, it is necessary to perform its detailed characterization. In this paper, the following characterization of EAF dust originating in the Republic of Serbia was performed: physical-mechanical and chemical characterization, determination of granulometric composition, and mineralogical characterization. Also, the EAF dust impact on the environment and human health was assessed (Leachability and Toxicity Characteristic Leaching Procedure (TCLP) tests). The results have shown that the Zn content is in the range 32 to 35 % and that the main mineralogical phases of the dust are zincite, franklinite, magnetite, and magnesioferrite. Granulometric analysis has shown that 80 % of the sample consists of particles less than 26 ?m in size. According to the leaching test results, the EAF dust is characterized as a hazardous waste due to the increased chloride content, while the TCLP test indicated dust toxicity due to the increased contents of Zn, Cd, and Pb.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"87 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89870451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind211110010b
S. Bošković, A. Karac, S. Vrhovac, A. Belic, B. Bugarski
A perfect dielectric model was incorporated into the OpenFOAM? software and used for investigation and, possibly, improvements of electrohydrodynamic calculations. Two different sets of numerical simulations were analyzed, in which two different fluids were present. The first set was one-dimensional, while in the second, a drop of one fluid was surrounded by the other fluid. It is shown that oscillations and possible artificial generation of a curl of the electric field strength can be observed at applying certain expressions or calculation strategies, which can be thus abandoned. Usage of dynamic meshes, at least those present in the used software, and of limiters for the gradient of the electric field strength can lead to large numerical errors. It is also shown that usage of certain cell face values could improve the results. An electric Courant number was derived by dimensional analysis, and it could be suggested for future calculations. Conclusions made in this paper are expected to be transferable to other more complicated models.
{"title":"Investigation of electrohydrodynamic calculations","authors":"S. Bošković, A. Karac, S. Vrhovac, A. Belic, B. Bugarski","doi":"10.2298/hemind211110010b","DOIUrl":"https://doi.org/10.2298/hemind211110010b","url":null,"abstract":"A perfect dielectric model was incorporated into the OpenFOAM? software and used for investigation and, possibly, improvements of electrohydrodynamic calculations. Two different sets of numerical simulations were analyzed, in which two different fluids were present. The first set was one-dimensional, while in the second, a drop of one fluid was surrounded by the other fluid. It is shown that oscillations and possible artificial generation of a curl of the electric field strength can be observed at applying certain expressions or calculation strategies, which can be thus abandoned. Usage of dynamic meshes, at least those present in the used software, and of limiters for the gradient of the electric field strength can lead to large numerical errors. It is also shown that usage of certain cell face values could improve the results. An electric Courant number was derived by dimensional analysis, and it could be suggested for future calculations. Conclusions made in this paper are expected to be transferable to other more complicated models.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80599417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind211224016k
M. Hadnadjev-Kostic, Dunja Sokolovic, S. Sokolovic, T. Laminger, Arpad Kiralj
In this study, fibre morphology of waste materials and its effect on packing phenomena and bed properties were investigated. Nine waste materials were used in bed coalescers. By scanning electron microscopy, it was determined that surfaces of all fibres were smooth, while cross-section differed from circular, rectangular to irregular. The fibres with circular cross-sections had diameters in the range of 12?0.8 to 40?4 ?m, while the fibres of polypropylene bags and sponges appeared as strips with the widths of 452?11 and 1001?14 ?m, respectively. It was also noticed that polyurethane fibres were connected forming a sponge-like structure, while polyethylene terephthalate fibres were interconnected at some points. In this work, experimental dependence of bed porosity on bed permeability was established for all investigated materials, which allows forming a fibre bed with desired permeability. The exception was the bed formed of fibres of polypropylene bags, which had the largest dimensions and yielded a different porosity-permeability dependence.
