Production Of Chloride Research Articles

ТЕХНОЛОГИЯ СИНТЕЗА ЖИДКОГО СИНТЕТИЧЕСКОГО ТЕХНИЧЕСКОГО МОЮЩЕГО СРЕДСТВА «ФЗ-26» И ЕГО ПРИМЕНЕНИЕ

The article presents findings from a study into disposal of the technological alkaline solution formed in the amount of 2000 tons/ a year, in course of the manufacture of polyvinyl chloride at JSC “Navoiyazot”. A composition of a liquid detergent based on synthetic surfactants and secondary raw materials – an alkaline solution formed during the synthesis of vinyl chloride, has been developed. Physicochemical properties of the developed composition have been determined, on the basis of which the laboratory regulations for production of technical detergents have been compiled. The possibility of creating an industrial technology for manufacture of technical detergent based on a secondary product – a process solution of alkali, which is expected to boost profitability of the polyvinyl chloride production and solve one of the environmental problems of this enterprise, is shown.

Performance descriptors of nanostructured metal catalysts for acetylene hydrochlorination.

Controlling the precise atomic architecture of supported metals is central to optimizing their catalytic performance, as recently exemplified for nanostructured platinum and ruthenium systems in acetylene hydrochlorination, a key process for vinyl chloride production. This opens the possibility of building on historically established activity correlations. In this study, we derived quantitative activity, selectivity and stability descriptors that account for the metal-dependent speciation and host effects observed in acetylene hydrochlorination. To achieve this, we generated a platform of Au, Pt, Ru, Ir, Rh and Pd single atoms and nanoparticles supported on different types of carbon and assessed their evolution during synthesis and under the relevant reaction conditions. Combining kinetic, transient and chemisorption analyses with modelling, we identified the acetylene adsorption energy as a speciation-sensitive activity descriptor, further determining catalyst selectivity with respect to coke formation. The stability of the different nanostructures is governed by the interplay between single atom-support interactions and chlorine affinity, promoting metal redispersion or agglomeration, respectively.

Rethinking our chemical legacy and reclaiming our planet

Rethinking our chemical legacy and reclaiming our planet

Innate and Adaptive Immunity in Workers of the Main Occupations Exposed to Fine Particulate Matter in Potassium Chloride Production

Background: Workplace air pollution with fine particulate matter in industrial premises contributes to imbalance of nonspecific and specific immunity factors, increasing the risk of developing premorbid conditions in workers. Objective: To study the features of phagocytic activity and subpopulation T-lymphocytes composition in workers engaged in the potassium chloride production. Material and methods: The study was conducted in 2019–2022 within the Research Program of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing on hygiene problems, Clause 2.2.18 “Development of approaches to early diagnosis of production-related diseases using genomic and postgenomic analysis technologies in workers associated with harmful factors of working conditions”, R&D No. 121081900044-4. The observation group consisted of 54 workers of the main occupations exposed, inter alia, to fine respirable particulate matter in potassium chloride production. The comparison group included 67 individuals having no occupational exposure to industrial hazards. We evaluated the phagocytic activity of peripheral blood leukocytes and determined the level of CD25+ and CD95+ differentiation cluster expression on T-lymphocytes by flow cytometry. Results: We measured high airborne concentrations of fine particles at workplaces of mill, centrifuge and filter operators, granulation and drying workers that were 6.6 and 7 times higher than those of PM2.5 and PM10 in the working environment of the administrative staff, respectively. We also observed that the ability of neutrophils to absorb and digest foreign particles was 20 % lower in the workers of the observation group (p = 0.047), while the proportions of CD25+ and CD95+ lymphocytes in them were 30 % and 60 % lower than those in the comparison group, respectively (p = 0.001–0.046). Conclusion: We established the effect of fine particulate matter as a priority workplace air pollutant on innate and adaptive immunity in workers of the main occupations in the potassium chloride production facility. Parameters of innate (phagocytic number) and adaptive (CD25+ and CD95+ lymphocytes) immunity are recommended for use in early diagnosis of immune dysfunction and the development of occupational diseases in workers with inhalation exposure to fine particles.

