J. C. S. Aguilar, Chosel P. Lawagon, James Mark M. Gallawan, Jeralyn G. Cabotaje
A chemically exfoliated graphene, functionalized with hydroxide, was prepared and used as an adsorbent for the removal of amoxicillin from aqueous solutions. This nanocomposite was recovered from chemically exfoliated graphite rods present in spent zinc-carbon batteries. The graphene-OH was determined to have a sheet-like morphology with high surface area (As,BET = 181 m2 g-1) . Its adsorption characteristics were observed at different adsorption time, initial amoxicillin concentrations, and adsorbent dosage to establish the kinetics, isotherm, and optimal adsorption conditions. Pseudo-first-order and pseudo-second-order models were used to study the kinetics, while Freundlich and Langmuir models were used to study the adsorption isotherms. Results showed that amoxicillin adsorption fitted with Langmuir isotherm with higher correlation than the Freundlich isotherm and followed the pseudo-second-order rate model. The removal efficiency increased as the adsorbent dosage was also increased. Similarly, increasing the adsorbent dosage from 1 g/L to 20 g/L, the adsorption capacity decreased from 36 mg/g to 4 mg/g. For recyclability, the adsorptivity of graphene – OH was shown to be slightly decreasing over the 5-cycles (99.75 % to 95.37 %). Based on the results, hydroxyl-functionalized graphene demonstrated high industrial potential for amoxicillin wastewater treatment.
{"title":"Hydroxyl-functionalized Graphene from Spent Batteries as Efficient Adsorbent for Amoxicillin","authors":"J. C. S. Aguilar, Chosel P. Lawagon, James Mark M. Gallawan, Jeralyn G. Cabotaje","doi":"10.3303/CET2186056","DOIUrl":"https://doi.org/10.3303/CET2186056","url":null,"abstract":"A chemically exfoliated graphene, functionalized with hydroxide, was prepared and used as an adsorbent for the removal of amoxicillin from aqueous solutions. This nanocomposite was recovered from chemically exfoliated graphite rods present in spent zinc-carbon batteries. The graphene-OH was determined to have a sheet-like morphology with high surface area (As,BET = 181 m2 g-1) . Its adsorption characteristics were observed at different adsorption time, initial amoxicillin concentrations, and adsorbent dosage to establish the kinetics, isotherm, and optimal adsorption conditions. Pseudo-first-order and pseudo-second-order models were used to study the kinetics, while Freundlich and Langmuir models were used to study the adsorption isotherms. Results showed that amoxicillin adsorption fitted with Langmuir isotherm with higher correlation than the Freundlich isotherm and followed the pseudo-second-order rate model. The removal efficiency increased as the adsorbent dosage was also increased. Similarly, increasing the adsorbent dosage from 1 g/L to 20 g/L, the adsorption capacity decreased from 36 mg/g to 4 mg/g. For recyclability, the adsorptivity of graphene – OH was shown to be slightly decreasing over the 5-cycles (99.75 % to 95.37 %). Based on the results, hydroxyl-functionalized graphene demonstrated high industrial potential for amoxicillin wastewater treatment.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"43 1","pages":"331-336"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73791594","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}
M. Bugge, N. Haugen, Tian Li, Jingyuan Zhang, Ø. Skreiberg
The overall objective of the modelling work is to develop CFD aided design tools for optimum grate fired biomass-to-energy (BtE) and waste-to-energy (WtE) plants. An important part of this work has been to develop a flexible detailed transient fuel-bed model taking into account drying, pyrolysis, and char combustion/gasification, for different fuels (i.e. MSW fractions, and softwood and hardwood, including their bark and GROT (branches and treetops)). The fuel-bed model has been implemented in a CFD tool, ANSYS Fluent.The fuel bed consists of a large number of thermally thick particles. In this work, the fuel bed model is made up of representative particles, and the motion of every representative particle is individually tracked (Lagrangian tracking through Fluent's Discrete Phase Model). Thermochemical degradation and conversion of the representative particles are calculated by a thermally thick single particle model (SPM), with boundary conditions obtained from the solutions of the gas phase equations. The SPM model then provides sources to the gas-phase equations. In the modelling approach, the gas phase is solved using the Reynolds Averaged Navier-Stokes (RANS) equations. Under the given conditions, the gas flow in the bed is laminar.The developed model was validated against detailed experimental results from pyrolysis of dried spruce wood pellets in an electrically heated fixed bed reactor, with varying final pyrolysis temperature (600-800°C), heating rate (5-20 K/min) and purge gas composition (none, 100% N2 and 90/10% N2/O2). The experimental results included transient temperature measurements in different locations in the reactor and inside the pellets bed throughout the thermal decomposition process, as well as gas measurements of permanent gases.Through the CFD simulations, the main experimental trends could be reproduced, verifying the validity of the detailed modelling approach. This work is a step towards detailed modelling of biomass grate combustion units, which is required to improve their environmental and energetic performance.