{"title":"The effect of fibre morphology on packing phenomena and bed properties in coalescers","authors":"M. Hadnadjev-Kostic, Dunja Sokolovic, S. Sokolovic, T. Laminger, Arpad Kiralj","doi":"10.2298/hemind211224016k","DOIUrl":"https://doi.org/10.2298/hemind211224016k","url":null,"abstract":"In this study, fibre morphology of waste materials and its effect on packing phenomena and bed properties were investigated. Nine waste materials were used in bed coalescers. By scanning electron microscopy, it was determined that surfaces of all fibres were smooth, while cross-section differed from circular, rectangular to irregular. The fibres with circular cross-sections had diameters in the range of 12?0.8 to 40?4 ?m, while the fibres of polypropylene bags and sponges appeared as strips with the widths of 452?11 and 1001?14 ?m, respectively. It was also noticed that polyurethane fibres were connected forming a sponge-like structure, while polyethylene terephthalate fibres were interconnected at some points. In this work, experimental dependence of bed porosity on bed permeability was established for all investigated materials, which allows forming a fibre bed with desired permeability. The exception was the bed formed of fibres of polypropylene bags, which had the largest dimensions and yielded a different porosity-permeability dependence.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91096732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220201002d
A. Dekanski
Although electrochemical systems for energy conversion and storage at first glance have excellent properties, both in terms of sustainability, renewable and environment safety, as well as functionality and application in various fields, especially in mobile devices, advance and application of these systems face many challenges and increasingly significant dilemmas.
{"title":"Challenges and doubts of electrochemical energy conversion and storage","authors":"A. Dekanski","doi":"10.2298/hemind220201002d","DOIUrl":"https://doi.org/10.2298/hemind220201002d","url":null,"abstract":"Although electrochemical systems for energy conversion and storage at first glance have excellent properties, both in terms of sustainability, renewable and environment safety, as well as functionality and application in various fields, especially in mobile devices, advance and application of these systems face many challenges and increasingly significant dilemmas.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77747630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220113012m
B. Malinovic, A. Borkovic, T. Djuričić
In this paper, the corrosion test of copper in hydrocracked base oil HC-6 was performed in the presence of an additive for extremely high pressures (EP additive) in different concentrations. EP additives are used to reduce wear in industrial applications, under high load conditions. Since most of these additives are sulfur-based, whose compounds can be corrosive at high temperatures, their use leads to corrosion of some materials. To prevent corrosion in the base oil with the EP additive, three commercial corrosion inhibitors are added. By chemical composition, the inhibitor RC 8210 is a derivate of dimercaptothia-diazole, RC 4220 is a synthetic neutral calcium sulfonate, and IRGAMET 39 is a derivative of tolutriazole. Efficiency of the inhibitors was monitored by standard test methods for corrosiveness to copper arising from petroleum products by the copper strip test (ASTM D-130) and the gravimetric method, while oxidation stability of the base oil was monitored by peroxide number determination. Oxidation was performed at 100?1?C for 3 and 24 h. Results of these studies have shown that IRGAMET 39 is the most effective inhibitor in the presence of the EP additive at both examined oxidation times.
{"title":"Copper strip corrosion testing in hydrocracked base oil in the presence of different inhibitors","authors":"B. Malinovic, A. Borkovic, T. Djuričić","doi":"10.2298/hemind220113012m","DOIUrl":"https://doi.org/10.2298/hemind220113012m","url":null,"abstract":"In this paper, the corrosion test of copper in hydrocracked base oil HC-6 was performed in the presence of an additive for extremely high pressures (EP additive) in different concentrations. EP additives are used to reduce wear in industrial applications, under high load conditions. Since most of these additives are sulfur-based, whose compounds can be corrosive at high temperatures, their use leads to corrosion of some materials. To prevent corrosion in the base oil with the EP additive, three commercial corrosion inhibitors are added. By chemical composition, the inhibitor RC 8210 is a derivate of dimercaptothia-diazole, RC 4220 is a synthetic neutral calcium sulfonate, and IRGAMET 39 is a derivative of tolutriazole. Efficiency of the inhibitors was monitored by standard test methods for corrosiveness to copper arising from petroleum products by the copper strip test (ASTM D-130) and the gravimetric method, while oxidation stability of the base oil was monitored by peroxide number determination. Oxidation was performed at 100?1?C for 3 and 24 h. Results of these studies have shown that IRGAMET 39 is the most effective inhibitor in the presence of the EP additive at both examined oxidation times.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88822886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220105013m
Saša Mićin, B. Malinovic, T. Djuričić
The aim of this study is the development and characterization of a carbon-based electrochemical sensor, modified with TiO2 nanoparticles for potential application in electroanalytical techniques. The influence of binder and modifier contents on morphological, physicochemical and electrochemical characteristics of the electrode material was investigated in order to determine the optimal ratio of the carbon material/binder/modifier. Carbon pastes were prepared from mixtures containing graphite powder, TiO2 nanoparticles and liquid hydrocarbons. Scanning electron microscopy showed that the electrode material becomes more compact with the addition and the increase in the binder material content, while increasing the proportion of TiO2 nanoparticles did not have any significant effect on the material morphology showing fairly homogeneous nanoparticle distribution in the graphite electrode material. The test results indicate that the modified carbon paste with 40 vol.% paraffin oil (PO) and 6-8 wt.% TiO2 nanoparticles is characterized by the lowest value of specific resistance. By applying cyclic voltammetry, the most pronounced degree of reversibility was obtained in relation to the standard reversible redox system ([Fe (CN)]-3/-4) for the electrode material with 30-40 vol.% PO and 8-10 wt.% TiO2 nanoparticles. Characterization of the electrode material based on carbon modified with TiO2 nanoparticles indicated that the optimal composition contains 40 vol.% PO and 6-8 wt.% TiO2 nanoparticles, which is important for application in electroanalytical techniques.
