Mixture Of Acetone Research Articles

Eco-Friendly Valorization and Utilization of Plant Waste as a Source of Tannin for Leather Tanning

In the present study, bark, which is the waste part of a tree, was utilized as a source of tannin for leather tanning after its value addition. The barks of Acacia nilotica L. and Eucalyptus globulus, which are abundantly available in Pakistan, were selected in this study. Different extraction techniques including mechanical, soxhlet, reflux and ultrasonic extraction were used for the extraction of tannin from the selected barks. The medium of extraction included aqueous as well as different solvent mixtures in different ratios. The solvent mixtures used in this study were methanol-water and acetone–water. The methanol–water ratio was kept (50:50) and the acetone–water ratio was maintained at (50:50 and 70:30). In the first step, the process of extraction was optimized for solvent mixtures and extraction time by taking a fixed dose (5 g) of each bark and a fixed volume of each extracting solvent mixture (150 mL). The total phenolic contents (TPC) of the bark extracts were determined by colorimetric assay (as mg GAE/g bark), taking gallic acid as the reference standard. The tannin contents (TC) of the bark extracts were determined by using the standard hide powder method (SLC 117). It was concluded that among the different extraction techniques, and among the solvent mixtures acetone–water in ratio (70:30), ultrasonic extraction resulted in maximum extraction of tannin (196.1 and 125.2 mg/g), respectively for A. nilotica and E. globulus. FTIR analyses of the dried extracts obtained from both barks were compared with FTIR of the most commonly used commercial vegetable tanning agent in the leather industry, i.e., mimosa. Results were comparable, which confirmed the presence of condensed tannin in both barks. The extracted tannin was applied on a pickle and wet blue leather to evaluate its tanning and re-tanning capability. Mimosa, the most abundantly used vegetable tanning material in the leather industry, was applied as a reference standard on the same pickle and wet blue leather for comparison. Different physical properties, such as leather shrinkage temperature, leather softness, tensile strength, percent elongation and breaking strength, were measured to evaluate the tanning efficacy of the extracted tannins. The results showed that tannin obtained from A. nilotica showed comparable physical properties to those of mimosa. It was concluded from the results that tannin obtained from locally available bark, i.e., A. nilotica, can be utilized as a vegetable tanning agent for the leather industry.

Adsorption of a Four-Component Mixture of Volatile Organic Compound Vapors on Modified Activated Carbons

This work aimed to evaluate the effect of activated carbon modifications on the adsorption of volatile organic compound vapors. In this study, two commercial activated carbons WG-12 and DT0 (Grand Activated Sp. z o.o.) were modified by melamine and dl-malic acid and heat treatment. Then, the activated carbons were used as adsorbents in the adsorption of a gaseous mixture of four volatile organic compounds (acetone, ethyl acetate, toluene, n-butyl acetate) from the air. The properties of modified adsorbents were described using thermogravimetric analysis, elemental analysis, Boehm titration, and iodine number. Adsorption processes were characterized by breakthrough curves, velocities of the sorption front migration, and the Yoon–Nelson model. The study showed that surface modifications of activated carbons affect the adsorption properties of a mixture of acetone, ethyl acetate, toluene, and n-butyl acetate. The introduction of nitrogen on the surface of the activated carbons did not significantly improve the adsorption efficiency. It was identified that increasing the degree of carbonization of the activated carbon favored the adsorption of the tested adsorbates. The adsorption process of this mixture occurs by diffusion and depends on the diffusion velocity of the adsorbate molecules in the pores. It has been demonstrated that the velocity of the sorption front migration is inversely proportional to the boiling point of the adsorbates. In addition, it was found that competitive adsorption takes place in this process. Modified adsorbents can be thermally regenerated with almost 100% efficiency and reused in the next adsorption process. Furthermore, the Yoon–Nelson model can be successfully used to describe the kinetics of this process up to the point of displacement.

Alleviation of Carbon Catabolite Repression through araR and xylR Inactivation in Clostridium acetobutylicum DSM 792.

