Neutralization Process Research Articles

Integrated system for electrolyte recovery, product separation, and CO2 capture in CO2 reduction

Challenges in CO2 capture, CO2 crossover, product separation, and electrolyte recovery hinder electrocatalytic CO2 reduction (CO2R). Here, we present an integrated electrochemical recovery and separation system (ERSS) with an ion separation module (ISM) between the anode and cathode of a water electrolysis system. During ERSS operation, protons from the anolyte flow through the anodic cation exchange membrane (CEM) into the ISM, acidifying the CO2R effluent electrolyte. Cations like K+ in the ISM flow through the cathodic CEM into the catholyte to balance the OH− ions from hydrogen evolution. ERSS recycles electrolyte-adsorbed CO2, recovers KOH with a 94.0% K+ yield, and achieves an 86.2% separation efficiency for CO2R products. The recovered KOH can capture CO2 from air or flue gas or be utilized as a CO2R electrolyte, closing the CO2 capture, conversion, and utilization loop. Compared to the conventional acid-base neutralization process, ERSS saves $119.76 per ton of KOH recovered and is applicable to other aqueous alkaline electrosynthesis reactions.

DETERMINATION OF MACRONUTRIENTS CONCENTRATION IN DRY FOLLIAGE OF SOPHORA MOLLIS TO USE GREEN LUMEN AS ORGANIC FERTILIZER

Background: Optimal plant growth and successful crop production rely on the availability of essential macronutrients, which include nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). These nutrients play critical roles in plant metabolism, soil fertility, and sustainable agriculture. Sophora mollis, a small deciduous shrub of the Fabaceae family, holds potential as an organic fertilizer due to its nutrient-rich foliage. Investigating its macronutrient profile provides insights into its suitability for addressing soil nutrient deficiencies and enhancing agricultural productivity. Objective: The aim of this study was to evaluate the macronutrient concentrations in the dry foliage of Sophora mollis and to assess its potential as an organic fertilizer for improving soil fertility and supporting sustainable agriculture. Methods: The research involved the collection of dry foliage from Sophora mollis plants in various regions of Skardu, Gilgit-Baltistan. The samples were dried, powdered, and analyzed in the laboratory. Nitrogen content was determined using the Kjeldahl method, which involved digestion, neutralization, distillation, and titration processes. The concentrations of phosphorus, potassium, calcium, and magnesium were analyzed using UV-Visible spectrophotometry. Appropriate standards were prepared for calibration, and the macronutrient concentrations were calculated based on established protocols. Results: The dry foliage of Sophora mollis demonstrated macronutrient concentrations of 3.9% nitrogen, 0.6% phosphorus, 4.2% potassium, 2.4% calcium, and 0.8% magnesium. These values closely aligned with the sufficient ranges required for plant growth. The results highlighted the nutrient-rich profile of Sophora mollis, indicating its potential as a sustainable organic fertilizer. Conclusion: The study concluded that the dry foliage of Sophora mollis is a promising source of essential macronutrients and can serve as an effective organic fertilizer. Its use in sustainable agricultural practices can improve soil fertility and support crop productivity, particularly in tropical and subtropical regions.

Optimization of chitosan-gelatin-based 3D-printed scaffolds for tissue engineering and drug delivery applications

