Feed Stage Research Articles

Optimized energy efficient reactive distillation for octane upgrading with economic and environmental considerations

Advancing fuel efficiency and production technologies can significantly reduce “Well to Wheels” and “Octane on Demand” emissions. This has been accomplished by integrating intensified technologies in fuel refineries. However, maintaining low energy consumption and high octane number while considering the impact of operating conditions under uncertainty on the process feasibility remains a challenge. Therefore, this article proposes a novel absorption heat pump reactive distillation (AHPRD). Aiming to maximize the economic potential of the AHPRD, an optimization framework that considers operating conditions under uncertainty (i.e. temperature (T), pressure (P), reflux ratio (RR), and feed stage (FS)) is developed. The optimization framework synchronizes Monte Carlo simulation and particle swarm optimization (PSO) to maximize the net present value (NPV). The framework used a hybrid Python-DWSim interface platform. The AHPRD was further investigated and compared against existing processes, namely, a conventional process refinery (CP) and reactive distillation (RD), to improve energy saving, increase financial return, and cut CO2 emissions. Attractively, the AHPRD outperforms existing processes, both economically and environmentally, doubling profit values and avoiding 52.2% − 77.4% of CO2 emissions. This study believes that the future direction will be to build an artificial intelligence model for process optimization and economic prediction.

Greenhouse gas emissions in US beef production can be reduced by up to 30% with the adoption of selected mitigation measures

Greenhouse gas (GHG) emissions from beef production in the United States are unevenly distributed across the supply chain and production regions, complicating where and how to reduce emissions most effectively. Using spatially explicit life cycle assessment methods, we quantify the baseline GHG emissions and mitigation opportunities of 42 practices spanning the supply chain from crop and livestock production to processing. We find that the potential to reduce GHGs across the beef sector ranges up to 30% (20 million tonnes CO2e reduced and 58 million tonnes CO2 sequestered each year relative to the baseline) under ubiquitous adoption assumptions, largely driven by opportunities in the grazing stage. Opportunities to reduce GHGs in the feed, grazing and feedlot stages vary across regions, yet large-scale adoption across the entire beef supply chain is important. These findings reveal promising locations and practices to invest in to advance mitigation goals and an upper-end theoretical potential for mitigation in the beef industry.

Sensitivity analysis of parameters on carbon dioxide desorption processes from aqueous monoethanolamine solution

AbstractCarbon dioxide (CO2) capture technologies are crucial for mitigating climate change, with post‐combustion capture (PCC) using chemical absorption being a leading method. However, the energy‐intensive solvent regeneration process presents a significant challenge, consuming up to 50% of the total energy in carbon sequestration. Despite extensive research on absorption, desorption studies remain limited. This study focuses on the desorption analysis through experimental runs in a pilot‐scale tray column with varying flow rates, validating an Aspen Plus model. The research compares the impact of the number of stages, feed stage position, column pressure, and reflux ratio between equilibrium and rate‐based models. The findings reveal enhanced desorption efficiency through optimized operational conditions, including reduced flow rates, additional equilibrium stages, feeding stage positioning closer to the condenser, elevated pressures, and lower reflux ratios. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Carbon footprint of synthetic nitrogen under staple crops: Afirst cradle-to-grave analysis.

More than half of the world's population is nourished by crops fertilized with synthetic nitrogen (N) fertilizers. However, N fertilization is a major source of anthropogenic emissions, augmenting the carbon footprint (CF). To date, no global quantification of the CF induced by N fertilization of the main grain crops has been performed, and quantifications at the national scale have neglected the CO2 assimilated by plants. A first cradle-to-grave life cycle assessment was performed to quantify the CF of the N fertilizers' production, transportation, and application to the field and the uses of the produced biomass in livestock feed and human food, as well as biofuel production. We quantified the direct and indirect inventories emitted or sequestered by N fertilization of main grain crops: wheat, maize, and rice. Grain food produced with N fertilization had a net CF of 7.4 Gt CO2eq. in 2019 after excluding the assimilated C in plant biomass, which accounted for a quarter of the total CF. The cradle (fertilizer production and transportation), gate (fertilizer application, and soil and plant systems), and grave (feed, food, biofuel, and losses) stages contributed to the CF by 2%, 11%, and 87%, respectively. Although Asia was the top grain producer, North America contributed 38% of the CF due to the greatest CF of the grave stage (2.5 Gt CO2eq.). The CF of grain crops will increase to 21.2 Gt CO2eq. in 2100, driven by the rise in N fertilization to meet the growing food demand without actions to stop the decline in N use efficiency. To meet the targets of climate change, we introduced an ambitious mitigation strategy, including the improvement of N agronomic efficiency (6% average target for the three crops) and manufacturing technology, reducing food losses, and global conversion to healthy diets, whereby the CF can be reduced to 5.6 Gt CO2eq. in 2100.

