The development and improvement of methods for the synthesis of environmentally friendly catalysts based on base metals is currently an urgent and promising task of modern catalysis. Catalysts based on nanoscale magnetite and maghemite have fast adsorption-desorption kinetics and high chemical activity. The purpose of this work was to obtain magnetic composites, determine their physicochemical characteristics and verify their activity in the process of liquid-phase oxidation of phenol with oxygen. Magnetic nanocomposites were obtained by chemical co-deposition of salts of ferrous and trivalent iron. The synthesized magnetic composites were studied by X-ray diffractometry, energy dispersive X-ray fluorescence and Mössbauer spectroscopy, IR-Fourier spectroscopy, elemental analysis. To increase the catalytic activity in oxidative processes, the magnetite surfaces were modified using cobalt nitrate salt. Further, CoFe2O4 was stabilized by adding polyethylenimine (PEI) as a surfactant. Preliminary studies of the oxidation of phenol with oxygen, as the most typical environmental pollutant were carried out on the obtained Fe3O4, CuFe2O4, CoFe2O4/PEI catalysts. The spectrum of the reaction product shows the presence of CH in the aromatic ring and double C=C bonds, stretching vibrations of the C=O groups of carbonyl compounds; the band at 3059 cm–1 corresponds to the presence of double C=C bonds, the band at 3424 cm–1 hydroquinone compounds. The band at 1678 cm–1 and the intense band at 1646 cm–1 refer to vibrations of the С=О bonds of the carbonyl group of benzoquinone. Peaks at 1366 cm–1 and 1310 cm–1 can be related to the vibrations of C–H and C–C bonds of the quinone ring. Thus it was demonstrated that produced magnetic composites based on iron oxide are quite effective in the oxidation of phenol with oxygen.

The Sulfur Dioxide (SO2) compound is a primary environmental pollutant worldwide, whereas elemental Sulfur (S) is a global commodity possessing a variety of industrial as well as commercial functions. The chemical relationship between poisonous SO2 and commercially viable elemental S has motivated this investigation using Density Functional Theory calculation of the relative transition state barriers for the 2-step Dehydro-sulfurization oxidation-reduction reaction. Additionally, doubly-charged nanoscale platelet Molybdenum Disulfide (MoS2), Armchair (6,6) Carbon Nanotube, 28-atom Graphene nanoflake (GR-28), and Fullerene C-60 are utilized as catalysts. The optimal heterogeneous and homogeneous catalysis pathways of the 2-step oxidation-reduction from SO2 to elemental S are further inspired by the biomimicry of the honeybee species multi-step bio-catalysis of pollen conversion to organic honey. Potential applications include environmental depollution, the mining of elemental sulfur, and the functionalization of novel technologies such as the recently patented aerial and amphibious Lynchpin TM drones.

Nowadays Air-Source Heat Pumps (ASHP) in combination with a Photovoltaic (PV) installation are a very promising option for a necessary and urgent energy transformation in European Union (EU). It is extremely important to develop solutions that will help maximize the use of energy generated from renewable energy sources (RES). Such issues include the problem of insufficient use of generated electricity in PV on-grid microinstallations in residential buildings. This paper's aim is to analyze the results of one-year-round operation of a PV array grid-connected hybrid installation with ASHP for domestic hot water (DHW) preparation in a residential building in Cracow, Poland in the context of increasing self-consumption (SC) of PV energy. Models of systems are built and simulated in Transient System Simulation Tool 18 (TRNSYS) software. Simulations were carried out for different scenarios involving different building electricity consumption profiles, PV system capacity and specified runtime management of ASHP. The novelty of this study lies in the evaluation of the impact of a certain range of conditions on the energy performance of the system, in particular on SC. The results showed that the use of ASHP, with specified runtime management, results in an increase in monthly SC values from 7 to 18%, and annual SC values up to 13%. Also determining the appropriate size of the used PV system depending on whether it is present ASHP in the installation is crucial to increase the value of the SC parameter. Overall, this study provides valuable insights into the potential benefits of PV panels and ASHP operating together, in particular on SC values.

In the article, were checked influences of microaeration, pH, and VSS (Volatile Suspended Solid) for sour cab-bage anaerobic digestion. Results fermentation of sour cabbage under the condition of small oxygen addition are presented in this research can be classified as dark fermentation or hydrogenotrophic anaerobic digestion. The investigations were carried out for two concentrations 5 g VSS /L and 10 g VSS /L of sour cabbage at pH 6.0. The oxygen flow rates (OFR) for 5 g VSS /L were in the range of 0.53 to 3.3 mL/h for obtaining 2% to 8% of oxygen. In cases of low pH and microaeration, ethylene production was observed at a level below 0.05% in biogas. The highest volume of hydrogen for 5 g VSS/L was obtained for flow rate 0.58 O2 mL/h, giving hydrogen concentration in biogas in the range of 0 to 20%. For VSS 5 g/L and oxygen flow rate 0.58 mL/h; 0.021 L of hydrogen is produced per gram of VSS. In this case, VSS 10 g/L and oxygen flow rate 1.4 mL/h at pH 6.0, 0.03 L of hydrogen is generated per gram. Microaeration from 0.58 mL/h to 0.87 mL/h was propitious for hydrogen production at 5 g VSS/L of sour cabbage and 1.4 mL/h for 10 g/L. Another relevant factor is the volatile suspended solid factor of sour cabbage that caused optimal hydrogen production at VSS 89.32%.

A series of supported CuO-based nanoparticle catalysts were prepared by impregnation method and used for the synthesis of glycerol carbonate from glycerol and CO2 in the presence of 2-cyanopyridine as a dehydrant and DMF as a solvent. The effects of supports (activated alumina, silicon dioxide, graphene oxide, graphene, and activated carbon), CuO loading amount, calcination temperature, and reaction parameters on the catalytic activity of catalyst were investigated in detail. XRD, FTIR, SEM, BET, and CO2-TPD were used for the characterization of the prepared catalysts. It is found that CuO/Al2O3 shows a higher catalytic activity, which depends on the CuO loading amount and calcination temperature. The surface area and amount of basic sites of the catalyst exhibit crucial effect on the catalytic activity of CuO/Al2O3. Furthermore, there is a synergistic effect between the catalyst and 2-cyanopyridine that the former has higher activation ability for glycerol and the latter acts not only as a dehydrant, but also as a promoter for CO2 activation. Recycling experiments reveal that this catalyst can be reused at least five cycles without any inactivation. Based on the experiment results and FTIR characterization, a possible reaction mechanism for the carbonylation of glycerol and CO2 is proposed.

Bauxite residue (BR), also known as red mud, is a by-product of the production of alumina via the Bayer process. Because of the high sodium oxide and other impurities content, this material is not used to obtain iron or other iron-containing products. In this paper, the hydro-chemical conversion of goethite (FeOOH) to magnetite (Fe3O4) in high-iron BR from the Friguia alumina refinery (Guinea) by Fe2+ ions in highly concentrated alkaline media was studied. The simultaneous extraction of Al and Na made it possible to obtain a product containing more than 96% Fe3O4. The results show that the magnetization of Al-goethite and Al-hemetite accelerates the dissolution of the Al from the iron mineral solid matrix and from the desilication product (DSP). After ferrous sulfate (FeSO4·7H2O) was added directly at the FeO:Fe2O3 molar ratio of 1:1 at 120 °C for 150 min in the solution with the 360 g L-1 Na2O concentration, the alumina extraction ratio reached 96.27% for the coarse bauxite residue size fraction (Sands) and 87.06% for fine BR obtained from red mud. The grade of iron (total iron in the form of iron element) in the residue can be increased to 69.55% for Sands and 58.31% for BR. The solid residues obtained after leaching were studied by XRD, XRF, TG-DTA, VSM, Mössbauer spectroscopy and SEM to evaluate the conversion and leaching mechanisms and the recovery ratio of Al from different minerals. The iron-rich residues can be used in the steel industry or as a pigment.

In this research, we present a comprehensive methodology to categorize perfumes based on their fragrance profiles and subsequently aid in creating innovative odoriferous molecules using advanced neural networks. Drawing from data on Parfumo and the Good Scents Company webpage (Parfumo, 2008; The Good Scents Company, 2021), the study employs sophisticated web scraping techniques to gather diverse perfume attributes. Following this, a k-means algorithm is applied for perfume clustering, paving the way for recommending similar scents to consumers. The process then bridges customer preferences to molecular design by incorporating their feedback into generating new molecules via graph neural networks (GNNs). Through converting the Simple Molecular Input Line Entry System (SMILES) representation into graph structures, the GNN facilitates the creation of new molecular designs attuned to consumer desires. The proposed approach offers promising avenues for consumers to pinpoint similar perfume choices, incorporating feedback, and for manufacturers to conceptualize new fragrant molecules with a high likelihood of market resonance.