The combination of biocompatible materials and advanced three-dimensional (3D) additive manufacturing technologies holds great potential in the development of finely tuned complex scaffolds with reproducible macro- and micro-structural characteristics for biomedical applications, such as tissue engineering and drug delivery. In this study, biocompatible printable inks based on chitosan, collagen and gelatin were developed and 3D-printed with a pneumatic-based extrusion printer. The printability of various chitosan–gelatin (CS-Gel) hydrogel inks was assessed by evaluating the quality of the printed constructs. The inks required an extrusion pressure of 150 ± 40 MPa with G22 and G25 nozzles for optimal printing. Inks with low chitosan concentrations (<4% w/v) exhibited poor printability, while inks with 4 % w/v chitosan and 1 % w/v gelatin (CG) demonstrated satisfactory extrusion and printing quality. The addition of collagen (0.1 % w/v) to the optimized ink (CGC) did not compromise printability. Post-printing stabilization using KOH produced self-supporting scaffolds with consistent morphological integrity, while weaker bases like NaOH/EtOH and ammonia vapors resulted in lower pore sizes and reduced structural stability. Water evaporation studies showed that neutralized samples had slower evaporation rates due to the strong intermolecular interactions formed during the neutralization process, contributing to a stable crosslinked network. FTIR spectra confirmed the formation of polyelectrolyte complexes in the CS-Gel and CS-Gel-Collagen blends, further enhancing structural stability. Swelling tests indicated that neutralized constructs maintained stability in different pH environments, with KOH-treated samples exhibiting the lowest swelling ratios and the highest structural stability. After optimizing the ink composition, 10 wt% Levofloxacin was loaded in the constructs as a model antibiotic and it’s in vitro release rate was quantified. Drug loading was approximately 4 % for both ink compositions GC and CGC. CG Levo released over 80 % of levofloxacin within the first hour, reaching full release in 24 h, indicating inadequate control, while CGK Levo exhibited slower initial release (55 % in 15 min) followed by stabilized release after 4 h, likely due to controlled diffusion from expanded constructs. These findings demonstrate that the developed hydrogel inks and optimized printing parameters can produce scaffolds suitable for tissue engineering applications. Finally, the cell compatibility of the 3D-printed constructs was confirmed with MTT assay on fibroblasts and the antimicrobial activity of the drug-loaded constructs was tested against E. coli and S. aureus, showing an increase of the bacteria free zone from 8 ± 0.4 mm of the control against E. coli up to 16.4 ± 0.37 mm in the presence of the KOH-treated CG Levo printed construct.

Effect of the cation-to-anion mass ratio of ionic liquid on plume neutralization characteristics for novel electrospray thruster

Abstract The ionic liquid electrospray thruster (ILET), a promising technology for space electric propulsion, has been gaining attention due to its theoretical capability to operate without an external neutralizer, which is a key component for traditional ion thrusters. Some experiments have shown that the cation-to-anion mass ratio significantly affects the self-neutralization of thruster plumes, but further depth research is still needed. Therefore, numerical simulations of ion emission process both in uni-thruster and bi-thruster modes of ILETs are conducted using particle-in-cell method, to investigate the effect of the cation-to-anion mass ratio in ionic liquid on plume neutralization characteristics. In bi-thruster mode, the anions and cations are emitted simultaneously, while in uni-thruster mode, only anions or cations are emitted under the action of electric field force. Plume neutralization characteristics of four ionic liquid propellants, with different cation-to-anion mass ratio, in bi-thruster mode are obtained and compared to the uni-thruster mode. The results show that the plume profile morphology is significantly dependent on operating mode of the thruster and the cation-to-anion mass ratio of ionic liquid. Unlike the circular profile in uni-thruster mode, the plume in bi-thruster mode exhibit distortion with vertical stratification. The contours of the high-potential region in bi-thruster mode also distort, showing stratification and a V-shape, respectively, influenced by the mass ratio. Ion beam neutralization in bi-thruster mode is primarily achieved through the horizontal displacement of anion and cation beams, as well as their interactions. The cation-to-anion mass ratio influences the oscillation effects of the mass center in anion and cation clouds during neutralization, which in turn affects the neutralization effect. Ionic liquids with a significant mass ratio difference between cations and anions necessitate a longer time and greater distance for neutralization under identical conditions. These findings are instrumental for understanding the plume neutralization process and advancing the design of ILETs.

Electrocatalytic Hydrogenation of Pyridines in an Anion-Exchange Membrane (AEM) Reactor and Its Mechanistic Analysis by in Situ XAFS Measurement

