High-purity Production Research Articles

RuSe2-CoTe Heterogeneous Surfaces Coated with NC Layer for Excellent HER Performance under Alkaline Condition.

Electrocatalytic hydrogen production has been a promising high-purity hydrogen production technology, attracting a large number of researchers' research interest. Ru has a hydrogen binding capacity similar to Pt, but its price is far lower than Pt, making it a promising alternative to Pt. However, a single Se electronic structure modulation is not sufficient to enable RuSe2 to be used for practical applications on a large scale due to the lack of electrons. Therefore, choosing a suitable way to electronically modulate the Ru atoms in RuSe2 can effectively improve the activity of the catalyst. Cobalt telluride (CoTe) can significantly enhance electrocatalytic performance due to tellurium's low electronegativity and excellent metal properties. In this work, the NC layer possesses excellent electrical conductivity and CoTe acts as an electron donor to optimize the electronic structure locally and trigger electron transfer efficiently. The RuSe2-CoTe/NC electrode requires an overpotential of only 25.4 mV (10 mA cm-2), which is superior to that of RuSe2/NF (65 mV) and CoTe/NC (115 mV). Meanwhile, the Tafel slope of RuSe2-CoTe/NC (67.8 mV dec-1) was better than that of RuSe2/NF (113.6 mV dec-1) and CoTe/NC (209.5 mV dec-1), showing that the build-up of the superior heterojunction makes the RuSe2-CoTe/NC with better hydrogen evolution reaction (HER) reaction kinetics. In addition, after 30 h of long-term stability testing, no significant decrease in catalytic activity was observed, proving the good stability of the RuSe2-CoTe/NC catalyst.

Infusion of Magnetic Nanocatalyst to Microwave Propped Synthesis of Bioactive Azaheterocycles

Abstract: Microwave-assisted synthesis is a powerful tool in organic chemistry, providing a rapid and efficient method for the synthesis of bioactive heterocycles. The application of micro-waves significantly reduces reaction times and increases percentage yields with high purity of the final product. To make the synthetic protocol greener, the application of the magnetic nanocata-lyst is a rapidly growing area of interest nowadays. Magnetic nanocatalyst, with its unique fea-tures like magnetic separable facile recovery from the reaction media heterogeneously, makes the overall synthetic strategy cleaner, faster, and cost-effective. Aiming this, in the present review, we will focus on the infusion of Magnetic nanocatalyst to microwave-assisted synthesis of vari-ous classes of azaheterocyclic compounds, including pyridines, pyrimidines, quinolines, and ben-zimidazoles. The synthetic methodologies involved in the preparation of these heterocycles are highlighted, along with their biological activities. Furthermore, in this review, the most recent and advanced strategies to incorporate nanocatalysts in the microwave-assisted synthesis of nat-ural products containing azaheterocyclic moieties in drug discovery programs are elucidated in detail, along with the incoming future scope and challenges.

Electrochemical Wastewater Refining: A Vision for Circular Chemical Manufacturing.

Wastewater is an underleveraged resource; it contains pollutants that can be transformed into valuable high-purity products. Innovations in chemistry and chemical engineering will play critical roles in valorizing wastewater to remediate environmental pollution, provide equitable access to chemical resources and services, and secure critical materials from diminishing feedstock availability. This perspective envisions electrochemical wastewater refining─the use of electrochemical processes to tune and recover specific products from wastewaters─as the necessary framework to accelerate wastewater-based electrochemistry to widespread practice. We define and prescribe a use-informed approach that simultaneously serves specific wastewater-pollutant-product triads and uncovers a mechanistic understanding generalizable to broad use cases. We use this approach to evaluate research needs in specific case studies of electrocatalysis, stoichiometric electrochemical conversions, and electrochemical separations. Finally, we provide rationale and guidance for intentionally expanding the electrochemical wastewater refining product portfolio. Wastewater refining will require a coordinated effort from multiple expertise areas to meet the urgent need of extracting maximal value from complex, variable, diverse, and abundant wastewater resources.

