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Response surface methodology (RSM) was employed to optimize the process parameters of the supercritical carbon dioxide extraction of hop cones in terms of their antifungal properties against Fusarium culmorum and Aspergillus niger. The effects of temperature (40–50 °C), pressure (200–300 bar), and CO2 consumption (25–75 kgCO2/kg) on the extraction yield, content of α- and β-acids, as well as pathogens' growth inhibition were investigated. Both pressure and CO2 consumption had a significant effect on antifungal properties. It was observed that the best results for antifungal properties were obtained when hop cones were extracted with pure carbon dioxide at the temperature of 50 °C, under the pressure of 300 bar with CO2 consumption at the level of 75 kgCO2/kg of feed for extraction. The highest antifungal properties of hop cone supercritical carbon dioxide extracts were analyzed as 100% for Fusarium culmorum and 68% for Aspergillus niger, calculated as the growth inhibition of tested pathogens. The aim of the study was to determine the optimum values of extraction parameters to achieve the maximum response and enable us to investigate the interaction of these parameters on the antifungal properties of hop cone extracts. [ABSTRACT FROM AUTHOR]

Ag nanoparticles in a Yb 2 O 3 matrix catalyzed the direct decomposition of N 2 O to the elements. Our investigations included X-ray powder diffraction and electron microscopy; they revealed a remarkable dependence of the catalytic activity on the catalyst preparation method that influenced the size of Ag crystallites. Simple precipitation followed by calcination resulted in the formation of a catalyst with rather large Ag crystallites, which showed low activity. In contrast, thermal decomposition of the mixed-metal Ag–Yb coordination polymer provided the Ag/Yb 2 O 3 catalytic system with distinctly smaller Ag crystallites. The coordination-polymer derived catalyst exhibited much higher activity in the deN 2 O process at moderate temperature range 400–500 °C. [ABSTRACT FROM AUTHOR]

Canola oil was hydrogenated on an industrial nickel catalyst at 180 |C under a wide range of pressures from 1.5 to 21 bar(a). The effect of hydrogen pressure on the hydrogenation characteristics and fatty acids profile was investigated. The hydrogenation kinetics were described by a simplified three-step model including linolenic acid. The apparent rate constants for the particular reaction steps (hydrogenation, isomerization) kx as well as rate constants kx0 and reaction orders in hydrogen were determined. The results reveal that with the increasing pressure an increase of values of all rate constants was observed, with the largest increase being observed for the rate constant of hydrogenation of monoenes to stearic acid (about 20 times). Moreover, with the increasing pressure the isomerization rate of cis dienes to trans dienes was found to become lower than the dienes hydrogenation rate. Analogously, the cis/trans monoenes isomerization rate was also found to decrease with the increasing pressure. The reaction orders of the hydrogenation steps with respect to hydrogen were in the range of 0.35 to 1.1. The kinetic model was verified by comparsion of predicted fatty acids contents with the experimental data of fatty acids profiles. It emerged that a simplified kinetic model proposed can be utilized to simulate the course of the hydrogenation process and concentrations of fatty acids at a certain iodine value. [ABSTRACT FROM AUTHOR]

The effect of the CO 2 saturation time of the aqueous suspension of the raw, primary low-surface ZnO on material properties has been investigated. The materials have been investigated by means of the following techniques: XRD, TG/DTG coupled with MS, N 2 physical sorption and SEM. The results reveal platelet-like hydrozincite as a product of saturation, which undergoes thermal decomposition to ZnO of the similar morphology. The modification of ZnO through the CO 2 saturation results in essential changes of the morphology. During the subsequent thermal decomposition porous structure is created with a simultaneous drastic increase of the specific surface area. All these changes lead to the conversion of “common” zinc oxide into active zinc oxide. [ABSTRACT FROM AUTHOR]