Efficient bioconversion processes of lignocellulose-derived carbohydrates into chemicals have received increasing interest in the last decades since they represent a promising alternative to petro-based processes. Despite efforts to adapt microorganisms to the use of such substrates, one of their major limitations remains their inability to consume multiple sugars simultaneously. In particular, the solventogenic model organism Clostridium acetobutylicum struggles to efficiently use second generation (2G) substrates because of carbon catabolite repression mechanisms that prevent the assimilation of xylose and arabinose in the presence of glucose. In this study, we addressed this issue by inactivating genes encoding transcriptional repressors involved in such mechanisms in the C. acetobutylicum strain DSM 792. Our results showed that the deletion of the two putative copies of xylR (CA_C2613 and CA_C3673) had little or no effect on the ability of the strain to consume xylose. Unlikely, the deletion of araR (CA_C1340) led to a 2.5-fold growth rate increase on xylose. The deletion of both araR and xylR genes resulted in the coassimilation of arabinose together with glucose, while xylose consumption remained inefficient. Transcriptional analyses of the wild-type strain and mutants grown on glucose, arabinose, xylose, and combinations of them provided a crucial, global overview of regulations triggered by the products of both araR and xylR in C. acetobutylicum. As suggested by these data, overexpression of xylA and xylB led to further improvement of pentose assimilation. Those results represent a step forward in the development of genetically modified strains of C. acetobutylicum able to coassimilate lignocellulosic-derived sugars. IMPORTANCE C. acetobutylicum is a strong candidate to produce chemicals of interest such as C3 and C4 alcohols. Used for more than a century for its capacity to produce a mixture of acetone, butanol, and ethanol from first generation (1G) substrates, its natural ability to assimilate a wide variety of monoosides also predisposes it as an auspicious organism for the valorization of lignocellulose-derived sugar mixtures. To achieve this purpose, a better understanding of carbon catabolite repression mechanisms is essential. The work done here provides critical knowledge on how these mechanisms occur during growth on glucose, arabinose, and xylose mixtures, as well as strategies to tackle them.

A novel photochemical conversion technique for reliable calibration of peroxyacetyl nitrate (PAN) analyzers

Photochemical synthesis of peroxyacetyl nitrate (PAN) through irradiating air mixtures of NO and acetone is prevailingly adopted for calibrating PAN analyzers, but few users of PAN analyzers provide evidence to certify the calibration reliability. Here we report a nonnegligible variation (up to ~50 %) of PAN synthesized in the calibration unit of a commercial PAN analyzer, whereas PAN synthesized in the two custom-made reactors could achieve stable values with variations of <2.5 %. Compared with a straight quartz tube flow reactor (SQTFR), PAN synthesized by a coiled quartz tube flow reactor (CQTFR) could achieve more stable (relative standard deviation: <0.66 % versus 2.49 %) and larger (PANCQTFR/PANSQTFR: 1.04–1.10) values. The residence time and reaction temperature of photochemical mixtures in CQTFR were found to be the key factors affecting PAN synthesis, with their optimal values of 30–60 s and 30–35 °C for achieving the highest PAN levels. The photochemical conversion efficiencies of NO to PAN in CQTFR under the optimal conditions were successfully measured to be 98.5 ± 0.5 % based on the alkaline-absorption method. Therefore, CQTFR is suggested to be adopted for calibrating PAN analyzers to reduce calibration uncertainties.

Control of side-stream pressure-swing distillation and extractive distillation for separating azeotropic mixture of cyclohexane and acetone

Dynamic controls of a side-stream pressure swing distillation (PSD) and extractive distillation (ED) process for cyclohexane and acetone separation are investigated. The processes operating parameters are optimized with a sequential iterative procedure based on the total annual cost (TAC). The dynamic result shows that for the side-stream PSD process, a modified control structure 2 (CS2) with the composition controller (CC) cascaded with the temperature controller 2 (TC2) can efficiently handle the feed disturbances, with the output signal being the ratio of reboiler duty to feed flow rate (QR/F). For the ED process, a modified control structure 4 (CS4) with the acetone product composition controller as the characteristic control loop can efficiently handle the disturbances which is controlled by the ratio of solvent flow to feed flow rate (S/F). A comparison of the side-stream PSD process and the ED process shows the former has decent dynamic performance.

