rss_2.0Polish Journal of Chemical Technology FeedSciendo RSS Feed for Polish Journal of Chemical Technology Journal of Chemical Technology Feed hold-up analysis in an unsteady stirred vessel by means of infinite series<abstract> <title style='display:none'>Abstract</title> <p>The use of a liquid level sensor made it possible to measure changes in gas hold-up over time in a stirred tank during unsteady mixing. These results were subjected to Fourier time series analysis and a model of gas hold-up changes in time was proposed. It allowed one to determine the model value of gas hold-up, which can be useful for characterizing gas hold-up during unsteady mixing and as a comparison to gas hold-up during steady mixing. The characteristic frequency was also determined, which corresponds to about twice the oscillation frequency. Model gas hold-up values for coalescing and non-coalescing systems were compared. Moreover, the change of the gas hold-up at constant maximum stirrer rotation frequency and variable gas flow rate for different oscillation frequencies was investigated.</p> </abstract>ARTICLEtrue of isoamyl acetate using protein-coated microcrystals of different lipases<abstract> <title style='display:none'>Abstract</title> <p>The goal of this study was the immobilization of different lipases as protein-coated microcrystals on K<sub>2</sub>SO<sub>4</sub> and their uses in the synthesis of isoamyl acetate in n-hexane medium. The optimum conditions, such as lipase variety, temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined. The highest conversion was obtained when protein-coated microcrystals of <italic>Thermomyces lanuginosus</italic> lipase (TLL-PCMCs) was used for the synthesis of isoamyl acetate. The optimum temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined to be 50 °C, 3.0, 30 mg, and 360 min, respectively. Under the optimized conditions, isoamyl acetate yield was obtained as 95%. TLL-PCMCs retained 90% of their initial activity after five repeat use in the isoamyl acetate synthesis. TLL-PCMCs may be used in the preparation of industrially important aroma compounds due its ease of preparation and efficiency.</p> </abstract>ARTICLEtrue and properties of chlorine and phosphorus containing rubber seed oil as a second plasticizer for flame retardant polyvinyl chloride materials<abstract> <title style='display:none'>Abstract</title> <p>The synthesis of multifunctional plasticizer using rubber seed oil can increase its added value and expand the application field of plasticized products. Recent studies on bio-based plasticizers focus on bio-based raw materials but products lack functionality. In this study, flame retardant phosphate and chlorine were introduced into the chemical structure of rubber seed oil to synthesis a nitrogen and phosphorus synergistic flame retardant plasticizer based on rubber seed oil(NPFP) and apply it to plasticize polyvinyl chloride (PVC). Thermal stability, limiting oxygen index, plasticizing property, solvent extraction resistance, and microstructure of plasticized PVC materials were characterized. The results showed that NPFP with excellent solvent extraction resistance can significantly enhance the limiting oxygen index and thermal stability of plasticized PVC materials, and can partially replace dioctyl phthalate(DOP) as multifunctional auxiliary plasticizer.</p> </abstract>ARTICLEtrue based paper coating with promoted grease resistivity, bio-degradable and mechanical properties<abstract> <title style='display:none'>Abstract</title> <p>The dominance of plastics in the packaging market is due to their low weight and thickness, which save transportation costs. However, their non-biodegradability poses a significant threat to the environment. Paper, on the other hand, is considered as a safer alternative due to its natural composition and biodegradability. The porous structure of paper limits its application in packaging, and its poor water resistance further restricts its use in humid environments. Therefore, lamination is a method useful tool to improve the barrier properties of paper. Additionally, the researchers are focusing on developing biodegradable and water-based coatings with anti-fat properties as a green alternative to plastic packaging. The impact of a new grease-resistant coating composed of starch, gelatin and sodium alginate on the mechanical properties of paper was investigated through tensile, tearing, and bursting strength tests. The results showed significant improvements in the mechanical properties of the coated paper sheets. Furthermore, the biodegradability test indicated that the paper samples coated with the new composition showed a 50% weight loss after one week of incubation in the soil, and after three weeks, they exhibited 100% weight loss, demonstrating their outstanding biodegradability.</p> </abstract>ARTICLEtrue in extraction and sensory properties of soapnut extract by fermentation<abstract> <title style='display:none'>Abstract</title> <p><italic>Sapindus</italic> saponins are potential biosurfactants that can widely be used to replace many chemical cleaning products. This study aimed to investigate the water extraction of saponins from the pericarps of <italic>Sapindus mukorossi</italic> and enhance the sensory properties of the extract by yeast fermentation. Extraction conditions including temperature, solid-to-liquid ratio, extraction time, and number of extraction times were studied. A yield of 21.4% was obtained by 2 h of extraction at 80 °C with a solid-to-liquid of 1/6 (w/v) and two times. Fermentation was used to purify the <italic>Sapindus</italic> extract, inoculum amount and fermentation time were optimized. The fermentation by <italic>S. cerevisiae</italic> (2%) within 4 days significantly improved the color and smell of aqueous extract, turbidity decreased by 75.6%, total sugar content decreased by nearly 50% and saponins content slightly decreased. These results could contribute to the development of industrial–scale production of <italic>Sapindus</italic> saponins.