{"title":"Validation of a Numerical Approach for Simulation of the Thermal Decomposition Behaviour of Biomass in Grate Combustion Plants","authors":"M. Bugge, N. Haugen, Tian Li, Jingyuan Zhang, Ø. Skreiberg","doi":"10.3303/CET2186013","DOIUrl":"https://doi.org/10.3303/CET2186013","url":null,"abstract":"The overall objective of the modelling work is to develop CFD aided design tools for optimum grate fired biomass-to-energy (BtE) and waste-to-energy (WtE) plants. An important part of this work has been to develop a flexible detailed transient fuel-bed model taking into account drying, pyrolysis, and char combustion/gasification, for different fuels (i.e. MSW fractions, and softwood and hardwood, including their bark and GROT (branches and treetops)). The fuel-bed model has been implemented in a CFD tool, ANSYS Fluent.The fuel bed consists of a large number of thermally thick particles. In this work, the fuel bed model is made up of representative particles, and the motion of every representative particle is individually tracked (Lagrangian tracking through Fluent's Discrete Phase Model). Thermochemical degradation and conversion of the representative particles are calculated by a thermally thick single particle model (SPM), with boundary conditions obtained from the solutions of the gas phase equations. The SPM model then provides sources to the gas-phase equations. In the modelling approach, the gas phase is solved using the Reynolds Averaged Navier-Stokes (RANS) equations. Under the given conditions, the gas flow in the bed is laminar.The developed model was validated against detailed experimental results from pyrolysis of dried spruce wood pellets in an electrically heated fixed bed reactor, with varying final pyrolysis temperature (600-800°C), heating rate (5-20 K/min) and purge gas composition (none, 100% N2 and 90/10% N2/O2). The experimental results included transient temperature measurements in different locations in the reactor and inside the pellets bed throughout the thermal decomposition process, as well as gas measurements of permanent gases.Through the CFD simulations, the main experimental trends could be reproduced, verifying the validity of the detailed modelling approach. This work is a step towards detailed modelling of biomass grate combustion units, which is required to improve their environmental and energetic performance.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"65 1","pages":"73-78"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83763916","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}
C. Menale, Andrea Mariani, M. Pieve, R. Trinchieri, R. Bubbico
This work deals with the risk related to the flammability and toxicity of low Global Warming Potential (GWP) refrigerants used in heat pumps for residential applications. Some new generation refrigerants were analyzed assuming to make a drop-in for a typical 50 kW heat pump, suited for small multi-family buildings (4 ÷ 6 dwellings). The theoretical maximum Coefficient of Performance (COP) was calculated for the selected fluids, identifying the best performing one from an energy point of view. Subsequently, an analysis of some of the potentially more dangerous accident scenarios was performed, considering the outdoor/indoor release of gases. More in detail, two accident scenarios were analyzed, assuming a refrigerant leak from a hole in the pipeline downstream of the heat pump compressor: in one case the gas is released in an open environment with an ignition near the release point (jet fire), in the other case the release happens within a confined environment. In both cases, the conditions in which it is possible to operate safely were determined.