Metagenomics and metabolomics reveal that gut microbiome adapts to the diet transition in Hyla rabbits

There is still a lack of longitudinal dynamic studies on the taxonomic features, functional reserves, and metabolites of the rabbit gut microbiome. An experiment was conducted to characterize the bacterial community of rabbits. By combining metagenomics and metabolomics, we have comprehensively analyzed the longitudinal dynamics of the rabbit gut microbiota and its effect on host adaptability. Our data reveal an overall increasing trend in microbial community and functional gene diversity and richness during the pre-harvest lifespan of rabbits. The introduction of solid feed is an important driving factor affecting rabbit gut microbiological compositions. Clostridium and Ruminococcus had significantly higher relative abundances in the solid feed stage. Further, the starch and fiber in solid feed promote the secretion of carbohydrate-degrading enzymes, which helps the host adapt to dietary changes. The rabbit gut microbiota can synthesize lysine, and the synthase is gradually enriched during the diet transformation. The gut microbiota of newborn rabbits has a higher abundance of lipid metabolism, which helps the host obtain more energy from breast milk lipids. The rabbit gut microbiota can also synthesize a variety of secondary bile acids after the introduction of solid feed. These findings provide a novel understanding of how the gut microbiota mediates adaptability to environment and diet in rabbits and provide multiple potential strategies for regulating intestinal health and promoting higher feed efficiency.

What will it take to get to 250,000 ppm brine concentration via ultra-high pressure reverse osmosis? And is it worth it?

The possibility of ultra-high pressure reverse osmosis (UHPRO) to replace thermal brine concentration promises to reduce up to 50 % of both energy consumption and capital cost. However, commercially available reverse osmosis (RO) membranes lose up to 50 % of their water permeability when operated up to 200 bar. Higher temperature operations such as in Middle East seawater desalination and brine mining further exacerbate compaction due to softening of the polysulfone support membrane. Assuming that pressure and temperature-related compaction issues can be resolved through innovations in membrane materials and/or module designs, this study asks the questions, “What will it take to get to 250,000 ppm via ultra-high pressure reverse osmosis? And is it worth it?” Herein we comprehensively examine a three stage RO process beginning with seawater RO (SWRO) to high-pressure RO (HPRO) and ultra-high-pressure RO (UHPRO). We elucidate the influence of thermophysical properties, hydraulic pressure, permeate flux, water permeability, feed spacer design, concentration polarization (CP), salt rejection and stage design on recovery and specific energy consumption (SEC). Our analysis of high rejection (HR) and high flux (HF) RO membranes reveals that while HF RO membranes boast superior water permeability and lower trans-membrane (hydraulic) pressure (TMP), they require higher operating flux, which leads to severe CP and operating pressures of 300 to 400 bar to meet the targeted brine concentration of ~250 g/L TDS. In addition, membrane compaction drives up the TMP, SEC, and capital cost of UHPRO systems. To bring the applied pressure below 300 bar, compaction-resistant UHPRO membranes and mass-transfer enhancing feed spacers will be required. The findings herein show that it will take time, money and technological innovation to enable UHPRO at commercial scale, and it may or may not be worth it. Further, this work makes clear the technological refinements needed to enable UHPRO membrane brine concentration.

ETHYL ALCOHOL - WATER SEPARATION BY EXTRACTIVE DISTILLATION: SIMULATION USING ASPEN PLUS™ AND EXPERIMENTAL VALIDATION

Dilute ethyl alcohol (ethanol, EtOH) is produced using fermentation (< 20 mass%), but it needs to be further purified because it contains large water content. EtOH forms an azeotrope with water and to separate this azeotrope, advanced separation processes like pressure swing distillation (PSD), azeotropic distillation (AD), and extractive distillation (ED) are employed. In this work, ethylene glycol (EG) was used as an entrainer in extractive distillation. Vapour liquid equilibrium (VLE) data was used to validate the chosen rigorous thermodynamic model. To find a workable range of operating parameters, sensitivity analysis was performed to find out the number of stages (N), feed stage (NF), distillate rate (DR), and reflux ratio (RR). Simulation shows that use of accurate operating parameters and correct entrainer can help to obtain almost pure EtOH (99.89 mole %, 99.92 mass %). In order to validate the theoretical findings from the simulation, experimental investigations in the form of batch and semi - batch distillation runs were conducted. It was seen from these runs that it is indeed possible to obtain EtOH with high purity. It was also verified that EG can be separated and recycled back with high purity with a very high recovery.