Efficient Decoupled Alkaline Water Electrolysis Using a Low-Cost Sodium Manganate Solid Redox Mediator

As an ideal energy carrier with clean, high efficiency and high energy density (142.351 kJ g-1), hydrogen is the most promising alternative to fossil fuels when it comes to decarbonizing the planet and energy supply. Today, however, the vast majority of hydrogen production occurs through fossil-fuel intensive processes which release vast amounts of CO₂ defeating the promise of decarbonizing the world. Among other hydrogen production processes, hydrogen production by electrolysis of water has broad application prospects as an alternative approach, and is very attractive for green energy development due to its advantages of cleanliness, environmental protection and zero emission.(1) Alkaline water electrolysis has dominated the current electrochemical hydrogen production industry for the past few decades, but issues such as gas product mixing and the use of renewable energy sources (e.g., solar, wind) remain inherent challenges.(2) To this end, in this paper, low-cost Na0.44MnO2 was chosen as a solid redox mediator to decouple the evolution of H2 and O2 in alkaline conditions, which can produce high-purity gas products directly in membrane-less electrolytic cells without gas purification. As an intermediate carrier for charge storage, the decoupling efficiency can reach 97% at a constant current of 2 mA/1.5 cm2. In addition, we performed the evolutionary reactions of hydrogen and oxygen separately under intermittent renewable energy conditions to achieve direct conversion of solar to hydrogen energy, which greatly enhances the flexibility of hydrogen production and further confirms the potential practical application of Na0.44MnO2. Figure 1. (a) CV curve of the Na0.44MnO2 electrode, and LSV curves of the Pt electrode for the HER and the RuO2/IrO2 electrode for the OER at a scan rate of 1 mV s-1 in 1M NaOH. (b) The charging/discharging curves of the Na0.44MnO2 electrode at different current densities. (c) Decoupled water electrolysis with Na0.44MnO2 electrode. (d) The stability performance of the separate H2/O2 generation at a current of 5 mA with a step time of 400 s. (e) Hydrogen purity test. Reference M. G. Schultz, T. Diehl, G. P. Brasseur and W. Zittel, science, 302, 624 (2003).M. Carmo, D. L. Fritz, J. Mergel and D. Stolten, International journal of hydrogen energy, 38, 4901 (2013).

Ammonia decomposition over Ru-coated metal-structured catalysts for COx-free hydrogen production

We report the development of Ru/Mg–Al oxide coated metal-structured catalysts with excellent heat and mass transfer characteristics for efficient clean H2 production from ammonia decomposition. Ammonia is a promising carrier for the mass transport of hydrogen and facilitates the production of COx-free hydrogen by decomposing into nitrogen and hydrogen. Ru nanoparticles are uniformly dispersed on the Mg–Al oxide layer of the FeCralloy monoliths and foams via precipitation. The catalytic activities depend on the surface area and loading of the catalysts and the metal dispersion in the oxide layer. At temperatures <650 °C, and a gas hourly space velocity (GHSV) of 3,000 h−1, monolithic catalysts with a large surface area and evenly distributed active metals perform excellently. Foam catalysts with excellent heat transfer performance better at temperatures >650 °C and GHSV >6,000 h−1. Foam catalyst stability is verified for 100 h in a 20 Nm3/h high-purity hydrogen production system.

An innovative strategy for spent LiCoO2 battery recycling based on chemical looping complementary reduction

The exponential development of new electric vehicles has led to the inevitable retirement of lithium-ion batteries as a power source. Recovery of spent lithium-ion batteries (LIBs) with remarkable resource and pollution characteristics is an essential solution to alleviate the shortage of lithium resources and drive the sustainable industrial development. Herein, a novel strategy was proposed as chemical looping complementary reduction (CLCR) for recycling valuable metals from spent LiCoO2 battery as chemical-looping cyclic carriers. The influencing factors of reduction temperature, time and H2 flows on reduction characteristics of LiCoO2 carriers were investigated on a laboratory-scale fixed bed. The results indicated that both high temperature and elevated H2 flows were conduce to enhancing LiCoO2 conversion with fairly high crystallinity and purity of reduction products (mainly Li2O and Co monomers) and 98.36 % conversion of LiCoO2 was attained at 1000 °C for 120 min with the H2 flow of 60 mL/min. Thermodynamic analysis proved that complementary matching properties existed between reduction temperature and H2 concentration affecting the phase equilibrium of products, while 650 °C ∼ 900 °C was favorable to obviate the formation of liquid LiOH and the loss of target products. Finally, the mechanism of CLCR along with its environmental and economic impacts were insightfully elaborated to provide a technical and cost-efficient scheme for spent LIBs recycling.

