The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Bart Van Der Bruggen - One of the best experts on this subject based on the ideXlab platform.
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Performance of solvent resistant nanofiltration membranes for purification of residual solvent in the pharmaceutical industry: Experiments and simulation
Green Chemistry, 2011Co-Authors: Siavash Darvishmanesh, Loghman Firoozpour, Johan Vanneste, Patricia Luis, Jan Degrève, Bart Van Der BruggenAbstract:This study explores the possibility of developing a sustainable extraction method for use in pharmaceutical production, based on purification with membrane processes. Two types of commercial polymeric organic solvent nanofiltration membranes (StarMem122 and DuraMem150) were selected and tested for their abilities to recover the solvent from a pharmaceutical/solvent mixture (5, 10, 50 mg L−1). Five different pharmaceutical compounds have been selected in this work, namely: Imatinib mesylate, Riluzole, Donepezil HCl, Atenolol and Alprazolam. Solvents tested in the experiment were those used in the manufacturing process, i.e., methanol, ethanol, iso-propanol and ethyl acetate. An acceptable performance (rejection over 90%) was obtained for DuraMem150 in all tested pharmaceutical and solvent mixtures except for iso-propanol. No flux was observed for iso-propanol over the DuraMem150 due to its high viscosity. No separation was observed by using StarMem122 for Imatinib mesylate in iso-propanol (over 80%). Commercially available solvent resistant nanofiltration (SRNF) membranes (StarMem™122 and DuraMem™150) show promising performances as alternative tools to traditional separation units such as distillation columns for the recovery of solvents. Furthermore, to evaluate the potential of SRNF as a substitution for traditional solvent recovery, a model was developed for nanofiltration membrane units and implemented in a common process simulation software (Aspen Plus). These models were based on the pore flow mechanism and describe a single membrane module. A membrane module is not available in Aspen Plus and in its Model Library. In this study, this shortcoming was overcome through implementation of the NF membrane module within the Aspen Custom Modeler link to Aspen Plus. The model has been tested for two model solutes (Disperse orange 3 and Disperse red 19) since the pharmaceutical physical Properties are not included in the Aspen Properties Database. The results presented here confirm the value of the Aspen Custom Modeler as a simulation tool for the use of NF as a novel and sustainable tool in pharmaceutical manufacturing.
Markus Haider - One of the best experts on this subject based on the ideXlab platform.
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dynamic modeling of co2 absorption from coal fired power plants into an aqueous monoethanolamine solution
Chemical Engineering Research & Design, 2013Co-Authors: Sebastian Posch, Markus HaiderAbstract:Abstract Among carbon capture and storage (CCS), the post-combustion capture of carbon dioxide (CO2) by means of chemical absorption is actually the most developed process. Steady state process simulation turned out as a powerful tool for the design of such CO2 scrubbers. Besides steady state modeling, transient process simulations deliver valuable information on the dynamic behavior of the system. Dynamic interactions of the power plant with the CO2 separation plant can be described by such models. Within this work a dynamic process simulation model of the absorption unit of a CO2 separation plant was developed. For describing the chemical absorption of CO2 into an aqueous monoethanolamine solution a rate based approach was used. All models were developed within the Aspen Custom Modeler® simulation environment. Thermo physical Properties as well as transport Properties were taken from the electrolyte non-random-two-liquid model provided by the Aspen Properties® database. Within this work two simulation cases are presented. In a first simulation the inlet temperature of the flue gas and the lean solvent into the absorber column was changed. The results were validated by using experimental data from the CO2SEPPL test rig located at the Durnrohr power station. In a second simulation the flue gas flow to the separation plant was increased. Due to the unavailability of experimental data a validation of the results from the second simulation could not be achieved.
Sajeev Kumar Asvin - One of the best experts on this subject based on the ideXlab platform.
