Diisopropyl Ether Research Articles

Experiment-based Abraham model solute descriptors for 2,3-dimethoxybenzoic acid from measured solubility data

ABSTRACT Mole fraction solubilities have been experimentally determined for 2,3-dimethoxybenzoic acid dissolved in propanenitrile and diisopropyl ether, in two more alkyl alkanoates (tert-butyl acetate, methyl butanoate), and in ten more alcohols (1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-methyl-1-propanol, 2-butanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, cyclopentanol) at 298.15 K using a spectrophotometric method of chemical analysis based on the Beer-Lambert law. Experiment-based solute descriptors for the monomeric form of the dissolved carboxylic acid solute have been calculated using the results from our solubility measurements, combined with published solubility data taken from the chemical literature. The calculated solute descriptors provide a reasonably accurate mathematical description of the observed solubility data, with the overall standard deviation between the observed and back-calculated values being 0.074 log units. The solute descriptors further suggest that the carboxylic acid solute does not undergo intramolecular hydrogen bonding in the 28 organic solvents considered in the current study.

Recovery of biofuel additives isopropyl alcohol and diisopropyl ether using ionic liquids with intermolecular interactions and process design

Isopropyl alcohol (IPA) and diisopropyl ether (DIPE) are widely used as biofuel additives in fuel processing. When IPA is produced by propylene hydration, a by-product IPA and DIPE is made. Since the existence of azeotropic point formed between IPA and DIPE, the separation of the azeotrope is achieved using special distillation technologies in industry, which requires high energy consumption. Liquid-liquid extraction was used to separate the mixture due to its energy saving in this work. Three imidazolium-based ionic liquids (ILs) 1-butyl-3-methylimidazolium thiocyanate ([BMIM]SCN), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]NTf2) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) were synthesized as the extractants. The influence of extraction time, extraction temperature, mass ratio of mixture (IPA + DIPE) to ILs and the initial content of IPA in the mixture (IPA + DIPE) on the extraction performance of ILs were studied. The optimal extraction conditions were determined using the response surface method (RSM). The results showed that the IL [BMIM]SCN had better extraction capacity for separation of the mixture (IPA + DIPE). The interactions between molecules were investigated by quantum chemical calculations. Finally, a conceptual separation process is designed to separate the mixture, which can provide a helpful technology to purify the biofuel additives.

Experimental study on combustion, performance, and emission characteristics of a homogeneous charge compression ignition engine fuelled with multiple biofuel-gasoline blends

For sustainable future mobility and power generation applications, there is a compelling need to develop flex-fuel engines that operate with multiple regional or season-specific biofuels. The present investigation focussed on mitigating agricultural diesel engines’ pollutant emission and performance problems. A systematic experimental study is carried out in a modified agricultural diesel engine to compare and evaluate the engine characteristics of the biofuel-gasoline blends fuelled Homogeneous Charge Compression Ignition (HCCI) mode. Seven different oxygenated biofuels: acetone, ethanol, methanol, isopropanol, isobutanol, ethyl acetate, and diisopropyl ether blended in gasoline, were investigated. 2-Ethylhexyl nitrate was used to improve the reactivity of fuel blends to the extent that lower engine loads could be reached. All the investigated biofuel-gasoline blends could produce permissible emission levels by suitably tuning the fuel proportions. The total nitrogen oxides and smoke emissions were below 2.8 and 0.0007 g/kWh, respectively, for all the investigated biofuel-gasoline blends at all the HCCI engine load conditions. The highest indicated thermal efficiency of 42% was attained using 60% ethanol/34% gasoline/6% 2-EHN blend in the HCCI engine at 4.63 bar BMEP (86% rated load), a notable 25% improvement compared to the conventional diesel engine. A detailed investigation was done to elucidate the HCCI engine performance (indicated thermal efficiency) trend variations with biofuel type and engine load. The Response Surface Method was adopted to correlate the maximum and the minimum engine load with the fuel composition and properties. The Desirability Approach provided the optimum fuel composition and properties to maximize the engine load range. The optimum solution achieved the engine load range of 20%–89% rated load. Overall, a compact, efficient, and clean HCCI combustion-based engine technology was developed that could be operated using multiple biofuels over an expanded load range.