Carbon dioxide and acetone mixtures as refrigerants for industry heat pumps to supply temperature in the range 150–220 oC

Industry decarbonization is a key a challenge towards the transition to climate neutrality. Indeed, there is a need to satisfy heat at temperatures higher than 150 °C in relevant industrial sectors by upgrading lower temperature heat flows, such as heat from renewable heat sources, ambient heat or industrial waste heat. High temperature heat pumps (HTHP) can upgrade such heat flows enabling great savings in carbon emissions. New refrigerants are needed to develop HTHPs achieving high performances at high temperatures. This paper proposes the use of a new zeotropic mixture composed of carbon dioxide and acetone as the refrigerant of HTHPs working in the temperature range of 150–220 °C. The new fluid is compared with existing pure refrigerants currently used. The thermodynamic characterization of the CO2/acetone mixtures shows temperature glides below 50 K for CO2 mass fractions up to 10%. The best HTHP performance is shown for the mixture 5% CO2/95% acetone in mass fraction. For instance, such a mixture obtains a COP of 5.63 when the target outlet sink temperature is 200 °C and the temperature difference between the outlet heat sink and the inlet heat source is 70 K, showing an improvement of 46% compared to pure acetone.

Effect of entrainers with different boiling point sequences on the design and performance for side-stream extractive distillation processes

BackgroundAn azeotropic mixture of acetone and n-heptane is commonly found in many pharmaceutical wastewaters. In this work, the separation of acetone / n-heptane was studied using intermediate- and high-boiling-point entrainers (benzene and p-xylene, respectively). MethodsTo maximize the economic benefits and mitigate the economic and environmental impact of the separation process, traditional extractive distillation and side-stream extractive distillation processes were developed for different entrainers. The sequential iteration method was employed to optimize the extractive distillation process, with the total annual cost as the constraint objective. Significant findingsThe results show that p-xylene can facilitate the separation of acetone / n-heptane, with high efficiency and low energy consumption, when using a double distillation column. Among the four separation processes developed, the p-xylene side-stream extractive distillation process delivers the best economic and environmental performance, with a total annual cost of 6.04 × 105 $/y and CO2 emissions of 1114.66 kg/y. Compared to the case of traditional p-xylene extractive distillation and benzene side-stream extractive distillation processes, the total annual cost of the p-xylene side-stream extractive distillation process was reduced by 9.56% and 49.22%, respectively, while the corresponding CO2 emissions were reduced by 15.71% and 48.85%.

Solubility and Data Correlation of 2-Bromo-5-hydroxypyrazine in Four Cosolvent Mixtures and Ten Mono-Solvents from 278.15 to 323.15 K

The experimental solubility of 2-bromo-5-hydroxypyrazine dissolved in 10 mono-solvents (methanol, ethanol, isopropanol, N,N-dimethylformamide (DMF), n-propanol, acetonitrile, acetone, ethylene glycol (EG), propylene glycol (PG), water) and cosolvent mixtures of methanol + water, ethanol + water, isopropanol + water, and DMF + water was determined by the isothermal saturation method between 278.15 and 323.15 K at 101.2 kPa. The largest solubility was observed in DMF + 2-bromo-5-hydroxypyrazine for mono-solvent systems and in DMF + water for mixed solvent systems. The Jouyban–Acree model (J–A), van’t Hoff–Jouyban–Acree model (V–J–A), and Apelblat–Jouyban–Acree model (A–J–A) were utilized to correlate the 2-bromo-5-hydroxypyrazine solubility in mixtures, and the Apelblat model, van’t Hoff model, λh model, and Jouyban model were used to correlate the 2-bromo-5-hydroxypyrazine solubility in 10 mono-solvents. The preferential solvation of 2-bromo-5-hydroxypyrazine in mixed solvents was researched by calculation of δx1,3. This study presents insights into modulating the 2-bromo-5-hydroxypyrazine crystallization process and in understanding equilibrium behaviors in different solvents.

Highly active and stable Ru–(OH)-based catalysts supported on Ni–manganite for the base-free aerobic oxidation of 5-hydroxymethyl furfural to 2,5-furan dicarboxylic acid in a noble water–organic solvent system

Highly efficient and robust Ru supported on nickel–manganite catalysts for selective conversion of 5-hydroxymethyl furfural into 2,5-furan dicarboxylic acid in a solvent mixture of noble water and acetone with eliminating homogeneous base addition.