The concentrated polyaluminum chloride with tailor-made distribution of Al species: synthesis, distribution and transformation of Al species, and coagulation performance

Production of concentrated polyaluminum chloride (PACl) with the proper distribution of Al species (Ala, Alb, and Alc) is still a challenging issue on both industrial and laboratory scale. Hence, the effects of total aluminum concentration (AlT) at high levels, regular basicity values, and low base injection rates on the distribution of Al species in PACl solutions were investigated using quadratic models. The results confirmed the possibility to synthesize tailor-made PACl solutions with a specified value of either Ala, Alb, or Alc within the range of 22–51%, 4–51%, or 0.5–74%, respectively. For instance, in agreement with the predicted value, a PACl sample rich in both Alb (42,200 ppm) and AlT was produced by applying the basicity of 1.7, AlT of 9.07% as Al2O3, and basification rate of 0.48 ml/h. In addition, the maximum Alc could be acquired by exploiting the highest C, B, and Q values. This condition also minimized both Ala and Alb. The trends of Ala and Alc changes by the increment of basicity were concave and convex, respectively, while Alb showed either a decreasing trend or a concave pattern based on the values of injection rate and AlT. The Alb-rich PACl sample was effectively applied for turbidity removal from synthetic wastewater at various pHs and initial turbidities. At best, residual turbidity of about 1% was observed after the coagulation process. These findings can be constructive for the production and application of tailor-made PACl.

CO2 mineralization of carbide slag for the production of light calcium carbonates

The production of polyvinyl chloride by calcium carbide method is a typical chemical process with high coal consumption, leading to massive flue gas and carbide slag emissions. Currently, the carbide slag with high CaO content is usually stacked in residue field, easily draining away with the rain and corroding the soil. In this work, we coupled the treatment of flue gas and carbide slag to propose a facile CO2 mineralization route to prepare light calcium carbonate. And the route feasibility was comprehensively evaluated via experiments and simulation. Through experimental investigation, the Ca2+ leaching and mineralization reaction parameters were determined. Based on the experiment, a process was built and optimized through Aspen Plus, and the energy was integrated to obtain the overall process energy and material consumption. Finally, the net CO2 emission reduction rate of the entire process through the life-cycle assessment method was analyzed. Moreover, the relationship between the parameters and the CO2 emission life-cycle assessment was established. The final optimization results showed that the mineralization process required 1154.69 kW·h·(t CO2)−1 of energy (including heat energy of 979.32 kW·h·(t CO2)−1 and electrical energy of 175.37 kW·h·(t CO2)−1), and the net CO2 emission reduction rate was 35.8%. The light CaCO3 product can be sold as a high value-added product. According to preliminary economic analysis, the profit of mineralizing can reach more than 2,100 CNY·(t CO2)−1.

Energy, economic, environment assessment and process safety of methylchloride plant using Aspen HYSYS simulation model

Methyl chloride is the starting material for various chemicals of industrial importance. Because of its toxic, flammable, and explosive nature, safety is also equally important. Based on its industrial importance and safety issues, this research focused on improving efficiency and process safety. In this research, a model simulating the methyl chloride production process through hydrochlorination of methanol is investigated. Using the simulation model results an attempt has been made to improve the methyl chloride production process plant's efficiency in the aspects of energy, economy, safety, and sustainability using process integration. Energy analysis improved the total utilities saving potential up to 36% by adding two new heat exchangers to the existing design. The payback period is reported as 0.63 years. Product cost is reduced by 2.78 USD per ton, Greenhouse gas emissions reduced by 26%, and carbon tax by 26.34%. The location of the pressure safety valves, orifice sizes are calculated for the entire process plant and the storage tank. A quantitative risk assessment was performed by hazard modeling studies using the ALOHA modeling tool for methyl chloride leak from the storage tank. The safety margin calculated is 1900 m. The results of this research can be implemented in process engineering design. The process design methodology using process integration and hazard modeling tools by integrating the energy, economic, and safety approaches at the initial design stages itself is useful to design efficient new plants and to increase the profitability and the safety of the existing methyl chloride production plants.

A Unified and Desymmetric Approach to Chiral Tertiary Alkyl Halides.

Enantioenriched tertiary alkyl halides are prevalent in bioactive molecules and can serve as versatile synthetic intermediates to construct complex structures. While conventional access to these motifs often hinges on stereoselective carbon-halogen or carbon-carbon bond formation reactions, desymmetric approaches using halogenated and prochiral tetrasubstituted carbons are largely elusive in comparison. Here, we report that a suite of dinuclear zinc catalysts with a prolinol- or pipecolinol-derived tetradentate ligand can reductively desymmetrize a large collection of easily available halomalonic esters to α-halo-β-hydroxyesters. These polyfunctionalized tertiary alkyl fluorides, chlorides, and bromides proved to be useful intermediates toward fluorinated drug analogs and polyhalogenated monoterpenes. The facile intramolecular epoxidation of the chiral chloride and bromide products has also enabled expeditious access to natural products containing tertiary alcohol motifs.