2-Propanol Dehydration on the Nodes of the Metal–Organic Framework UiO-66: Distinguishing Catalytic Sites for Formation of Propene and Di-isopropyl Ether

2-Propanol Dehydration on the Nodes of the Metal–Organic Framework UiO-66: Distinguishing Catalytic Sites for Formation of Propene and Di-isopropyl Ether

Soft sensor model predictive control for azeotropic distillation of the separation of DIPE/IPA/water mixture

BackgroundA novel advanced control scheme for azeotropic distillation (AD) shows superiority in improving product quality and economic benefit. MethodsA soft sensor model predictive control (SS-MPC) strategy was developed for the separation of the diisopropyl ether (DIPE)/ isopropyl alcohol (IPA)/water mixture via AD. The soft sensor model was built based on time-delayed neural networks (TDNN), while the weight of the SS-MPC controller was optimized by multi-objective genetic algorithm. Significant findingsProduct purity of two distillation columns was controlled simultaneously by the proposed soft sensor model predictive controller, meanwhile, avoiding the measurement of composition in practice. The dynamic performance was compared with the conventional PID scheme and MPC scheme in the face of ±10 % feed disturbances. The results show that SS-MPC can better control the product purity than PID without using the composition detection instruments.

Shock Tube/Laser Absorption Measurements of the High-Temperature Spectra and Decomposition of Propyl Ethers.

This work presents measurements of temperature-dependent absorption spectra and thermal decomposition rates of propyl ethers, specifically di-n-propyl ether (DnPE) and diisopropyl ether (DiPE), which are two renewable fuel candidates. We employed a broadband rapid-tuning MIRcat-QT laser, operating in the scan/fixed-wavelength mode in combination with a shock tube. Spectral measurements were performed over the wavelength range of 8.4-11 μm (909.1-1190.5 cm-1), covering the strongest infrared absorption bands of the studied ethers, at temperatures of 559-853 K and pressure near 1 bar. These high-temperature spectra help in selecting the optimum wavelength for sensitive and selective measurements of the target ethers. Based on the criteria of high sensitivity, minimum interference, and insensitivity to temperature and pressure variations, we selected a wavelength of 1121.82 cm-1 for high-temperature diagnostics of DnPE and DiPE. Absorption cross sections at the selected wavelength of 1121.82 cm-1 were measured over 550-1500 K, and pressures ranging from 0.3-1.4 bar. This diagnostic was then applied to study the high-temperature pyrolysis of these ethers by measuring their time histories behind the reflected shock waves. Our experimentally measured overall decomposition rate coefficients for DnPE and DiPE are given as (unit of s-1) kDnPE = 1.25 × 1027 × T-3.483 × exp(-37620 K/T) and kDiPE = 5.26 × 1023 × T-2.857 × exp(-32360 K/T).

Investigation of Effects of Sulfuric Acid in Single Wafer Cleaning Process Using Isopropyl Alcohol

Isopropyl alcohol (IPA) was used in the drying process to remove the contamination after the wet cleaning process. Regardless of the types of chemical solutions, the IPA is more strictly controlled because it is used. However, when the IPA was exposed to low acid concentration, the IPA polymers were generated to the di-isopropyl ether, isopropyl acetate, and di-isopropoxy methane. And the pH of IPA rapidly changed by about 1.99 in ppm level concentration. Generated IPA polymers were adsorbed on the wafer surface. These polymers can occur defects, and the probability increases as the concentration increases. Scanning mobility particle sizer (SMPS) measurement system can be measured the impurity in IPA solution. The total impurity concentration was increased by the concentration of H2SO4 with the same results in both gas chromatography mass spectrometry (GCMS) and time of flight secondary ion mass spectrometry (ToF-SIMS). SMPS results can be correlated with the concentration of impurities. In this paper, IPA polymers were defined by acid contamination, and these polymers have affected the Si wafer surface. In addition, the SMPS measurement system was introduced for the detection of impurities in IPA solutions.