Extractive Distillation of Ethanol/Water with 1-Butyl-3-Methylimidazolium Bromide Ionic Liquid as a Separating Agent: Process Simulation

Ethanol purification has become of great interest recently because ethanol can be used as renewable energy, solvent in many industries, and for medicinal purposes. The separation of ethanol from water is challenging because the azeotropic point has appeared in this binary mixture. Extractive distillation technology is one of the most interesting methods to separate ethanol from water due to the competitiveness of its energy consumption and capital investment costs. Ionic liquids such as 1-butyl-3-methylimidazolium bromide [BMIM] [Br], categorized as a green solvent, produce a significant salting-out effect in the ethanol-water system. This makes ionic liquid a promising solvent in ethanol-water separation. This study simulated the extractive distillation of an ethanol-water system with 1-butyl-3-methylimidazolium bromide as a solvent. The simulation and sensitivity analysis were performed on the Aspen Plus Process Simulator to obtain the optimum configuration. The NRTL thermodynamic model was used in this study. The effects of the number of stages (NS), binary feed stage (BFS), entrainer feed stage (EFS), and reflux ratio (RR) on the ethanol concentration with minimum energy requirements were studied. The most optimal configurations to produce a high ethanol concentration with less energy are NS 28, BFS 22, EFS 4, and RR 1.5.

Numerical Simulation of a Valorisation-Oriented Hybrid Process for the Bio-Oil-Related Separation of Acetol and Acetic Acid

Biomass as a whole offers a more diverse potential for valorisation than any other renewable energy source. As one of the stages in the separation of bio-oil involves a liquid mixture of acetol and acetic acid, and as both components are particularly well suited for valorisation, a hybrid method was developed for their separation with a high purity level through an approach combining liquid–liquid extraction and distillation. In order to design and simulate the flowsheet, the ChemCAD 7.0 simulation software was used. Sensitivity analyses were carried out to investigate the influence of the different parameters in the distillation columns, such as the reflux ratio, the feed stage location, and the vapour/bottom molar flow ratio. The effect of different extractants and of their excess on the separation process, as well as the possibility of regenerating the extractant, was also studied. Tri-n-octylamine was accordingly selected as a separating agent that was fully recycled. The end result for separating an initial 48/52 wt% acetol/acetic acid liquid mixture was acetol with a purity of 99.4 wt% and acetic acid with a purity of 100 wt%.

Flowsheets for hydroxyacetone–phenol binary mixture separation: The use of special distillation methods

Objectives. To study the possibility of hydroxyacetone–phenol binary mixture (a constituent of a mixture of phenol production by the cumene method) separation in flowsheets based on the use of distillation special methods. This is the addition of separating agents to increase the relative volatility of the components of the original mixture, and the variation of pressure in the columns.Methods. A computational simulation in Aspen Plus® was used as the research method. Mathematical modeling of the vapor–liquid equilibrium was carried out using a local compositions model Non-Random Two Liquid. The viability of the latter was confirmed by comparing experimental and calculated on phase equilibrium data, and azeotropic data. The average relative error does not exceed 3%.Results. The dependence of the composition and boiling point of the hydroxyacetone–phenol azeotrope on pressure was determined in a computational experiment (as the pressure increases, the azeotrope is enriched with phenol). The possibility of using a complex of columns operating under different pressures to separate the mixture was shown (the shift of the azeotrope is about 9%). The change in the relative volatility of components of the original mixture in the presence of a high(diethylene glycol) and a low-boiling (acetone) separating agent was investigated. Both solvents are selective agents used in extractive and re-extractive distillation processes. Three technological separation flowsheets containing two distillation columns were proposed.Conclusions. The study established the operation parameters of the columns (number of theoretical stages, feed stages of the original mixture and separating agent, and reflux ratio) and energy consumption (total heat supplied to the columns boiler) of three separation flowsheets ensuring the production of products of a given quality (not less than 0.99 mol fractions). The flowsheet with diethylene glycol is characterized by the lowest energy consumption. It is recommended that complexes of extractive and re-extractive distillation be further optimized. This enables the second product of cumulus production—acetone—to be involved in the technological cycle.

