rss_2.0Polish Journal of Chemical Technology FeedSciendo RSS Feed for Polish Journal of Chemical Technology Journal of Chemical Technology Feed of the corrosion resistance for stainless steel 316 by applying laser shock peening<abstract><title style='display:none'>Abstract</title> <p>This research paper focuses on enhancing the surface characteristics of the 316 stainless steel (SS316) alloy, including roughness, microhardness, and corrosion resistance. Where the application of ND-YAG laser technology, a highly relevant and timely area, was investigated deeply. The Q-switching Nd: YAG Laser was used with varying laser energy levels within the context of the laser shock peening (LSP) technique. The corrosion resistance of the 316 ss alloy is evaluated in a corrosive environment of 500 mL of saliva (with a pH of 5.6) through electrochemical corrosion testing. Corrosion rate was determined based on the analysis of polarization curves. The outcomes of this research reveal that as the laser energy was increased, there was a noticeable enhancement in the mechanical properties of the 316 ss alloy’s surface. Importantly, the corrosion rate experiences a significant reduction, decreasing from 4.94 mm/yr to 3.59 mm/yr following laser shock peening (LSP) application.</p> </abstract>ARTICLEtrue and applications of iron oxides reduction processes<abstract><title style='display:none'>Abstract</title> <p>The present review handles the main characteristics of iron oxide reduction and its industrial applications. The reduction of iron oxide is the basis of all ironmaking processes, whether in a blast furnace or by direct reduction and/or direct smelting processes. The reduction characteristics of iron ores control the efficiency of any ironmaking process and the quality of the produced iron as well. Many controlling parameters should be considered when discussing the reducibility of iron ores such as equilibrium phase diagrams, reduction temperature, pressure, gas composition, and the nature of both iron ores and reducing agent. The different factors affecting the main routes of ironmaking will be highlighted in the present review to give a clear picture for each technology. Moreover, further innovations regarding the reduction of iron oxides such as reduction by green hydrogen will be discussed.</p> </abstract>ARTICLEtrue of drops dimensions and rheological properties in production of multiple emulsion in a vessel<abstract><title style='display:none'>Abstract</title> <p>The structure and size of droplets of the inner phase of a multiple emulsion and rheological properties of the produced multiple emulsion are presented in this paper. The multiple emulsion was produced in a stirred vessel equipped with four baffles. In the study, two different stirrers: turbine impeller and Rushton turbine impeller were used. The liquids used in the produced multiple emulsion were: distilled water and refined sunflower oil. 8 g and 16 g lecithin from soya beans were used as an emulsifier. The preparation time was respectively 15 min. and 45 min. The structure of the obtained emulsions is presented in the form of photos taken with the diagnostic inverted microscope. The results size of droplets were presented in the form of graphics as a distribution of drops. The rheological properties of the multiple emulsion were presented graphically and it was described using the rheological model.</p> </abstract>ARTICLEtrue of calcination temperatures on optical and magnetic properties of FeWO nanoparticles<abstract><title style='display:none'>Abstract</title> <p>Calcination temperature is a crucial parameter that can be easily controlled to induce a change in material properties. Herein, iron tungstate (FeWO<sub>4</sub>) was synthesized via a hydrothermal method using iron(II) sulfate heptahydrate and sodium tungstate dihydrate as precursors and calcined at the temperature between 300 <sup>o</sup>C and 700 <sup>o</sup>C. With increasing calcination temperature, the saturation magnetization of FeWO<sub>4</sub> nanoparticles decreased from 6.6 emu/g for FeWO<sub>4</sub> to 0.4 emu/g for FeWO4_700, whereas their band gaps increased from 1.95 eV for FeWO<sub>4</sub> to 2.20 eV for FeWO4_700. More crystallinity and crystal defects, and morphological changes at higher calcination temperatures contributed to varying magneto-optical properties of FeWO<sub>4</sub> nanoparticles.