Optimized Solvents for the Maceration of Phenolic Antioxidants from Curcuma xanthorrhiza Rhizome using a Simplex Centroid Design.

Curcuma xanthorrhiza Roxb., from the Zingiberaceae family, is a famous plant native to Indonesia that is highly effective in treating diseases due to the various chemical compounds it contains. This study aims to optimize the extraction process for the phenolic content, with its antioxidant activity, from the rhizome of C. xanthorrhiza using different solvent (water, acetone, methanol, and ethanol) systems based on the simplex centroid design using the Design Expert 13.0 program. Total phenolic content (TPC) was analyzed by colorimetry using Follin-Ciocalteu, while the antioxidant activity was measured based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) using a spectrophotometer. To measure TPC and DPPH, a special cubic model was used; to measure FRAP, a linear model was utilized. Each model demonstrated a good match with the R2 values for TPC (0.9808), DPPH (0.9583), and FRAP (0.7872). The combination of a mixture of water (0.409), acetone (0.307), and methanol (0.284) with a desirability level of 0.723, resulted in a TPC of 34.112 mg gallic acid equivalent (GAE)/g dry weight (DW), DPPH of 26.533 μmol Trolox equivalent (TE)/g DW, and FRAP of 92.353 μmol TE/g DW. This showed a high extraction efficiency which was optimal. The best condition to extract the rhizomes of C. xanthorrhiza was a ternary combination of solvents including water, acetone, and methanol in the proportions of 0.409, 0.307, and 0.284, respectively, with a desirability level of 0.723.

Dual nature of volatility on drop wetting dynamics of acetone–isopropanol mixtures on ultrathin smooth oil films

Volatile drop impacts are commonplace among various industrial and natural processes and are most often studied under Leidenfrost conditions, where a vaporized film sustains the drop weight or reverses drop momentum. The vapor thrust generated is, therefore, a function of many variables such as the enthalpy of vaporization, the superheat, the specific heat capacity of the vapor, vapor thermal diffusivity, and the vapor film thickness. In this study, volatile drop impact and wetting dynamics of acetone and isopropanol mixtures at a normal temperature and pressure were shown to generate enough thrust from evaporation alone during the impact process and allow for unique contact dynamics. Volatility was controlled by varying the acetone concentration in isopropanol mixtures [O(1–10 kPa)] to keep surface tension relatively constant, while the vapor pressure and viscosity increased. Wetting onset was tracked using a high-speed optical total internal reflection microscopy technique where an increase in the vapor pressure enhanced wetting onset (i.e., pure acetone). However, the concentrations between ≈ 49% and 66% isopropanol, which have vapor pressures of ≈11.3–14.8 kPa, respectively, caused drops to rebound at We up to We ≈ 21, beyond the classic disjoining pressure dominant regime of We &amp;gt; 10.

Тoxic components of vape aerosol

In the article, the authors review toxic effects of the va-pour of electronic nicotine delivery systems’ (ends’), or vaping. Nicotine, the main component of the ends’ li-quids, is addictive, while ionization of nicotine increases its solubility and allows to use the liquids in electronic cig-arettes with higher concentrations of dissolved nicotine. рН value of liquid nicotine is decreased when various ac-ids are added to the nicotine freebase, most well-known and most commonly used being: lactic, benzoic, 4-оxo-pentanoic, salycilic, malic, and tartaric acids. Such feelings as tickling in the throat, headache, cough, and others are fewer when vaping. Besides nicotine, vaping cartridg-es contain flavourants; approximately 85% ends’ liquids contained flavourants at concentrations higher than 1 mg/ml, 37% — &gt;10 mg/ml. Some products contained menthol and ethyl maltol in concentrations 30 and 100 times higher that their cytotoxic values. Оne of smoke liquids contained cinnamaldehyde in concentrations around 343 mg/ml, which is more than 100,000 times higher its cytotoxic value. Some compounds, which by themselves are not toxic, may form toxic substances when heated. For example, propylene glycol when ox-idized produces a mixture of acetone, aldehyde, lactic acid, formaldehyde, and acetaldehyde; while oxidation of glycerine leads to the formation of formaldehyde, al-dehyde, and acrylaldehyde. The study showed that 150 heating cycles led to the loss of chrome and iron from cantal coils (up tо 19 % and 58 %, respectively); iron and nickel from nichrome coils (up tо 14% and 43%, respec-tively). Some data show the risk for the development of bronchial asthma (BA), other respiratory diseases, and overall unfavourable impact of the ends’ vapour on cardio-vascular system, and ENT organs. Electronic cig-arettes may enhance genotoxic effects of the tobacco smoke cancerogenes. Conclusion. Both nicotine, fla-vourants, smoke liquids’ heating products (propylene, glycol, glycerine), and metals may have unfavourable impact on health. More and more studies appear that demonstrate such toxic effects, or cancerogenesis in an-imal or cell models.