3,4-Dichlorobenzoic acid biodegradation by the Edwardsiella tarda: Effect of Some Growth Conditions

The biodegradation of 3,4-DiChlorobenzoic acid was investigated by using Edwardsiella tarda and it used 3,4-DCBA as sole carbon and energy source. Several concentrations of 3,4-D CBAs (1mM, 2mM ,3mM ,4mM and 5mM) were used. The highest rate of degradation of 3,4-D CBAs was obtained at a concentration (2mM). The experiments were included substrate concentration, temperature, pH, starvation, adaptation, carbon and nitrogen sources. The degradation ability was monitored through the release of chloride disappearance of the substrate and finally the growth of bacterial cells on that substrate. The optimal temperature and pH for the bacteria were 42ºC and 7.5, respectively. Adaptation of the cells on 3,4-DCBA for 48 hours and cells starvation for 24 hours and 48 hours increasing the initial degradation rate. The carbon sources affected the 3,4 –DCBA degradation differently from that on chloride and cell mass production. Nitrogen sources supplied (yeast extract, L-proline, casein, NH4, K-Nitrate, arginine, urea and glycine). Urea and casine caused a repression in 3,4-DCBA degradation. Catechol 1,2 dioxygenase activity was found to be present in cell free extracts suggesting that 3,4-DCBA is catabolized by ortho-ring cleavage pathway.

Effect of Mammalian Tissue Source on the Molecular and Macroscopic Characteristics of UV-Cured Type I Collagen Hydrogel Networks

The tissue source of type I collagen is critical to ensure scalability and regulation-friendly clinical translation of new medical device prototypes. However, the selection of a commercial source of collagen that fulfils both aforementioned requirements and is compliant with new manufacturing routes is challenging. This study investigates the effect that type I collagen extracted from three different mammalian tissues has on the molecular and macroscopic characteristics of a new UV-cured collagen hydrogel. Pepsin-solubilised bovine atelocollagen (BA) and pepsin-solubilised porcine atelocollagen (PA) were selected as commercially available raw materials associated with varying safety risks and compared with in-house acid-extracted type I collagen from rat tails (CRT). All raw materials displayed the typical dichroic and electrophoretic characteristics of type I collagen, while significantly decreased lysine content was measured on samples of PA. Following covalent functionalisation with 4-vinylbenzyl chloride (4VBC), BA and CRT products generated comparable UV-cured hydrogels with significantly increased averaged gel content (G ≥ 97 wt.%), while the porcine variants revealed the highest swelling ratio (SR = 2224 ± 242 wt.%) and an order of magnitude reduction in compression modulus (Ec = 6 ± 2 kPa). Collectively, these results support the use of bovine tissues as a chemically viable source of type I collagen for the realisation of UV-cured hydrogels with competitive mechanical properties and covalent network architectures.

Electron-deficient Cu site catalyzed acetylene hydrochlorination

Rational design of catalytic sites to activate the CC bond is of paramount importance to advance acetylene hydrochlorination. Herein, Cu sites with electron-rich and electron-deficient states were constructed by controlling the impregnation solutions. The π electrons flowing from acetylene to Cu site are facilitated over the electron-deficient Cu sites, achieving high activation of CC bond. The contradiction between the increased activation of acetylene required for enhanced catalytic activity and the resistance of Cu site to reduction by acetylene required for maintaining catalytic stability can be balanced by establishing strong interactions of Cu site with pyrrolic-N species. The catalytic activity displays a volcano shape scaling relationship as a function of Cu particle size. Tribasic copper chloride is concomitantly generated with the construction of electron-deficient Cu sites. The H–Cl bond of HCl can be activated over the tribasic copper chloride, accelerating the surface reaction of vinyl chloride production. This strategy of inducing electron deficiency provides new insight into the rational design of catalysts for the synthesis of vinyl chloride with a high catalytic performance.

In situ electrochemical investigation of the reaction progress between Zr and a CuCl-SnCl2 mixture in a LiCl-KCl molten salt.