The effect of the precursor ageing time on the structure, thermal decomposition, specific surface area, active copper surface area as well as on the morphology of the precursors and catalysts oxide forms was investigated. The hydroxycarbonate precursor, with the composition corresponding to industrial catalysts, was prepared via coprecipitation method from the solutions of copper and zinc nitrate with a mixture of sodium aluminate and sodium carbonate at pH = 7.4 and then aged in the mother liquor. The activity of the prepared catalysts in the LT-WGS reaction was compared under conditions similar to those in the industrial process. The results reveal that the precursor ageing influences the precursor phase composition, the active copper surface area and the catalytic activity. The activity decreases with the increasing ageing period but the activity concerned a single surface copper atom (TOF) is constant and independent of the ageing time. [ABSTRACT FROM AUTHOR]

Highlights: [•] Characteristics of the CuZnAl-LDH precursor and ex-LDH materials as active copper catalysts. [•] In situ XRD studies of the initial layered structure recovery–memory effect. [•] Structural and textural changes of CuZnAl-LDH calcined up to 400°C reversible to a large extent. [•] Above 600°C the formation of irreversible highly crystalline non-layered oxides. [•] Correlation between the heat effect and degree of structure recovery. [ABSTRACT FROM AUTHOR]

Abstract: The transformations of a series of complex CuZnZrAl hydroxycarbonates as copper catalyst precursors have been investigated. The materials have been prepared by the coprecipitation method and characterized by means of XRD, ICP-OES, TG-MS, TPR and N2O chemisorption. The results reveal that the Zr/Al ratio has got an influence on the formation of hydrotalcite-like phases of copper–zinc–aluminum hydroxycarbonates. The increase of ZrO2 content results in the increase of amorphous phase content in the hydroxycarbonate precursors. Moreover, the increase of ZrO2 content causes the formation of CuO crystallites at higher temperatures during calcination. At the lower calcination temperatures (up to ca. 400°C) the incorporation of zirconium oxide results in the decrease of CuO crystallite size in the calcined mixed oxides compared to the Zr-free sample. At higher calcination temperatures a reversed effect was observed. Two different thermal decomposition pathways of the precursors with and without alumina were observed. [Copyright &y& Elsevier]

Abstract: The tetradentate [OSSO]-type bis(phenol) ligands, [{2,2′-(HOC6H2-4,6-R2)2CH2SCH2CH2SCH2}] (R =  t Bu, 2; Br, 3) react with MBz4 (M = Zr, Hf) to yield the corresponding dibenzyl complexes, [M{2,2′-(OC6H2-4,6-R2)2CH2SCH2CH2SCH2}Bz2] (R = Br, M = Zr, 4Br ; Hf, 5Br ; R =  t Bu, M = Hf, 5) in a good to very good yield. Zirconium diamido complexes, [Zr{2,2′-(OC6H2-4,6-R2)2CH2SCH2CH2SCH2}(NMe2)2] (R =  t Bu, 6; Br, 6Br ) were prepared in a reaction of the corresponding disodium salt of 2 or 3 generated in situ with ZrCl2(NMe2)2(THF)2. Heating of 6 with TMSCl at 35 °C afforded zirconium dichloro complex, [Zr{2,2′-(OC6H2-4,6- t Bu2)2CH2SCH2CH2SCH2}Cl2] (7), whereas the titanium analog 8 was prepared in a direct reaction with TiCl4. While for complexes 4Br , 5, 5Br , 6, 6Br and 7 single C 2-symmetric isomers were observed in solution at room temperature, as revealed by the NMR spectroscopic data, titanium complex 8 formed as a mixture of cis-α (8a) and cis-β (8b) isomers in a ratio of approx. 20:80% (measured in CD2Cl2). The VT NMR studies revealed a reversible conversion of 8a into 8b above 60 °C. The X-ray crystal structure determination of complexes 4Br , 5Br and 7 confirmed their C 2-symmetrical configuration in the solid state with cis-arranged benzyl/chloro groups and the trans-coordination of two bulky phenolato moieties. The zirconium dibenzyl complexes exhibit good catalytic activities in homopolymerization of 1-hexene (atactic poly(1-hexene), PDI = 1.5–1.7) and vinylcyclohexane (isotactic poly(vinylcyclohexane), PDI = 1.2–1.8) upon activation with a co-catalyst. In both polymerizations no increase of activity was observed for the complex 4Br with electron-withdrawing substituents on phenolate rings. Moreover, polymerization of liquid propylene catalyzed by the titanium dichloro isomeric mixture 8 afforded at 5 °C ultrahigh molecular weight atactic/isotactic polypropylene mixtures. [Copyright &y& Elsevier]

