The P-V-T relationship was measured for ethane for 3 isotherms, propane for 10 isotherms, and dimethyl ether (DME) for 10 isotherms using a constant volume method in the temperature range from 350.00 to 450.00 K, and pressure up to 8.341 MPa. Saturated vapor pressure was also measured for propane, butane, and DME by a static method in the temperature range from 238.31 to 402.70 K, and pressure from 57.06 to 5015.5 kPa. The P-V-T relationship of DME showed similar trends to the light hydrocarbons, and the pressure dependence of the compressibility factor was apparently shifted by 20 K for that of propane. The 8 constants in the Benedict-Webb-Rubin (BWR) equation of state were determined for DME. Applying corresponding state theory, 5 constants were evaluated from only the reduced BWR constants for propane and butane. The other 3 constants were determined from the experimental data of the compressibility factor for DME at 402.00 K. The averaged absolute deviation in the compressibility factor was 0.33 % over the whole range of experiments. The saturated vapor pressure deviation was 1.42 % except for the temperature range lower than 293 K.
1,3-Butadiene is a useful C4 carbon source for the production of basic chemicals; but use as carbon feedstock often presents regioselectivity problems arising from its conjugated diene structure. This review summarizes the functionalization of 1,3-butadiene with carbon electrophiles by using homogeneous transition metal catalysts. A copper catalyst generated by treatment of Cu salt with alkyl Grignard reagent catalyzed internal carbon selective reductive alkylation of 1,3-butadiene with alkyl fluoride as a carbon electrophile and the alkyl Grignard reagent as a hydride source. In contrast, nickel promoted dimerization and alkylarylation of 1,3-butadiene with a similar combination of substrates. Using polyfluoroarenes as the carbon electrophiles, similar transformations proceeded to achieve the functionalization of 1,3-butadiene. The substrate scope as well as details of the reaction mechanism of these transformations are discussed.
Japan Petroleum Energy Center (JPEC) and partners have been developing “Petroleomics” as a new refining technology since 2011. Petroleomics can be a technology to achieve the ultimate method based on molecular reaction models with molecular level analyses of heavy oil. After the fundamental stage taking five years, our petroleum informatics database includes more than 25 million chemical structures of heavy oil components constructed with the aid of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Subsequently, reaction modeling studies were applied to residue hydrodesulfurization (RDS) and the aggregation model for asphaltenes to sediments, both of which are particularly important subjects in heavy oil upgrading. Our Petroleomics project is now in the application stage to attempt three major investigations: a molecular database of crude oils including unconventional oils, total optimization of RDS and residue fluid catalytic cracking (RFCC) operations with reaction modeling, and the mechanism of asphaltene aggregation responsible for fouling and plugging in some heavy oil upgrading processes. Further progress in Petroleomics is expected to achieve practical applications in refineries, such as advanced performance diagnosis, operational optimization, and catalyst and process development.
Sulfur tolerance properties of rhodium phosphide (Rh2P) were qualitatively and quantitatively evaluated by the temperature-programmed sulfidation (TPS) technique. The TPS profile of the Rh/SiO2 catalyst demonstrated a peak attributed to Rh2S3 formation around 400 °C. The TPS profiles of P-added Rh (Rh–P) catalysts showed this peak shifted to higher temperatures and lower intensity with higher P/Rh ratio or reduction temperature. Quantitative analysis of TPS profiles revealed that the amount of reacted H2S was remarkably lower (about 80 %) with P/Rh ratio more than 1.5, compared with Rh catalyst. The amount of reacted H2S decreased with greater intensity of the Rh2P peak in the XRD pattern, indicating that Rh2P has high sulfur tolerance. Furthermore, the relationship between P/Rh ratio and S/Rh ratio (calculated from TPS profile) of Rh–P catalysts agreed with the reported S/Rh value, showing the TPS method has high validity for qualitative analysis. We conclude that the TPS technique is a superior method for evaluation of sulfur tolerance for phosphide catalysts, and Rh2P has remarkably high sulfur tolerance compared with Rh catalyst.
Methylated nitrogen-substituted SBA-15 (MeNSBA-15) was demonstrated to catalyze cyclic carbonate synthesis using β,γ -unsaturated alcohol and CO2. The methylated nitrogen in the framework acts as the catalytic active site. The turnover frequency (TOF) as function of CO2 partial pressure and β,γ -unsaturated alcohol concentration reflected the major active surface species. The CO2 dependence could be explained by the adsorption equilibrium of CO2 over the active site. The formation of carbamate species is the key to this reaction. Less β,γ -unsaturated alcohol is adsorbed on the catalytic site than CO2. The reaction could involve the following five steps; carbamate formation, interaction of β,γ -unsaturated alcohol with the carbamate species, deprotonation and associated C–O bond formation, intramolecular cyclization, and desorption of the unsaturated cyclic carbonate. Compared with cyclic carbonate synthesis from cyclic ether, the difference in pressure dependence of the cyclic carbonate syntheses could be explained by the competing adsorption (or activation) of the counter reactants with CO2. The adsorption of β,γ -unsaturated alcohol on the methylated nitrogen is much less than that of cyclic ether.
The mechanism of NO adsorption on CeO2 and the effects of O2, CO2, and H2O were studied by in-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS). NO species were adsorbed on CeO2 to form anionic nitrosyl groups. Formation of these anionic nitrosyl (–NO−) groups was associated with degradation of bidentate carbonate species and peak shift of the surface hydroxyl groups, indicating competitive adsorption of NO with CO2 and interaction of –NO− with hydroxyl groups. Evaluation of the changes in anionic nitrosyl groups in the presence and absence of O2, CO2, and H2O showed that co-flow of O2 promoted NO adsorption whereas co-flow of CO2 or H2O suppressed NO adsorption, which supports the competitive adsorption mechanism of NO with CO2 and H2O. The competitive adsorption mechanism suggests that degradation of CeO2 by NO adsorption will be small in a gas mixture with high contents of H2O and CO2.