Comparative analysis of isopropyl alcohol dehydration using ionic liquids and deep eutectic solvent

The current article deals with the separation of the azeotropic mixture of isopropyl alcohol (IPA) and water using an ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and Deep Eutectic Solvents (DESs), Choline Chloride/glycerol (Glyceline) and Choline Chloride/Ethylene Glycol (Ethaline). Conventional dimethyl sulfoxide (DMSO) solvents are used to compare the results for IPA dehydration. Process modelling and simulation were carried out in the Aspen Plus simulator (v.8.6). The NRTL model was used to calculate the thermodynamic properties as well as the vapour-liquid equilibria of the ternary systems. The process parameters such as entrainer flow rate, binary feed stage, entrainer feed stage, column stages, reflux ratio, reboiler and condenser duties were evaluated using sensitivity analysis and design spec tools of the simulator. The industrial process for both systems, containing a separation column and a recovery column, was simulated at a steady state. Both processes were optimised using the optimisation tool of the simulator and compared based on the energy requirement. Further, based on the simulation results, we proposed an alternate process design for solvent recovery using a flash drum. The results show that more than 99.9 mol% IPA purity can be achieved using both ILs as well as DESs. The overall energy requirement for the separation of IPA-water mixture using [EMIM][BF4] entrainer in a conventional process was found to be lower than DMSO. The proposed alternate process further reduces the energy requirement compared to the conventional process for both IL and DESs systems.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance, intestinal development and gut microbiota of broilers in large-scale production.

Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300mg/kg mixed MG. The results revealed that dietary MG significantly (P<0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10wk of age, and decreased the serum lipopolysaccharide at 3 and 7wk of age. The triglyceride level of chickens at 3, 5 and 10wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

OPTIMIZATION OF TECHNICAL AND ECONOMIC PARAMETERS FOR THE NATURAL GAS LIQUEFACTION PROCESS AT A LOW-TONNAGE UNIT WITH A MIXED REFRIGERANT

Liquefaction technologies of natural gas using a mixed refrigerant cycle provide a high liquefaction coefficient at low specific energy consumption, but are characterized by high requirements for the organization of production. There is no methodology for simultaneous optimization of the technical and economic parameters for the production process of liquefied natural gas and the composition of the refrigerant in publications, and therefore a combined optimization criterion is needed to achieve the minimum cost of liquefied natural gas. The aim of the work is to determine optimal pressure for natural gas inlet compression, taking into account the minimization of the complex criterion – the conditionally variable part of the cost of liquefied natural gas. The results were obtained using an applied calculation program, and the method of differential evolution was chosen as an optimization method. The optimization was carried out using the OCMR PEGAZ 1.0 program. The article considers the influence of the discharge pressure of the low-pressure natural gas inlet compressor on the technical characteristics of heat exchange equipment, the energy efficiency of the liquefaction process and the economic characteristics of a low-tonnage liquefied natural gas production plant under conditions of optimized composition and flow rate of mixed refrigerant. A method of optimizing process parameters taking into account economic indicators is proposed, regularities of changes in the optimal composition of mixed refrigerant depending on the discharge pressure of the natural gas inlet compressor are determined. It is determined that with an increase in the discharge pressure of the natural gas inlet compressor, the optimal content of components in the mixed refrigerant changes as follows: methane and n-pentane decrease, and ethane and isobutane increase. It is shown that the optimal discharge pressure range of the natural gas inlet compressor is 6,0±0,5 MPag, which leads to the best total energy efficiency of inlet compression and circulation of mixed refrigerant, equal to 0,25 kWh/kg of LNG, and its cost is minimal. The assessment of capital costs at this pressure will allow choosing the optimal technology of natural gas liquefaction at the FEED stage, which will reduce the cost of production of liquefied natural gas and reduce the payback period to 5 years.