Using of the organic base tetramethylammonium hydroxides (TMAH) is a viable, cheap and fast route, for the MgZnAl-LDH type materials synthesis by both co-precipitation and mechano-chemical methods. TMAH provided several advantages as smaller quantity of water required in the washing step compared to the use of inorganic alkalis, prevention of LDH contamination with alkali cations, acting as template molecule in texture tailoring along with disadvantages as its presence in small quantities in the resulting layered materials. Regardless the use of organic / inorganic bases and co-precipitation / mechano-chemical methods, zincite stable phase was found in all the synthesized solids. The basicity of catalysts followed the trend: mixed oxides > reconstructed > parent LDH. The memory effect of LDH is supported only by the presence of Mg and Al cations, while Zn remains as zincite stable phase. The catalytic activities for Claisen-Schmidt condensation of benzaldehyde with cyclohexanone provided values higher than 90% after 2h, with a total selectivity in 2,6-dibenzylidenecyclohexanone, while in self-condensation of cyclohexanone no more than 7.29% after 5h. These behaviors depended on catalysts basicity as well as the planar rigidity of the compound.

Simultaneously with the development of industrial society, wastewater with organic pollutants has caused various environmental problems. The most majority of organic pollutants in water and wastewater are persistent, reason which can cause serious problems for human health, animal health, and for the whole environment. Therefore, efficient treatment methods for wastewater with highly concentration of organic compounds are immediately necessary. During the last years, the prescribed and non-prescribed consumption of antibiotics has grown a lot worldwide. Big quantities of antibiotics are discharged into wastewater because their incomplete absorption by living organisms, but at small concentrations present in aquatic environments represents a major risk for the human health and environment protection. The paper presents the main advantages and disadvantages of advanced oxidation processes, but also current state and new perspectives in the field of environment protection. Advanced oxidation processes (AOPs) are often used in the field of treatment of different types of wastewater. AOPs are based on physicochemical processes that create significant structural changes in chemical species, their commercialization at a wide scale may result in cost reductions that are desirable for environmental applications. The majority of antibiotics may be eliminated using physicochemical processes, such as photo-Fenton, photolysis, ozonation, electrooxidation, heterogeneous catalysis, and other bio processes. In comparison to conventional chemical processes, AOPs provide superior oxidation efficiency, ideal operating costs, and zero secondary pollutants.

The present paper deals with the complex study of the CO2 capture from combined heat power plant flue gases using the efficient technological scheme design – membrane cascade type of «Continuous Membrane Column». In contrast to well-known multi-step or multi-stage process designs, the cascade type of separation unit provides several advantages. That apparatus conceptually refers to the distillation columns. Here, the separation process is implemented in it by creating two counter current flows. In one of them is depleted by the high-permeable component in a continuous mode, meanwhile the other one is enriched. Taking into account, that the circulating flows rate overcome the withdrawn ones, there is a multiplicative growth in separation efficiency. A comprehensive study of the CO2 capture using membrane cascade type of «Continuous Membrane Column» includes the determination of optimal membrane material characteristics, the sensitivity study of the process and feasibility evaluation. It was clearly demonstrated that proposed process provides the efficient CO2 capture, which meets the modern requirements in terms of CO2 content (≥ 95 mol.%), recovery rate (≥ 90 %) and residual CO2 concentration (≤ 2 mol.%). Moreover, it was observed, that it is possible to process CO2 with purity up to 99.8 mol.% at the same recovery rate. This allows use of this specific process design in the CO2 pretreatment operations in the production of high-purity carbon dioxide.

Biomass exploitation is a global trend due to the circular economy and the environmentally friendly spirit. Numerous applications are now based on the use of biomass derived products. Hydrogen sulfide (H2S) is a highly toxic and environmentally hazardous gas, which emitted from various processes. Thus, the efficient removal of this toxic hazardous gas following cost effective processes is an essential requirement. In this study, we present the synthesis and characterization of biomass-derived activated-carbon/zinc-oxide (ZnO@AC) composites from different biomass sources as potential candidates for H2S sorption. The synthesis involved a facile method for activated carbon production via pyrolysis and chemical activation of biomass precursors (spent coffee, Aloe-Vera waste leaves, and corncob). Activated carbon production was followed by the incorporation of zinc oxide nanoparticles into the porous carbon matrix using a simple melt impregnation method. The synthesized ZnO@AC composites were characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and nitrogen porosimetry. The H2S removal performance of the ZnO@AC composites was evaluated through sorption experiments using a handmade apparatus. Our findings demonstrate that the Aloe-Vera, Spent-coffee, and Corncob derived composites exhibit superior H2S sorption capacity up to 106 mgH2S/gads., 66 mgH2S/gads., and 47 mgH2S/gads. respectively.

The combination of wet-lab experimental data on multi-site combinatorial mutations and machine learning is an innovative method in protein engineering. In this study, we present an improved innovative sequence–activity relationship (innov'SAR) methodology based on novel descriptors and digital signal processing (DSP) to construct a predictive model. In this improved approach, 21 experimental (R)-selective amine transaminases from Aspergillus terreus (AT-ATA) were used as an input to predict higher thermostability than that predicted using the existing data. We successfully improved the determination coefficient (R2) of the model from 0.66 to 0.92. In addition, root mean square deviation (RMSD) and root mean square fluctuation (RMSF) were estimated and conformation analysis based on molecular dynamics simulations was performed to verify the enhanced thermal stability of the screened mutants. The improved innov'SAR algorithm enhanced the predictive accuracy, suggesting a method for modifying the stability of AT-ATA, which may help in directed evolutionary screening and open up new avenues for protein engineering.

The increading emission of carbon dioxide to the atmosphere has urged the scientific community to investigate alternatives to alleviate such emissions being the principal contributor to the greenhouse gas effect. One major alternative is carbon capture and utilisation (CCU) towards the production of value-added chemicals using diverse technologies. This work aims at the study of the catalytic potential of different cobalt-derived nanoparticels for methanol syntheis from carbon dioxide hydrogenation. Thanks to its abundance and cost-efficacy, cobalt can serve as an economical catalyst compared to noble-metal-based catalysts. In this work, we present a systematic comparison among different cobalt and cobalt oxide nanocomposites in terms of their efficiency as catalysts for carbon dioxide hydrogenation to methanol as well as how different supports can enhance their catalytic capacity. The oxygen vacancies in the cerium oxide act as carbon dioxide adsorption and activation sites, which facilitates a higher methanol production yield.

The Bayer process is the maim method of alumina production worldwide. The use of low-quality bauxites for alumina production results in the formation of a significant amount of technogenic waste - bauxite residue (BR). The Bayer reductive method is one possible way to eliminate BR stockpiling, but it requires high-pressure leaching at temperatures higher than 220 °C. In this research, the possibility of boehmitic bauxite atmospheric pressure leaching at both the first and second stages or high-pressure leaching at the second stage with the simultaneous reduction of hematite was investigated. Bauxite and solid residue after NaOH leaching were characterized using XRD, SEM-EDS, and Mössbauer spectroscopy methods. The first stage of leaching under atmospheric pressure with the addition of Fe(II) species in a strong alkali solution (330-400 g L–1 Na2O) results in a partial reduction of the iron minerals and an extraction of more than 60% of Si and 5-25% of Al (depending on caustic modulus of solution) after 1 h. The obtained desilicated bauxite was subjected to atmospheric leaching at 120 °C in a strong alkali solution (350 g L-1) or high-pressure leaching at 160-220 °C using the Bayer process mother liquor in order to obtain a concentrate with a magnetite content higher than 83 wt. %.

Iron and chromium based alloys have found wide application in various fields of science and technology. Primary carrier based on Fe-Cr-Al alloy is used in block catalysts for high-temperature hydrocarbon conversion, in production of block metal catalysts for neutralization of toxic gases released during operation of internal combustion engines, as well as those present in smoke emissions from enterprises. Influence of thermal action on Fe-Cr-Al alloy foil and stability of secondary carrier on its surface was studied. Elemental composition of the surface layer of X15U5 alloy foil does not remain constant during heating and depends on the thermal treatment mode. Some of the elements come to surface and elemental composition of surface layer can differ significantly from that observed in the bulk of foil sample. This implies the possibility of changing the adhesive and adsorption properties of the foil surface, as well as the need to take this fact into account when supporting a secondary carrier and active phase to the foil. Applied technique of phosphating and supporting a secondary carrier to the foil surface makes it possible to obtain a sufficiently stable coating. There is no shedding of the secondary carrier from foil surface during high-temperature treatment in air.