Evaluation of Performance Improvement of Gasoline Fuels by Adding Propanol, Ethanol, and Diisopropyl Ether along with Metal Oxides of CeO2 and Fe2O3

Many studies focusing on the composition of gasoline with any type of fuel additives have shown that the overall engine performance has a significant impact on reducing emissions. In this research work, ethanol, isopropanol, and diisopropyl ether as oxygenated additive with cerium oxide (CeO2) and iron(III) oxide (Fe2O3) as metal nanoparticles were combined with pure gasoline. Due to the more oxygen they have in their structure, these alcohol additives reduce pollutants and complete combustion. Metal nanoparticles also improve the performance of the engine due to the proper potential. To check the efficiency of the new fuel, a four-stroke engine connected to a dynamometer and an analyzer tested different conditions: speed of 1500 and 2000 rpm and loading percentage of 30 and 40%. Analyzed data include the engine power, and the amount of CO, CO2, HC, and NOx released. The power of the engine on gasoline fuel was 14.43 at 1500 rpm, and once the test was repeated with mixed fuel with additives, it increased to 17.5, which indicates an improvement in engine performance. The amount of CO emissions at 1500 rpm with gasoline fuel was 3.25, and once repeating the test with the same engine rpm with mixed fuel, it decreased to 1.68. The amount of CO2 at 1500 rpm with gasoline fuel was 3.8 and repeating the test with mixed gasoline, it was 5.7. The amount of HC emission with gasoline was 65, and it was 62 when tested with mixed fuel. The amount of NOx released in comparison of gasoline fuel with mixed fuel reached from 264 to 533. The performance improvement and pollutant emissions are fully described in the conclusion section. The analyzed data were calculated and transformed into a model. Among the additives used, isopropanol and CeO2 nanoparticles had better results in optimizing the fuel, reducing the pollutants, and increasing the engine performance. The optimization results show that the use of isopropanol (5%) and CeO2 (1.39 wt. %) as well as diisopropyl ether (4 wt. %) at high engine speed (1504.97 rpm) can be improved engine performance and reduce exhaust gas emissions.

Thermodynamics of ternary mixtures of oxygenated fuel: Diisopropyl ether + ethanol + n-octane

Depleting conventional fossil fuels and growing greenhouse gases have fascinated the researcher’s heed for the use of green and clean fuels. Thereby, such fuels can be obtained by blending gasoline with the oxygenated fuel additives to reduce the toxic gaseous emissions and enhance the fuel efficiency in the motor engine. In this regard, various thermodynamic properties like densities (ρ), speeds of sound (u) and refractive indices (nD) of the ternary mixture of diisopropyl ether (1) + ethanol (2) + n-octane (3) were experimentally measured at different temperatures (298.15 K to 318.15 K) and at 0.1 MPa. The excess molar volume (VmE), deviation in sound speed (Δu), excess isentropic compressibility (κsE), excess available volume (VaE), excess free length (LfE) and refractive index deviation were evaluated using their corresponding experimental data. Different correlations and analytical rules have been used for conceptual assessment of speed of sound and refractive index of mixtures. The effect of temperature on the above stated thermodynamics properties has also been investigated.

Novel intensified process for di-isopropyl ether production from isopropanol etherification using reactive distillation technology

The preparation of di-isopropyl ether (DIPE), as an important chemical solvent, by isopropanol (IPA) etherification is limited by chemical equilibrium and azeotropic formation in its production processes. A novel sustainable etherification process based on reactive distillation (RD) coupled with extractive distillation is proposed. The reaction of IPA etherification was carried out by cation exchange resin NKC-9 in a 250 mL autoclave and fitted by a pseudo-homogeneous model. According to the reaction kinetic, the IPA etherification RD model was established. To confirm the viability of RD and the accuracy of the model, pilot-scale RD experiments for generating DIPE were investigated. Based on the established model matching the pilot scale experiments, the operating conditions of the etherification RD column were optimized by sensitivity analysis. The simulation results show that the conversion of IPA in the RD column can be increased from 18.2 % to 77.9 % compared with autoclave and the yield of DIPE in the whole process flowsheet can reach 99.9 %, which demonstrates that combining reactive distillation with extractive distillation technology is a feasible and advantageous solution for DIPE production.