Cyclic amines are useful compounds used as building blocks of pharmaceuticals. According to the US Food and Drug Administration (FDA), approximately 20 % of small molecular pharmaceuticals contain cyclic amines, which can be obtained by hydrogenation of nitrogen-containing aromatic compounds. Notably, piperidines are prominent among inhibitor, antihistamine, and anesthetic. [1] A number of reactions using homogeneous [2] and heterogeneous [3] catalysts have been reported for the production of cyclic amines via hydrogenation of nitrogen-containing aromatic compounds. However, these require high temperature and high-pressure conditions and H2 gas as a reductant, leading to a large amount of energy consumption and CO2 emission. In addition, acid is also used in these hydrogenation reactions to activate the nitrogen-containing aromatic compounds in some cases. However, this procedure requires neutralization and purification processes in the reaction workup, and causes corrosion of the reactor. In contrast, electrochemical hydrogenation of nitrogen-containing aromatic compounds is a promising method because electrochemical reactions can be carried out under mild conditions. For example, the reduction of pyridine to piperidine requires six electrons and six protons. However, it is difficult to obtain the desired piperidine by direct electron transfer through conventional cathodic reduction because of the formation of radical anions, resulting in dimerization and partial hydrogenation reactions. [4] In this work, we developed an electrocatalytic hydrogenation system using an anion exchange membrane (AEM) reactor. Using an AEM reactor equipped with carbon-supported Rh as the cathode catalyst, the hydrogenation of pyridine to piperidine was achieved at ambient temperature and pressure without any additives in the catholyte.To gain insights into the reduction behavior of carbon-supported Rh during electrolysis, we also performed Rh K-edge in situ X-ray absorption fine structure (XAFS) measurements using a tailor-made AEM reactor equipped with polyimide windows for the X-rays. As a result, Rh (0) was found to be an active catalyst for the electrocatalytic hydrogenation of pyridine.The authors gratefully acknowledged support by JST CREST Grant No. JP65R1204400, Japan.[1] E. Vitaku, D. T. Smith, and J. T. Njardarson, J. Med. Chem. 2014, 57, 10257–10274.[2] R. Adam, J. R. Cabrero-Antonino, A. Spannenberg, K. Junge, R. Jackstell, and M. Beller, Angew. Chem. 2017, 129, 3264–3268.[3] K. Murugesan, V. G. Chandrashekhar, C. Kreyenschulte, M. Beller, R. V. Jagadeesh, Angew. Chem. Int. Ed. 2020 , 59, 17408–17412.[4] J. G. Keay Comprehensive Organic Synthesis 1991, 8, 579-602. Figure 1

A novel neutralization process for improving dehydration performance of industrial by-product gypsum

By-product gypsum, produced through the traditional neutralization precipitation method for treating industrial acidic wastewater, is difficult to recycle due to its high moisture content. In this study, we proposed a novel neutralization process i.e. the two-stage neutralization method. By-product gypsum was used as an alkaline neutralizer and recycled as seed crystals for the first time. The original by-product gypsum has the poor dehydration performance due to its small particle size and the presence of colloids on its surface. After adding the by-product gypsum to the acidic wastewater, the ratio of CaO/SO3 in the system descended and colloids were dissociated. On the one hand, the alkaline component of the incomplete reaction continues to play a neutralizing role. On the other hand, CaSO4·2H2O particles act as seed crystals, promoting rapid growth of new crystals along their surface, which effectively improved crystallization performance and dehydration performance of the neutralization slag (outward discharge of slag). Compared with the original method, the wet weight of the neutralization slag is decreased from 186.0 g/L to 88.8 g/L, and the water cut is declined from 64.5 % to 34.1 %. The utilization ratio of the carbide slag augmented from 63.0 % to 99.47 %.

A new process for preparing ultrafine WC-Co cemented carbide by doping yttrium within the ammonium metatungstate solution

Ultrafine WC-Co cemented carbide has superior performance of high strength and high hardness, which is widely used in industrial fields. In the traditional process, high temperature carburization method is used to prepare tungsten carbide, and solid-phase mechanical milling method is used to mix grain growth inhibitor (Cr3C2) and tungsten carbide, which easily lead to large WC particle size and uneven WC grain size distribution in WC-Co cemented carbide, thus affecting mechanical properties of the alloy. In the new process, based on the genetic relationship between the particle size of ammonium paratungstate and tungsten carbide, ultrafine ammonium paratungstate uniformly doped with yttrium was firstly obtained by adding a certain amount of ammonia and yttrium oxide into the ammonium metatungstate solution. Then the ammonium paratungstate was calcined to obtain yttrium-doped tungsten trioxide, which was then converted into yttrium-doped ultrafine tungsten carbide powders by introducing carbon monoxide at a low temperature. Finally, the ultrafine WC-Co cemented carbide was prepared by pressure sintering. During the neutralization and crystallization process of ammonium metatungstate solution, the yttrium-doped ultrafine ammonium paratungstate (Fischer particle size 8.4 μm) with narrow particle size distribution and regular morphology was prepared. The yttrium-doped ammonium paratungstate was calcined at 500 °C for 90 min in air atmosphere to obtain yttrium-doped tungsten trioxide powder with a Fischer particle size of 4.5 μm and narrow size distribution. Then the yttrium-doped tungsten trioxide and carbon monoxide gas were reacted at 920 °C for 3h to obtain yttrium-doped ultrafine tungsten carbide powder with a Fischer particle size of 0.32 μm and a specific surface area of 4.44 m2/g, and ultrafine WC-Co cemented carbide with tungsten carbide grain size of 0.28 μm was obtained by pressure sintering. The yttrium uniform distributed effectively inhibited the abnormal growth of tungsten carbide grains. Compared with the WC-Co cemented carbide prepared by solid-phase mechanically mixing tungsten carbide powder and chromium carbide, the yttrium-doped WC-Co cemented carbide had a smaller average tungsten carbide grain size and a more homogeneous microstructure. The prepared yttrium-doped WC-Co cemented carbide had a hardness (HRA) of 94.6, a bending strength of 4841 M, and a coercive force of 42.3 KA/c.