Mercury (Hg (II)) contamination is indefatigable global hazard which causes severe permanent damages to human health. Extensive research has been carried out to produce mercury adsorbents however they are still facing certain challenges limiting their upscaling. Herein we reported the synthesis of novel amine impregnated inverse vulcanized copolymer for effective mercury removal. Poly(S-MA) was prepared using sulfur and methacrylic acid employing inverse vulcanization method following by functionalization. The polyethylenime (PEI) was impregnated on poly(S-MA) to increase the adsorption active sites. The developed adsorbent was then characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR confirmed formation of copolymer and successful impregnation of PEI and SEM revealed composite porous morphology of the copolymer. Amine impregnated copolymer (amine@poly(S-MA)) outperformed poly(S-MA) in mercury as it showed 20 % superior performance with 44.7 mg/g maximum adsorption capacity. The adsorption data best fits the pseudo second order which indicates that the chemisorption is most influential mechanism in this case indicating the involvement of NH2 in mercury removal. The adsorption is mainly monolayer on homogenous surface as indicated by 0.76 value of Redlich-Peterson exponent (g) which describes the adsorption nature advent from R2 value of 0.99.

Thin-wall heat pipe is an efficient heat transfer component, which has been widely used in the field of heat dissipation of high-power electronic equipment in recent years. In this study, the orange peel morphology defect of thin-wall heat pipes after bending deformation was analyzed both for the macro 3D profile and for the micro-formation mechanism. The results show that after high temperature sintering treatment, the matrix grains of heat pipe are coarsened seriously and formed a strong Goss texture, while a certain annealing twins with the unique Copper orientation are retained. The distribution of Schmid factor value subjected to the uniaxial stress indicate the inhomogeneity of intergranular deformation exist among the annealing twins and matrix grains. The annealing twin exhibit a “hard-oriented” component during the deformation; thus, it plays a role as barrier and hinder the slipping of dislocation. As the strain accumulates, part of the annealing twins may protrude from the surface of heat pipe, forming a large-scale fluctuation of the surface as the so called the “orange peel” morphology. The 3D profile shows the bulged twins mostly perpendicular to the drawing direction, with about 200-300μm in width and 10-20μm in height.

The crystal structure of a polymorph of Glycyl-L-alanine HI.H2O was synthesized from chiral cyclic Glycyl-L-alanine dipeptide, known to show molecular flexibility in different environments. The space group is polar (P21) and therefore pyroelectricity and optical second harmonic generation properties are allowed by symmetry. We report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than the semi-organic ferroelectric Triglycine Sulphate (TGS) crystal. Furthermore, the polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic Barium Borate (BBO) single crystal.

Scientific advancements in the food industry have resulted in the discovery of natural substances that can serve various functions in food. Essential oils, in particular, can act as food preservatives or flavoring agents due to their abundance of natural antioxidants, which possess preservative properties. In this study, the composition of Thymus vulgaris essential oil was determined using GC-MS and HS-SPME. The essential oil obtained from Thymus vulgaris L. through hydro-distillation yielded approximately 4%. GC/MS analysis of the essential oil identified 11 components, with a predominant presence of oxygenated monoterpenes (56.97%). Notably, carvacrol (37.63%) and thymol (17.35%) were present in significant amounts, accounting for 54.98% of the overall composition. The in vitro antioxidant activity of the essential oil was evaluated using three methods. The DPPH free radical scavenging test yielded an IC50 of 0.51±0.11 mg mL-1. The β-carotene/linoleic acid bleaching test resulted in an IC50 of 2.58±0.10 mg mL-1. Finally, the ABTS assay indicated relatively lower antioxidant activity compared to ascorbic acid.

Acoustic focusing of particle flow in microfluidics has been shown to be an efficient tool for particle separation for various chemical and biomedical applications. The mechanism behind the method is the selective effect of the acoustic radiation force on distinct particles. In this way, they can be selectively focused and separated. The technique can also be applied under stationary conditions, i.e., in the absence of fluid flows. In this study, the manipulation of self-propelled particles, such as Janus particles, in an acoustofluidic setup is investigated. In experiments with self-propelled Janus particles and passive beads, we explore the interplay between self-propulsion and the acoustic radiation force. Our results demonstrate unusual and potentially useful effects such as selective trapping, escape and assisted escape in binary mixtures of active and passive particles. We also analyze various aspects related to the behavior of Janus particles in acoustic traps in the presence and absence of flows.

This review provides an extensive overview of the developments in the field of polymer science, focusing on the solid-state modification (SSM) of thermoplastic materials. The background of the study places thermoplastics within the context of their increased use over the past century, highlighting their versatility in various applications and the associated environmental and health concerns due to certain additives. The methods section delves into the specifics of SSM, a technique that involves the incorporation of monomers or oligomers into the amorphous phase of polymers through multiple exchange reactions, distinguishing it from traditional melt polymer modification methods. The results section outlines the unique aspects of SSM and its increasing recognition for its potential to enhance material performance in areas such as catalysts and composites. It also discusses the application of SSM in modifying different thermoplastic polymers, highlighting various studies demonstrating the method's effectiveness in altering polymer properties. Finally, this work emphasizes SSM's importance in environmental sustainability and its potential in the recycling and upcycling of plastic materials. It acknowledges the challenges and future perspectives in the field, particularly regarding the scalability of SSM techniques for industrial applications and their role in advancing a circular economy in the polymer industry.

Glycerol is the main residue in the biodiesel production industry; therefore, their valorisation is crucial. Acetalization of glycerol towards fuel additives as solketal (2,2-dimethyl-1,3-dioxolan-4-methanol) is of high interest, promoting circular economy since it can be added to the biodiesel or even fossil-diesel to improve their quality and efficiency. Straightforward prepared metal-organic framework (MOF) materials of MOF-808 family were applied to the valorisation of glycerol for the first time. In particular, MOF-808(Hf) revealed to be an effective heterogeneous catalyst to produce solketal under moderate conditions: small amount of the MOF material (only 4wt% of glycerol), ratio 1:6 of glycerol/acetone and temperature of 60 ºC. The high efficiency of MOF-808(Hf) was associated with the high amount of acid centres present in its structure. Furthermore, its structural characteristics such as window opening cavities size and pore diameters showed to be ideal to reuse this material during at least ten consecutive reaction cycles without losing activity (conversion > 90% and selectivity > 98%). Remarkably, it was not necessary the washing or other activation treatment of the MOF-808(Hf) catalyst between cycles (no pore blockage occurred) and it maintained structural integrity after the ten cycles, confirming to be a sustainable heterogeneous catalyst to the glycerol valorisation.

Most petrochemical plants still maintain a Proportional-Integral-Differential controller(PID) system, which is a feedback control system. However, gradually, the PID system is being extended and introduced to the Advanced Process Controller (APC) system, which is an integrated control system of feedforward and feedback that predicts external influences in advance. In the process of conducting on-site plant tests and calculating APC model parameter for the application of APC systems, a problem arises that Model Parameter are implemented differently depending on the proficiency of APC engineers. To minimize this problem, a technique for estimating APC model parameter without a plant test is required. In order to estimate the APC model parameter, it is necessary to train on dynamic interval data. In this paper, we use statistical techniques such as PELT, Linear Kernel, and Radial Basis Function Kernel of Change Point Detection (CPD) to extract dynamic data with minimum Mean Absolute Error (MAE) from time series data of a real petrochemical plant. Then, the hyper parameter is fixed and the APC model parameter is estimated by learning the dynamic section data. By applying the estimated APC model parameter to the APC Model Tool and measuring the fitting rate, it was confirmed that it is possible to estimate the APC model parameter with excellent control performance without plant test.

Ultralong carbon nanotubes (UCNTs) are highly demanded for nanocomposites applications because of their magnificent physical and chemical properties. UCNTs are synthesized by catalytic chemical vapor deposition (CCVD) method and, before using as fillers in nanocomposites, should be purified from residual catalyst and non-CNT particles without significant destruction or scissoring of UCNTs. The role of water vapor for purification of UCNTs is investigated, the importance of water assistance in this process is confirmed. It was shown that wet air treatment of products of UCNTs CCVD synthesis under mild conditions can be used to decrease sufficiently residual catalyst content without significant carbon losses in comparison with the results obtained with dry air, while the residual iron content was shown to influence heavily on the subsequent oxidation of different forms of carbons, including UCNTs. The increasing of D/G ratio of Raman spectra after wet air treatment of products of UCNTs CCVD synthesis makes it possible to conclude that iron catalyst particles transform into iron oxides and hydroxides that caused inner structural strains and destruction of carbon shells improving removal of the catalyst particles by subsequent acid treatment. UCNTs purification with water assistance can be used to develop economically and ecologically friendly methods for obtaining fillers for nanocomposites of different applications.