</p> </abstract>ARTICLEtrue hydrogenation of heavy oil and coal mixtures<abstract> <title style='display:none'>Abstract</title> <p>Coal liquefaction and heavy oil processing have become the urgent need for national energy strategic technology reserves in China. However, the inactivation of solid catalysts in these processes is an inevitable problem. Therefore, a self-catalysed method was proposed. The properties of raw oil could be changed by adding a modifier, as it has the function of self-catalysis, and the additional catalyst is no longer needed. The effect of 200 ppm modifier on the hydrogenation of heavy oil and 500 ppm on the hydrogenation of coal and oil were investigated. The results showed that modifiers could be miscible with heavy oil at 50~100 °C and could change the properties of oil. When the temperature exceeded 250 °C, the sulfur element in the heavy oil combined with the metal element brought in by the modifier to form a particle with the size of 2–8 nm, which could interact with the hydrogen molecule to activate the hydrogen molecule. Activated hydrogen atoms further formed the complexes with nickel, vanadium, calcium, iron, and other elements in heavy oil to achieve the purpose of purifying and lightening the oil phase. Therefore, the self-catalysed method could be widely used in oil refining and would greatly promote the development of the oil refining and catalysis industry.</p> </abstract>ARTICLEtrue of the effects of recycling on process control<abstract> <title style='display:none'>Abstract</title> <p>The union of different devices in order to obtain a specific response for a process is commonly called a control system. For a control system, it is necessary to have one or more controllers. Among the most used in the industrial sector are the PID and PI controllers. Next to these controllers is the control software. Scilab is a good example of control software. It is characterized as free code software, with no cost for its acquisition, in addition to having a large computational power and integrated tools, such as Xcos, intended for modeling and simulation. For the union with Scilab, there is Arduino. Such a mixture can be used, for example, to control liquid levels in tanks. In this context, the present work aims to study the tank-level control system based on PID and PI controllers through the union between Scilab and Arduino. Phenomenological models were developed based on closed-loop control (feedback control system) of the process with two tanks not coupled with recycle. Furthermore, for comparison purposes, two approaches were used for each process: one considering the saturation of the manipulated variable and the other without the presence of such saturation. At first, there was a need to implement an anti-windup system. For tuning the controller parameters, the ISE method was used, executed through a programming code developed in Scilab. The parameters found for the two systems were tested on a made-up experimental bench. Therefore, using the block diagrams and the method here called “ISE method”, satisfactory values were obtained for the control parameters. These were ratified in the tests carried out in the experimental module. Level control was achieved with greater prominence for the PI controller since there is one less parameter to be tuned and processed by the system. This controller provided results close to the PID controller for cycles up to 50%. In general, the PI controller showed maximum response deviations smaller than the PID, such as deviations of 1.55 cm and 2.40 cm, respectively, for the case with 75% recycle. It was also clear the influence of the saturation of the manipulated variable on the system response, but not on the tuning of the controller parameters.</p> </abstract>ARTICLEtrue of production process of epoxidized soybean oil with high oxygen content through response surface methodology<abstract> <title style='display:none'>Abstract</title> <p>The epoxidation process of soybean oil (SBO) and peracid produced by 50 wt% hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and formic acid (FA) was studied with sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) as a catalyst. Three reaction parameters, including reaction temperature, FA-to-SBO ratio, and H<sub>2</sub>O<sub>2</sub>-to-SBO ratio, were investigated, along with the combined effect on oxirane value (OV). Based on response surface methodology (RSM), the Box-Behnken design (BBD) was used to optimize the process parameters. According to the results, the calculated OV (7.34%) and the experimental OV (7.31%) were signifi cantly in agreement. The product was confi rmed as epoxidized soybean oil (ESO) by IR and NMR characterization methods. These results demonstrated the reliability of RSM to optimize the SBO reaction to produce ESO with high oxygen content.</p> </abstract>ARTICLEtrue Release of Drug Facilitated Through Chemically Crosslinked Polyvinyl Alcohol-Gelatin (PVA-GE) Hydrogels. A sustainable biomedical approach<abstract> <title style='display:none'>Abstract</title> <p>The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coefficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.