Enhanced hydrogen production coupled with ethanol electrocatalytic oxidation by flow-through self-supporting electrode

Electrocatalytic oxidation of ethanol to value-added production is an ideal replacement of the conventional anodic oxygen evolution reaction (OER) for efficient hydrogen (H2) production due to the lower electric potential energy and higher safety. However, the sluggish mass transfer rate of reactants commonly is the crucial limitation of electrocatalytic oxidation efficiency. Here, Ni(OH)2 nanosheet is immobilized on nickel foam (NF) to fabricate a flow-through self-supporting electrode (Ni(OH)2/NF) served as anode for ethanol electrocatalytic oxidation, in coupling with high-purity H2 production at the cathode. The potential for electrocatalytic oxidation of ethanol and H2 evolution was significantly reduced by 200 mV compared to pure water splitting at 25 mA cm−2. The boundary layer thickness on the anodic electrode surface could be decreased from 86.66 μm to 66.21 μm with the flow rate increased from 0 to 0.82 cm min−1. Compared to the batch mode, The conversion rate of ethanol can be increased from 59 % to 100 % and the selectivity of acetic acid can be increased from 88 % to 100 % under the flow-through mode. The Faraday efficiency of the anode achieved an increase from 76 % to over 99 % and the H2 production of the cathode increased by 31 % under the flow-through mode.

Robust Design of a Dimethyl Ether Production Process Using Process Simulation and Robust Bayesian Optimization.

As greenhouse gases such as CO2 continue to promote global warming, the reduction of CO2 emissions is attracting increasing attention. In this study, we design a process for producing dimethyl ether (DME), which is a promising means of using CO2 as a resource. Design variables such as temperature and pressure need to be optimized to reduce CO2 emissions while maintaining high product purity and DME production. Conventional process designs determine these design variables from the chemical background and through trial-and-error simulations, which are very time-consuming. The proposed method optimizes the design variables efficiently by repeating the process simulations and selecting promising candidates for the design variables using machine learning. For an adaptive design of experiments, Bayesian optimization is used to achieve the objectives of the DME process while efficiently optimizing the design variables. In addition, we also optimize the design variables considering variations in the temperature and pressure data, meaning robust Bayesian optimization. The proposed method successfully identifies design variables that satisfy all experimental targets in an average of 54 simulations while achieving 100% of the targets with product purity 0.95-1.00, amount of DME in the product 350-845 kmol/h, and CO2 emissions 0-835 kmol/h, confirming the effectiveness of the proposed robust Bayesian optimization method.

Estimating the effect of the main design parameters on the effectiveness of high-purity hydrogen production from raw hydrocarbons in membrane catalytic devices

The paper presents the results of the application of a physically grounded mathematical model, verified through numerous practical examples, intended for estimating the effect of some design factors (membrane thickness and the system of high-purity hydrogen outlet from the under-membrane space of membrane elements) on the effectiveness and efficiency of the production of highly pure hydrogen from the products of steam conversion of hydrocarbons in advanced membrane catalytic devices.

Modulating electrodeposition of ultralow Pt into 2D MoCu-POMOF-derived MoO2/MoOC for boosted hydrogen evolution reaction

Electrochemical water splitting is regarded as a promising technology for production of high purity, high volume hydrogen. It is critical to create robust and highly active electrocatalysts in order to minimize the cost of hydrogen generation and enable large-scale commercial production. In this work, a new 2D MoCu-POMOF, [Cu(4-pyz)]4@(PMo12O40) (4-pyz = 4-(pyridin-4-yl)benzoic acid) was prepared by a simple hydrothermal method, in which PMo12 nanocluster was encapsulated into cavity of 2D Cu-MOF. The successful establishment of the model in addition to the goal of uniformly dispersed Mo sources target oxygen-rich PMo12 nanoclusters can also provide rich Mo source and self-oxidative properties for MoO2 formation. Cu-MOF provides a special layered structure, which ensures the integrity and stability of the structure and provides a rich C source for pyrolysis and improves the conductivity. Ultralow Pt nanoparticles can reduce free energy of hydrogen evolution, which are embedded in MoO2/MoOC with porous structure and high electrochemical active surface area. MoO2/MoOC and highly dispersed Pt nanoparticles synergistically promote the HER catalysis. Pt@MoO2/MoOC demonstrated the excellent HER activity with a low overpotential of 98.99 mV vs. RHE. This work yielded highly active and high stability molybdenum-based HER electrocatalysis and provides the potential for energy conversion.