In this work, the use of graphite-like carbon nitride (g-C3N4) with improved texture characteristics for the synthesis of supported palladium catalysts of dehydrogenation of nitrogen-containing heterocycles was studied. This process is key to the creation of liquid organic carrier technology (LOHC) using N-heterocycles as reversibly hydrogenated/dehydrogenated substrates. For the preparation of g-C3N4-mca supports with advanced textural characteristics, well-established technology of the melamine cyanurate complex carbonization and standard techniques of adsorption precipitation together with wet impregnation were used for the synthesis of Pd-containing systems. The activity of the synthesized catalysts was studied in decahydroquinoline dehydrogenation. The high weight content of extractable hydrogen (7.2 wt %) and the high extraction rate, respectively, make it possible to consider these substances as the most promising N-heterocyclic compounds for this technology. It was shown that an increase in the specific surface area of g-C3N4 allows for achieving a slightly lower, but comparable fineness of palladium particles for the 1 wt% Pd/MCA-500 sample, compared to the standard 1 wt% Pd/C. In this case, the catalytic activity of 1 wt% Pd/MCA-500 in dehydrogenation of both substrates exceeded the analogous parameter for catalysts supported by nitrogen free supports. This regularity is presumably associated with the electron-donor effect of surface nitrogen, which favorably affects the dehydrogenation rate as well as the stability of catalytic systems.

The development of oxidation processes with generating powerful radicals is the most interesting and thought-provoking dimension of peroxymonosulfate (PMS) activation. In this study, a magnetic spinel CuFe2O4 was successfully prepared by a facile, non-toxic, cost-efficient co-precipitation method with the synergetic effect of photocatalytic PMS oxidation against recalcitrant benzotriazole (BTA) pollutant. The high particle dispersion and large surface area (201.898 m2/g) provided a high photocatalytic activity with CuFe2O4. The obtained results from the central composite design (CCD) analysis confirmed the optimum degrading rate of BTA reached 81.4% at the optimum operational condition of CuFe2O4= 0.4 g/L, PMS= 2 mM, BTA= 20 mg/L after 70 min irradiation time. As such, the active species capture experiments revealed the presence of •OH, SO4•‒, O2•‒ and h+ species in CuFe2O4/UV/PMS system where SO4•‒ was dominated for BTA photodegradation. The combination of photocatalysis and PMS activation enhanced the consumption of metal ions in redox cycle reactions, thus preventing metal leaching and maintain the recyclability with reasonable mineralization efficiency which achieved more than 40% total organic carbon removal after four batch experiments. A retardant effect on BTA oxidation was observed with comparing the water’s common anion constituents as HCO3‒ > Cl‒ > NO3‒ > SO2‒. Results from intermediates identification showed that the transformation pathway of BTA developed as the deprotonation, hydrolysis and ring cleavage processes promoting the practical potential of photo-absorbing CuFe2O4 catalyzed PMS which can be a promising method due to convenient magnetic separation form the solution.

The utilization of lignocellulosic biomass as an alternative energy source presents a promising opportunity to achieve a future energy system that is clean and free from CO2 emissions. To realize this potential, it is crucial to develop effective techniques for converting biomass and organic solid waste into secondary energy sources. Among the available options, hydrogen production stands out due to its numerous advantages, including its cleanliness, versatility in conversion and utilization technologies, high energy efficiency, and dense energy content per unit weight. This article offers a comprehensive overview of different conversion pathways and important technologies for generating hydrogen from biomass and organic solid waste. It specifically focuses on the thermochemical conversion process, which shows promise as an economically viable approach. While certain thermochemical conversion processes are still in the developmental phase, utilizing organic biomass for hydrogen production is widely recommended due to its ability to yield higher amounts of end products and its compatibility with existing facilities. However, it should be noted that this method necessitates a substantial amount of energy due to its endothermic nature. The article also explores alternative hydrogen conversion technologies and their potential for utilizing organic biomass as a feedstock, while addressing the challenges and limitations associated with these methods.

In this work Cu2O nanoparticles (NPs) were created in-situ on graphene functionalized with Thermomyces lanuginosus lipase (G@TLL) where site-oriented supported TLL acted as template and binder in the presence of copper salt by tailorable synthesis under mild conditions, producing a heterogeneous catalyst. Cu2O NPs was confirmed by XRD and XPS. The TEM microscopy showed that the nanoparticles were homogeneously distributed over the G@TLL surface with sizes of 53 nm and 165nm. This G@TLL-Cu2O hybrid was successfully used in the degradation of toxic organic compounds such as trichloroethylene (TCE) and Rhodamine B (RhB). In the case of TCE, the hybrid presented a high catalytic capacity, degrading 60 ppm of product in 60 min in aqueous solution and room temperature without the formation of other toxic subproducts. In addition, a TOF value of 7.5 times higher than the unsupported counterpart (TLL-Cu2O) was obtained, demonstrating the improved catalytic efficiency of the system in the solid-phase. The hybrid also presented an excellent catalytic performance for the degradation of Rhodamine B (RhB) obtaining a complete degradation (48ppm) in 50 min in in aqueous solution and room temperature and with the presence of a green oxidant as H2O2.

This study revealed the synthesis of cross-linked chitosan/Citrus reticulata peel waste (C/CRPW) composites that could be used as low-cost and green bio-adsorbents for the removal of Congo red (CR) dye from aqueous solutions. C/CRPW composites containing different amounts of Citrus reticulata peel waste (CRPW) and chitosan were prepared and cross-linked with glutaraldehyde. The composites were characterized by FESEM, FTIR, and BET. The C/CRPW composites as a new type of bio-adsorbents displayed superior adsorption capability toward anionic CR molecules and the adsorption capacities increased by incorporation of CRPW. Effects of different ambient conditions such as contact time, pH, adsorbent dosage, initial adsorbate concentration, and temperature were fully studied. The conditions which obtained 43.57 mg/g of the highest adsorption capacity were conducted at pH 4, initial concentration of 100 mg/L, adsorbent dosage of 2.0 g/L, and contact time of 24 hours at 328 K. The adsorption data was found to follow the pseudo-second-order kinetic model and the Freundlich isotherm model. According to the findings of this investigation, it was observed that the C/CRWP composites can be used as adsorbents due to their advantages of simple preparation process, environmentally friendly, renewable, efficient, and low-cost.

In this article, the biocatalytic oxidation of ethanol into acetaldehyde was studied using a catalase entrapped within monolithic polyampholyte cryogel, p(APTAC-co-AMPS), derived from an anionic monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), and a cationic monomer, (3-acrylamidopropyl) trimethylammonium chloride (APTAC) as catalyst. Macroporous polyampholyte cryogels containing various amounts of catalase were synthesized in situ under cryo-polymerization conditions at a molar ratio of monomers [APTAC]:[AMPS] = 75:25 mol.% in the presence of 10 mol.% cross-linking agent, N,N-methylenebisacrylamide (MBAA). The conversion of ethanol into acetaldehyde in good-to-high yields was observed in flow-through and batch type reactors under optimal conditions: at T = 10-20 C, pH = 7.1, [C2H5OH]:[H2O2] = 50:50 vol.%. According to SEM image the pore sizes of p(AMPS-co-APTAC) cryogel vary from 15 to 55 μm. The catalytic activity of catalase entrapped within monolithic polyampholyte cryogel in the conversion of ethanol into acetaldehyde was evaluated through the determination of such kinetic parameters as Michaelis constant (Km), the maximum enzymatic rate (Vmax), activation energy (Ea), turnover number (TON) and turnover frequency (TOF). The catalase encapsulated within monolithic polyampholyte cryogel exhibits a high conversion of ethanol into acetaldehyde. The advantages and disadvantages of flow-through and batch type reactors were highlighted.

The annual energy matrix has been changing in the last years because of the necessity of less dependence on fossil fuels, which are running out on the planet. Therefore, a study was started to simulate the most efficient production of H2 through COMSOL Multiphysics®, as it is a gas that in the future will be essential to supply the world's energy necessities, due to its easy to get and insert in piped gas pipes. From this study, we were able to present an optimization of parameters that presents good indications of how to obtain efficient hydrogen production in an idealized reactor.

In this paper, the extraction of essential oil (EO) from thyme by consecutive use of ultrasound and microwave treatments is presented. The aim of the study was to apply an ultrasound pre-treatment of thyme leaves to enhance the thymol content and the extraction yield of the EO obtained by microwave-assisted hydro-distillation (MWHD). Compared with the conventional hydro-distillation (CHD), the consecutive use of ultrasound and microwave treatments resulted in a 72% lower extraction time. When the ultrasound pre-treatment (using the ultrasonic processor with an amplitude of 70%) was applied, the EO content was 23% higher compared to the extraction without pre-treatment. The EO samples were analyzed by GC/MS. The results showed that the major component, thymol, varied from 43.54% (by CHD) to 65.94% (by consecutive use of ultrasound and microwave treatments).