Molecular Dynamics Simulation of Diisopropyl Ether Using Various Interatomic Potentials

A comparative assessment of the accuracy of determining the density and viscosity has been carried out for diisopropyl ether using the method of classical molecular dynamics using three potentials. The accuracy of determining the viscosity coefficients when using equilibrium and nonequilibrium calculation methods was also investigated.

Molecular Dynamics Simulation of Diisopropyl Ether Using Various Interatomic Potentials

A comparative assessment of the accuracy of determining the density and viscosity has been carried out for diisopropyl ether using the method of classical molecular dynamics using three potentials. The accuracy of determining the viscosity coefficients when using equilibrium and nonequilibrium calculation methods was also investigated.

Influence of imidazolium based ionic liquids with different anions on liquid–liquid phase behavior for separation of azeotropic mixture isopropyl alcohol + diisopropyl ether

During production of isopropyl alcohol (IPA) by propylene hydration, a mixture of diisopropyl ether (DIPE) and IPA is obtained as a byproduct. Because DIPE and IPA have similar boiling points, an azeotrope can be formed. It is not feasible to separate the mixture (DIPE + IPA) using conventional distillation technology. In this work, the mixture (DIPE + IPA) was separated by liquid–liquid extraction and three imidazolium based ionic liquids (ILs) with different anions including 1-butyl-3-methylimidazolium thiocyanate ([BMIM]SCN), 1-butyl-3-methylimidazolium dicyanamide ([BMIM]DCA) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]NTf2) were selected as the extractants. The effect of the ILs on liquid–liquid phase behavior for the ternary systems (DIPE + IPA + ILs) was discussed. Partition ratio (P) and selectivity (S) were calculated to assess the extraction ability of the ILs. The NRTL thermodynamic model was used to correlate the experimental data. The interactions between the ILs and (DIPE / IPA) were explored by analyzing electrostatic potentials, hydrogen bond length and reduced density gradient, which can help to design the ILs with reasonable structures for separating such azeotropic mixtures.

SURFACE MORPHOLOGY AND TEXTURE ANALYSIS H3PMo12O40/TiO2 CATALYSTS

The results of research on the surface morphology and textural properties of H3PMo12O40/TiO2 catalysts are introduced in this article. The nature of the effect of additives on the surface structure and dimensional characteristics of titanium dioxide modified with phosphomolybdic acid was defined: after the introduction of the modifier, there is a tendency to decrease the specific surface area, the more, the higher the content of H3PMo12O40; without exception, all H3PMo12O40 -containing samples are characterized by the content of crystallites of larger average sizes (41–80 µm) than the original sample; samples containing particles with an average radius of about 60–80 µm have the highest activity; porosity changes symbiotically with the indicators of the total pore volume - it decreases with an increase of the amount of H3PMo12O40, which is associated with the blocking of small pores by the modifier. It is concluded that the specific surface area and fineness are not the key factors responsible for the high catalytic activity in the process of converting isopropyl alcohol to diisopropyl ether. Keywords: titanium dioxide, phosphomolybdic acid, scanning electron microscopy, morphology, specific surface area