Constants of Stability of Cobalt(II) Complexes with Glycylglycinate Ions in Aqueous Acetone Solutions

Potentiometric titration is used to determine constants of stability of cobalt(II) glycylglycinate complexes at a temperature of 298 K and the ionic strength of 0.1 M solutions in aqueous acetone solutions. It is established that in contrast to aqueous solutions, cobalt(II) mono-glycylglycinates, bis-glycylglycinates, and tris-ligand complexes can all form in water–acetone mixtures. The stability of cobalt(II) complexes with glycylglycinate ions grows along with the concentration of acetone in a solution.

Solubility Data, Modeling, and Solvent Effect of 8-Isoquinolinamine in Four Mixed Solvents and Ten Monosolvents from 278.15 to 323.15 K

The equilibrium solubility of 8-isoquinolinamine in methanol, ethanol, n-propanol, isopropanol, N,N-dimethylformamide (DMF), acetonitrile, acetone, propylene glycol (PG), ethylene glycol (EG), and water, and aqueous mixtures of methanol/ethanol/n-propanol/isopropanol plus water was experimentally measured by the isothermal saturation method at 278.15–323.15 K under 101.2 kPa. The mole fractions of 8-isoquinolinamine in monosolvents were obtained to be maximum in neat DMF. For the four binary mixed solvent systems, the amount of 8-isoquinolinamine dissolved in n-propanol + water is more than that in the other three systems. The mole fractions of 8-isoquinolinamine in pure solvents were correlated using the Apelblat model, van’t Hoff model, and Wilson model, and the calculated value of the Apelblat model was the closest to the experimental value. The Jouyban–Acree model, modified Apelblat–Jouyban–Acree model, and van’t Hoff–Jouyban–Acree model were applied to calculate the solubility of 8-isoquinolinamine in the four solvent mixtures. The feedback obtained by comparing the experimental data with the calculated data is that the calculated data from the Jouyban–Acree model was relatively close to the experimental results. Solvent effects as a powerful tool can be used to estimate interactions at the molecular level, and the results showed that solvent–solvent intermolecular interactions contribute to dissolution. van’t Hoff plots are adopted as a method to show the relationship between ln(x) and 1/T.

Organic solvent reverse osmosis (OSRO) for the recovery of hemicellulosic derivatives after wood-pulping with a deep eutectic solvent

This work investigates the recovery of a deep eutectic solvent (DES) used for pulping wood, by removing remnant hemicellulosic derivatives using reverse osmosis (RO). Xylose and its dehydration product furfural are considered representative hemicellulosic derivatives, and a lactic acid-choline chloride DES was used. Various diluting solvents were considered for the RO feed, namely pure water and binary water-organic solvent (ethanol, acetone, and methanol) mixtures. The results in this work show that the xylose rejection is high in water as well as in the presence of organic solvents such as acetone (with 97% rejection in aqueous acetone solvent and 95% in pure water using the RO membrane). On the other hand, furfural is rejected poorly by the RO membrane in all media (below 60% in all solvents). Finally, based on these results, a separation scheme was proposed to attain a complete mass recovery of each component of this mixture.