With the development of health service, animal husbandry, aquaculture and chemical industry, more and more pollutants are discharged into the water environment, including antibiotics and heavy metal ions. These hazard substances pose a great threat to environment safety and human health. As two kinds of new green solvents, ionic liquids (ILs) and deep eutectic solvents (DESs) are widely used in various fields including separation and environmental engineering, which are attracting huge attention from academia and industry. In this study, the optimal ionic liquid and deep eutectic solvent were selected and their complex with β-cyclodextrin (β-CD) were firstly prepared by simple and effective inclusion way. After necessary characterization and analysis, two kinds of complex were applied to prepare a special sorbent disc with two different sides by adding diluent (excipient) and pressing under 5~15 MPa. As the result, the IL and DES could be stably immobilized on the disc and play the key role in selective adsorption for targets. Besides that, the experiments of different hazardous substances achieved the expected results. Based on this study, the complex disc showed a lot of merits in the separation performance, easy preparation and use, simple operation, and good stability. It was believed to be a useful tool for water purification and detection.

The presented work is aimed at studying the gas transport characteristics of polymeric hollow-fibre gas separation membranes. Such materials as: polysulfone (PSF), polyphenylene oxide (PFO), polyetherimide (PEI), polyetherimide with polyimide (PEI+PI) were studied on the example of air mixture separation. The values of the permeances of pure gases O2 and N2 and the mixed permeances of oxygen and nitrogen during air separation were obtained. Mathematical models of the gas separation process built on the basis of these values show significant discrepancies. To obtain a gas mixture with 95 mol.% nitrogen from air, taking into account the mixture permeance, 15.8% more PSF membrane area is required than taking into account the permeance of pure gases. For a PPO membrane this value is 13.9%, for PEI 19.8% less area is required, and for PEI+PI 15.9% less. In the design of industrial or semi-industrial membrane installations, such discrepancies can lead to significant errors, including technical and economic ones.

Fine chemicals are produced in small annual volume batch processes (often <10,000 tonnes per year), with a high associated price (usually > $10/kg). As a result of their usage in the production of speciality chemicals, in areas including agrochemicals, fragrances and pharmaceuticals, their necessity will remain high for the foreseeable future. This review article assesses current methods used to produce fine chemicals with heterogeneous catalysts, including both well-established methods as well as newer experimental methods. A wide range of methods utilising microporous and mesoporous catalysts has been explored, including their preparation and modification before use in industry. Their potential drawbacks, as well as benefits, have been analysed, with their feasibility compared to newer, recently emerging catalysts. The field of heterogeneous catalysis for fine chemical production is a dynamic and ever-changing area of research. This deeper insight into catalytic behaviour and material properties will produce more efficient, selective, and sustainable processes in the fine chemical industry. The findings from this article will provide an excellent foundation for further exploration and a critical review in this field of fine chemical production using micro- and mesoporous heterogeneous catalysts.

In this paper, a quick and efficient method for preparation of scopolamine hydrobromide with high purity was introduced, named as magnetic field induced crystallization. Based on the solubility difference between scopolamine and scopolamine hydrobromide, salifying crystallization was selected and then treated with the synergistic effect of magnetic field to achieve the aim of scopolamine purification. The effects of crystallization solvents and magnetic field intensity on the crystallization process of scopolamine hydrobromide, as well as the influnence of magnetic field on the crystal growth direction were investigated. The results revealed that after treatment under magnetic field, the shortened induction time (25.64%-75.46%), the increased purity of crystals (0.95%-2.92%) and the improved recovery rate (4.51%-10.78%) were achieved. Furthermore, we also found that magnetic field could destroy the hydrogen bond in the solution, and change the physical properties of the mother liquid, so as to promote the nucleation formation and crystal growth. The above experiments suggested that the external magnetic field has the potential to be a feasible method for scopolamine preparation.

Elevated ammonium (NH4+) concentrations in untreated waterways contribute to eutrophication and dissolved oxygen depletion, which cause severe degradation of water quality. Ion exchange processes are a robust, low operational cost and efficient option for ammonium removal with zeolites being the most widely used. Geopolymers are a sustainable and low-cost option compared to zeolites that follows the same ion exchange technology. In the present study, a metakaolin-based porous geopolymer was synthetized, characterised and validated as adsorbent material. The laboratory batch tests showed a maximum adsorption capacity (Qm) of 18.35 mg/g being 27% higher than reference zeolites. Kinetics followed the Weber-Morris rate equation being the intraparticle diffusion the limiting process and continuous experiments indicated a maximum removal of 97% in the first hours. The material was validated in a wastewater treatment pilot plant where values in pH, electrical conductivity and NH4+ concentration were monitored. The obtained data indicated that the material achieved up to 80% NH4+ removal which is similar to traditional zeolites. The results demonstrate that this sustainable, low-cost and easy-to-install metakaolin-based geopolymer can be used effectively for NH4+ treatment.

The synthesis 2-tert-butyl-4-methylphenol is of great significance because of its widely application in industry, and the development of highly efficient catalyst is necessary to the alkylation of p-cresol and tert-butyl alcohol. Here, an efficient and mild method was established, caprolactam was chosen as hydrogen-bonding acceptor, p-toluenesulfonic acid was employed as hydrogen-bonding donor, and deep eutectic solvent (DES) was prepared to catalyze the alkylation reaction. The structure of the DES catalyst was characterized by 1H NMR spectra, thermogravimetric analysis and fourier transform infrared spectra (FT-IR). In addition, response surface design based on Box-Behnken method was employed to optimize the alkylation reaction process parameters, the study of reaction kinetics was also carried out subsequently. The recycle performance of the catalyst was evaluated by recovery experiments, and a good result was obtained. Comparing with the literature reported, we here provide a mild method to the synthesis of 2-tert-butyl-4-methylphenol.

The exploitation of bio-based foams implies an increase in the use of renewable biological resources to reduce the rapid consumption of petroleum-derived resources. Both tannins and furfuryl alcohol are derived from forestry resources and are therefore considered as attractive precursors for the preparation of tannin-furanic foams. In addition, toughening modification of tannin-furanic foams using polyvinyl alcohol (PVOH) resulted in a more flexible network-like structure, which imparts excellent flexibility to the foams with acquirement of relative properties that are even close to those of polyurethane foams, which are the most used polymers for fabrication of insoles for athletes. In addition, the addition of PVOH did not affect the thermal insulation of the foams, resilience and elongation at break, while reducing the brittleness of the samples and improving the mechanical properties. Also the observation of the morphology of the foam indicated that the compatibility between PVOH and tannin-furanic resin is good, and the cured foam does not show fragmentation or collapse, while the bubble pore structure is uniform. The developed flexible foam derived from biomass resources endowed the foam good thermal insulation properties and high mechanical properties, and the samples exhibited suitable physical parameters to be used as flexible insoles for athletes.

In recent decades, perovskite-type compounds (ABB′O3) have been exhaustively studied due to their unique ferroelectric properties. In this work, a systematic study aiming to prepare fine particles in the binary system SrZrO₃–SrTiO₃ was conducted under hydrothermal conditions in a KOH (5 M) solution at 200 °C for 4 h under a constant stirring speed of 130 rpm. The precursors employed were SrSO₄ powder (< 38 μm size) and coprecipitated hydrous gels of Zr(OH)₄•9.64 H₂O (Zr-gel) and Ti(OH)₄•4.5H₂O (Ti-gel), which were mixed according to the stoichiometry of the SrZr_1-xTixO₃ in the compositional range of 0.0>x>100.0 mol% Ti⁴⁺. The XRD results revealed the formation of two crystalline phases rich in Zr⁴⁺, an orthorhombic structured SrZr0.93Ti0.07O3 and a cubic structured SrZr0.75Ti0.25O3 within the compositional range of 0.1–0.5 mol of Ti4+. A cubic perovskite-structured solid solution, SrTi1-xZrxO3, was preferentially formed within the compositional range of 0.5>x>0.1 mol% Ti⁴⁺. The SrZrO₃ and SrZr_0.93Ti_0.07O₃-rich phases had particle sizes averaging 3 m with a cubic morphology. However, a remarkable reduction in the particle size occurred on solid solutions prepared with hydrous Ti-gel over contents of 15 mol% Ti⁴⁺ in the reaction media, resulting in the formation of nanosized particles agglomerates with cuboidal shape self-assembled via a 3D hierarchical architecture, the sizes of these particles varied in the range between 141.0–175.5 nm. The limited coarsening of the particles is discussed based on the Zr-gel and Ti-gel dehydration capability differences that occurred under hydrothermal processing.