Comparative study of electroreduction of iron oxide using acidic and alkaline electrolytes for sustainable iron production

Sustainable iron production is largely driven by the urgency to reduce the extensive energy consumption and emissions in the iron/steel sectors. Low-temperature electroreduction of iron oxide technology is thus revived since it directly utilizes (green) electrical energy with a competitive energy consumption compared to the thermochemical reduction approach. In the present work, we perform theoretical and experimental studies for comparison of electroreduction of iron oxide in aqueous alkaline and acidic electrolytes. Electrochemical reduction and deposition behavior are experimentally investigated using a lab-scale cell containing an electrolyte suspended with micron-sized Fe2O3 (hematite) powders. The effects of current density and hematite mass fraction on current efficiency are evaluated, as well as the total energy consumption. Results of chrono-potentiometry and cyclic voltammograms (CV) reveal the electrochemical properties of each system. The CV's cathodic peaks, corresponding to the reduction of iron oxides to iron, are observed only in the alkaline system where the iron oxide can be reduced at about −1.4 V (vs. Ag/AgCl). It is also found that the alkaline system has higher current efficiency (25–30% higher) and lower energy consumption (∼30% lower) than the acidic system. The cleaning of the deposit is also easier for the alkaline system, resulting in an iron product of high purity. Concerning the electrochemical performances and practicality, the alkaline electroreduction system shows promising potential for sustainable iron production.

Ionic liquids for highly efficient methyl chloride capture and dehydration

AbstractA new methyl chloride (CH3Cl) capture and dehydration process using two ionic liquids (ILs) was designed and systematically studied. ILs [EMIM][Ac] and [EMIM][BF4] were screened out as CH3Cl capture and drying absorbents through the COSMO‐RS model. The result of solubility experiment suggests [EMIM][Ac] has an excellent solvent capacity for CH3Cl at mild operation conditions. The bench‐scale CH3Cl absorption experiments further confirmed the outstanding CH3Cl capture ability of [EMIM][Ac]. Besides, the water content of outlet gas can be decreased to 452 ppm (mass fraction) using [EMIM][BF4] in the dehydration experiment. The industrial‐scale CH3Cl capture and dehydration process was simulated and optimized. Compared to the benchmarked triethylene glycol process, IL process has higher product purity (99.99 wt%), and lower energy consumption. The quantum chemical calculations clearly revealed the relationship between hydrogen bond and separation performance. This study provides a decision‐making basis for designing green process associated with volatile organic compounds.

State-of-the-art and novel approaches to mild solubilization of inclusion bodies.

Throughout the twenty-first century, the view on inclusion bodies (IBs) has shifted from undesired by-products towards a targeted production strategy for recombinant proteins. Inclusion bodies can easily be separated from the crude extract after cell lysis and contain the product in high purity. However, additional solubilization and refolding steps are required in the processing of IBs to recover the native protein. These unit operations remain a highly empirical field of research in which processes are developed on a case-by-case basis using elaborate screening strategies. It has been shown that a reduction in denaturant concentration during protein solubilization can increase the subsequent refolding yield due to the preservation of correctly folded protein structures. Therefore, many novel solubilization techniques have been developed in the pursuit of mild solubilization conditions that avoid total protein denaturation. In this respect, ionic liquids have been investigated as promising agents, being able to solubilize amyloid-like aggregates and stabilize correctly folded protein structures at the same time. This review briefly summarizes the state-of-the-art of mild solubilization of IBs and highlights some challenges that prevent these novel techniques from being yet adopted in industry. We suggest mechanistic models based on the thermodynamics of protein unfolding with the aid of molecular dynamics simulations as a possible approach to solve these challenges in the future.

Rare Earth Elements Recovery from Primary and Secondary Resources Using Flotation: A Systematic Review

Rare earth minerals (REMs) contain rare earth elements (REEs) that are important in modern technologies due to their unique magnetic, phosphorescent, and catalytic properties. However, REMs are not only non-renewable resources but also non-uniformly distributed on the Earth’s crust, so the processing of REE-bearing secondary resources via recycling is one potential route to ensure the long-term sustainability of REE supply. Flotation—a method that separates materials based on differences in their surface wettability—is a process applied for both mineral processing and recycling of REEs, especially when the particles are fine and/or a high-purity product is required. In this review, studies about rare earth flotation from 2012 to 2021 were systematically reviewed using the PRISMA guideline. It was found that most REM flotation research works focused on finding better collectors and depressants while, for recycling, studies on advanced flotation techniques like froth flotation, ion flotation, solvent sublation, electroflotation, and adsorbing colloid flotation with an emphasis on the recovery of dissolved REEs from aqueous solutions dominated.