Hybrid Model using Bond Graph-TCN Network and Event Triggered Predictive Control of pH Neutralization Process

The pH neutralization process is a concrete decisive unit in major reactor units of industrial process control loops. This article presents a new fuzzy-based hybrid 'Bond Graph-Temporal Convolution Network' (BG-TCN) model, structured for the convoluted dynamics of a real-time pH neutralization unit, known for its complexity and high nonlinearity. The TCN scheme suggested in this article, exploits a one-dimensional causal convolution strategy within a residual learning framework to execute dilated causal convolutions through time series data analysis. Conversely, Bond Graph (BG) is a graphical tool, designed on an energy-centric approach, to represent energy transfer and interactions across different compartments of the nonlinear pH neutralization system. Furthermore, a linguistic fuzzy rule-based inference system is encompassed to handle uncertainties from BG and TCN models, allowing smooth integration and flexible transition between these two approaches. Additionally, the performance of the hybrid BG-TCN model is assessed against the individual TCN and BG models in a Python environment. On top of that, this article also envisions an event-triggered predictive control utilizing a fuzzy event handler mechanism to demonstrate the efficacy of the proposed hybrid BG-TCN in attaining precise set point tracking for closed-loop servo and regulatory problems.

In-silico Studies, Synthesis, and Antacid Activities of Magnesium (II) Complexes.

Nowadays, acidity is a severe problem worldwide caused by excessive gastric acid secretion by the stomach and proximal intestine. Antacids are drugs capable of buffering stomach acid. Therefore, in our research work, we have reported the in-silico studies, synthesis, characterization, and evaluation of antacid activities of magnesium (II) complexes via the acid-base neutralization process. In this research, some magnesium complexes were synthesized and their antacid behavior was compared with marketed products. Also, in-silico studies were performed on H+/K+ ATPase (Proton pump). All synthesized compounds were characterized by various spectroscopic techniques like UV-Vis, FT-IR, XRD, and DSC techniques. Spectroscopic analysis results showed that the semicarbazone ligand shows keto-enol isomerism and forms a coordinated stable complex with magnesium ions in the crystalline phase. The FT-IR results confirmed the presence of Mg-O stretching, N-H bending, and C=N stretching vibrations in Mg (II) complexes. The antacid activities of Mg (II) complexes were excellent as compared to the semicarbazone ligand and comparable with that of marketed antacid drugs like ENO, and Pantop-D. Insilco studies also confirmed that semicarbazone ligand and its Mg (II) complexes were both found to be fitted into the active sites of molecular targets, and Mg (II) complexes showed better binding affinities towards macromolecular as compared to semicarbazone ligand.

Comprehensive research facility for negative ion source neutral beam injection at CRAFT: design and first operations

Abstract Neutral beam injection (NBI) has been proven as a reliable heating and current drive method for fusion plasma. For the high-energy NBI system (particle energy &gt; 150 keV) of large-scale fusion devices, the negative ion source neutral beam injection (NNBI) system is inevitable, which can obtain an acceptable neutralization efficiency (&gt; 55%). But the NNBI system is very complex and challengeable. To explore and master the key NNBI technology for future fusion reactor in China, an NNBI test facility is under development in the framework of the Comprehensive Research Facility for Fusion Technology (CRAFT). The initial goal of CRAFT NNBI facility is to achieve a 2 MW hydrogen neutral beam at the energy of 200–400 keV for lasting 100 s. In the first operations of the CRAFT NNBI facility, a negative ion source with dual RF drivers was developed and tested. By using the 50 keV accelerator, the long-pulse and high-current extractions of negative hydrogen ions have been achieved and the typical values were 55.4 keV, 7.3 A (~ 123 A/m2), 105 s and 55.0 keV, 14.7 A (~ 248 A/m2), 30 s, respectively. By using the 200 keV accelerator, the megawatt-class negative hydrogen beam has also been achieved (135.9 keV, 8.9 A, 8 s). The whole process of the gas neutralization of negative ion beam, electric removal of residual ions, and beam transport have been demonstrated experimentally.