</p> </abstract>ARTICLEtrue effect of bottom sediment on biomass production by Italian ryegrass and maize<abstract xml:lang="en"><title style='display:none'>The effect of bottom sediment on biomass production by Italian ryegrass and maize</title><p>A two-year pot experiment (2005 and 2006) was conducted to estimate an effect of dredged bottom sediment from Rożnów Reservoir addition to the light, very acid soil on the plant biomass production. The sediment was applied in the amount from 1 to 20% of the substratum mass. Italian ryegrass (<italic>Lolium multiflorum</italic> L.) and maize (<italic>Zea mays</italic> L.) were cultivated as the successive test plants. The lowest amount of plant biomass was obtained on the soil (control) and each sediment addition to the substratum caused an increase of the biomass production, both tops as well as the roots of the plant. Larger sediment additions (7% and more) caused a significant increase of the yield, of both the individual plant species and the total biomass during the two years of the experiment. The bottom sediment added to the light, very acid soil distinctly improved the plant yielding and the way of biomass utilisation should be assessed on the basis of its chemical composition analysis.</p></abstract>ARTICLEtrue model of the meat waste management<abstract xml:lang="en"><title style='display:none'>A model of the meat waste management</title><p>The European Union produces about 18 million tons of waste from meat industry per year. The real danger of the BSE disease caused a necessity of looking for a new alternative solution of meat waste management. The proposed solution of meat industry waste management would create meat production waste free with the use of the cleaner production method. Cleaner production includes: pollution prevention, reduction of the source, recovery of materials and energy (for example: the recovery of blood plasma and protein hydrolisate from bone sludge) and their recycling. The thermal processing of meat industrial waste (bone sludge, meat-bone meal and odour) is anticipated, too. Ashes from meat calcining have the phosphorus content close to its concentration, of the typical phosphoric raw materials. That confirmed the possibility of using such ashes as the substitute of phosphoric raw materials. The target model of waste free meat waste management included the results of the implemented and current research.</p></abstract>ARTICLEtrue organic and mineral fertilizers: Technology and utility properties<abstract xml:lang="en"><title style='display:none'>Granulated organic and mineral fertilizers: Technology and utility properties</title><p>This work presents the selected aspects of a technological concept for the production of organic and mineral fertilizers from communal sludge stabilized with volatile ash, by using two methods of granulation: coating and pressure. The presented concept is the effect of optimization, taking into account an interference of a number of factors exerted onto the fertilizing values and the mechanical strength of the final products. The fertilizers (contain ash from brown coal) obtained according to that method are characterized by a sufficient (according to law) content of organic matter (35,73% w/w), total nitrogen (1,70% w/w), phosphorus P<sub>2</sub> O<sub>5</sub> (3,62% w/w) and after the modification, also potassium K<sub>2</sub>O (8,43% w/w). The mechanical properties are better for the granulates, prepared by using pressure granulation (15,1 kG/cm<sup>2</sup>) and allow for their transportation, storage and application.</p></abstract>ARTICLEtrue morphological and dispersive characterization of commercial titanium dioxides<abstract xml:lang="en"><title style='display:none'>The morphological and dispersive characterization of commercial titanium dioxides</title><p>The physicochemical and dispersive characterizations were conducted on the selected commercial titanium dioxides produced by, Z. Ch. POLICE, S. A. The dispersive properties were defined in detail by an analysis of particle size distribution and polydispersity index. Moreover, the microscope studies were executed to evaluate the surface morphology of the studied TiO<sub>2</sub> forms. The profiles of titanium dioxides sedimentation in water were determined and the specific surface areas were defined by the BET method.</p></abstract>ARTICLEtrue reactor for toxic and recalcitrant water contaminants<abstract xml:lang="en"><title style='display:none'>Band reactor for toxic and recalcitrant water contaminants</title><p>This paper deals with the problem of the photocatalytic reactor construction. The supported TiO<sub>2</sub> on γ- Al<sub>2</sub>O<sub>3</sub> modified with Mo or V addition was used as the photocatalyst, whereas phenol and formaldehyde were chosen as the model pollutants. The counter - current contact of reagents and catalysts is the main advantage of the construction and enables a significant COD reduction of the highly concentrated wastewaters.</p></abstract>ARTICLEtrue influence of ozonation on the activated carbon adsorption of phenol and humic acid<abstract xml:lang="en"><title style='display:none'>The influence of ozonation on the activated carbon adsorption of phenol and humic acid</title><p>To study the influence of ozonation on the activated carbon adsorption, a model solution containing approximately 8 mg/dm<sup>3</sup> of humic acid and approximately 1 mg/dm<sup>3</sup> of phenol has been ozonated, and then adsorption kintetics and adsorption isotherm experiments have been performed. The applied ozone doses ranged from 1 to 3 mg O<sub>3</sub>/dm<sup>3</sup>, and a contact time was 1 min. In the adsorption experiments, the commercial activated carbon CWZ-30 (Gryfskand Sp. z o.o., Hajnówka, Poland) has been used. Phenol adsorption under equilibrium conditions was determined by the Freundlich isotherm equation, and the modified Freudlich isotherm equation has been employed for the determination of humic acid equilibrium adsorption. The applied oxidation conditions resulted in color, chemical oxygen demand (COD), total organic carbon (TOC) and UV<sub>254</sub> absorbance removal, by 4 - 13%, 3 - 6%, 3 - 7%, respectively. After ozonation, phenol concentration decreased by 6 - 23%. These changes in the model solution did not affect the humic acid adsorption, however, they deteriorated phenol adsorption.