{"title":"Development and characterization of electrochemical sensors based on carbon modified with TiO2 nanoparticles","authors":"Saša Mićin, B. Malinovic, T. Djuričić","doi":"10.2298/hemind220105013m","DOIUrl":"https://doi.org/10.2298/hemind220105013m","url":null,"abstract":"The aim of this study is the development and characterization of a carbon-based electrochemical sensor, modified with TiO2 nanoparticles for potential application in electroanalytical techniques. The influence of binder and modifier contents on morphological, physicochemical and electrochemical characteristics of the electrode material was investigated in order to determine the optimal ratio of the carbon material/binder/modifier. Carbon pastes were prepared from mixtures containing graphite powder, TiO2 nanoparticles and liquid hydrocarbons. Scanning electron microscopy showed that the electrode material becomes more compact with the addition and the increase in the binder material content, while increasing the proportion of TiO2 nanoparticles did not have any significant effect on the material morphology showing fairly homogeneous nanoparticle distribution in the graphite electrode material. The test results indicate that the modified carbon paste with 40 vol.% paraffin oil (PO) and 6-8 wt.% TiO2 nanoparticles is characterized by the lowest value of specific resistance. By applying cyclic voltammetry, the most pronounced degree of reversibility was obtained in relation to the standard reversible redox system ([Fe (CN)]-3/-4) for the electrode material with 30-40 vol.% PO and 8-10 wt.% TiO2 nanoparticles. Characterization of the electrode material based on carbon modified with TiO2 nanoparticles indicated that the optimal composition contains 40 vol.% PO and 6-8 wt.% TiO2 nanoparticles, which is important for application in electroanalytical techniques.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80450261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220114008p
Dragana Prokić-Vidojević, Sandra Glisic, Radojica Pešić, A. Orlović
Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method and supercritical drying in excess solvent and investigated in the reaction of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained with and without the use of mesitylene in the synthesis step, have shown increased conversions of up to 70 % in the desulphurization of 4,6-DMDBT, when compared to conventional Co/Mo hydroprocessing catalysts. This observation is of importance for conversion of highly refractory 4,6-DMDBT and hydroprocessing to produce ultra-low sulphur diesel fuels, ULSD. In order to quantify the extent of desulphurisation, which proceeds via a hydrogenation route, conversions of DBT and 4,6-DMDBT along with evolution of reaction products characteristic for the direct desulphurisation route and the hydrogenation route were monitored by using a gas chromatography?mass spectrometry (GC-MS) analytical technique. The reaction was performed at 630 K and 6 MPa in a batch catalytic reactor. The experimental results were used in the Hougen-Watson kinetic model describing DBT and 4,6-DMDBT desulphurisation on ? and ? active sites. Kinetic parameters of this complex catalytic kinetics were determined by using a Genetic Algorithm method and minimum deviation function. Values of calculated kinetic parameters and values of the ratio of 3-methylcyclohexyltoluene (MCHT and dimethyl biphenyl (DMBPH) expressed as the MCHT/(MCHT+DMBPH) ratio ranging between 0.66 and 0.94, have confirmed that the hydrogenation route is the dominant route for desulphurisation of 4,6-DMDBT.