Scenario Design for the Evaluation of Human–Machine Interaction in Modular Process Plants

AbstractOperators in modular process plants face new demands due to features like increasing automation and digitalization combined with an architecture allowing for reconfigurations in short time spans. However, operators must be able to master process control tasks at all times. For research purposes on topics like supporting operators in their performance in process control of modular process plants, this article aims at developing scenarios of such plants. Based on three conceptual levels describing the relation of chemical processes and their modularized realization and a neutralization process as use case, four scenarios were developed. Having the common task to increase the throughput, the scenarios differ in terms of complexity and constraints that need to be considered for process control.

Исследование методов и современных технических решений очистки аэрозольных выбросов промышленности

The analysis and characterization of aerosol emissions into the atmosphere are given, the ways of formation of primary and secondary aerosols are considered. The process of atmospheric aging of aerosols, which has a negative impact on the environment, is considered. The functional links between aerosol emissions, their source and impact on climate and public health are presented. The possible influence of the reactions of liquid and solid aerosol particles on the properties of atmospheric air is considered. The main methods of purification of industrial aerosol emissions are considered: adsorption purification, thermal and catalytic neutralization, chemisorption and absorption purification. The ways of increasing the efficiency of adsorption processes, for example, the separation of adsorbent in the apparatus, are analyzed. The essence of the process of thermal neutralization of gas mixtures is described, it is established that thermal installations based on the direct combustion method work more efficiently when combining thermal and catalytic neutralization methods, designs of combined equipment are presented, and ways to increase the intensity of the apparatus are considered. The process of gas purification based on the absorption process is considered. It is determined that absorption plants for cleaning gases from harmful components are the most effective and efficient due to the high level of technical implementation of the process. The development and improvement of the main absorber equipment is aimed at achieving maximum cleaning efficiency with an optimal pressure drop that determines energy consumption. The analysis shows the negative impact of natural and anthropogenic aerosols on the environment. In order to correctly solve the problem, information on the sources, composition and properties of aerosols is needed to select the most effective and economically profitable cleaning method, which will help reduce the anthropogenic load on the atmosphere.

A model free adaptive control method based on self-adjusting PID algorithm in pH neutralization process

In this paper, a new model free adaptive control method based on self-adjusting PID algorithm (MFAC-SA-PID) is proposed to solve the problem that the pH process with strong nonlinearity is difficult to control near the neutralization point. The MFAC-SA-PID method also solves the problem that the parameters of the model free adaptive control (MFAC) method are not easy to be adjusted and the effect is not obvious by introducing a fuzzy self-adjusting algorithm to adjust the controller parameters. Then the convergence and stability of the MFAC-SA-PID method are proved in this paper. In the simulation study, the control performance of the MFAC-SA-PID method proposed in this paper is compared with the traditional MFAC method and the improved model free adaptive control (IMFAC) method, respectively. The results show that the proposed MFAC-SA-PID method has better control effect on the pH neutralization process. The MFAC-SA-PID control performance also outperforms the traditional MFAC method and IMFAC method when step input disturbances are added, which indicates that the MFAC-SA-PID method has better robustness and stability.

Utilisation of acid-tolerant bacteria for base metal recovery under strongly acidic conditions.

Hydrometallurgical bioprocesses for base metal recovery in environmentally friendly electronic device waste (e-waste) recycling are typically studied under neutral pH conditions to avoid competition between metals and hydrogen ions. However, metal leachate is generally strongly acidic, thus necessitating a neutralisation process in the application of these bioprocesses to e-waste recycling. To solve this pH disparity, we focused on acid-tolerant bacteria for metal recovery under strongly acidic conditions. Four acid-tolerant bacterial strains were isolated from neutral pH environments to recover base metals from simulated waste metal leachate (pH 1.5, containing 100 or 1000 mg L-1 of Co, Cu, Li, Mn, and Ni) without neutralisation. The laboratory setting for sequential metal recovery was established using these strains and a reported metal-adsorbing bacterium, Micrococcus luteus JCM1464. The metal species were successfully recovered from 100 mg L-1 metal mixtures at the following rates: Co (8.95%), Cu (21.23%), Li (5.49%), Mn (13.18%), and Ni (9.91%). From 1000 mg L-1 metal mixtures, Co (7.23%), Cu (6.82%), Li (5.85%), Mn (7.64%), and Ni (7.52%) were recovered. These results indicated the amenability of acid-tolerant bacteria to environmentally friendly base metal recycling, contributing to the development of novel industrial application of the beneficial but unutilised bioresource comprising acid-tolerant bacteria.