{"title":"Risk Assessment and Selection of Low Gwp Refrigerants for Heat Pumps in Residential Applications","authors":"C. Menale, Andrea Mariani, M. Pieve, R. Trinchieri, R. Bubbico","doi":"10.3303/CET2186042","DOIUrl":"https://doi.org/10.3303/CET2186042","url":null,"abstract":"This work deals with the risk related to the flammability and toxicity of low Global Warming Potential (GWP) refrigerants used in heat pumps for residential applications. Some new generation refrigerants were analyzed assuming to make a drop-in for a typical 50 kW heat pump, suited for small multi-family buildings (4 ÷ 6 dwellings). The theoretical maximum Coefficient of Performance (COP) was calculated for the selected fluids, identifying the best performing one from an energy point of view. Subsequently, an analysis of some of the potentially more dangerous accident scenarios was performed, considering the outdoor/indoor release of gases. More in detail, two accident scenarios were analyzed, assuming a refrigerant leak from a hole in the pipeline downstream of the heat pump compressor: in one case the gas is released in an open environment with an ignition near the release point (jet fire), in the other case the release happens within a confined environment. In both cases, the conditions in which it is possible to operate safely were determined.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"9 1","pages":"247-252"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84579222","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}
Andrea Maffini, Marco Morando, A. Saba, G. Bonvicini, B. Fabiano
Purpose of this paper is to draw a balance of a decade of resources and energy efficiency auditing activities and studies, carried out in Eastern Europe, Central Asia and Africa, aimed to support International Financial Institutions (IFIs) in improving their sustainability performances and in reducing the global environmental impact of their customer Companies. The auditing framework was designed as a step-by step sequence:Job Assignment from the Bank, based on specific Terms of Reference;Submission of a questionnaire, tailored to the particular agro-industrial sector (i.e., dairy, tomatoes processing, slaughterhouse, etc.);Multi-disciplinary team assessment of industrial facilities, by means of an on-site survey and meetings with the managers of the agro-industrial company for the discussion of relevant issues;Preparation of a draft report to be discussed with IFI and Company;Preparation of a final report including remarks from IFI and Company.The paper will present the results by developing proper sustainability and safety performance indicators, in terms of energy consumption and reduction of GHG emissions reduction, as well as control of water pollution and waste generation, and their safe disposal. In designing and performing the actual auditing process, a great attention was paid to the considerations for the global environment and safety implications, especially in selecting the technologies, not limiting the efforts to the usual CAPEX and OPEX reductions and to the local impact parameters. Conclusions are drawn regarding the practical possibility of incorporating audit results in terms of environmental sustainability into the overall decision-making process.
{"title":"A Decade International Experience Into Effective Resources and Energy Efficiency Auditing","authors":"Andrea Maffini, Marco Morando, A. Saba, G. Bonvicini, B. Fabiano","doi":"10.3303/CET2186128","DOIUrl":"https://doi.org/10.3303/CET2186128","url":null,"abstract":"Purpose of this paper is to draw a balance of a decade of resources and energy efficiency auditing activities and studies, carried out in Eastern Europe, Central Asia and Africa, aimed to support International Financial Institutions (IFIs) in improving their sustainability performances and in reducing the global environmental impact of their customer Companies. The auditing framework was designed as a step-by step sequence:Job Assignment from the Bank, based on specific Terms of Reference;Submission of a questionnaire, tailored to the particular agro-industrial sector (i.e., dairy, tomatoes processing, slaughterhouse, etc.);Multi-disciplinary team assessment of industrial facilities, by means of an on-site survey and meetings with the managers of the agro-industrial company for the discussion of relevant issues;Preparation of a draft report to be discussed with IFI and Company;Preparation of a final report including remarks from IFI and Company.The paper will present the results by developing proper sustainability and safety performance indicators, in terms of energy consumption and reduction of GHG emissions reduction, as well as control of water pollution and waste generation, and their safe disposal. In designing and performing the actual auditing process, a great attention was paid to the considerations for the global environment and safety implications, especially in selecting the technologies, not limiting the efforts to the usual CAPEX and OPEX reductions and to the local impact parameters. Conclusions are drawn regarding the practical possibility of incorporating audit results in terms of environmental sustainability into the overall decision-making process.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"39 1","pages":"763-768"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76662174","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}
Vyacheslav Dyudnev, V. Korotkii, S. Novgorodtsev, Stanislav Boldyryev, Alessandro Di Pretoro, Julia Bragina, M. Trusova, F. Manenti
In recent years, energy efficiency has been one of the topics of major concern from a worldwide perspective as clearly stated by the International Energy Agency (IEA,2021). The energy waste reduction not only improves the process performances from an economic perspective but reduces as well the equivalent CO2 emissions. This research work is the product of a collaboration between the SIBUR petrochemical company and the Tomsk and Milan Polytechnic Universities during the Process Operations Management program aiming at the training of the personnel and at the troubleshooting practical problems of the petrochemical industry.
