Separation Of Thiophene Research Articles

Opportunities Using Boron to Direct Reactivity in the Organic Solid State

AbstractThis Account describes work by our research group that highlights opportunities to utilize organoboron molecules to direct chemical reactivity in the organic solid state. Specifically, we convey a previously unexplored use of hydrogen bonding of boronic acids and boron coordination in boronic esters to achieve [2+2]-photocycloadditions in crystalline solids. Organoboron molecules act as templates or ‘shepherds’ to organize alkenes in a suitable geometry to undergo regio- and stereoselective [2+2]-photocycloadditions in quantitative yields. We also provide a selection of publications that served as an inspiration for our strategies and offer challenges and opportunities for future developments of boron in the field of materials and solid-state chemistry.1 Introduction1.1 Template Strategy for [2+2]-Photocycloadditions in the Solid State2 Boronic Acids as Templates for [2+2]-Photocycloadditions in the Solid State2.1 Supramolecular Catalysis of [2+2]-Photocycloadditions in the Solid State Using Boronic Acids3 Boronic Esters as Templates for [2+2]-Photocycloadditions in the Solid State3.1 Application of Photoproducts: Separation of Thiophene from Benzene through Crystallization3.2 Crystal Reactivity of B←N-Bonded Adducts: The Case of Styryl­thiophenes4 Conclusions and Perspectives

Rational design of double salt ionic liquids as extraction solvents: Separation of thiophene/n‐octane as example

AbstractAlthough double salt ionic liquids (DSILs) offer significant advantages over classical two‐ion ionic liquids as separation solvents, relevant studies are still scarce and a systematic DSIL selection method is thus highly desirable. In this contribution, a rational method for designing DSILs as extraction solvents is proposed and exemplified by the thiophene/n‐octane separation. The effects of additional degrees of freedom for DSIL design (i.e., double cations and/or anions and the ion ratio) on the thermodynamic properties are first analyzed by COSMO‐RS. Then, a multilevel DSIL design method combining the prediction of infinite dilution thermodynamic properties, the estimation of physical properties, the evaluation of phase equilibrium behavior, and the experimental validation is proposed. By applying this method, [C2MIm][OAc] x[NO3]1‐x (x = [0, 1]) and [C2MIm][OAc] x[SCN]1‐x (x = [0.70, 1]) are identified as promising DSIL solvents for the thiophene/n‐octane separation. Correspondingly, the liquid–liquid equilibria of {DSILs + thiophene + n‐octane} with the designed DSILs are experimentally studied.

Separation of thiophene, or benzothiophene from model fuel using glycols. Liquid–liquid phase equilibria and oxidative desulfurization study

In this work the possibility of use glycols in extractive desulfurization will be discussed based on liquid–liquid phase equilibria (LLE) measurements for {glycol (1) + aromatic sulfur compound (2) + heptane (3)} ternary systems at T = 308.15 K and at pressure p = 0.1 MPa. Based on the experimental data, the performance of three glycols: diethylene glycol, triethylene glycol and polyethylene glycol (PEG 200) in the extraction of thiophene, or benzothiophene from heptane were determined. The selectivity, S, and solute distribution ratio, β derived from the experimental equilibrium data, were calculated and used to determine the efficiency of the tested glycols as a solvent for the extraction of sulfur compounds from model fuels. The NRTL equation was successfully used to correlate the experimental tie-lines and calculate the phase composition error in mole fraction in the ternary systems. The average root mean square deviation (RMSD) of the phase composition was less than 0.017. Additionally, the extractive desulfurization (EDS) of model fuels has been studied using diethylene glycol, triethylene glycol, polyethylene glycols (PEG 200), [BMIM][BF4] and eutectic mixtures of ([BMMOR][Br with diethylene glycol, or triethylene glycol). The oxidative extractions (ODS) were performed using different oxidative agents: the mixture of hydrogen peroxide with acetic acid, or formic acid, or benzoic acid, or iron (III) chloride and vanadium (V) oxide as well as the mixture of oxygen with N-hydroxyphthalimide (NHPI). Many parameters including the type of extractant and oxidizing agents, extraction time and temperature, as well as the ratio of the volume of model fuel to the volume of the extractant and number of extraction cycles on the extraction efficiency, were considered and discussed.