</p> </abstract>ARTICLEtrue action of ozone and UV radiation towards obtaining adipic acid from cyclohexane/one<abstract><title style='display:none'>Abstract</title> <p>A lot of research is constantly underway in the world to develop new or improve the current processes of the chemical industry to make them more effective and environmentally friendly. The described research on the oxidation of cyclohexane or cyclohexanone to adipic acid with a coupled action of UV radiation and oxygen–ozone mixture, instead of the currently used oxidation with HNO<sub>3</sub>, is part of this trend. Gas chromatography was used to determine process indicators, such as cyclohexane conversion and selectivity to AA, which exceeded 50% at 25 <sup>o</sup>C, after 16 h. This method can also be used for the preparation of other dicarboxylic acids from cycloalkanes, which proves its universal character.</p> </abstract>ARTICLEtrue, characterization, and molecular modeling of novel 1,3,4-oxadiazole derivatives of mefenamic acid<abstract><title style='display:none'>Abstract</title> <p>A novel series of 1,3,4-oxadiazole derivatives of mefenamic acid was obtained by reacting hydrazones of mefenamic acid with anhydrous acetic anhydride. The mefenamic hydrazones were obtained by reacting different substituted aldehydes with mefenamic acid hydrazide. All the compounds were characterized by spectral data and elemental analysis. Molecular docking studies of all the compounds were performed against COX-1/COX-2 enzymes. Compound <bold>4</bold> and compound <bold>10</bold> were found to have the highest potential to bind with COX-1 while compound <bold>3</bold>, compound <bold>6</bold>, and compound <bold>10</bold> were found to have the highest potential to bind with COX-2 enzyme.</p> </abstract>ARTICLEtrue, structural, thermal, and morphological characterization of Ru(III) complex with gatifloxacin and its utility to obtain RuO nanostructures<abstract><title style='display:none'>Abstract</title> <p>In this work, the reaction between the drug gatifloxacin (as a ligand) with Ru(III) ions was investigated and the resulting complex was structurally and morphologically characterized. The structural properties of the complex were assessed using elemental analyses, molar conductance, thermogravimetry, UV-Vis, and IR spectroscopies, where the morphological characteristics were evaluated using SEM-EDX and XRD methods. The analyses suggested that two ligand molecules were coordinated to the Ru(III) ion via the nitrogen atoms of piperazine rings. The complex was formulated as [Ru(L)<sub>2</sub>(Cl)<sub>2</sub>]Cl, where the Ru(III) ion has a six-coordinate mode, and the coordination sphere is complemented by chlorine atoms. The interaction of the ligand with the Ru(III) ions leads to the product having an organized smooth plate-like structure with a main diameter of 39.42 nm. The RuO<sub>2</sub> oxide in the nanoscale range was generated by the thermal decomposition of the [Ru(L)<sub>2</sub>(Cl)<sub>2</sub>]Cl complex at 600 <sup>o</sup>C for 3 hours. SEM micrographs indicated that the RuO<sub>2</sub> material possesses uniform and organized microstructures with many internal cavities enabling it to be used as a catalyst for the heterogeneous degradation of dyes and organic pollutants.</p> </abstract>ARTICLEtrue of (2E)-3,7-dimethyl-2,6-octadien-l-ol (geraniol) transformation process parameters using Response Surface Method (RSM)<abstract><title style='display:none'>Abstract</title> <p>This paper presents the results of studies on the transformation of geraniol (GA) in the presence of the natural mineral bentonite. The paper determines the influence of temperature, catalyst content, and reaction time on the course of the process. In order to determine the most favorable process conditions, the catalytic tests were carried out without solvent and under atmospheric pressure. Three functions were chosen to determine the most favorable process conditions: GA conversion and the selectivities of the main products: linalool – LO and beta-pinene – BP. In addition, the paper optimize GA transformation process based on response surface methodology (RSM). The impact of the most relevant process indicators was presented. For all factors of the method, their effects on all primary parameters were determined in the form of second-degree polynomials, and such process conditions were determined to achieve their maximum.</p> </abstract>ARTICLEtrue two phase-system stabilized by tween 40 and 80 surfactants: multiparametric study<abstract><title style='display:none'>Abstract</title> <p>The purpose of this study was to investigate the impact of process parameters such as interfacial tension, type of surfactants, and their concentration on simple oil-in-water dispersion. Explored systems were prepared with 5% liquid paraffin oil and aqueous phase with emulsifiers Tween 40 of concentrations from 0.008325 mM to 0.025 mM and Tween 80 with concentrations ranging from 0.00375 mM to 0.011 mM. All systems were characterized in terms of their density and interfacial tension. In the next step analysis of droplet size distributions and mean droplet diameter was performed. The results showed that the size of paraffin droplets decreased as the concentration of surfactants grew. This trend is accompanied by decrease in the interfacial tension between phases. The correlation between mean drop size and the energy input and physical properties of both liquids was developed. The last step provides scientific evidence for the formulation of stable droplets of liquid paraffin.