Case Study of a 29 year-old Female with Ulcerative Proctitis

Our case report discusses SR a 29-year-old, physically active mother with weight - 150 lbs., height- 66 inches, and a BMI of 24. SR presented with a diagnosis of Ulcerative Proctitis of two years duration and with immediate need to address rectal bleeding (lower rectum and anus). No open wound, no hemorrhoids; only leaking fatigued tissue. Previous medications included mesalamine suppository prescribed when blood drainage was excessive -did not help extensively. Integrative planUlcerative Proctitis signifies inflammation, repair deficit and immune burden. This plan prioritizes reducing overall burden on the immune system, restoring healing and inducing repair. We used the LRA by ELISA/ACT® tests for delayed food and chemical sensitivities. This test was performed on February 5, 2021. Strong reactionsChicken, Sugar, Beet, Chamomile, FD & C Yellow # 6, D & C Green# 5, Locust Bean Gum, Benzyl Acetate, Parsnip Moderate reactionsPeanut, Carob, Swordfish, Geotrichum candidum, Toluene,Okra, RadishSR avoided the strong reactions for six months and moderate ones for three months- she discovered toluene in her lubricant! A supportive supplement regimen was also initiated – starting with the Ascorbate Vitamin C calibration (C cleanse) protocol. Other nutrients included a combination of L-carnitine, sulfur amino acids such as methionine, cysteine, and Omega 3 fats. SR continued the C cleanse weekly and took ~6 g buffered ascorbate daily. She also incorporated avocado in her diet to augment healthy fat intake.Eight months later there was already a significant decrease in blood loss. The LRA by ELISA/ACT test was repeated on October 16, 2021. Strong reactionsCow Dairy (group), Brewer's Yeast,1,2 Dichlorobenzene, Yogurt (Cow), Parsnip Moderate reactionsChocolate/Cocoa, Tuna, Processed Cheese (Cow), Mango, Eggplant, Tapioca, D & C Green #8, Benzopyrene, Beryllium Oxide, Isopropyl Ether, Catfish, Rapeseed/Canola Oil, Scallion/Spring Onion. Final outcomeThis second test showed a decrease in number of strong reactions, signaling improvement in immune tolerance. Omega 3 index close to 8% is healthy and SR's omega index increased to 7.38% and Omega 6/3 ratio improved to 4.8: 1.In 10 months

Stereospecific and selective enzymatic resolution of carboxylic acid derivatives in organic solvents

Enzymes such as lipases and proteases have been used as catalysts in nearly anhydrous organic solvents such as diisopropyl ether and hexane to carry out stereospecific and selective enzymatic resolutions of carboxylic acid derivatives such as 2-bromohexadecanoic acid, which may be used for prevention and treatment of bone loss-related diseases and β-phenyllactic acid, which has a role as a human metabolite.

The radiative surface hopping (RSH) algorithm: Capturing fluorescence events in molecular systems within a semi-classical non-adiabatic molecular dynamics framework.

In this article, we present the radiative surface hopping algorithm, which enables modeling fluorescence within a semi-classical non-adiabatic molecular dynamics framework. The algorithm has been tested for the photodeactivation dynamics of trans-4-dimethylamino-4'-cyanostilbene (DCS). By treating on equal footing the radiative and non-radiative processes, our method allows us to attain a complete molecular movie of the excited-state deactivation. Our dynamics rely on a semi-empirical quantum mechanical/molecular mechanical Hamiltonian and have been run for hundreds of picoseconds, both in the gas phase and in isopropyl ether. The proposed approach successfully captures the first fluorescence processes occurring in DCS, and it succeeds in reproducing the experimental fluorescence lifetime and quantum yield, especially in the polar solvent. The analysis of the geometrical features of the emissive species during the dynamics discards the hypothesis of a twisted intramolecular charge transfer state to be responsible for the dual emission observed experimentally in some polar solvents. In a nutshell, our method opens the way for theoretical studies on early fluorescence events occurring up to hundreds of picoseconds in molecular systems.

Ti/Zr/O Mixed Oxides for the Catalytic Transfer Hydrogenation of Furfural to GVL in a Liquid-Phase Continuous-Flow Reactor

This work aims to develop an efficient catalyst for the cascade reaction from furfural to γ-valerolactone in a liquid-phase continuous reactor. This process requires both Lewis and Brønsted acidity; hence, a bifunctional catalyst is necessary to complete the one-pot reaction. Ti/Zr/O mixed oxide-based catalysts were chosen to this end as balancing metal oxide composition allows the acidity characteristics of the overall material to be modulated. Oxides with different compositions were then synthesized using the co-precipitation method. After characterization via porosimetry and NH3-TPD, the catalyst with equimolar quantities of the two components was demonstrated to be the best one in terms of superficial area (279 m2/g) and acid site density (0.67 mmol/g). The synthesized materials were then tested using a plug flow reactor at 180 °C, with a 10 min contact time. Ti/Zr/O (1:1) was demonstrated to be the most promising catalyst during the recycling tests as it allowed obtaining the highest selectivities in the desired products (about 45% in furfuryl isopropyl ether and 20% in γ-valerolactone) contemporaneously with 100% furfural conversion.