The requirement for developing tools capable of detecting and monitoring heavy metals (HMs) has recently taken on more significance due to worries about their toxic effect on human health and aquatic habitats. In this study, a simple electrochemical sensing carbon paste electrode (CPE) based on composite of Zinc/Iron layered double hydroxide (LDH) and polyaniline (PANI) was developed for the determination of lead ions in aquatic solutions. For this purpose, Zn-Fe LDH/PANI was prepared and characterized by Fourier transform infrared (FTIR), X ray diffraction (XRD), and scanning electron microscopy (SEM). Modified carbon electrode based Zn-Fe LDH/PANI was electrochemically characterized compared with unmodified electrode in FCN as a redox probe using cyclic voltammetry (CV). Thus, Zn-Fe LDH/PANI was utilized as sensing material for the electrochemical determination of lead ions using differential pulse voltammetry (DPV). Zn-Fe LDH/PANI/CPE show limits of detection (LOD) and quantification (LOQ) of 167.8 nM and 559.4 nM, respectively. Zn/Mg/Fe LDH was prepared using co-precipitation method and characterized by XRD, FTIR, SEM and BET, used for removal of Pb+2 ions. Removal process was investigated at different conditions as pH, metal ion concentrations, starting adsorbent dose at first and contact time. Zn/Mg/Fe LDH was evaluated as an effective adsorbent material for lead ions elimination in aquatic solutions, with capacity of adsorption 700 mg/g. The elimination of lead ions on Zn/Mg/Fe LDH fitted the pseudo first-order kinetics model and the isotherm was matched with Langmuir model. Studies revealed that the ideal removal conditions were pH = 5.0, an adsorbent mass of 0.05 g, and 20 ml of 50 ppm metal ion concentration at 60 min. The Zn-Fe LDH/PANI composite also showed potential anti-cancer properties against lung cancer cells (A549) while maintaining safety for normal lung fibroblast cells (WI-38). Collectively, advancements in electrochemical sensors offer promising solutions for lead ion detection, with wide-reaching applications in wastewater treatment and cytotoxicity assessment. These innovations have the potential to enhance environmental monitoring and public health safety.

The present study focuses on the development and optimization of a highly efficient unique hybrid technique — membrane-assisted gas absorption (MAGA) in designing the separation unit, which provides the improvement in mass-transfer of a target component during the natural gas processing in terms of sweetening stage. A novel design of membrane-assisted gas absorption cell is used to enhance the ratio between absorbent amount and membrane surface available for permeation. The performance tests were implemented on example of two gas mixtures separation: one is model ternary gas mixture and the second is quasi real natural gas, which includes number of hydrocarbons, nitrogen, acid impurities and xenon. For both cases, the MAGA unit demonstrated high acid gases removal efficiency, and high recovery of hydrocarbons. The ultimate efficiency of studied system was up to 96 and 61 % of removed acid gases with hydrocarbons losses up to 1 % at highest productivity. In this way, the residual sum of acid gases content may be lowered to 1 vol.% using the heat-free hybrid membrane-assisted gas absorption unit maintaining suitable recovery rate of methane, ethane, propane and n-butane. Nevertheless, the overall efficiency of the process may be enhanced using the specific absorption agents with aqueous amino alcohol solutions.

Printed circuit boards (PCBs) make up 3 to 5% of all electronic waste. The metal content of spent PCBs can reach 40%. They usually contain valuable metals - Ag, Au, Pd, as well as other metals such as Cu, Sn, Pb, Cd, Cr, Zn, Ni and Mn. However metallic part of whole PCB is 40-60% including Cu layers between the fiberglass-polymer layers. The paper describes economics of the the valuable metals (Ag, Au, Pd) containing concentrate preparation from raw PCB. Considered the influence of pre-treatment method of PCB before the extraction of valuable metals on the extraction self-cost change. The disintegration method is based on the high-energy impact of the particles of the material to be ground, thus causing the separation of the metallic components of the PCB. In the course of the work, single and double direct grinding by the method of disintegration was studied. For the calculation the test batch 10’000 kg of two types of PCB were taken for estimation of the self costs and potential profit in case of complete valuable metals (Ag, Au, Pd) plus Cu extraction. Is shown that from 10’000 kg of studied PCB is possible to obtain 1144 and 1644 kg of metal-rich concentrate, which further should be subjected to electro-hydrochlorination for metals leaching. The main findings shows, that despite of high content of Cu in studied PCB, the commercial value is insignificant in total income from the Ag, Au and Pd sale. Was established correlation of the self-cost decrease after separative disintegration of PCB by metal content increase (by specific metals such as Au, Ag, Pd and also Cu) with the metal potential yield after extraction.

Reductive leaching in the Bayer cycle using of iron (2+) allows Al extraction to be significantly increased by magnetization of Al-goethite and Al-hematite. However, the use of expensive iron (2+) salts or iron powder as a source of iron (2+) leads to a significant increase in production costs. In this work, the feasibility of a new method, the reductive leaching of bauxite using an electrolysis process, was investigated. Reduction of iron minerals of boehmitic bauxite in both Bayer solution and purely alkaline solutions were carried out. Experiments were performed using a plate cathode and a bauxite suspension in alkaline solution, as well as using a bulk cathode with a stainless-steel mesh at the bottom of the cell as the current supply. During the electrolysis process, the potential of the cathode relative to the reference electrode was measured as a function of current at different concentrations of solid (100-300 g L–1) and suspension temperatures (95-120 °C). It is shown that the current efficiency using suspension and plate cathode with the predominant deposition of Fe doesn’t exceed 50% even with the addition of magnetite to increase the contact of solid phase with the current supply. With the use of a bulk cathode, the reduction of iron minerals leads predominantly to the formation of magnetite with the efficiency of using electric current more than 80%. As a result of preliminary desilication and electroreduction it is possible to extract more than 97% of Al from bauxite, and to increase the iron content in the bauxite residue to 57-58%.

The processes of hydrogen reduction of silicon and germanium chlorides under the conditions of high-frequency (40.68 MHz) counteracted arc discharge stabilized between two rod electrodes are investigated. The main gas-phase and solid products of plasma-chemical transformations are determined. Thermodynamic analysis of SiCl4 + H2 and GeCl4 + H2 systems for optimal process parameters was carried out. Using the example of hydrogen reduction of SiCl4 by the method of numerical modeling, gas-dynamic and thermal processes for this type of discharge are investigated. The impurity composition of gas-phase and solid reaction products is investigated. The possibility of single-stage production of high-purity Si and Ge mainly in the form of compact ingots, as well as high-purity chlorosilanes and trichlorogermane, is shown.

This review focuses on an extensive synopsis of the recent improvements in the field of CO2 hydrogenation over structured zeolites including their properties, synthesis methods, and characterization approaches. The role of bimodal mesoporous structures surface oxygen vacancies, and the Si/Al ratio in improving catalytic activity is highlighted. The porosity, thermal stability, and structural integrity are also discussed in the review along with how structured zeolites are affected by electrical and plasma interactions. The synthesis methods are analyzed in detail by comparing the benefits and drawbacks of the bottom-up techniques, such as hard templating, soft templating, and non-templating on the one side; and the top-down approaches, e.g. dealumination, desilication, and recrystallization on the other. This review also draws attention to the necessity of overcoming the difficulties arising from these synthesis techniques, for example, micropore-induced diffusion restrictions and morphological constraints, employing innovative approaches and optimization strategies. Conventional and advanced characterization techniques are pointed out in this respect as crucial for understanding the catalytic mechanism and the dynamic behavior, hence, beneficial in the advancements of research on structured zeolites with higher efficiency and activity. The review ends with a perspective that highlights the necessity of further research in the improvement of synthesis approaches and characterization procedures of the structured zeolites to increase their catalytic activity in CO2 hydrogenation, a critical process of paramount importance in the global effort to reduce excessive carbon emissions and combat climate change..