Abstract: The chemistry of the hydride complexes of the rare-earth metals has been dominated by complexes with metallocene and half-sandwich ligand frameworks. In contrast to hydride complexes supported by cyclopentadienyl ligands, only relatively few examples of non-metallocene hydride complexes have been reported in the literature. Such complexes are potentially of some interest in view of their chemical reactivity and catalytic applications. This review surveys the chemistry of non-metallocene hydride complexes up to mid-2007, some spectroscopic and structural aspects as well as their reactivity. [Copyright &y& Elsevier]

The 18-crown-6 (18C6) ether adduct of sodium hexachloroiridate [Na(18C6)]2[IrCl6]·xH2O (1) was found to catalyze an addition of methanol to a variety of nonfunctionalized alkynes RC≡CH (R = H, nPr, nBu, nPen, Ph, HC≡C(CH2)4) yielding the corresponding Markovnikov addition products (ketals) and in the cases of hex-1-yne and hept-1-yne also anti-Markovnikov ones (acetals, <10%). Furthermore, the reaction of methanol with octa-1,7-diyne resulted in a double Markovnikov addition to only one triple bond, yielding 7,7-dimethoxyoct-1-yne with 80% degree of conversion. On the other hand, the regioselectivity in an addition of methanol to functionalized terminal alkynes of the type RC(O)C≡CH (R = OMe, Me) was found to be towards anti-Markovnikov products (70–93%). In these two cases vinyl ether intermediates were observed NMR spectroscopically in the course of the reactions. [Copyright &y& Elsevier]

The 18-crown-6 (18C6) ether adduct of sodium hexachloroiridate [Na(18C6)]2[IrCl6]·xH2O (1) was found to catalyze an addition of methanol to a wide variety of internal alkynes RCCR′ (R/R′ = Et/Et, Me/Et, Me/nPr, Me/nBu, Me/tBu, Me/Ph, Et/nPr, Et/Ph) yielding the corresponding ketals and, due to the presence of water traces, their hydrolysis products (ketones). The regioselectivity of the addition of methanol to unsymmetrically disubstituted internal alkynes is governed by steric and electronic factors, being the highest in the case of pent-2-yne, hex-2-yne and hept-2-yne (80–85%). In the case of MeC≡CCO2Me, an alkyne having an electron-withdrawing substituent, the addition was found to be 100% regioselective, with two methoxy groups going to the side away from an ester group. Furthermore, in the analogous addition of methanol to MeO2CC≡CCO2Me, besides the vinyl ethers (E)/(Z)-MeO2CC(OMe)=CHCO2Me, a cyclotrimerization product (C6(CO2Me)6) was also observed. A comparison of the catalytic potential of other iridium compounds in the addition of methanol to hex-3-yne revealed that all examined ionic hexachloroiridates ([Na(18C6)]2[IrCl6]·xH2O, Na2[IrCl6]·6H2O, H2[IrCl6]·6H2O, Na3[IrCl6]·xH2O) were catalytically active, whereas [IrCl(CO)(PPh3)2] and [(IrCl2Cp*)2] were found to be almost inactive (degree of conversion <10%). However, the best results were obtained for the crown ether adduct 1. Moreover, in the addition of CD3OD to hex-3-yne, [Na(18C6)]2[IrCl6]·xH2O (1) was also found to catalyze a H/D exchange of protons in the neighborhood of a keto group or a quaternary carbon of a ketal with a degree of deuteration >97%. [Copyright &y& Elsevier]