Recent advances and prospects in high purity H2 production from sorption enhanced reforming of bio-ethanol and bio-glycerol as carbon negative processes: A review

Hydrogen has wide applications in the chemical and petroleum industries and is a clean energy carrier for electrical power generation and transportation. However, in current industries, H2 is mainly obtained from the steam reforming of natural gas and coal gasification, which resulted in huge emissions of CO2 (greenhouse gasses) and high energy consumption for H2 purification. Hence, developing H2 production technology in sustainable routes with low carbon emissions is still urgent. Sorption-enhanced steam reforming of bio-ethanol (SESRE) and sorption-enhanced steam reforming of bio-glycerol (SESRG), which coupled in-situ CO2 capture with the steam reforming of bio-ethanol or bio-glycerol, are promising strategies to yield high purity of H2 without emitting CO2 into the atmosphere. In these strategies, high purity of H2 can be produced when the high energy-consumption process such as H2 purification is avoided; besides, negative CO2 emissions can be achieved when the captured CO2 is used or sequestered. The catalysts play a pivotal role in the steam reforming processes, and the dual-functional materials (DFMs) are well regarded as the most promising solid catalysts that contribute to high-purity H2 production and CO2 capture. Thus far, there is no criterion to guide DFMs engineering for H2 generation in the SESRE and SESRG processes. Hence, in this work, a comprehensive review of the recent advances and prospects in SESRE and SESRG is presented, which provides constructive insight into the development of SESRE and SESRG technology. The optimum operating conditions in the SESRE and SESRG systems are analyzed via thermodynamics and kinetics, and the recent research progress of the DFMs is critically reviewed. Furthermore, the reforming reaction pathways and reaction mechanisms were discussed to improve the understanding of DFMs design. Finally, the prospect and challenges in the SESRE and SESRG strategies are outlooked.

Green synthesis of SiO2 nanoparticles from Egyptian white sand using submerged and solid-state culture of fungi

This work aims to successfully produce silica nanoparticles (SNPs) from Egyptian white sand using the fungal bioleaching process as a cost-effective and eco-friendly approach. The impact of fungus cultivation techniques (submerged culture SMC and solid-state culture SSC) on the characteristics of the produced SNPs has been investigated. In addition, the most promising fungal isolates for each culture method were selected and identified by morphological and molecular methods. The biosynthesized SNPs were fully characterized by DLS, FTIR, XRD, SEM, EDX, and HRTEM studies. DLS results showed that Aspergillus niger solid-state culture had developed SNPs with a mean particle size distribution of about 3.6 nm, whereas Penicillium crustosum submerged culture developed SNPs with 50.7 nm. SEM images revealed that the prepared SNPs under SMC and SSC have sphere-shaped particles with smooth surfaces and semi-homogeneous characteristics. Moreover, the HRTEM imaging confirmed the spherical shape with an average size of 3.5 and 28.8 nm for the nanosilica synthesized during solid-state and submerged culture, respectively. Based on the results, we recommended using SSC to produce silica nanoparticles from white sand with a small nano-size, high purity, and better economical production. The scientific advances focused on some particular fungi's capacity to manufacture SNPs with high purity, small size, and techniques that were both economical and environmentally beneficial.Graphical

A highly carboxylated sponge-like material: preparation, characterization and protein adsorption

Producing of high-purity protein products using separation materials is critical to the biopharmaceutical industry. Efforts to achieve protein adsorption materials with large adsorption capacity and high processing efficiency have been challenging. Herein, a highly carboxylated sponge-like monolithic adsorbent material was prepared by using SiO2 nanofibers as a rigid support framework, and esterification crosslinking reactants with polyvinyl alcohol (PVA)/polymeric carboxylic acid (polyacrylic acid, PAA) as a functional organic binder, which were modified in situ on the nanofiber framework. The obtained PVA/PAA sponge-like monolithic adsorbent material (PVA/PAA SMAM) exhibits a porous structure and possesses mechanical stability and recoverability of underwater compression. The high porosity provides more sites for carboxyl groups, making PVA/PAA SMAM rich in carboxyl groups. Experiments showed that PVA/PAA SMAM selectively adsorbes proteins with high isoelectric points. Using Cytochrome C (Cyt-C) as the main model protein with a high isoelectric point, the maximum adsorption of Cyt-C by the PVA/PAA SMAM at pH = 9 was 3079.3 mg/g with a rapid equilibration time (40 min), which is clearly superior to the currently reported Metal-organic frame structure (MOF) composites for Cyt-C adsorption. The isothermal adsorption model for the Cyt-C adsorption of the PVA/PAA SMAM material agrees well with the Freundlich adsorption model and the quasi-first kinetic model. Excellent mechanical and chemical structural stability endow the PVA/PAA SMAM material with protein elution capacity and good reusability, and secondary structure of the protein after elution was unchanged. Subsequently, selective adsorption and separation of Cyt-C from porcine heart supernatant was successfully achieved with PVA/PAASMAM material. This work provides new materials with excellent performance for various bio-separation applications.