The significant environmental issue of water pollution caused by emerging contaminants un-derscores the imperative for developing novel cleanup methods that are efficient, economically viable, and that are intended to operate at high capacity and under continuous flows at the in-dustrial scale. This study shows the results of the operational design to build a prototype for the retention at lab scale of pollutants residues in water by using as adsorbent material, insoluble polymers prepared by β-cyclodextrin and epichlorohydrin as a cross-linking agent. Laboratory in batch tests were run to find out the adsorbent performances against furosemide and hydro-chlorothiazide as pollutants model. The initial evaluation concerning the dosage of adsorbent, pH levels, agitation, and the concentration of pharmaceutical pollutants enabled us to identify the optimal conditions for conducting the subsequent experiments. The adsorption kinetic and the mechanisms involved were evaluated revealing that that the experimental data perfectly fit the pseudo second order model being the adsorption process mainly governed by chemisorption. According to the KF constants values of 0.044 (L/g) and 0.029 (L/g) for furosemide and hydro-chlorothiazide, respectively and determination coefficient (R2) higher than 0.9 for both com-pounds, Freundlich yielded the most favorable outcomes, suggesting that the adsorption process occurs on heterogeneous surfaces involving both chemisorption and physisorption processes. The maximum monolayer adsorption capacity (qmax) obtained by Langmuir isotherm reveal a saturation of the β-CDs-EPI polymer surface 1.45 times higher for furosemide (qmax = 1.282 mg/g) than hydrochlorothiazide (qmax = 0.844 mg/g). Based on these results, the sizing design and building of a lab scale model were conducted, which in turn will be used later to evaluate its performances working in continuous flow in a real scenario.

Carbonization of a biopolymer (lignin) in self-propagating high-temperature synthesis (SHS) led to the production of 2D graphene structures. With the help of modern analytical methods (Raman spectroscopy, X-ray diffraction) and electron microscopy, the resulting product was confirmed to have a few-layer 2D graphene structure. The predicted photovoltaic properties of the resulting few-layer graphene were implemented for laser ignition of a model pyrotechnic composition based on porous silicon. A phenomenological model of the formation mechanism of 2D graphene structures under the conditions of the SHS process is proposed.

Layered double hydroxides (LDHs) have emerged as promising catalysts for various acid-base catalytic reactions. Due to their unique structure and regulatable dual acid-base properties, they offer more environmentally friendly and sustainable alternatives to traditional liquid acid and base catalysts. This study introduces the structural composition, preparation methods, and acid-base catalytic properties of LDHs-based catalysts. Recent application progress of LDHs and rehydrated LDHs, LDHs-based metal nanocatalysts, and LDHs-based mixed metal oxide catalysts used as solid acid-base catalysts in acid-base green catalytic conversion is reviewed. The challenges and prospects of LDHs-based catalysts as green and sustainable catalysts are summarized and proposed.

Hydrothermal carbonization of cellulose was examined at 240 ℃ for 1 h. Ammonium sulfate and thiourea were selected as the doping sources of inorganic nitrogen and organic nitrogen for the preparation of supercapacitor carbon. The effect of boric acid on the properties of the resulting hydrochar after KOH activation was examined. The results showed that the proportion of functional groups and the specific surface area of the activated hydrochar would be reduced after the addition of boric acid, and the pore-forming process of the micropores would be inhibited. The hydrochar obtained from the reaction of cellulose and organic nitrogen compounds had better pore size distribution and electrochemical properties after activation. The largest specific surface area (952.27 m2 g-1) was obtained when only thiourea was used as the only doping source. In the three-electrode system, the specific capacitance resulting activated hydrochar reached 236.25 F g-1 at a current density of 1 A g-1. After 20,000 cycles of charging and discharging at a current density of 10 A g-1, the capacitance retention rate reached 99.96%. Therefore, this study proves that the supercapacitor carbon with good electrochemical properties could be obtained by the direct reaction of cellulose with organic nitrogen compounds.

PdRe/Al2O3 catalysts are highly selective for hydrogenation of furfural to furfuryl alcohol (FAL). Moreover, synergy between the metals can result in greater specific activity (higher turnover frequency, TOF) than exhibited by either metal alone. Bimetallic catalyst structure depends strongly on the metal precursors employed and their addition sequence to the support. In this work, PdRe/Al2O3 catalysts were prepared by: (i) co impregnation (CI) and sequential impregnation (SI) of  Al2O3 using HReO4 and Pd(NO3)2, (ii) SI using NH4ReO4 and [Pd(NH3)4(NO3)2], (iii) HReO4 addition to a reduced and passivated Pd/Al2O3 catalyst, and (iv) impregnation with the double complex salt (DCS), [Pd(NH3)4(ReO4)2]. Raman spectroscopy and temperature-programmed reduction (TPR) evidence larger supported PdO crystallites in catalysts prepared using Pd(NO3)2 than [Pd(NH3)4(NO3)2]. Surface [ReO4]- species detected by Raman exhibit TPR peak temperatures from ranging 85 to 260°C (versus 375°C for Re/Al2O3). After H2 reduction at 400°C, the catalysts were characterized by chemisorption, temperature-programmed hydride decomposition (TPHD), CO diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and scanning transmission electron microscopy (STEM) with energy-dispersive x-ray (EDX) spectroscopy. The CI catalyst containing supported Pd-Re alloy crystallites had a TOF similar to Pd/Al2O3 but higher (61%) FAL selectivity. In contrast, catalysts prepared by methods (ii-iv) containing supported Pd-Re nanoparticles exhibit higher TOFs and up to 78% FAL selectivity.

This work aimed at producing lactic acid (LA) from sugarcane bagasse after steam explosion at 195 ºC for 7.5 and 15 min. Enzymatic hydrolysis was carried out with Novozymes’ Cellic CTec3 and/or Cellic HTec3, whereas fermentation was performed with Bacillus coagulans DSM2314. Water-washing of pretreated solids before enzymatic hydrolysis improved both hydrolysis and fermentation yields. The presence of xylo-oligosaccharides (XOS) in substrate hydrolysates reduced hydrolysis efficiency, but their effect on fermentation was negligible. The presence of fermentation inhibitors in C5 streams was circumvented by adsorption on activated carbon powder with no detectable sugar losses. High carbohydrates-to-LA conversions (Yp/s) of 0.88 g·g-1 were obtained from enzymatic hydrolysates of water-washed steam-exploded materials that were produced at 195°C, 7.5 min and the use of centrifuged-but-never-washed pretreated solids decreased Yp/s by 16%. However, when the detoxified C5 stream was added at a 10% ratio, Yp/s was raised to 0.93 g·g-1 for an LA productivity of 2.55 g·L-1·h-1. Doubling the pretreatment time caused a decrease in Yp/s to 0.78 g·g-1, but LA productivity was the highest (3.20 g·L-1·h-1). For pretreatment at 195°C for 7.5 min, elimination of water washing seemed feasible, but the use of longer pretreatment times made it mandatory to eliminate fermentation inhibitors.

Yellow nanorod Mg-MOF-74 was obtained by solvothermal synthesis method. XRD、N2 adsorption-desorption isotherms、SEM and TGA results suggest that the particle size of Mg-MOF-74 reaches 400 nm after the introduction of sodium acetate in the precursor of Mg-MOF-74. Besides, the morphology of Mg-MOF-74 was changed from cauliflower to rod particles. At the same time, the BET specific surface area and pore volume of Mg-MOF-74 were also increased a lot. Then the CO2 dynamic adsorption capacity of Mg-MOF-74 was measured by self-made fix bed under 30 ℃、0.1 bar CO2 partial pressure. The results show that the CO2 adsorption capacity of Mg-MOF-74-N2 reaches 3.67 mmol/g and its CO2 adsorption capacity remains unchanged after 10 times CO2 adsorption-desorption cycles.

This paper is devoted to an accurate determination of the London dispersive and polar free energy of adsorption, the two Lewis acid γs+ and base γs- components of polar surface energy γsAB of 2D single-crystalline and polycrystalline covalent organic frameworks such as TAPPy-TPA-COFs. Inverse gas chromatography (IGC) at infinite dilution was used to quantify the different surface parameters of the different materials. From IGC measurements, one determined the net retention time of the adsorption of n-alkanes and several polar solvents on single-crystalline and polycrystalline covalent organic frameworks. The free surface Gibbs energy of adsorption was obtained for the various organic molecules at different temperatures from their net retention volume values. The separation between the London dispersive energy and the polar energy of adsorbed molecules was carried out by using a new thermodynamic parameter PSX chosen as new indicator variable and taken into account the deformation polarizability and the harmonic mean of the ionization energies of solvents and solid materials, derived from London dispersion equation. The obtained results are very promising for the accurate determination of the surface thermodynamic parameters of adsorption of organic solvents on solid surfaces.

Plastic materials have revolutionized modern life, particularly in the domain of food packaging, owing to their versatility, lightweight nature, and ease of processing. However, the environmental ramifications of non-degradable plastics have raised concerns. Polylactic acid (PLA), derived from renewable sources, presents a sustainable alternative due to its biodegradability and exceptional barrier, mechanical, and safety properties. Nevertheless, the high UV transmittance of PLA limits its use for photosensitive food and pharmaceutical packaging, where UV radiation can lead to nutritional loss and spoilage. Various methods have been explored to enhance the UV-blocking capabilities of PLA, including the integration of inorganic nanoparticles and surface coatings. Despite advancements, these approaches often compromise the inherent transparency of PLA. Incorporating large conjugated groups can maintain transparency but introduces additional challenges. This paper reviews modification methods to enhance PLA's UV-barrier properties and anticipates its expanded utility in food and drug packaging, promoting UV resistance and diversifying PLA's applications.