The iridium dinitrogen complex [IrCl(N2)(PPh3)2] (1) was found to react with alkynylsilanes RC≡CSiR'3 to form the vinylidene iridium(I) complexes trans-[IrCl{=C=CR(SiR'3)} (PPh3)2 (R/R′=Ph/Me, 2; Me/Me, 3; Bn/Me, 4; SiMe3/Me, 5; SiEt3/Et, 6; iPr/Me, 7) and with Me3SiC≡CC(O)R to yield the iridium η2-alkyne complexes trans-[IrCl{η2-Me3SiC≡CC(O)R}(PPh3)2] (R=OEt, 9; Me, 11). Complex 9 was found to isomerize upon heating or upon UV irradiation yielding the vinylidene complex trans-[IrCl{=C=C(SiMe3)CO2Et}(PPh3)2] (10). The reaction of 1 with Me3SiC≡C—C≡CSiMe3 yielded the complex trans-[IrCl{=C=C(SiMe3)C≡CSiMe3}(PPh3)2] (8), whereas with MeO2CC≡CCO2Me the iridacyclopentadiene complex [Ir{C4(CO2Me)4}Cl(PPh3)2] (13) was formed. The complexes were characterized by means of 1H, 13C and 31P NMR spectroscopy as well as by IR spectroscopy and microanalysis. [Copyright &y& Elsevier]

Due to their numerous health benefits associated with various diseases and anti-oxidation properties, the phenolic compounds collectively referred to as phytochemicals have attracted a lot of interest, however, a single extraction method for polyphenols has not been developed yet. Supercritical fluid extraction, a green extraction method, provides the final product without organic solvent residues. In this work the extraction of lavender was performed using supercritical carbon dioxide. A statistical experimental design based on the Box-Behnken (B-B) method was planned, and the extraction yields and total phenolic contents were measured for three different variables: pressure, temperature and extraction time. The ranges were 200–300 bar, 40–60 °C and 15–45 min. The extracts yields from scCO2 extraction were in the range of 4.3–9.2 wt.%. The highest yield (9.2 wt.%) was achieved at a temperature of 60 °C under the pressure of 250 bar after 45 min. It also corresponded to the highest total phenolic content (10.17 mg GAE/g extract). Based on the study, the statistically generated optimal extraction conditions to obtain the highest total phenolic compounds concentration from flowers of Lavandula angustifolia were a temperature of 54.5 °C, pressure of 297.9 bar, and the time of 45 min. Based on the scavenging activity percentage (AA%) of scCO2 extracts, it is concluded that the increase of extraction pressure had a positive influence on the increase of AA% values. [ABSTRACT FROM AUTHOR]

The separation of phenolic compounds by supercritical fluid extraction has been widely studied throughout the last two decades. This is evidenced by a number of publications and articles. Supercritical fluid extraction (SFE) has become thus the effective method of separating the mentioned group of compounds. On the other hand, SFE is a beneficial approach in plant waste materials utilization and reduction of environmental burdens caused by the wastes. The aim of the study is to gather and systematize available information on the phenolic compounds separation that have been reported so far as well as to evaluate whether there is one optimal supercritical fluid extraction method for the phenolic compounds. [ABSTRACT FROM AUTHOR]

Dandelion is a sustainable biomass that has occasional use in the food and pharmaceutical industry. However, commercial use of its extracts is restricted by the lack of systematic information on safety, composition, and biological activity. To broaden dandelion use, the present study brings new knowledge on extracts from dandelion seeds that could find application as safe and functional food ingredients. The employed two-step supercritical fluid extraction process, followed by the conventional extraction, enabled the separation of extracts with increased content of phenolics, tocopherols, and essential fatty acids. Those compounds were found to be the major components of dandelion extracts, reaching high values up to 799 mg GE/g, 249 mg α-TE/g, and 75%, respectively. The extracts also contained significant amounts of flavonoids (up to 20.5 mg QE/g) and pigments (chlorophyll A up to 1.0 g/kg, chlorophyll B up to 0.3 g/kg, and carotenoids up to 0.1 g/kg). This study revealed new bioproducts that express strong antioxidant (reaching IC50 values up to 132.5 μg/mL) and antimicrobial activity (with minimum inhibitory concentrations up to 80.0 μg/mL). Among the tested 23 microbial strains, the extracts exhibited the strongest activity against food-borne pathogens Micrococcus luteus and Bacillus subtilis. Furthermore, the antitumor and antiviral activity of separated dandelion biological products was evaluated. [ABSTRACT FROM AUTHOR]