{"title":"Energy Analysis and Process Simulation for the Energy Efficiency Improvement of Existing Chemical Plants","authors":"Vyacheslav Dyudnev, V. Korotkii, S. Novgorodtsev, Stanislav Boldyryev, Alessandro Di Pretoro, Julia Bragina, M. Trusova, F. Manenti","doi":"10.3303/CET2186120","DOIUrl":"https://doi.org/10.3303/CET2186120","url":null,"abstract":"In recent years, energy efficiency has been one of the topics of major concern from a worldwide perspective as clearly stated by the International Energy Agency (IEA,2021). The energy waste reduction not only improves the process performances from an economic perspective but reduces as well the equivalent CO2 emissions. This research work is the product of a collaboration between the SIBUR petrochemical company and the Tomsk and Milan Polytechnic Universities during the Process Operations Management program aiming at the training of the personnel and at the troubleshooting practical problems of the petrochemical industry.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"1 1","pages":"715-720"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77198229","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}
D. Bosch, Lukáš Rendl, Fabian Plangger, Angela Hofmann, Guenter Langergraber
As the use of medicine increases worldwide, more and more drugs are found in wastewaters. It is now known that wastewater is a main pathway to enter the environment. Even state-of-the-art WWTPs are not able to remove these organic micropollutants (OMPs), or only to a limited extent. Therefore, an additional treatment step can be required and activated powdered carbon (APC) could be a possible solution. In this work, phosphoric acid is used for chemical impregnation and further activation. Two reactor approaches were used, a standard tubular (TR) and a fluidized bed reactor (FBR). Reaction times (RT) vary between 0.5 and 2/1 h at 700 to 1000 °C. For comparison, various parameters were carried out, such as specific surface area (SSA), total carbon (TC), yield and pore size distribution. The new FBR achieved higher SSA (1354.19 m2g-1) and a better pore distribution while using less impregnation agent (IA), lower temperatures and a shorter RT.
{"title":"Chemical Activation of Biochar with H3PO4 - A Comparison between Two Reactor Types","authors":"D. Bosch, Lukáš Rendl, Fabian Plangger, Angela Hofmann, Guenter Langergraber","doi":"10.3303/CET2186001","DOIUrl":"https://doi.org/10.3303/CET2186001","url":null,"abstract":"As the use of medicine increases worldwide, more and more drugs are found in wastewaters. It is now known that wastewater is a main pathway to enter the environment. Even state-of-the-art WWTPs are not able to remove these organic micropollutants (OMPs), or only to a limited extent. Therefore, an additional treatment step can be required and activated powdered carbon (APC) could be a possible solution. In this work, phosphoric acid is used for chemical impregnation and further activation. Two reactor approaches were used, a standard tubular (TR) and a fluidized bed reactor (FBR). Reaction times (RT) vary between 0.5 and 2/1 h at 700 to 1000 °C. For comparison, various parameters were carried out, such as specific surface area (SSA), total carbon (TC), yield and pore size distribution. The new FBR achieved higher SSA (1354.19 m2g-1) and a better pore distribution while using less impregnation agent (IA), lower temperatures and a shorter RT.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"62 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85783193","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}