Coarse-grained molecular dynamics simulations are employed to investigate the spatiotemporal evolution of vesicles (polymersomes) by the self-assembly of randomly distributed amphiphilic BAB triblock copolymers with hydrophilic A and hydrophobic B blocks in an aqueous solution. The vesiculation pathway consists of several intermediate structures, such as an interconnected network of copolymer aggregates, a cage of cylindrical micelles and a lamellar cage. The cage-to-vesicle transition occurs at a constant aggregation number and practically eliminates the hydrophobic interfacial area between the B block and solvent. Molecular reorganization under-lying the sequence of morphology transitions from a cage-like aggregate to a vesicle is nearly isentropic. The end-to-end distances of isolated copolymer chains in solution and those within a vesicular assembly follow log normal probability distributions. This is attributed to the pre-ponderance of folded chain configurations in which the two hydrophobic end groups of a given chain stay close to each other. However, the probability distribution of end-to-end distances is broader for chains within the vesicle as compared to that of a single chain. This is due to the swelling of the folded configurations within the hydrophobic bilayer. Increasing the hydropho-bicity of the B block reduces the vesiculation time without qualitatively altering the self-assembly pathway.

The demand for high-energy-density batteries necessitates novel anode materials. Transition metal oxides (TMOs) show promise due to their high capacity, sustainability, and cost-effectiveness. However, TMO-based anodes face challenges related to expansion and conductivity. This study presents a two-step dilution crystallization method to fabricate porous ZnO nanoflowers at a moderate temperature. In-situ integration with carbon nanotube dispersants enhances conductivity and reduces agglomeration. The resulting composite anode exhibits impressive initial discharge capacity (2314.2 mAh g-1) and cycling stability (580.5 mAh g-1 over 50 cycles). This study provides a facile approach for next-generation anode materials.

Biodiesel is one of the most popular biofuels as it is a promising substitute of the conventional diesel fuel, but for now it cannot be used as a stand-alone fuel due to its low oxidative stability. For this reason, the last years there have been efforts for its upgrading through the partial hydrogenation of the fatty acid methyl esters (FAMEs) that biodiesel consists of. This procedure succeeds in resolving the problem of low oxidative stability, but in some cases a new problem arises as the non-selective hydrogenation is deteriorating the fuel’s cold flow properties, which are crucial for its operation without damaging the vehicle’s engine. More specifically, the problem of deteriorated cold flow properties is caused by the formation of trans-monounsaturated FAMEs and fully saturated FAMEs while the hydrogenation reaction is taking place. The hydrogenated biodiesels are preferred to contain more cis-monounsaturated FAMEs, because these are considered to have the best combination between high oxidative stability and good cold flow properties. As a result, various systems and methods have been tested in order to achieve a selective partial hydrogenation of biodiesel’s FAMEs. In this review article, the catalytic systems and methods that stood out in various researches are presented and the factors that lead to the best possible outcome are investigated and discussed.

Owing to the growing concerns due to dwindling fossil fuel reserves, increasing energy demand and climate emergency, it is imperative to develop and deploy sustainable energy technologies to ensure future energy supply as well as transition to the net zero world. In this context, there is great potential in the biorefinery concept for supplying drop in biofuels in the form of biodiesel. Biodiesel as a fuel can certainly bridge the gap where electrification or the use of hydrogen is not feasible, for instance heavy vehicles, farm and marine transportation sector. However, biodiesel industry also leads to formation of large amount of crude glycerol as the byproduct. Crude glycerol due to presence of several impurities may not be a suitable feedstock for all high value products derived from glycerol but fits well with glycerol esterification for producing glycerol acetins, which have numerous applications. This review critically looks at the processes using nanostructured solid/liquid acid catalysts for glycerol esterification including the economic viability of the scale up.

A problem of efficacy of crystal growth methods for crystallization from solution or melt has been investigated. Axial vibrational control (AVC) technique was considered as a perspective method to manage both heat-mass transfer and chemical component composition of the melts in the case of crystallization of complex chemical compounds. Numerical modeling and the search for generalized dependencies made it possible to predict the AVC parameters that provide optimal heat and mass transfer modes for creating flat liquid-solid interfaces, as well as the component composition of dissociated melts of various chemical compounds – Ge, NaNO3, CdTe.

The SBA-15 loaded with methylene blue was successfully prepared by sample adsorption of methylene blue in SBA-15 and is characterized by an XRD, SEM, FTIR, and BET. The photocatalytic activity for methyl orange (MO) degradation was investigated under visible light irradiation under LEDs. Experimental results demonstrate that the SBA-15-MB exhibited higher photocatalytic activity than SBA-15 under visible light irradiation. The degradation efficiency of MO (50 ppm) by SBA-15-MB could reach 80% within 180 min under 25W LED visible light. The photocatalytic activity of SBA-15 could be attributed to the excitation of methylene blue by visible light, the transfer of electrons from methylene blue to SBA-15, and the production of radicals at the surface of SBA-15.

A series of Zn-modified Hβ (Zn/Hβ) catalysts were prepared by using the different zinc precursors such as ZnSO4·7H2O, ZnCl2, C4H6O4Zn·2H2O and Zn(NO3)2·6H2O, and their catalytic performance in the ethanol conversion to propylene reaction was evaluated. Results indicate the amount and strength distribution of acid sites of the Zn/Hβ catalysts were easily tuned by employing different type of zinc precursors. More importantly, when the Zn species were introduced to the Hβ, the propylene yield was significantly enhanced, whereas the yields of the byproducts such as ethylene and C2-C4 alkanes were remarkably suppressed. For the catalyst prepared by using the ZnCl2 precursor (Zn/Hβ-C), a higher propylene yield up to 43.4% was achieved as a result of the moderate amount and distribution of acid sites. The average coking rate of the used Zn/Hβ catalysts strongly depended on the amount of total acid sites, especially the strong acid sites, i.e., the higher the amount of total acid sites of the catalyst, the greater the average coking rate. For the catalyst prepared by using the ZnSO4·7H2O precursor, Zn/Hβ-S exhibited a better stability even after depositing more coke, which is due to the higher amount of strong acid sites.

This paper presents the results of investigations into the pyrolysis of waste polypropylene in a laboratory fixed-bed batch reactor. The experiments were designed and verified in such a way as to allow the application of the Response Surface Methodology (RSM) in the development of an empirical mathematical model that quantifies the impacts mentioned above. The influence of the mass of the raw material (50, 100 and 150 g), together with the reactor temperature (450, 475 and 500 °C) and the reaction time (45, 50 and 75 min) was examined. It has been shown that the mass of the raw material, i.e. the filling volume of the reactor, has a significant influence on the pyrolysis oil yield. This influence exceeds the influence of reactor temperature and reaction time. This was explained by observing the temperature change inside the reactor at three different spots at the bottom, middle and top of the reactor. Recorded temperature diagrams show that with greater masses of feedstock, local overheating occurs in the middle part of the reactor, which leads to overcracking of vapor products, and from there to an increased formation of non-condensable gases, i.e. reduced yield of pyrolytic oil.

The reactivity of 3,5-di-(pyridin-4-yl)-1,2,4-thiadiazole (L1) with 1,4-diiodotetrafluorobenzene (1,4-DITFB) was explored and the halogen-bonded 1:1 co-crystal (1) was successfully isolated and structurally characterized.

Biobased greases are derived from renewable resources, being considered more environmentally friendly, and offering comparable performance with petroleum-based greases. In this study, lubricating greases from frying cooking oils were prepared, thus valorizing waste, in order to obtain sustainable and environmentally friendly products. 12 batches (500 g each) were produced from sunflower and palm frying oils, with 20% by weight calcium/ lithium stearate soaps prepared in situ, and additivated with 15% wt. cellulose or lignin sulphate. The greases were rheologically characterized. Their consistency was assessed by the penetration test, performed before and after working the greases. Dropping point determinations offered information about the stability at higher temperatures, and oil bleeding tests were performed. The average values of the friction coefficient (COF), the contact resistance and the wear scar diameter were measured, through mechanical tests. Additivated greases prove to be comparable with those obtained from mineral oils, with good rheological properties, soft consistency and good antiwearing behavior, e.g.in open or total- loss lubricating systems, like in open gears and certain food processing machinery; they are thermally stable, and prone for use in low-loading working mechanisms.