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Modelling of Multi-Tubular Fixed-Bed Reactor for Fischer-Tropsch Synthesis to Produce Synthetic Crude Using Syngas Obtained from the Work’s Arising Gases of an Integrated Steel Mill
2019Co-Authors: Sajeev Kumar AsvinAbstract:Steelmaking process is a highly carbon-intensive process. This is mainly due to the use of coke as a reducing agent in the blast furnaces to produce carbon-rich pig iron, which in turn, is used for the production of low-carbon steel in the basic oxygen furnaces. The exhaust gases from the blast and basic oxygen furnaces, which mainly contain CO and CO2, are utilised for electricity generation, and thus, these pollutants are released to the atmosphere. One of the possible ways to treat these work’s arising gases (WAGs) is to convert them into syngas, which can then be further converted into syncrude via Fischer-Tropsch synthesis (FTS). The FTS syncrude can then be further refined and processed to produce liquid fuels such as gasoline, kerosene, diesel, etc. These synthetic fuels are sulphur-lean and are essentially capable of replacing the existing fossil-derived liquid fuels, thus contributing to curbing the carbon emissions.The main objective of this thesis was to develop a detailed model of a multi-tubular fixed-bed reactor (MTFBR) to produce synthetic crude from syngas via Fischer-Tropsch synthesis (FTS). The model was then used to simulate a reactor that utilises the syngas obtained from the processing of work’s arising gases of an integrated steel mill to produce synthetic crude. The FTS product distribution was modelled using the kinetic model based on CO-insertion mechanism, developed by Todic et al. A basic MTFBR model was initially developed using the equations and assumptions from the fixed-bed reactor model of Todic, and the basic MTFBR model was able to produce similar results as that of the Todic’s model, with slight deviations in the temperature and pressures profiles. The basic MTFBR model was then further improved to render it comparable with the commercial FT reactors. The main improvements in the model include the dynamic extraction of thermodynamic and transport Properties of the system components using Aspen Properties; calculation of dynamic vapour-liquid equilibrium, liquid holdup and catalyst effectiveness factor; and the use of improved heat transfer and pressure drop equations.A sensitivity analysis was performed to determine the effect of design and process parameters on the performance of the MTFBR model. The most crucial design parameter was observed to be the tube diameter as it had a considerable effect on the heat management and the pressure drop in the reactor bed. The most important process parameters for the reactor were observed to be the inlet temperature and the feed flow rate. A simplified FTS gas loop process was also modelled in Aspen Plus in order to introduce a recycle stream into the MTFBR. The effect of tail gas recycle for the recovery of unreacted H2 and CO was also studied, and it was observed that higher recycle ratios resulted in lower conversions per pass; however, overall CO conversions were observed to increase until a maximum, and then decrease thereafter. The optimum conditions for the simplified gas loop process were estimated to be with an inlet temperature of 484.5K and a total recycle of tail gas to the recovery section, for a inlet pressure of 30 bar. Optimised process conditions resulted in a CO conversion per pass of 46%, an overall CO conversion of 89%, a C5+ selectivity of 86.6%, a CH4 selectivity of 6.2%, and a C5+ productivity of 252,540 tonnes/y. The optimised model results, in terms of C5+ selectivity and overall CO conversion, were also pretty much inline with the available data from the Shell SMDS plant in Bintulu.Sustainable Energy Technolog
Asvin Sajeev Kumar - One of the best experts on this subject based on the ideXlab platform.