The main aim of this study was to evaluate the oils from chamomile seeds as a new source of bioactive compounds suitable for human consumption. A green extraction technique with supercritical carbon dioxide (sc-CO2) at pressures up to 450 bar and temperatures up to 60 °C was employed for the production of a high amount of biologically active oil. Additionally, exhausted waste material was re-extracted using sc-CO2 with the addition of ethanol. By optimization in operating pressure, temperature, production cost, fraction of milled seeds, and co-solvent addition, the amount of separated chamomile oil increased from 2.4 to 18.6% and the content of unsaturated fatty acids up to 88.7%. Oils contained α-bisabolol oxide A and B in amounts up to 1.4%. Linoleic acid was detected in an amount up to 711.1 mg/g and α-linolenic acid up to 27.5 mg/g. The total phenolic content in separated oil reached 80.4 mg GAE/g while the total flavonoid content reached 11.6 mg QE/g. The obtained chamomile oils showed antioxidant activity with an IC50 of up to 3.9 mg/mL. Among the 23 tested microorganisms, the antimicrobial activity of oils was the most pronounced against Gram-positive bacteria. The cytotoxic activity of oils was tested on normal and cancer-derived cell lines. Results indicated a significant potential for oil from chamomile seeds, produced in an eco-friendly manner, as a functional food. [ABSTRACT FROM AUTHOR]

In this study a multi-residue determination method for 36 pesticides in dried hops was reported. The sample preparation procedure was based on the acetate buffered QuEChERS method. A few mixtures of dispersive solid phase extraction (dSPE) sorbents consisting PSA, C18, GCB, Z-Sep and Z-Sep+ were investigated to clean-up the supernatant and minimize matrix co-extractives. The degree of clean-up was assessed by gravimetric measurements, which showed the best results for mixtures containing the Z-Sep+ sorbent. This is the first study to apply Z-Sep+ sorbent for hops material and the first to improve the method for pesticide residues determination in hops. Samples were analysed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and the procedure was validated according to the SANTE/11813/2017 document at four concentration levels: 0.02, 0.05, 0.1 and 1 mg/kg. The limits of quantification (LOQ) were in the range of 0.02–0.1 mg/kg. For all active substances, the trueness (recovery) ranged from 70 to 120% and the precision (RSDr) value was <20%. Specificity, linearity and matrix effect were also evaluated. The validated method was applied to the analysis of 15 real dried hop samples and the relevant data on detected residues were included. [ABSTRACT FROM AUTHOR]

The article discusses the result of a study concerning rare earth metal alkyl and hydride complexes stabilized by a cyclen-driven macrocyclic ancillary ligand. Me3TACD ligand was introduced as a monoanionic ancillary environment for the stabilization of rare earth metal alkyl and hydride with properties distinct from other monoanionic ligands.

The effect of a copper modifier on physicochemical properties of coprecipitated precursors and final Ni–Cu/Al 2 O 3 catalysts for benzene to cyclohexane hydrogenation was investigated. Based on the studies of physicochemical properties, the influence of copper on the catalytic activity and selectivity of Ni–Cu/Al 2 O 3 systems was discussed. The addition of copper resulted in a decrease of the specific and nickel surface area, improvement of the selectivity and a slight decrease of the benzene hydrogenation activity compared to the reference catalyst. A decrease of methylcyclopentane and methylcyclohexane by-products formation on the surface of Ni–Cu/Al 2 O 3 catalyst containing 10–17 wt% CuO by, respectively, 70% and 10% was observed. The results reveal a distinct, beneficial effect of the Ni/Al 2 O 3 modification by copper on the catalyst selectivity. However, this effect depends on temperature and is limited to ca. 20 wt% CuO, above this content the activity was found to decrease considerably. [ABSTRACT FROM AUTHOR]

The effect of steam gasification on the surface composition, surface area, pore size distribution as well as on the morphology of the carbon supports has been investigated. Materials have been characterized by nitrogen physisorption, mercury porosimetry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Model samples of the Co–Mo–K catalysts with the same composition have been prepared on carbon supports differing in the temperature of steam gasification process. Catalytic activity measurements have been carried out in a gradientless reactor in a kinetic regime at low partial pressures of reagents. A relationship between textural parameters of the supports and the catalysts activity has been estimated. The highest activity in the SGS process has been determined for the Co–Mo–K/SRO/40.49 supported catalyst. [ABSTRACT FROM AUTHOR]