Nowadays one of the topics of greatest interest to the scientific community is the search for new eco-friendly technologies that allow the production of energy. In particular, one of the main players in this area is hydrogen. Several innovative processes are proposed in the literature for the production of hydrogen. One of these is the heterogeneous photocatalysis. Furthermore, it is also interesting to evaluate the source from which hydrogen is obtained. An interesting solution is glucose, one of the most familiar biomass, which can be used to produce hydrogen from a photocatalytic process. For this reason, in this work we propose the use of Ni as active phase supported on LaFeO3 photocatalyst for the renewable H2 production from glucose aqueous solution. Perovskite photocatalysts are quite encouraging materials for H2 production from aqueous solution owing to their stability in water. Low-cost nickel can be used to improve the performance of perovskites, modifing their surface and thus avoiding the use of expensive noble metal based cocatalysts. Specifically, the LaFeO3 catalyst was prepared by solution combustion synthesis using citric acid as organic fuel. A specific amount of Ni was deposited on LaFeO3 surface by chemical reduction method, using sodium borohydride (NaBH4) as a reducing agent. The prepared samples were characterized by different techniques, such as XRD and UV-Vis. The photocatalytic tests were carried out in a pyrex cylindrical reactor equipped with a N2 distributor device and irradiated by four UV lamps (emitting at 365 nm) positioned at the same distance from the external surface of the reactor (about 30 mm). The tests were realized with a solution volume equal to 80 ml, an initial concentration of glucose equal to 5550 µmol L-1 and a catalyst dosage equal to 1.5 g L-1. The experimental results evidenced that the presence of Ni on LaFeO3 surface enhanced the H2 production and in particular the highest hydrogen production (about 2242 µmol L-1 after 4 h of irradiation time) was obtained with Ni/LaFeO3, whereas the raw LaFeO3 was able to produce a lower H2 amount (about 1394 µmol L-1 after the same irradiation time).
当今科学界最感兴趣的话题之一是寻找新的环保技术来生产能源。特别是，这一领域的主要参与者之一是氢。文献中提出了几种生产氢的创新工艺。其中之一是多相光催化。此外，评估氢的来源也很有趣。葡萄糖是一种有趣的解决方案，它是我们最熟悉的生物质之一，可以通过光催化过程产生氢。因此，在本研究中，我们提出在LaFeO3光催化剂上使用Ni作为活性相，用于葡萄糖水溶液再生制氢。由于钙钛矿光催化剂在水中的稳定性，它是一种非常令人鼓舞的水溶液制氢材料。低成本的镍可以用来改善钙钛矿的性能，改变它们的表面，从而避免使用昂贵的贵金属基助催化剂。其中，以柠檬酸为有机燃料，采用溶液燃烧合成法制备了LaFeO3催化剂。以硼氢化钠(NaBH4)为还原剂，采用化学还原法在LaFeO3表面沉积了一定量的Ni。用XRD、UV-Vis等方法对制备的样品进行了表征。光催化试验在一个装有氮气分配装置的热阻圆柱形反应器中进行，并在距离反应器外表面相同距离(约30 mm)的四个紫外灯(发射波长为365 nm)照射下进行。实验条件为:溶液体积为80 ml，葡萄糖初始浓度为5550µmol L-1，催化剂用量为1.5 g L-1。实验结果表明，Ni在LaFeO3表面的存在促进了氢气的生成，特别是Ni/LaFeO3的氢气产量最高(照射4 h后约2242µmol L-1)，而原始LaFeO3的氢气产量较低(照射相同时间后约1394µmol L-1)。
{"title":"Enhanced Photocatalytic Hydrogen Production from Glucose Aqueous Solution Using Nickel Supported on LaFeO3","authors":"V. Vaiano, G. Iervolino, D. Sannino","doi":"10.3303/CET2186025","DOIUrl":"https://doi.org/10.3303/CET2186025","url":null,"abstract":"Nowadays one of the topics of greatest interest to the scientific community is the search for new eco-friendly technologies that allow the production of energy. In particular, one of the main players in this area is hydrogen. Several innovative processes are proposed in the literature for the production of hydrogen. One of these is the heterogeneous photocatalysis. Furthermore, it is also interesting to evaluate the source from which hydrogen is obtained. An interesting solution is glucose, one of the most familiar biomass, which can be used to produce hydrogen from a photocatalytic process. For this reason, in this work we propose the use of Ni as active phase supported on LaFeO3 photocatalyst for the renewable H2 production from glucose aqueous solution. Perovskite photocatalysts are quite encouraging materials for H2 production from aqueous solution owing to their stability in water. Low-cost nickel can be used to improve the performance of perovskites, modifing their surface and thus avoiding the use of expensive noble metal based cocatalysts. Specifically, the LaFeO3 catalyst was prepared by solution combustion synthesis using citric acid as organic fuel. A specific amount of Ni was deposited on LaFeO3 surface by chemical reduction method, using sodium borohydride (NaBH4) as a reducing agent. The prepared samples were characterized by different techniques, such as XRD and UV-Vis. The photocatalytic tests were carried out in a pyrex cylindrical reactor