</p> </abstract>ARTICLEtrue Comprehensive Review on Graphene Oxide Based Nanocomposites for Wastewater Treatment<abstract><title style='display:none'>Abstract</title> <p>With the paramount development of industry and agriculture sector, levels of different pollutants like, heavy metal ions, pharmaceuticals, organic dyes, biological waste and other pollutants are becoming serious. The ecosystem and human health suffered greatly from the adverse effects of these pollutants. The disposal of these pollutants has become an urgent issue for the human society. Graphene oxide base nanocomposites have generated an excellent extent of focus as desirable alternatives for the adsorptive elimination of contaminants from aqueous systems owing to their enhanced surface area and multiple functional groups for adsorption. Graphene oxide (GO) as a graphene derivative exhibited superior features as obtainable in a graphene sheet. Moreover, the addition of oxygen functional group at the edges and basal plane of graphene further enhanced the efficiency of the graphene by providing sites for the attachment of different metals on the surface. On the underlying adsorption processes, graphene-based nanocomposites for specific contaminants are designed and currently employed for wastewater treatment. This review presents the ongoing development of GO base nanocomposites and their useful applications, understanding how well graphene-based nanocomposites adsorb pollutants and how that relates to the ways in which pollutants interact with adsorbents is crucial. This study highlights newly developed trends in the creation of graphene oxide based nanocomposites to eliminate different heavy metal ions, dyes, pharmaceuticals, and oils spills from effluent water. The focus is on various graphene oxides nanocomposites application for the removal of different pollutants and regeneration of graphene oxide base nanocomposites after several adsorption cycles. Other challenges and potential directions for designing efficient GO based nanocomposites as adsorbents are also presented along with the problems of current studies.</p> </abstract>ARTICLEtrue and experimental studies of carbon dioxide separation on zeolite fixed bed by cyclic pressure swing adsorption<abstract><title style='display:none'>Abstract</title> <p>The paper presents the results of experimental and model studies of the pressure swing adsorption (PSA) process in a column with a zeolite 13X bed with a height of 0.5 m. The gas mixture consisted of CO<sub>2</sub> (10–20%), N<sub>2</sub>, and H<sub>2</sub>O (RH 50%) in different ratios. As a result of the column tests, concentration, and temperature evolutions were obtained for each of the adsorption and desorption stages, which were used to determine the breakthrough and bed saturation times and other parameters important for the analysis of the column operation. A mathematical model of the PSA process for the separation of CO<sub>2</sub> from the gas mixture was developed. The system of second-order partial differential equations was solved using Matlab software. The research focuses on adsorptive CO<sub>2</sub> capture and shows the influence of water vapor and operational parameters on the quality of model validation.</p> </abstract>ARTICLEtrue of complexation of microelement ions by biodegradable IDHA chelator in water and simulated fertilization environment<abstract> <title style='display:none'>Abstract</title> <p>The degree of complexation of microelement ions by the biodegradable chelating agent - IDHA was examined in the work. The tests were carried out in water and in a simulated fertilizer environment. In order to compare the obtained results, tests were also carried out for the commonly used EDTA. The performed analyzes allow to determine the influence of the presence of compounds containing macroelements on the degree of binding of microelement ions by the biodegradable IDHA and EDTA chelators. The obtained results make it possible to determine the optimal conditions for the chelation of cations by IDHA, which in the future may be used in the production of micronutrient fertilizers on a large scale.