The study aimed toward the development of biocompatible and biodegradable polymeric films (starch-chitosan and starch-chitosan-cyclodextrin) with biologically valuable green tea leaf extract using an environmentally friendly integrated process of supercritical fluid extraction (SFE) and supercritical solvent impregnation (SSI). The SFE-SSI process parameters were selected through the initial estimation of the SFE parameters effect (temperatures 35 and 70 °C and the addition of co-solvents ethanol, ethanol/water, and water). The present early-stage work showed that an increase in temperature increased extraction yield (from 0.9 to 4.2%) and caffeine content while it decreased polyphenolic and pigment content as well as antioxidant activity and extract loading onto films (from 7.1 to 0.1%). The addition of co-solvents to sc-CO 2 had an adverse effect on extract yield, composition, and loading. The highest recorded total phenolic, flavonoid, chlorophyll A, and caffeine content in extracts were 136.5 mg GE/g, 22.7 mg RE/g, 8.1 mg/g, and 460.0 mg/g, respectively. [Display omitted] • The SFE-SSI process for films loading with green tea leaves extracts was presented. • Starch-chitosan films with and without cyclodextrin were loaded with tea extracts. • Increase from 35 to 70 °C increased extract separation but decreased its loading. • Co-solvents had adverse effect on tea extract yield, composition, and loading. [ABSTRACT FROM AUTHOR]

Abstract: The effects of cesium doping (in the concentration range up to 5wt.% Cs2O) introduced into a copper catalyst with the composition corresponding to that for the industrial catalysts used for low-temperature water–gas shift process (LT-WGS) have been investigated. Precursors and catalysts have been characterized by XRD, ICP-OS, TPD-EGA, N2O chemisorption, TPR, N2 physisorption and reaction rates for WGS and methanol synthesis under the pressure of 2.5MPa have been determined. The results reveal that the cesium doping inhibits radically methanol synthesis, with the optimal Cs2O content being <1wt.%. [Copyright &y& Elsevier]

Ni/La–Al 2 O 3 and Ni/Ce–Al 2 O 3 catalysts with a small amount of promoters intended for prereforming of LNG were characterized by XRF, N 2 adsorption-desorption, XRD, H 2 chemisorption, HRTEM and XPS. The catalytic activity was evaluated in methane steam reforming both in the kinetic and diffusion regime, at temperatures characteristic of pre-reforming. Carbonaceous deposit was analysed by TPO-MS method. The nature and location of the coke were studied by HRTEM. La or Ce addition into Ni–Al system causes the increase of the active surface area of Ni by enhancing its dispersion. Studies at kinetic regime have shown that the promoted catalysts have almost twice the activity than reference Ni–Al catalyst. This effect was not confirmed by measurements in the diffusion regime on whole catalyst tablets. Almost identical textural properties of catalysts and diffusive limitations related to them but not the catalytic properties of the material itself appeared to be crucial factors. The presence of La (but not Ce) causes a significant increase in resistance to coking. [Display omitted] • Ni/Al 2 O 3 and Ni/M/Al 2 O 3 (M = La or Ce) were tested in methane steam reforming. • Catalytic activity was evaluated both in the kinetic and diffusion regime. • The promoters increased the catalytic activity at kinetic regime almost twice. • An effect of additives was not confirmed in diffusive regime. • The addition of La 2 O 3 caused a significant increase in resistance to coking. [ABSTRACT FROM AUTHOR]