Industrial experience in using cyclic distillation columns for food grade alcohol purification

This study provides novel details about the industrial use of cyclic distillation in the production of food-grade alcohol, which confirmed the theoretical predictions of increasing separation efficiency. Increasing the profitability of the production of ethanol food grade is primarily associated with an increase in product quality and reduction of energy costs per unit of production. One of the ways to solve these problems is to improve the ethanol purification technology by using cyclic distillation, which allows reduction of energy costs and higher productivity by removing impurities at a higher concentration (leading also to waste reduction). The purification of ethanol from impurities (head and intermediate type) is carried out in hydro-selection columns. Critically, the volatility of most components depends on the actual ethanol concentration on the stage. This study investigated the distribution of ethanol on the trays depending on the water feed stage to the column and showed the optimal distribution of hydro-selective water in an industrial column to allow the highest possible separation efficiency of components during cyclic distillation. A cyclic distillation column with 15 Maleta trays was superior in separation capacity and performance as compared to a traditional column with 50 bubble cap trays.

DEVELOPMENT OF SOLVENTS ALCOHOL MIXTURE SEPARATION TECHNOLOGY

The paper is devoted to the development of a technology for the regeneration of caprolactam solvents containing n-butanol, amyl alcohol, cyclohexanone, cyclohexanol, as well as isoamyl alcohol and cyclopentanone in impurity amounts. To study the phase equilibrium and the separation process, a computational experiment using AspenPlus V.10.0 was selected. The parameters of the Non Random Two Liquid equation allow reproducing the vapor-liquid equilibrium data and azeotropic properties of the system with a relative error not exceeding 5%. Separation of the mixture by conventional distillation is difficult, which is caused by the presence of three binary azeotropes, as well as three pairs of components characterized by close volatility. The structure of the vapor-liquid equilibrium diagram becomes more complex due to the appearance of new azeotropes with a decrease in pressure. A technological flowsheet for solvent regeneration based on the use of continuous distillation was proposed. The flowsheet contains five columns. At the first stage, preliminary fractionation of the mixture is assumed (the mode of sharp distillation in the first column) with complete separation of cyclohexanone and cyclohexanol in the bottom (vacuum distillation is used to separate this pair) and of a mixture of butanol and amyl alcohol with impurity components in the distillate. Extractive distillation with ethylene glycol was proposed to purify butanol and amyl alcohol from impurities. In the presence of the latter, the volatility of butanol increases in relation to other components. The fourth column is designed for the regeneration of the separating agent. Amyl alcohol separation is provided on the bottom of fifth column. The column operation parameters (the number of stages, the feed stage, the reflux ratio, the ratio of the quantities of the initial mixture and the separating agent) that meet the minimum energy consumption and ensure the production of commercial-quality substances are determined.

Pengaruh Variasi Kondisi Operasi pada Kolom Distilasi Ekstraktif terhadap Sifat Fisis Pelarut Hidrokarbon Terdearomatisasi

Solvent is one of the important components in chemical processes. The type of solvent that is often used in the paint and coating industry is a hydrocarbon-based solvent which consists of a diverse complex mixture of liquids and contains aliphatic, alicyclic and aromatic (C5-C8) elements. Aromatic hydrocarbons are environmental pollutants that are known to be toxic, carcinogenic and mutagenic, so a hydrocarbon-based solvent with an aromatic content of less than 1% is needed. An appropriate separation method for separating aromatic and nonaromatic components having close boiling points is extractive distillation with a sulfolane entrainer. In this study, a distillation system with a sulfolane entrainer was run using the process simulation software Aspen Plus with the aim of understanding the effect of the amount of sulfolane, feed stage and number of stages on the physical properties of hydrocarbon-based solvents. This simulation is focused on the variation of the ratio of sulfolane: crude feed (7:1, 7.5:1, 8:1, 8.5:1), the variation of the feed stage (10th stage to the 35th stage) and the variation of the number of stages (70, 75, 80). It was found that the number of stages did not affect the density and flash point of the solvent. An increase of number of stage will decrease the solvent flash point and density. Significant decreament also can be found when the sulfolane to crude feed ratio is increased. However, the physical properties of the current dearomatized solvent is close to the properties of commercial product namely SBP 65/70 from one of oil and gas companies.