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Modelling of Multi-Tubular Fixed-Bed Reactor for Fischer-Tropsch Synthesis to Produce Synthetic Crude Using Syngas Obtained from the Work’s Arising Gases of an Integrated Steel Mill
2019Co-Authors: Asvin Sajeev KumarAbstract:Steelmaking process is a highly carbon-intensive process. This is mainly due to the use of coke as a reducing agent in the blast furnaces to produce carbon-rich pig iron, which in turn, is used for the production of low-carbon steel in the basic oxygen furnaces. The exhaust gases from the blast and basic oxygen furnaces, which mainly contain CO and CO2, are utilised for electricity generation, and thus, these pollutants are released to the atmosphere. One of the possible ways to treat these work’s arising gases (WAGs) is to convert them into syngas, which can then be further converted into syncrude via Fischer-Tropsch synthesis (FTS). The FTS syncrude can then be further refined and processed to produce liquid fuels such as gasoline, kerosene, diesel, etc. These synthetic fuels are sulphur-lean and are essentially capable of replacing the existing fossil-derived liquid fuels, thus contributing to curbing the carbon emissions. The main objective of this thesis was to develop a detailed model of a multi-tubular fixed-bed reactor (MTFBR) to produce synthetic crude from syngas via Fischer-Tropsch synthesis (FTS). The model was then used to simulate a reactor that utilises the syngas obtained from the processing of work’s arising gases of an integrated steel mill to produce synthetic crude. The FTS product distribution was modelled using the kinetic model based on CO-insertion mechanism, developed by Todic et al. A basic MTFBR model was initially developed using the equations and assumptions from the fixed-bed reactor model of Todic, and the basic MTFBR model was able to produce similar results as that of the Todic’s model, with slight deviations in the temperature and pressures profiles. The basic MTFBR model was then further improved to render it comparable with the commercial FT reactors. The main improvements in the model include the dynamic extraction of thermodynamic and transport Properties of the system components using Aspen Properties; calculation of dynamic vapour-liquid equilibrium, liquid holdup and catalyst effectiveness factor; and the use of improved heat transfer and pressure drop equations. A sensitivity analysis was performed to determine the effect of design and process parameters on the performance of the MTFBR model. The most crucial design parameter was observed to be the tube diameter as it had a considerable effect on the heat management and the pressure drop in the reactor bed. The most important process parameters for the reactor were observed to be the inlet temperature and the feed flow rate. A simplified FTS gas loop process was also modelled in Aspen Plus in order to introduce a recycle stream into the MTFBR. The effect of tail gas recycle for the recovery of unreacted H2 and CO was also studied, and it was observed that higher recycle ratios resulted in lower conversions per pass; however, overall CO conversions were observed to increase until a maximum, and then decrease thereafter. The optimum conditions for the simplified gas loop process were estimated to be with an inlet temperature of 484.5K and a total recycle of tail gas to the recovery section, for a inlet pressure of 30 bar. Optimised process conditions resulted in a CO conversion per pass of 46%, an overall CO conversion of 89%, a C5+ selectivity of 86.6%, a CH4 selectivity of 6.2%, and a C5+ productivity of 252,540 tonnes/y. The optimised model results, in terms of C5+ selectivity and overall CO conversion, were also pretty much inline with the available data from the Shell SMDS plant in Bintulu.
Richard G. Ball - One of the best experts on this subject based on the ideXlab platform.
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Water Activity-Mediated Control of Crystalline Phases of an Active Pharmaceutical Ingredient
Organic Process Research & Development, 2007Co-Authors: Narayan Variankaval, Claire Lee, Ralph Calabria, Nancy N. Tsou, Richard G. BallAbstract:A systematic investigation of the polymorph−hydrate system for Compound I was carried out with the objective of understanding the phase relationships between the different forms as it relates to crystallization conditions. The ternary phase diagram was determined from solubility and KF measurements of the supernatant liquor for Compound I−water−ethanol mixtures. Water concentrations were converted to water activities using the NRTL-RK model as implemented in Aspen Properties. These water activities were then used in defining phase boundaries between anhydrous and the various hydrated forms of Compound I. Since the critical water activity at the phase boundaries between anhydrous and hydrated forms in water−cosolvent systems is independent of the nature of the cosolvent it can be used to extrapolate the water concentrations defining ternary phase boundaries in any other cosolvent−water system. This was demonstrated in the cases of acetonitrile−water and dimethyl acetamide−water. Triple points (anhydrate−hy...