In this study, potential antifungal properties of a brown alga Fucus vesiculosus were evaluated. The algal extract was obtained with the use of supercritical fluid extraction (scCO2) at a temperature of 50 °C under a pressure of 300 bar. The aqueous solution of the extract at the concentration of 0.05%, 0.2%, 0.5% and 1.0% was studied against pathogenic fungi on a liquid RB medium. This study is the first report on antifungal properties of the brown algae F. vesiculosus scCO2 extract against Fusarium culmorum and Fusarium oxysporum phytopathogens. The concentrations of the studied extract (0.5% and 1.0%) were demonstrated to have an ability to inhibit 100% growth of macroconidia within 144 h, as well as an ability to cause their total degradation. As a result of the study, the antifungal effect of fucosterol against F.culmorum was also indicated. The total macroconidia growth was inhibited by 1.0% fucosterol. Moreover, at lower concentrations (0.05–0.2%) of fucosterol, macroconidia were characterized by shorter length and structural degradation was observed. The mycelial growth of Fusarium oxysporum (Fo38) by 1% scCO2F. vesiculosus extract was analyzed at the level of 48% after 168 h of incubation, whereas 100% extract was found to be effective in F. culmorum (CBS122) and F. oxysporum (Fo38) growth inhibition by 72% and 75%, respectively after 168 h of incubation. [ABSTRACT FROM AUTHOR]

Two different extraction methods were used for a comparative study of essential oils obtained from the Humulus lupulus scCO2 (sc-supercritical) extract: microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD). As a result, the best conditions for the maximum essential oil production were determined for the MAHD method at 335 W microwave power for 30 min at water to raw material ratio of 8:3. The obtained essential oils were enriched in β-myrcene in the amount of 74.13%–89.32% (wt%). Moreover, the first application for determination of the above-mentioned volatile compounds by supercritical fluid chromatography (SFC) with photo-diode array detection (PDA) is presented, which in comparison with gas chromatography coupled with mass spectrometry (GC-MS/MS) resulted in similar values for β-myrcene and α-humulene in obtained samples within less than 1 min. [ABSTRACT FROM AUTHOR]

Four different techniques (co-precipitation, urea homogeneous precipitation, citrate sol-gel auto-combustion, solid state formate assisted) were used in preparation of a series of Cu/ZnO/AlO catalysts, having a nominal composition: (Cu/Zn) = 2.5 and (Cu + Zn)/Al = 3. The catalytic materials were investigated by various methods. The activity of the CuZnAl catalysts in the LT-WGS process was compared. The results revealed that the co-precipitation technique and subsequent thermal decomposition provided the Cu/ZnO/AlO catalyst with the higher specific surface area and more advantageous surface morphology. It was shown that co-precipitation of hydroxycarbonate precursors at constant pH and their subsequent thermal treatment provided the most active WGS catalyst compared to other techniques. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The present study was focused on improving the supercritical fluid extraction process dedicated to the recovery of highly valuable extract from Silybum marianum seeds. At first, the process was tested using supercritical CO 2 at temperatures of 40 and 80 °C and pressures ranging from 100 to 300 bar. Obtained values were described using two literature models with acceptable agreement of experimental and calculated data. Further, the effect of the equipment design and process scale-up was investigated in four high-pressure units having volumes in the range from 280 mL to 40 L resulting in extraction yields up to 26 %. Based on the values of the parameters determined at the laboratory scale, the extraction process was successfully transferred to a semi-industrial scale. Finally, estimated costs for supercritical extract production in Poland for the year 2021 using a 1000 L high-pressure unit amounted to the price of 35.9 EUR per kg of extract. [Display omitted] • Kinetic of the SFE process significantly differs for four units having volumes from 0.28 to 40 L. • Three lab-scale units showed variation in extraction yield from 11.9 % to 18.0 %. • Sovova's model can be used for description the presented SFE process phenomenology. • Scale-up study showed a good agreement between laboratory and semi-industrial scale unit. • Economic evaluation indicated optimal industrial process of 3 h and extract cost of 35.9 EUR/kg. [ABSTRACT FROM AUTHOR]