Investigation on Tensile Properties of Polylactide-Nanoclay (PLA/ MMT) Surface Modification Nanocomposites

Polylactic acid (PLA) has gained significant attention as an environmentally friendly biopolymer, but its limited mechanical properties have hindered broader applications. Nanoparticles such as montmorillonite (MMT) offer a promising approach to address this limitation. The intercalation of MMT with polymer chains can significantly impact the mechanical properties of the nanocomposites. Hence, this paper investigated the effect of surface-modified montmorillonite (MMT) nanoparticles on the mechanical properties of polylactic acid (PLA) nanocomposites. The acetylation process of MMT was carried out followed by neutralisation process with NaOH. PLA granules and acetylated-modified MMT were mixed, crushed into granular form, and moulded. The effect of varying concentrations of modified MMTs on the tensile strength, elongation at break, and maximum force of PLA/MMT nanocomposites was evaluated using the ASTM D638 standard. FTIR results showed shifts in peak intensities in regions 2750 cm-1- 2810 cm-1 led to changes in the aliphatic and aromatic regions, which confirmed the presence of acetylation. Controlled surface modification improved interfacial interactions and load distribution, enhancing overall mechanical performance. The incorporation of surface-modified MMT in PLA/MMT nanocomposite increased the maximum force, Young's modulus, elongation at breaks and tensile strength. PLA/1wt% MMT and the PLA/7wt% MMT compositions exhibited good mechanical properties. However, the PLA/5 wt% MMT blendis deemed more suitable for food applications, such as disposable cups, plates, and cutleries, due to its lower elongation point. In conclusion, the hydrophilic properties of MMT and the hydrophobic properties of PLA are compatible due to the synergistic effects during surface modification which enhance the overall performance of the nanocomposites.

Impact of energy consumption patterns on peak emissions in China's carbon neutralisation process

The investigation of the impact of energy consumption patterns on peak emissions in China is pertinent and crucial for achieving global climate goals. The study aims to form a forecast of carbon emissions in China and diagnose the achievement of established decarbonization goals based on structural changes in primary energy consumption until 2030. To achieve the goal, the study formed a Dynamic stochastic general equilibrium (DSGE) model with the implementation of Markov chains. The obtained research results yield important insights into the influence of various scenarios on carbon emissions in China by the year 2030. Specifically, considering structural transformations, an increase in emissions by 15 % can be anticipated, which is 7 % less than predicted by the classical scenario. Among the proposed scenarios, the Net Zero scenario is deemed the most efficient, where emissions could reach a level of 8509.5 million tons of CO₂. Conversely, the New Momentum scenario proves to be the most precarious, as it entails an escalation in coal usage, leading to a 4 % increase in emissions, amounting to 13264.84 million tons of CO₂. The contribution of this study is the approach to conducting carbon emission projections, which is based on the DSGE model with the implementation of Markov chains. This makes it possible to assess the adequacy of the set targets for carbon reduction based on alternative scenarios, which in crisis conditions can overlap and thus complement each other.

Characterization of Continuous Neutralization of a Chemical Warfare Agent and Its Simulants.

The persistent threat posed by chemical warfare agents (CWAs) necessitates the development of efficient and safe methods for their neutralization. In this study, we investigated the continuous neutralization of CWAs and their simulants using flow chemistry, which combines the benefits of safety, precise control over reaction parameters, and scalability. We focused on the integration of continuous-flow reactors to achieve controlled and rapid neutralization, thus addressing challenges such as the need for rapid reaction kinetics and the establishment of robust pathways for neutralization. Because the flow-chemistry approach can contribute significantly to the development of neutralization technologies for CWAs, we performed a thorough characterization in terms of reaction kinetics and neutralized product identification. The results demonstrated that the proposed continuous-flow-type neutralization reaction was faster and more efficient than batch-type neutralization reactions. Furthermore, in the early stages of the neutralization reaction, flow-type neutralization not only required less neutralizing agent than batch-type neutralization but was also faster. Thus, the chemical neutralization process proposed in this study can be used as a pragmatic foundation for developing demilitarization methods for CWAs.