{"title":"Desulphurisation of dibenzothiophene and 4,6–dimethyl dibenzothiophene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: kinetic parameters estimation and modelling","authors":"Dragana Prokić-Vidojević, Sandra Glisic, Radojica Pešić, A. Orlović","doi":"10.2298/hemind220114008p","DOIUrl":"https://doi.org/10.2298/hemind220114008p","url":null,"abstract":"Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method and supercritical drying in excess solvent and investigated in the reaction of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained with and without the use of mesitylene in the synthesis step, have shown increased conversions of up to 70 % in the desulphurization of 4,6-DMDBT, when compared to conventional Co/Mo hydroprocessing catalysts. This observation is of importance for conversion of highly refractory 4,6-DMDBT and hydroprocessing to produce ultra-low sulphur diesel fuels, ULSD. In order to quantify the extent of desulphurisation, which proceeds via a hydrogenation route, conversions of DBT and 4,6-DMDBT along with evolution of reaction products characteristic for the direct desulphurisation route and the hydrogenation route were monitored by using a gas chromatography?mass spectrometry (GC-MS) analytical technique. The reaction was performed at 630 K and 6 MPa in a batch catalytic reactor. The experimental results were used in the Hougen-Watson kinetic model describing DBT and 4,6-DMDBT desulphurisation on ? and ? active sites. Kinetic parameters of this complex catalytic kinetics were determined by using a Genetic Algorithm method and minimum deviation function. Values of calculated kinetic parameters and values of the ratio of 3-methylcyclohexyltoluene (MCHT and dimethyl biphenyl (DMBPH) expressed as the MCHT/(MCHT+DMBPH) ratio ranging between 0.66 and 0.94, have confirmed that the hydrogenation route is the dominant route for desulphurisation of 4,6-DMDBT.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74699997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind210914001p
M. Popović, N. Vukić, Milanka Djiporović-Momčilović, J. Budinski-Simendic, Ivana Gavrilović-Grmuša, J. Popović, I. Ristić
Addition of poly(diallyldimethylammonium chloride) (PDDA) on the performances of urea-formaldehyde (UF) adhesives was evaluated in this work. Three types of UF adhesives were prepared, one without PDDA addition, and two types with PDDA addition of 1 and 3 wt.% per dry UF adhesive mass. These UF adhesive systems were used for producing experimental particleboard panels. The addition of PDDA decreased the thickness swelling of the panel samples, while the internal bond of the particleboards increased significantly only at the highest PDDA content (3 wt.%). Differential scanning calorimetry (DSC) was applied to address the influence of PDDA on UF adhesive curing kinetics. DSC scans were performed in non-isothermal regimes using different heating rates (5, 10, and 20 ?C?min?1). The activation energy (Ea) of the curing reaction showed slightly lower values for the UF adhesive systems containing PDDA. However, the peak temperatures and enthalpy of reaction did not change significantly. The Kissinger-Akahira-Sunose and Friedman iso-conversional methods were applied to investigate the effects of PDDA addition on the UF adhesive curing process.
{"title":"Effects of poly(diallyldimethylammonium chloride) addition on the curing kinetics of urea-formaldehyde adhesives for particleboards","authors":"M. Popović, N. Vukić, Milanka Djiporović-Momčilović, J. Budinski-Simendic, Ivana Gavrilović-Grmuša, J. Popović, I. Ristić","doi":"10.2298/hemind210914001p","DOIUrl":"https://doi.org/10.2298/hemind210914001p","url":null,"abstract":"Addition of poly(diallyldimethylammonium chloride) (PDDA) on the performances of urea-formaldehyde (UF) adhesives was evaluated in this work. Three types of UF adhesives were prepared, one without PDDA addition, and two types with PDDA addition of 1 and 3 wt.% per dry UF adhesive mass. These UF adhesive systems were used for producing experimental particleboard panels. The addition of PDDA decreased the thickness swelling of the panel samples, while the internal bond of the particleboards increased significantly only at the highest PDDA content (3 wt.%). Differential scanning calorimetry (DSC) was applied to address the influence of PDDA on UF adhesive curing kinetics. DSC scans were performed in non-isothermal regimes using different heating rates (5, 10, and 20 ?C?min?1). The activation energy (Ea) of the curing reaction showed slightly lower values for the UF adhesive systems containing PDDA. However, the peak temperatures and enthalpy of reaction did not change significantly. The Kissinger-Akahira-Sunose and Friedman iso-conversional methods were applied to investigate the effects of PDDA addition on the UF adhesive curing process.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86370171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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