Determination of fatty acid profiles and bioactive properties of body wall and viscera of Holothuria atra collected from Lombok Island, Indonesia

Holothuria atra is one of the most abundant sea cucumbers found in Indonesia and known to possess various bioactivities. In this study we determined the antioxidant, antibacterial activity, and fatty acids of body wall and viscera of H. atra. Samples were collected from North Lombok. Fatty acid profile of fresh H. atra was examined by gas chromatographic quantification. Four different solvents (ethanol, methanol, ethanol mixed with water, and ethanol mixed with acetone) were used to extract the phenolic content of the viscera and body wall of H. atra. It is found that the fatty acids eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) amount of body wall were higher than viscera of H. atra; The results showed H. atra contained 8.56% EPA and 1.6% DHA in the body wall followed by 0.1% EPA and o.37 DHA in the viscera. The extract of body wall of H. atra using ethanol acetone mixture has low antioxidant activity with value of 16.05±0.78mg/mL and the strong antioxidant activity was found in ethanolic extract of H. atra viscera (2.77±0.88 mg/mL). Antibacterial activity of body wall and viscera of H. atra against gram negative and positive bacteria including Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus aureus were conducted by using agar diffusion method.

Micronization of Levofloxacin Hydrochloride by the Supercritical Antisolvent Precipitation Method from Single-Phase and Two-Phase CO2–Acetone Mixtures

Micronization of Levofloxacin Hydrochloride by the Supercritical Antisolvent Precipitation Method from Single-Phase and Two-Phase CO2–Acetone Mixtures

Humidity effect on real-time response of tetranitro-oxacalix[4]arene-based surface plasmon resonance (SPR) acetone sensor at room temperature

We report the effect of humidity on the acetone sensitivity of nano-sized thin films obtained by spin coating the oxacalix[4]arenes(1,3) molecules on suitable substrates in this work. The surface morphologies and volatile organic compound (VOC) sensor properties of spin-coated thin films were examined using atomic force microscopy (AFM) and surface plasmon resonance (SPR), respectively. It was determined that the sensitivities calculated from the measurements performed using a mixture of acetone and water vapor were 14% and 11% incorrect for the 1 and 3 thin film sensors, respectively, compared to those performed with dry air and acetone mixture.

Artificial olfaction based on tafel curve for quantitative detection of acetone ethanol gas mixture

This work established an artificial olfaction based on a single mixed potential type gas sensor. By identifying the Tafel curve, artificial olfaction can determine the concentration of each component in the acetone and ethanol vapor mixture. To save a long testing circle, a finite element model was built to efficiently output the Tafel curves of the sensor for different concentrations of vapor mixtures. Based on the Tafel curve data obtained from the simulation, different classification algorithms were trained to determine the operating state of the sensor. Among them, eXtreme Gradient Boosting (XGB) had a 99% accuracy in determining whether the sensor is saturated or not. Then three different regression algorithms (XGB, Gradient Boosting Decision Tree (GBDT), and Random Forest (RF)) were trained to identify acetone and ethanol vapor concentrations. The results showed that XGB and GBDT were the most effective in identifying acetone and ethanol vapor. The mean absolute percentage errors for the identified acetone and ethanol in the gas mixture were 11.3% and 23%, respectively. The above results indicated that it was feasible and effective to use Tafel curves to detect VOC gases.

Ultra-high-performance supercritical fluid chromatography-mass spectrometry for the analysis of organic contaminants in sediments.

A nontarget screening method was developed based on D-optimal designs for ultra-high performance supercritical fluid chromatography with positive and negative electrospray ionization mode mass spectrometry. A mixture of organic contaminants such as pesticides, steroids, surfactants, phenolic and fatty acids, and polycyclic aromatic hydrocarbon derivatives, was used for the optimization. An aprotic mixture of dichloromethane and acetone [3:1] performed overall best as the injection solvent. The highest peak capacities (n) were accomplished at the shallowest gradient (1%B/min), ammonium formate (n = 378 in negative ionization mode), or ammonium acetate (n = 327in positive ionization mode) in methanol as the modifier. Capillary voltage, make-up solvent flow rate, water, and additive concentration were the most significant factors for improving peak intensity: higher peak intensities were obtained at lower additive concentrations (5mM ammonium formate), and with 5% water in positive ionization mode. Conversely, water had detrimental effects in negative ionization mode. The optimized method was used to quantify organic contaminants in 17 freshwater sediment samples from Copenhagen, Denmark. Out of 50 monitored contaminants, 35 were detected in at least one sample. Further, the method has a potential for target and nontarget screening analysis of organic contaminants in solid matrices.