The electrochemical behaviors of CuCl, SnCl2 and a CuCl–SnCl2 mixture were investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). The reduction potentials of Cu(i) and Sn(ii) on CV curves are −0.49 and −0.36 V, respectively, while the reduction potentials of Cu(i)–Sn(ii) in the CuCl–SnCl2 mixture almost overlap. The co-chlorination reaction progress between CuCl–SnCl2 and Zr was also studied by monitoring the concentration changes of Cu(i), Sn(ii) and Zr(iv) ions in situ by CV, SWV and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses. The results indicate that during the reaction, the concentration of Zr(iv) ions increases gradually, while those of Cu(i) and Sn(ii) decrease rapidly until they disappear. When the molar ratios of Cu(i) to Sn(ii) are 1 : 1 and 1 : 0.5, the reaction between Cu(i) and Zr is faster but cannot exceed twice that of Sn(ii) and Zr in a short time. When the theoretical product of ZrCl4 is a constant, and with the proportion of CuCl to SnCl2 decreasing from 1 : 0 to 0 : 1, the chlorination reaction time periods increase from 40 to 170 min. Chloride products such as CuxSny, SnxZry, and CuxZry, are formed with different molar ratios. The coupling effect caused by the formation of alloys will promote the chlorination reaction when the ratios of CuCl to SnCl2 are 0.66 : 0.17 and 0.5 : 0.25. The results provide a theoretical basis for the electrolytic refinement of zirconium.

Defective Graphitic Carbon as a High Chlorine Conversion Catalyst for Methyl Chloride Production from Methane

Defective Graphitic Carbon as a High Chlorine Conversion Catalyst for Methyl Chloride Production from Methane

Effects of Time, Temperature, and Sebum Layer on Dermal Migration Rate of Plasticizers in Polyvinyl Chloride Products

Effects of Time, Temperature, and Sebum Layer on Dermal Migration Rate of Plasticizers in Polyvinyl Chloride Products

Reactivity of a Carene-Derived Hydroxynitrate in Mixed Organic/Aqueous Matrices: Applying Synthetic Chemistry to Product Identification and Mechanistic Implications

β-hydroxynitrates (HN) are a major class of products formed during OH and NO3 initiated oxidation of terpenes. Their production contributes significantly to secondary organic aerosol (SOA) formation and NOx sequestration. However, studying the condensed phase reactions of this important class of molecules has been hindered by the lack of commercially available authentic standards. The goal of this work was to examine the influence of water concentration and solvent identity on product yields of a tertiary HN derived from 3-carene prepared in house. To assess the role of water on conversion chemistry, bulk-phase reactions were conducted in DMSO-d6, a non-nucleophilic solvent, with a gradient of water concentrations, and analyzed with 1H NMR. Product identifications were made by comparison with authentic standards prepared in house. Four major products were identified, including an unexpected diol produced from carbocation rearrangement, diol diastereomers, and trans-3-carene oxide, with varying yields as a function of water concentration. Product yields were also measured in two protic, nucleophilic solvents, MeOD-d4 and EtOD-d6. Finally, reactions with added chloride formed alkyl chloride products in yields approaching 30%. These results are among the first to highlight the complexities of nucleophilic reactions of hydroxynitrates in bulk, mixed aqueous/organic media and to identify new, unexpected products.

Phosphine-oxide organic ligand improved Cu-based catalyst for acetylene hydrochlorination

Considering the disadvantages of Cu-based catalyst for acetylene hydrochlorination, such as poor dispersion, severe carbon deposition and insufficient active sites, supported Cu-complex catalysts were synthesized by using phosphine-oxide organic compounds as ligands. A local active domain was successfully constructed based on the complexation of Cu atom to heteroatomic structure in meticulously selected ligands, in which the phenyl group acts as an electron donor to change the CuCl2 active site electronic structure. The density functional theory calculation proved the existence of a strong interaction between triphenylphosphine oxide and CuCl2, and synchronously, electrons on the benzene ring were transferred to the Cl atom in CuCl2, stabilizing the Cu species. This superior activity may be attributed to the heightened adsorption of HCl and weakened C2H2 and vinyl chloride adsorption by the constructed local active domain, which impedes the carbon deposition that promotes the continuous exposure of active sites. Under the reaction conditions: T = 180 ℃, GHSVC2H2 = 180 h−1 and VHCl/VC2H2 = 1.2, the C2H2 conversion of 15%Cu7%TPPO/AC reaches 88%, which was over 30% higher than 15%Cu/AC catalyst. The significantly improved activity and stability of the proposed catalyst provides a reference for green and sustainable production of vinyl chloride.

Chlorine production for water disinfection by the means of photovoltaic panels

In this contribution a possibility of electrochemical production of chlorine for water disinfection, by using photovoltaic panels from solar energy, is described. A simple way of chloride production by means of a photovoltaic panel, comparable with classical electrical power source was performed on an experimental device. By using photovoltaic panel with nominal output 50 W and solar irrigation 380 – 550 W/m2 chlorine production was 0.3 mg/min, which represents amount of chlorine sufficient for disinfections of approximately 4000 l water per day.