Comparison of Extractive and Heteroazeotropic Distillation of High-Boiling Aqueous Mixtures

The processes of extractive distillation and heteroazeotropic distillation of mixtures containing water and a high-boiling component (propionic acid, acetic acid, 1-methoxy-2-propanol) are compared. Entrainers declared in the literature as effective agents for these processes were selected as separating agents. A distillation process simulation in AspenPlus V.11.0 is made. Parametric optimization is carried out and the column operation parameters (number of stages, feed stage, reflux ratio) that meet the minimum energy consumptions and ensure the production of marketable substances are determined. It is shown that the process of heteroazeotropic distillation is more energy-efficient compared to extractive distillation by more than 50%, due to the introduction of an entrainer that lowers the boiling point of process. In addition, in some cases (acetic acid + water with vinyl acetate, propionic acid + water with hexane, cyclohexane, cyclohexanol), one of the columns in the separation flowsheet can be abandoned due to the significantly limited mutual solubility.

Mixed Ionic Liquids as Entrainers for Aromatic Extraction Processes: Energy, Economic, and Environmental Evaluations

Experimental measurements for the vapor–liquid equilibria (VLE) of benzene + 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]), benzene + 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]), and benzene + mixed ionic liquids (ILs) (equimolar [EMIM][NTf2] + [EMIM][EtSO4] mixture) are performed. The non-random two liquid (NRTL) model binary interaction parameters are then obtained by fitting the new VLE data and the liquid–liquid equilibrium data previously reported. The interactions between chemical species are analyzed using quantum chemical calculations and the COSMO-SAC method, and it is found that the interactions between benzene and ILs are strongly attractive. Taking as a reference the industrial process that uses sulfolane as the entrainer, several novel industrial processes are proposed, which involve either pure ionic liquids [EMIM][NTf2] and [EMIM][EtSO4] or their mixtures as the extractant for separating aromatic hydrocarbons (benzene) and paraffins (n-hexane). The optimal operating parameters, such as the number of theoretical stages, the extractant-to-hydrocarbon feed ratio, the reflux ratio, and the feed stage, are determined for the different processes. Steady-state process simulations are performed to evaluate the total annual cost (TAC) and the environmental impact (carbon dioxide emissions). It is shown that significant savings in energy consumption (reduction of 19.6–48.7%), TAC (reduction of 6.3–27.1%), and CO2 emissions (reduction of 17.8–47.6%) can be achieved for the processes that use IL extractants, compared to the process based on sulfolane extractant. The proposed IL extractant and the corresponding process are promising alternatives to conventional solvents and processes for aromatic extraction.

Dynamic Simulation of a Reactive Distillation Column for Ethyl Acetate Production: Optimization of Operating Conditions Using Response Surface Methodology

In this study, we aimed to determine the optimum operating conditions for the production of ethyl acetate (EtAc) through the esterification of ethanol (EtOH) with acetic acid (HAc) in a reactive distillation (RD) column. For this, the designed column was simulated for the production of EtAc. HAc flow rate, EtOH flow rate, HAc feed stage, EtOH feed stage, reflux ratio, and reactive feed temperatures were changed and the effects of these parameters on EtAc production were observed. Central Composite Design was employed to define the optimum operating conditions for the RD column. The determination coefficient R2 was equal to 0.9197 suggesting a good relationship between the predicted and simulated responses. Adjusted R2 and predicted R2 values obtained from the program were 0.8823 and 0.7956, respectively. The optimal conditions for the EtAc production response were HAc flow rate of 120.00 kmol/h, EtOH flow rate of 150.00 kmol/h, HAc feed stage 6, EtOH feed stage 14, reflux ratio 2.2, and feed temperature 70.28 °C, which were designated by the maximum desirability function.

Ionic exchange membranes in the pharmaceutical industry – Review

In line with the longer life expectancy, the pharmaceutical sector, responsible for the continuous development, production and supply of new drugs to cope with the population’s healthcare, has been consistently growing. This scenario illustrates the use of some innovative technologies in industrial processes as the major contributing factor. Amongst these technologies, membrane separation technology stands out. This technique affords the filtration and separation of biological molecules at the nanoscale, resulting in a more expedited manufacturing process and a higher purified end product. Depending on the driving force applied, the separation process involves different approaches, feed stages, different pores’ sizes or permeates. In the scope of membrane separation technology, electrodialysis (ED) uses an electrical potential difference as the driving force to separate ions based on their charge. In this sense, ion-exchange membranes are the most widely used separation materials in purifying systems as they have the advantage of partitioning species of different charges. The present study evaluates two ion-exchange membranes' aptitude as separators for ED filtration of some industrial chemical processes. Keywords: Ionic-exchange membranes, separation technology, pharmaceutical industry wastewater treatment, electrodialysis