</p> </abstract>ARTICLEtrue behaviour of polar solvent and water vapours on Sorbonorit B4 activated carbon<abstract> <title style='display:none'>Abstract</title> <p>In this work, the affinity of the heterogeneous Sorbonorit B4 (SB4) activated carbon toward methyl ethyl ketone (MEK), isopropyl alcohol (IPA), n-propyl alcohol (NPA) and isobutyl alcohol (IBA), and water vapours was examined. Adsorption equilibrium measurements demonstrate a higher adsorption capacity of water vapour than organic compounds at relative pressures above 0.4. The adsorption capacities of SB4 at the same vapor pressure followed the order: NPA&gt; IPA&gt; MEK&gt; IBA. The Langmuir, Dubinin-Radushkevich, Dubinin-Astakhov, and Toth isotherm models were chosen to describe experimental results. Based on the multi-temperature isotherms, the values of the isosteric heat of adsorption were determined for various adsorbate loading. The results indicate a strong influence of VOC molecule structures and the surface heterogeneity of SB4 on the adsorption efficiency. For IPA-SB4 pair, the maximum temperature rise in a fixed-bed bed in the adsorption process and the energy requirement for regeneration were calculated and experimentally verified.</p> </abstract>ARTICLEtrue and applications of iron oxide reduction processes<abstract> <title style='display:none'>Abstract</title> <p>The present review handles the main characteristics of iron oxide reduction and its industrial applications. The reduction of iron oxide is the basis of all ironmaking processes, whether in a blast furnace or by direct reduction and/or direct smelting processes. The reduction characteristics of iron ores control the efficiency of any ironmaking process and the quality of the produced iron as well. Many controlling parameters should be considered when discussing the reducibility of iron ores such as equilibrium phase diagrams, reduction temperature, pressure, gas composition, and the nature of both iron ores and reducing agent. The different factors affecting the main routes of ironmaking will be highlighted in the present review to give a clear picture of each technology. Moreover, further innovations regarding the reduction of iron oxides such as the reduction by green hydrogen will be discussed.</p> </abstract>ARTICLEtrue research on the removal characteristics of simulated radioactive aerosols by a cloud-type radioactive aerosol elimination system<abstract> <title style='display:none'>Abstract</title> <p>Radioactive aerosols in the confined workplace are a major source of internal exposure hazards for workers. Cloud-type radioactive aerosol elimination system (CRAES) have great potential for radioactive aerosol capture due to their high adsorption capacity, lack of cartridges and less secondary contamination. A CRAES was designed and constructed, and a FeOOH/rGO composite was directly prepared by a hydro-thermal method to characterise and analyse its morphology, chemical structure and removal efficiency for simulated radioactive aerosols. The results show that the FeOOH/rGO composite works in synergy with the CRAES to effectively improve the removal efficiency of simulated radioactive aerosols. A 30-minute simulated radioactive aerosol removal rate of 94.52% was achieved when using the experimentally optimized composite inhibitor amount of 2 mg/L FeOOH/rGO with 0.2 g/L PVA as a surfactant. Therefore, the CRAES coupled with the composite inhibitor FeOOH/rGO has broad application potential for the synergistic treatment of radioactive aerosols.</p> </abstract>ARTICLEtrue simulation and improvement of combustor structure in 3D printed sand recycling system<abstract> <title style='display:none'>Abstract</title> <p>In this paper, a new combustor with an output of 5 t/h is designed based on a computational particle fluid dynamics (CPFD) model. The flow field simulation is combined with the combustion simulation to analyze the internal two-phase flow, temperature field, and combustion products. The combustor structure was optimized. The simulation results show that the recovery efficiency of the waste sand and the energy utilization of the combustor can be improved under the original structure. The sand bed has a significant effect on flow field characteristics. The increase in particle temperature in the combustor increases the efficiency of waste sand recovery by increasing the height of the sand bed by 50 mm. The utilization rate of natural gas is increased and the economic efficiency is improved. The feasibility of the CPFD method can simulate the flow field characteristics inside the combustor very effectively.