Insights into how poly aluminum chloride and poly ferric sulfate affect methane production from anaerobic digestion of waste activated sludge

Poly aluminum chloride (PAC) and poly ferric sulfate (PFS) are widely used in wastewater treatment and sludge dewatering, resulting in their amounts being accumulated substantially in waste activated sludge (WAS). Till now, however, little information about their influence on WAS digestion is available. This work therefore aims to provide insights into how PAC and PFS affect sludge anaerobic digestion. The experimental results showed that PFS's inhibition to methane production was much severer than PAC, in control reactor (0 mg Al or Fe /g TSS), the maximum cumulative methane production was 152.99 ± 7.18 mL/g VSS, when flocculants concentration increased to 30 mg Al/g TSS or 30 mg Fe/g TSS, the yields decreased to 129.54 ± 6.18 mL/g VSS and 89.52 ± 4.82 mL/g VSS respectively. Mechanism explorations exhibited that protein in WAS could bond with flocculants, which would inhibit protein bioconversion. It was also observed that the apparent activation energy (AAE) of organic solubilisation of PAC and PFS-contained sludge were increased by 38.58% and 18.67% respectively. Meanwhile, compared to the PFS, PAC led to more serious suppression of hydrolysis and acidogenesis processes, with propionic acid used as substrate, PFS inhibit methanogenesis more severely than PAC. Illumina MiSeq sequencing analyses showed that the number of sulfate-reducing bacteria (SRB) enriched obviously in PFS reactor. The results revealed that although PFS reduced methane production more severely than PAC, the reduction was mainly enforced by the activity of SRB but not organic enmeshment. Furthermore, PAC severely suppresses acetotrophic methanogens but PFS depress hydrogenotrophic methanogenesis microorganism mainly. Additionally, malodor control and dewaterability enhancement of digested sludge can be realized with PAC existence. The finding obtained in this study would provide insights into the PFS or PAC-involved sludge anaerobic digestion system and might support the important implication for further manipulate WAS treatment in the future.

Flexible and economical operation of chlor‐alkali process with subsequent polyvinyl chloride production

AbstractDemand response (DR) can compensate for imbalances in variable renewable energy supplies. This possibility is particularly interesting for electrochemical processes, due to their high energy intensity. To determine the technical feasibility and economic viability of DR, we chose the chlor‐alkali process with subsequent polyvinyl chloride production, including intermediate storage for ethylene dichloride. We estimate the maximum possible cost savings of implementing load flexibility measures. A process model is set up to determine the system characteristic. Subsequent optimizations result in the facility's best possible dispatch depending on additional and minimum power load, storage volume, and cost of a load change. Real plant data are used to specify model parameters and validate the system characteristic and the plant dispatch. An economic evaluation reveals the economic advantages of efficiency and flexibility. The approach can be used to analyze the DR potential of other chlorine value chains or facilities with high electricity demand in general.

Sustainable potassium chloride production from concentrated KCl brine via a membrane-promoted crystallization process

Potassium chloride (KCl) is a vital fertilizer to boost the global crop yield. However, current technologies for KCl production suffer from high energy consumption and complicated operations. Herein, we demonstrate a novel membrane-promoted crystallization (MPC) process for the sustainable production of KCl from concentrated KCl brine, together with water recovery. The MPC process reduces the capital expenditure and simplifies the complex operations by taking advantage of low-grade heat and a tubular hierarchical membrane (macroporous α-Al2O3 substrate, γ-Al2O3 interlayer and mesoporous hydrophilic ZrO2 top layer). The presence of template-directing molecules P123 is vital in obtaining the mesoporous structure of ZrO2 top layer by acting as a scaffold during the sol-gel process and preventing the meso-structural shrinkage in the annealing stage. The hierarchical membrane provides capillary forces to drive KCl brine transport from the inner shell of the membrane towards the outer surface. The continuous supply of KCl brine and water evaporation result in heterogenous nucleation and subsequent KCl crystal growth via a tip-growth mechanism, leading to abundant needle-shaped KCl whiskers on the outer surface based on the in-situ optical observation. The obtained KCl whiskers have a very small contact area with the membrane, thereby endowing facile KCl removal from the membrane surface to allow for the consecutive cycles. The MPC process exhibits a high KCl production of 134.3 g/m2 and excellent water recovery of 738.7 g/m2 for KCl brine (15 wt%) at 60 °C. Moreover, high performance and structural integrity of the membrane are retained after five cycles. The MPC process provides a new and promising approach for the sustainable production of KCl from KCl brine.