Global carbon neutrality and China's contribution: The impact of international carbon market policies on China's photovoltaic product exports

China's photovoltaic (PV) product exports satisfy the renewable energy demand for international carbon market construction, contributing to the global carbon neutralization process with China's power. Based on the panel data of PV trade from 2000 to 2020, this paper empirically investigates the impact of global carbon market policies on China's PV product exports and its potential impact mechanism using a multi-period DID model. The study results show that (1) International carbon market policies significantly promote the export of Chinese PV products. (2) Mechanism analysis shows that two essential transmission channels are increased demand for renewable energy and reduced consumption of traditional fossil energy in carbon market countries. (3) Carbon market maturity strengthens the positive effect of the international carbon market on China's PV product exports. (4) Further research finds that international carbon market policies affect China's PV exports more pronounced in high-income, trade-friendly, and high-technology countries. The results of this paper reveal the vital contribution of China's PV industry in promoting global climate governance and environmental protection and provide some insights into how to promote and improve the shared prosperity and sharing of the renewable energy industry in the context of global carbon neutrality.

Development of High-Performance Bipolar Membranes with Optimal Junction Properties for Efficient Electro-Membrane Processes

A bipolar membrane (BPM) is a special type of ion-exchange membrane in which an anion-exchange layer (AEL) and a cation-exchange layer (CEL) are combined. Water molecules can be easily dissociated at the interface of the BPM by the strong electric field generated when a reverse bias voltage is applied through the membrane. Such dissociation leads to the generation of proton and hydroxide ions, which are then transported through the CEL and AEL, respectively, resulting in the production of acid and base solutions. Under a forward bias, these ions are drawn back to the bipolar interface, where they neutralize each other. The energy derived from this neutralization process, represented as a junction potential (JP) value, is a key factor in the BPM's efficiency. BPMs with ideal JP values are critical for achieving high separation and energy efficiencies in electro-membrane processes. Furthermore, for the prolonged operation of these processes, BPMs must possess a highly adhesive bipolar junction. Our work includes the development of a novel BPM with an ideal JP and a highly adhesive bipolar junction. This BPM has been applied to various electro-membrane processes, including an acid-base flow battery and direct seawater electrolysis. The BPMs are fabricated using poly(phenylene oxide) (PPO)-based ionomers, and incorporates an iron-based catalyst and a reinforcing material. These additions enhance the water-splitting performance and the durability of the interface between the ion-exchange layers. The prepared BPMs not only demonstrated excellent interfacial adhesiveness and mechanical properties but also achieved a water-splitting efficiency of 98% or higher. In comparison to commercial BPM, the electro-membrane processes utilizing the prepared BPM exhibited superior performance. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MEST) (NRF-2022M3C1A3081178 & NRF-2022M3H4A4097521).

Prediction models to control final control elements for neutralization process in chemical industries

AbstractBACKGROUNDIndustrialization continues to increase in the 21st century, as industries start moving towards automation. Manufacturing of a component/item requires a lot of resources and energy. Usage of water in industries has increased in recent years, as it is used as both a resource and an energy generating source. Neutralization of a processed liquid is carried out by addition of solution through final control elements and most industries are utilizing pneumatic‐based control valves, which have a disadvantage in the regulation of additives.RESULTSA motorized valve system is introduced, which is compared with the pneumatic system in terms of their performance. The proposed system is implemented with different controllers such as proportional–integral controller tuned using linear matrix inequalities, modified internal model controller, model predictive controller and nonlinear autoregressive (NAR) model, where the final control elements are tested for pH neutralization. On implementation of the proposed system the NAR model has proven to be better under the motorized control valve system for the neutralization process, with a peak value of 7.08 (pH), settling time of 75.16 s, rise time of 5.96 s, maximum overshoot of 10.1%, slew rate of 0.21 per second, integral square error of 0.95, integral absolute error of 0.48 and integral time absolute error of 1.88.CONCLUSIONBased on the results obtained it is observed that the NAR controller utilized with motorized control valve has better functionality in neutralizing a solution. © 2024 Society of Chemical Industry (SCI).