</p> </abstract>ARTICLEtrue on extracts as potential cosmetic raw materials<abstract> <title style='display:none'>Abstract</title> <p>In the study, the possibility of an application of <italic>Ajuga reptans</italic> leaf and root extracts in antipollution cosmetics was investigated. The influence of <italic>Ajuga</italic> extracts on the skin condition was also evaluated. Both leaf and root <italic>Ajuga</italic> ethanolic extracts were obtained and added to the developed cosmetic formulations. Two types of emulsion W/O and O/W, washing gels and eye serum, containing as an active substance <italic>Ajuga</italic> extracts were prepared. For the stable formulations physicochemical and user properties were studied. The obtained results show that cosmetic products, containing the <italic>Ajuga reptans</italic> extracts, positively affect the skin condition: causing an improvement in the degree of skin hydration and elasticity, reducing the skin pores size and skin hyperpigmentation, and reducing the wrinkles depth.</p> </abstract>ARTICLEtrue of Palm Olein and Coconut Oil Blend using Two High-Shear Continuous Stirred Tank Reactors<abstract> <title style='display:none'>Abstract</title> <p>This study aimed to synthesize structured lipids containing high mono- and diacylglycerol by glycerolysisinteresterification of palm olein and coconut oil blend in two high-shear continuous stirred tank reactors in series. The result showed that various flow rates of 11 mL/min to 23 mL/min did not significantly increase mono- and diacylglycerol concentration, while at a flow rate of 26 mL/min only a low concentration of mono- and diacylglycerol was formed. However, a flow rate 20 mL/min and an agitating speed of 2000 rpm produced mono- and diacylglycerol concentration of 61.7% with the highest productivity of 2.1%/min and a triacylglycerol conversion of 64.6%. The slip melting point, melting point, hardness, emulsion capacity, and stability were 23.77 <sup>o</sup>C, 30 <sup>o</sup>C, 14.6 N, 65.15%, and 59.15%, respectively. The product’s solid fat content at 25 <sup>o</sup>C was lower than cocoa butter. The product contained β’ and β crystals, thus it can be applied as a cocoa butter substitute.</p> </abstract>ARTICLEtrue on safe disposal of cephalosporins based on kinetic pyrolysis mechanism<abstract> <title style='display:none'>Abstract</title> <p>Based on the global goals for cleaner production and sustainable development, the pyrolysis behavior of cephalosporin residues was studied by TG-MS method. The influence of full temperature window on the safe disposal of residues was analyzed based on the “3-2-2” and “1+1” of thermal analysis kinetics, and the gas by-products of thermal degradation were monitored. Results showed that the pyrolysis of distillation residues were divided into low and high-temperature zones, including six stages. Maximum error rate (8.55%) by multiple scan rate was presented based on “3-2-2” pattern and maximum total fluctuation (33.7) by single scan rate was presented based on “1+1” pattern, which implied that the comprehensive multi-level comparison method was very reliable. The <italic>E</italic> value “E” of six stages showed an increasing trend ranging 166.8 to 872.8 kJ/mol. Lg<italic>A</italic><sub>(mean)</sub> was 27.28. Most mechanism function of stage 1, 2 were Z-L-T equation (3D), stage 3, 4, 6 were Avrami-Erofeev equation (AE3, AE4, AE2/3) and stage 5 was Reaction Order (O2). In addition, various small molecular micromolecule substances were detected such as C<sub>2</sub>H<sub>4</sub>O, C<sub>2</sub>H<sub>6</sub>, NH<sub>3</sub>, CH<sub>4</sub>, CO<sub>2</sub> under full temperature windows and a possible pyrolysis path of residues was provided.</p> </abstract>ARTICLEtrue of citronellal and geraniol from citronella () oil by vacuum fractional distillation: Effect of operating conditions on the separation<abstract> <title style='display:none'>Abstract</title> <p>This study used fractional distillation to separate citronellal and geraniol from citronella (<italic>Cymbopogon winterianus</italic>) essential oil to improve their market value. The one-factor-at-a-time methodology investigated operating parameters’ optimum conditions and effects, including system pressure, packing types, and column height. All investigations were evaluated based on their main fraction’s citronellal and geraniol content and recovery. Regarding the effect of the variables, a higher system pressure improved the separation while increasing the temperature range of each fraction and distillation time. The packing types would also improve the separation by providing a large surface area. Finally, the column height also positively impacted the separation. In the optimum citronella oil fractionation, citronellal content experienced a 2.5-fold increase, from 37.68% to 94.33%. Geraniol purity reached 40.61% from an initial content of 17.33% in the raw CW oil. The distillation could recover up to 90.00% of citronellal and 68.18% of geraniol.</p> </abstract>ARTICLEtrue