Elucidating the effect of the physicochemical properties of organosolv lignins on its solubility and reductive catalytic depolymerization

Unsatisfactory solubility and recalcitrant condensed structures of isolated lignins (technical lignins) severely limit their processability into renewable materials, fuels, and chemicals. Therefore, a comprehensive understanding of the structural and physicochemical properties of isolated lignins is of great value in explaining their performance in the solubilization and further depolymerization to high-value applications. In this work, we investigated the solubilization and depolymerization performance of organosolv lignins from three different sources (beech (L01), birch (L02), and wheat straw (L03)). We applied sequential solvent fractionation as a tool to subdivide parent lignins into four more homogeneous subfractions (SF1, SF2, SF3, and IF), with a gradual increase in molecular weight and interunit linkages and a decrease in phenolic –OH group from SF1 to IF. The solubility tests of the parent lignins and their subfractions at ambient conditions were carried out in six organic solvents (n-hexane, diisopropyl ether, ethyl acetate, ethanol, methanol, and acetone) with large differences in Hansen solubility parameters. Among the solvents studied, the solvents with δp > 8 MPa1/2 demonstrated a high solubilization yield of organosolv parent lignins and their subfractions. The solubilization behavior of parent lignins and subfractions was further described based on their inherent structural properties, such as molecular weight and functional group content (phenolic –OH and –COOH). The structure–reactivity characteristics of parent organosolv lignin and their subfractions were also investigated under different conditions in the presence of catalyst-containing transition (NiHTC-500) and noble (Pd/C) metals as active centers. Strong structural correlations between parent lignin/subfractions and depolymerized lignin oils were derived using GC-FID/MS, GPC, 1H–13C HSQC NMR, and 31P NMR.

Economy, environmental assessment and energy conservation for separation of isopropanol/diisopropyl ether/water multi-azeotropes via extractive distillation coupled pervaporation process

This wok proposed the extraction distillation coupled pervaporation (ED+PV) technology process using two different solvents to separate isopropanol (IPA) and diisopropylether (DIPE) from DIPE/IPA/H2O ternary heterogeneous azeotropes in industrial wastewater from the synthesis of isopropanol in this study. Based on strict design specifications, simulation and sequential iteration methods are used for process design and optimization. Compared to the ethylene glycol (EG)-EG+H2O process and the 1,3-propanediol (PDO)-IPA+H2O process, the total annual cost (TAC) of the EG-IPA+H2O process decreased by 20.76% and 7.86% (PDO). Compared to the EG-EG+H2O process, the TAC of the PDO-IPA+H2O process reduced 14%, but the global warming potential (GWP) and human toxicity of the PDO-IPA+H2O process increased 11.3% and 4.07% respectively. Compared to the PDO-IPA+H2O process, the EG-IPA+H2O process saves 7.86% (TAC), 9.78% (GWP) and 9.85% (human toxicity). The ED+PV process with EG is superior to PDO in factors of TAC, energy consumption, human toxicity and environment. The EG-IPA+H2O process changed the separation order of the products of the multi-azeotropic system, reduced the cost and energy conservation of the system, and enhanced the environmental protection evaluation of the process, is the best process through life cycle assessment for analyzing the economy, energy conservation, environmental assessment and human toxicity, designing cleaner products, controlling waste discharge, and promoting the chemical purification industry. This work provides a new process design and optimized separation ideas, will have a good guiding significance for the research and application separation of multi-azeotropic mixture with mixed solvents in organic wastewater from the cleaner chemical production, has been up to standard wastewater discharge process, and realized the development goal of carbon peak and carbon neutrality in the sustainable development of chemical clean industry.