Lavandula angustifolia is one of the most widely cultivated non-food crops used in the production of essential oil; it is used in perfumery, aromatherapy, pharmaceutical preparations, and food ingredients. In this study, supercritical fluid extraction (SFE) and molecular distillation (MD) were combined, primarily to enrich scCO2 extracts with lavender oxygenated monoterpenes, avoiding thermal degradation, hydrolysis, and solvent contamination, and maintaining the natural characteristics of the obtained oils. Molecular distillation was developed for the first time for the extraction of crucial lavender fragrance ingredients, i.e., from two scCO2 extracts obtained from dry flower stems of lavender cultivated in Poland and Bulgaria. The best results for high-quality distillates were obtained at 85 °C (EVT) and confirmed that linalyl acetate content increased from 51.54 mg/g (initial Bulgarian lavender extract, L-Bg-E) and 89.53 mg/g (initial Polish lavender extract, L-Pl-E) to 118.41 and 185.42 mg/g, respectively, corresponding to increases of 2.3 and 2.1 times in both distillate streams, respectively. The distillates, light oils, and extracts from lavender were also evaluated for their antimicrobial properties by determining the minimum inhibitory concentration (MIC) by the broth microdilution method. Generally, Gram-positive bacteria and Candida spp. were more sensitive to all distilled fractions and extracts than Escherichia coli (Gram-negative bacteria). [ABSTRACT FROM AUTHOR]

Abstract: The Fe2O3-based catalysts have numerous advantages for HT-deN2O process applications. The possibility of enhancing their activity by various metal oxide modifiers addition (Al, Zr, Ce, La, Cu, Cr) has been investigated. The catalysts were prepared by the coprecipitation method and their physicochemical properties were characterized by N2 sorption, XRF and XRD methods. A quartz gradientless reactor was used for activity evaluation at the temperature range of 500–900°C. The modifiers efficiency was compared and the activity of hematite catalysts at 800̊C was found to increase in the following order: Cr

Abstract: Potassium promoted Co–Mo catalysts supported on flash-calcined alumina for sour WGS process have been prepared. The oxide form of samples has been characterized by ICP-OES method, N2 adsorption, temperature-programmed reduction (TPR) and the sulfides form after the catalytic activity test by means of XPS. Catalytic activity measurements were carried out in gradientless reactor in a kinetic region at low partial pressure of reagents. A strong effect of the promoter addition sequence to the support has been observed. The highest activity in the WGS process was determined for the potassium promoted Co–Mo/Al2O3 catalyst with a K/Mo ratio of 0.06 obtained by a simultaneous impregnation of flash-calcined alumina with aqueous solution of K and Mo salts. Potassium addition significantly changes reducibility and decreases total surface area of catalysts. XPS results show that the catalyst activity is correlated with the surface concentration of Mo5+ and Co–Mo–S species. Potassium addition enhances the formation of such species. The method of potassium incorporation to the catalyst has been suggested and its optimal content has been determined. The catalyst obtained can be implemented in industrial processes of hydrogen and syngas production from feedstocks with high sulfur content. [Copyright &y& Elsevier]

The complexes NEt[sub 4] [Fe(NS[sub 3] )(CNR)] (1), [Fe{Fe(NS[sub 3] )(CNR)}[sub 2] -S,S' ] (2), [Co{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (3), and [Ni{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (4) (R = Me, t-Bu, or C[sub 6] H[sub 11] (Cy)) have been prepared and the X-ray crystal structures of NEt[sub 4] [Fe(NS[sub 3] )(CNMe)] (1a) and [Fe{Fe(NS[sub 3] )(CNCy)}[sub 2] -S,S' ] (2c) have been determined. Mössbauer and IR spectroscopic data and room temperature magnetic moments for these complexes are reported.Key words: iron, cobalt, nickel, thiolate, isocyanide.On a préparé les complexes de NEt[sub 4] [Fe(NS[sub 3] )(CNR)] (1), [Fe{Fe(NS[sub 3] )(CNR)}[sub 2] -S,S' ] (2), [Co{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (3) et [Ni{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (4) (R = Me, t-Bu ou C[sub 6] H[sub 11] (Cy)) et on a déterminé les structures de NEt[sub 4] [Fe(NS[sub 3] )(CNMe)] (1a) et de [Fe{Fe(NS[sub 3] )(CNCy)}[sub 2] -S,S' ] (2c) par diffraction des rayons X. Pour chacun de ces complexes, on a déterminé les spectres de Mössbauer et IR ainsi que les moments magnétiques à la température ambiante.Mots clés : fer, cobalt, nickel, thiolate, isocyanure.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]