Separation of Thiophene from Aliphatic Hydrocarbons Using Tetrahexylammonium-Based Deep Eutectic Solvents as Extracting Agents

Catalytic hydrodesulfurization is the common process that is used in the industry to achieve low sulfur concentrations in oil fuels. However, it is usually conducted at relatively high pressure and temperature resulting in an expensive and energy-consuming process. Aiming to reduce the energy requirements of this separation, liquid–liquid extraction is considered. In this work, two deep eutectic solvents (DESs) were evaluated for their extraction properties of sulfur derivatives from two aliphatic hydrocarbons via liquid–liquid extraction. The mixtures thiophene/n-hexane and thiophene/n-octane were selected as oil models. The selected DESs were: (i) tetrahexylammonium bromide/ethylene glycol with molar ratio = 1:2 (DES 1) and (ii) tetrahexylammonium bromide/glycerol with molar ratio = 1:2 (DES 2). To confirm the suitability of the DESs for the system {aliphatic + thiophene + DES}, the binary solubility of thiophene/DES and aliphatic/DES was measured at T/K = 298 and atmospheric pressure. Then, the liquid–...

Pore Size Dependence of Adsorption and Separation of Thiophene/Benzene Mixtures in Zeolites

Grand canonical ensemble Monte Carlo simulations were applied to study the adsorption and separation of thiophene from binary and ternary mixtures of benzene and n-alkanes in nine types of zeolites. Adsorption of thiophene is important for removing sulfur from gasoline. The computed pure component adsorption isotherms are in good agreement with experimental results for FAU zeolites. The calculated Qst for thiophene in FAU were found to be 33–46 kJ/mol depending on uptake, in good agreement with the experimental data. The adsorption heats as a function of zeolite pore diameter suggest high thiophene affinity when the pore diameter is between 4.6 and 5 A. Binary mixture simulations at two different compositions show that FER is very selective toward thiophene over benzene at 373 K. The thiophene selectivity shows a significant dependence on pore size in binary mixtures, and the smaller thiophene molecule can replace benzene at elevated pressures due to size entropy effects for some zeolites. For ternary mix...

Solvent extraction of aromatic sulfur compounds from n-heptane using the 1-ethyl-3-methylimidazolium tricyanomethanide ionic liquid

The ionic liquid 1-ethyl-3-methylimidazolium tricyanomethanide ([EMIM][TCM]) has been tested as a solvent for the separation of sulfur compounds from aliphatic hydrocarbon. Liquid–liquid phase equilibrium data have been determined for ternary systems containing the ionic liquid, thiophene or benzothiophene and n-heptane. The influence of temperature on the separation of thiophene from n-heptane was determined. High solubility of sulfur compounds and practical immiscibility of aliphatic hydrocarbon in ionic liquid have been found. The values of selectivity and solute distribution ratios have been calculated for all systems and compared with literature data for other 1-ethyl-3-methylimidazolium-based ionic liquids. High values of selectivity were obtained. The experimental data were correlated using the NRTL equation, and the binary interaction parameters have been reported. The phase equilibria diagrams for the ternary mixtures including the experimental and calculated tie-lines have been presented.

Molecular simulations for adsorption and separation of thiophene and benzene in Cu-BTC and IRMOF-1 metal–organic frameworks

We use Grand Ensemble Monte Carlo (GCMC) simulations to study the adsorption of thiophene and benzene in Cu-BTC and IRMOF-1 metal–organic frameworks (MOFs). We calculated the adsorption isotherms of pure components and analyze the sitting of the molecules in the two types of structure for the different adsorption pressure. The simulations show that electrostatic interactions between adsorbate and MOF atoms dominate the adsorption mechanism. The bulk compositions of 10:90, 50:50 and 90:50 for thiophene–benzene were studied. The results show that thiophene molecules are preferentially adsorbed over benzene molecules in the pressure range under study for IRMOF-1 while preferentially adsorbed over benzene in the low pressure range for Cu-BTC. IRMOF-1 has a significantly higher adsorption capacity than Cu-BTC, while the adsorption selectivity of thiophene over benzene is observed to be higher in the latter at low pressure, which proves that the separation efficiency is largely affected by shape and nature of linkers of structure.

Some problems associated with the chromatographic analysis of thiophene hydrodesulphurization products

Adsorption of thiophene on the walls of stainless steel sample loops, even at relatively high temperatures (up to 180°C), is shown to result in significant errors in the chromatographic analysis of thiophene. A chromatographic system is described which allows a good separation of thiophene and C4 hydrocarbons resulting from the catalytic hydrogenolysis of thiophene.

(147)チオフェン系化合物に関する研究(第1報)粗ベンゼンよりチオフェンをニトロチオフェンとして分離する試み

(147)チオフェン系化合物に関する研究(第1報)粗ベンゼンよりチオフェンをニトロチオフェンとして分離する試み