equipped with a N2 distributor device and irradiated by four UV lamps (emitting at 365 nm) positioned at the same distance from the external surface of the reactor (about 30 mm). The tests were realized with a solution volume equal to 80 ml, an initial concentration of glucose equal to 5550 µmol L-1 and a catalyst dosage equal to 1.5 g L-1. The experimental results evidenced that the presence of Ni on LaFeO3 surface enhanced the H2 production and in particular the highest hydrogen production (about 2242 µmol L-1 after 4 h of irradiation time) was obtained with Ni/LaFeO3, whereas the raw LaFeO3 was able to produce a lower H2 amount (about 1394 µmol L-1 after the same irradiation time).","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"12 1","pages":"145-150"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87268410","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}
An analysis of the performance of a membrane reactor for the production of pure hydrogen through ammonia decomposition is presented here. The system is numerically studied under a wide range of operating conditions to identify those most favorable for the production of pure hydrogen. The underlying idea is that, in the case of ammonia decomposition, a membrane reactor allows to operate at low temperature not only because the selective removal of hydrogen shifts the equilibrium of the reactor towards the products, but also because the reaction rate is enhanced by the removal of hydrogen, which at low temperatures inhibits the kinetics of ammonia decomposition.
{"title":"Numerical Analysis of the Performance of Membrane Reactors for Nh3 Decomposition","authors":"M. A. Murmura, M. Annesini","doi":"10.3303/CET2186139","DOIUrl":"https://doi.org/10.3303/CET2186139","url":null,"abstract":"An analysis of the performance of a membrane reactor for the production of pure hydrogen through ammonia decomposition is presented here. The system is numerically studied under a wide range of operating conditions to identify those most favorable for the production of pure hydrogen. The underlying idea is that, in the case of ammonia decomposition, a membrane reactor allows to operate at low temperature not only because the selective removal of hydrogen shifts the equilibrium of the reactor towards the products, but also because the reaction rate is enhanced by the removal of hydrogen, which at low temperatures inhibits the kinetics of ammonia decomposition.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"259 1","pages":"829-834"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90522979","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}
A. Patti, G. Cicala, C. Tosto, L. Saitta, D. Acierno
This study focuses on the characterization of 3D printed parts by fused deposition modelling (FDM) technique made from a composite filament, highly loaded of stainless-steel microparticles, prepared at different infill density (0, 50, 100%). Thermo-mechanical properties, morphological aspects and heat transport behaviour of the developed specimens have been investigated by dynamic-mechanical analysis (DMA), thermal diffusivity measurements and scanning electron microscopy (SEM). Experimental results allowed to attest a drastic reduction of storage modulus in the range of testing temperatures by reducing the infill density. In the meantime, an increment of dissipation factor was shown in lesser stiff samples at temperatures near to the ambient. The same increasing trend did not appear in the case of thermal diffusion that showed closer values for samples at 0 and 50% of infill, and an augment in the case of infilling level of 100%. This outcome, explained through SEM pictures, was attributed to the difficulty in realization of perfect empty internal structures within 3D parts. A supporting analysis by IR spectroscopy was conducted on the composite surface to gain qualitative information about constituting polymer filament. Further considerations on the porosity of systems have been obtained elaborating SEM micrographs with ImageJ software.