Recycling of lithium and fluoride from LiF wastewater from LiF synthesis industry by solvent extraction

The LiF synthesis industry produces a large amount of wastewater that contains ∼0.36 g/L lithium and ∼1.10 g/L fluorine. The traditional treatment solidified fluoride by excessive CaO, resulting in waste of lithium resources and generation of CaF2-CaO solid waste. To recover the Li and F from the LiF wastewater, a two-section solvent extraction process using acidic solvent and mixed solvent as organic solvent was designed and the extraction mechanism were systematically investigated. The result showed that Li extraction was extracted by a cation exchange mechanism with D2EHPA (di-2-ethyl hexyl phosphoric acid), 99.72% Li recovery and battery-grade LiCl solution (3.40 g/L) were achieved by mixed the LiF aqueous with the saponified D2EHPA at 25 ℃ for 6 mins with 4.60 equilibrium pH. After then, F was recovered by mixed neutral solvent system, which coordination binding with HF molecule. The ultimately residue contains ∼1 mg/L Li and < 6 mg/L F. Besides, high-purity LiF products (LiF>99.95%) was generated by stripping with LiOH, F recovery is 99.45%. 2-stage extraction process realizes lithium and fluoride recovery with short process, no pollution and great prospect of industrialization.

A dual-cycle regeneration to recover high-value and high-purity FePO4 from real wastewater for Li-battery application

The recovery of high-purity and high-value FePO4 raw materials from wastewater has great prospects in LiFePO4 battery industry due to the huge demand for new energy vehicle. However, the conventional in-situ FePO4 precipitation, as well as ex-situ PO43− adsorption-alkali regeneration, was incapable of efficiently obtaining high-purity products. To solve these problems, a dual-cycle regeneration method of Fe-NH2-polyacrylonitrile (PAN) adsorbent and H2SO4 desorbing solution was proposed to ex-situ FePO4 recovery from wastewater for Li-battery application. Benefitted from coordination interaction and electrostatic attraction, the maximum PO43− adsorption capacity of Fe-NH2-PAN reached 73.1 ± 0.4 mg/g. The average PO43− removal rate of continuous flow devices were 88.5% and 91.3% when treating low-P-concentration (0.22 mg/L) municipal wastewater (MW) and high-P-concentration (48.9 mg/L) slaughterhouse wastewater (SW) respectively. Furthermore, high-purity FePO4 analyzed by XRD spectra was achieved from the desorption solution at pH ∼1.6, resulting in the ultrahigh P recovery efficiencies of 91.4 ± 3.2%−96.3 ± 2.5% for SW and 82.7 ± 3.5% for MW. Besides, the LiFePO4/C electrodes made of recycled FePO4 exhibited a better discharge capacity (37.3 − 55.8 mAh/g) than that of commercial FePO4 agent (32.2 − 35.1 mAh/g) from 80 to 132 cycles, which showed the promising feasibility of recovering FePO4 from wastewater for Li-battery application.

Dynamic modeling and optimal control of reactive batch distillation: An experimental case study

In the present study, dynamic modeling, optimal operation and control of a reactive batch distillation process is illustrated based on experimental and simulation studies using methyl acetate production case study. An equilibrium stage model, incorporating non-ideal VLE and start-up region of heating, is developed based on data generated on an experimental unit by identifying five input parameters representing uncertainties. The optimal control problem is solved using genetic algorithm, considering the objective function identified on the basis of trend analysis using the developed dynamic model, to find the optimal reflux ratio, heat input to the reboiler, and mole ratio of methanol to acetic acid in the initial reaction mixture. Open-loop and closed-loop implementations clearly illustrate the improved performance with respect to the quantity of methyl acetate in the distillate product with a reasonably high conversion and product purity within reasonably short batch duration, illustrating the successful optimal control implementation experimentally.