</p></abstract>ARTICLEtrue applications of statistical methods of the design of experiments in chemical technology and environment protection<abstract xml:lang="en"><title style='display:none'>Uncommon applications of statistical methods of the design of experiments in chemical technology and environment protection</title><p>The review of literature related to the applications of statistic methods of design of experiments in chemical technology and environment protection was presented in the work. The research that consists of two stages: a stage of choosing the best variables describing an experimental object and a stage of proper experimental investigation, seems particularly interesting.</p><p>An interesting example of an application of statistical strategies in environmental protection is the optimization of photoactivity of TiO<sub>2</sub>/SiO<sub>2</sub> mixture, received by a sol-gel technique. TiO<sub>2</sub>, due to its specific feature, was applied in the photocatalytic methods of removing toxic compounds from water and air. In the experiments there were used two designs - the fractional factorial design 2<sup>5-1</sup> (as the elimination one) and the central composite design (as the proper one). Following the data analysis from the elimination plan two variables were eliminated, which helped to simplify the research object.</p><p>Among other uncommon applications of the design of experiments: the optimization of the conditions for the extraction of natural pigments used in dyeing food, the production of fatty acid methyl esters used as diesel oil substitutes (biodiesel) and the optimization of a supercritical fluid extraction methodology for the analysis of castor oil, should be mentioned.</p></abstract>ARTICLEtrue of chemical aids in the process of deinking sludge thickening<abstract xml:lang="en"><title style='display:none'>Optimization of chemical aids in the process of deinking sludge thickening</title><p>The authors have analyzed a modern technological line of the latest chemicals for the recovered paper processing and de-inking in terms of reducing the amount of wastes arising during the production. The authors have also investigated the effectiveness of selected chemical aids (coagulants and flocculants) supporting the process of sludge dewatering. 12 different types of flocculants were tested. The best chemical agent was selected as well as its optimal dosage. The highest dynamics of sludge dewatering improvement (expressed by the dewatering time under standard conditions) was observed with the ECR3 agent dosage of 6 - 6.5 kg per tonne of the absolutely dry sludge. Long-term analyses of the tested line have proved that the retention aid and its dosage were selected correctly.</p></abstract>ARTICLEtrue management concepts supported by information technology<abstract xml:lang="en"><title style='display:none'>Environmental management concepts supported by information technology</title><p>The genesis and development of environmental management concepts are presented. An overview of the current environmental management ideas, programmes and systems, including Sustainable Development, Responsible Care, Cleaner Production, environmental management based on ISO 14000, and EMAS is provided. Selected computer-aided tools and techniques for improving the quality of environmental management are proposed.</p></abstract>ARTICLEtrue of the post-filtration lye from the SCS method of soda production<abstract xml:lang="en"><title style='display:none'>Utilization of the post-filtration lye from the SCS method of soda production</title><p>The mutual solubility of salts in the NaVO<sub>3</sub>-NaNO<sub>3</sub>-H<sub>2</sub>O system was investigated at 293 - 323 K temperature range by the method of isothermal saturation of solutions. A fragment of the solubility polytherm for that system was plotted, based on the obtained data. The investigated system is a part of the quaternary NH<sub>4</sub>NO<sub>3</sub>-NaVO<sub>3</sub>-NH<sub>4</sub>VO<sub>3</sub>-NaNO<sub>3</sub> system, and it is necessary for plotting the solubility isotherm as a planar projection according to Janecke, since it defines one edge of its square. Knowledge of the isotherm for that quaternary system is necessary to determine the optimal utilization conditions for the post-filtration lye, formed during the soda production from NaNO<sub>3</sub> by the Solvay method, using NaVO<sub>3</sub>.</p></abstract>ARTICLEtrue release fertilizers<abstract xml:lang="en"><title style='display:none'>Controlled release fertilizers</title><p>The efficiency of nitrogen assimilation by plants is rather low and this is a serious problem in view of environmental protection. Improvement of nitrogen absorption can be carried out through the developing, producing and applying the controlled release fertilizers. Biodegradable chitosan has been proposed as an alternative material in the production of controlled release fertilizers.</p></abstract>ARTICLEtrue