{"title":"Characterization of 3D Printed Highly Filled Composite: Structure, Thermal Diffusivity and Dynamic-mechanical Analysis","authors":"A. Patti, G. Cicala, C. Tosto, L. Saitta, D. Acierno","doi":"10.3303/CET2186257","DOIUrl":"https://doi.org/10.3303/CET2186257","url":null,"abstract":"This study focuses on the characterization of 3D printed parts by fused deposition modelling (FDM) technique made from a composite filament, highly loaded of stainless-steel microparticles, prepared at different infill density (0, 50, 100%). Thermo-mechanical properties, morphological aspects and heat transport behaviour of the developed specimens have been investigated by dynamic-mechanical analysis (DMA), thermal diffusivity measurements and scanning electron microscopy (SEM). Experimental results allowed to attest a drastic reduction of storage modulus in the range of testing temperatures by reducing the infill density. In the meantime, an increment of dissipation factor was shown in lesser stiff samples at temperatures near to the ambient. The same increasing trend did not appear in the case of thermal diffusion that showed closer values for samples at 0 and 50% of infill, and an augment in the case of infilling level of 100%. This outcome, explained through SEM pictures, was attributed to the difficulty in realization of perfect empty internal structures within 3D parts. A supporting analysis by IR spectroscopy was conducted on the composite surface to gain qualitative information about constituting polymer filament. Further considerations on the porosity of systems have been obtained elaborating SEM micrographs with ImageJ software.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"51 1","pages":"1537-1542"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84829480","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}
Twin screw granulation (TSG) has been applied to wet granulation, although its application in melt granulation has been more limited. This work explores potential advantages of hot melt granulation using twin screw extrusion. Four main operating and formulation parameters were investigated: screw speed, number of mixing elements, temperature, and binder percentage. Combinations of these factors were then studied to determine their impact on the quantity and characteristics of granules within the desired size range of 125 – 1000 µm. A screening design of experiments (DOE) study was used with each factor set at three levels, to investigate individual factor effects and interactions. Two types of mixing elements were studied: kneading block (KB) and chaotic elements. The type and number of mixing elements were found to be paramount in contributing to the quantity and characteristics of granules formed. Results obtained agreed with previous findings in literature on the influence of different screw elements on the characteristics of granules formed by twin screw granulation. Additionally, the study revealed the unique impact which different mixer elements have on both granule production and characteristics. Depending on the specific need or use of granules in required applications, the granulation process can be effectively designed to meet the end product quality and outcome.
{"title":"Effect of Mixing Elements on Granule Formation in Hot Melt Twin Screw Granulation","authors":"Nana K. G. Sekyi, N. Rahmanian, A. Kelly","doi":"10.3303/CET2186219","DOIUrl":"https://doi.org/10.3303/CET2186219","url":null,"abstract":"Twin screw granulation (TSG) has been applied to wet granulation, although its application in melt granulation has been more limited. This work explores potential advantages of hot melt granulation using twin screw extrusion. Four main operating and formulation parameters were investigated: screw speed, number of mixing elements, temperature, and binder percentage. Combinations of these factors were then studied to determine their impact on the quantity and characteristics of granules within the desired size range of 125 – 1000 µm. A screening design of experiments (DOE) study was used with each factor set at three levels, to investigate individual factor effects and interactions. Two types of mixing elements were studied: kneading block (KB) and chaotic elements. The type and number of mixing elements were found to be paramount in contributing to the quantity and characteristics of granules formed. Results obtained agreed with previous findings in literature on the influence of different screw elements on the characteristics of granules formed by twin screw granulation. Additionally, the study revealed the unique impact which different mixer elements have on both granule production and characteristics. Depending on the specific need or use of granules in required applications, the granulation process can be effectively designed to meet the end product quality and outcome.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"188 1","pages":"1309-1314"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85629156","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：