Applied Petrochemical Research最新文献

A detailed steady-state catalytic-reforming unit (CRU) reactor process model is simulated in this work, and for the first time, different compressibility Z factor correlations have been applied using gPROMS software. The CRU has been modeled and simulated with the assumption that the gas phase behaves like an ideal gas. This is assumed for the four reactors in series and for different conditions of hydrogen–hydrocarbon ratio (HHR), operating temperature, and pressure. The results show that the Z factor varies at every point along the height of the reactors depending on reaction operating pressure, temperature, and HHR ratio. It also shows that the magnitude of deviation from ideal gas behaviour can be measured over the reactor height. The Z factor correlation of Mahmoud (J Energy Resour Technol Trans ASME 136:012903, 2014) is found to be suitable for predicting the Z factor distribution in the reactors.

Converting plastic wastes into fuels through catalytic cracking is continuously gaining interest from researchers worldwide. In this study, the influence of iron on ZSM-5 (Fe-ZSM-5) catalyst on the reforming of the gaseous products of thermal decomposition of low-density polyethylene (LDPE) was investigated. The acidified ZSM-5 catalysts (0, 0.3, 0.6 and 1?wt% of Fe) were prepared and characterized by XRD, BET, FTIR and SEM techniques. In particular, the effects of temperature (400, 450 and 500?°C) and catalyst loading (0.5, 0.75, 1.0, 1.25 and 1.5?g) on a two-stage (pyrolyser and reformer) decomposition of the LDPE wastes into fuel were studied. The liquid fraction produced was characterized using FTIR and GC/MS techniques. The study showed that the increase in pyrolysis temperature (400–500?°C) increases the volume of non-condensable gas (31–58?wt%) and decreases the volume of the condensates (69–41?wt%) in both the thermal and catalytic pyrolyses. However, the trend was at higher level for the catalytic pyrolysis. The increase in temperature for the thermal pyrolysis had less significant effect on the aromatization content of the liquid condensate compared to the catalytic pyrolysis. The FTIR results show a significant increase in aromatic contents and decrease in the aliphatic of the liquid fraction for the catalytic pyrolysis reforming when compared with thermal pyrolysis. The GC/MS results confirmed the aromatic hydrocarbon compositions, predominantly p-xylene, increased relatively to about 70% in the liquid fraction for the best catalyst (1.25?g of catalyst and 1?wt% iron loading on ZSM-5 at 450?°C).

The transhydrogenation of pentane (P) and 1-hexyne (1HY) was investigated over 4% CrO_x/Al₂O₃ and potassium-doped 4% CrO_x/Al₂O₃ catalysts over a range of temperatures (523–773?K) with a 5:1 P:1HY ratio. Over the CrO_x/Al₂O₃ catalyst, transhydrogenation clearly occurred at temperatures below 625?K where the yield of alkenes was higher for the co-fed system than for a combination of the individual yields. Due to the acidic nature of the alumina, many of the products were alkylated olefins and alkylated hydrocarbons formed by coincident alkylation and isomerisation. When pentane was added to a feed containing 1-hexyne, the extent of carbon deposition was reduced. By comparing transhydrogenation to limited hydrogen 1-hexyne hydrogenation at 623?K, it was shown that the processes of hydrogenation and transhydrogenation were different, with hydrogenation favouring alkanes, while transhydrogenation favoured alkenes. This may be because pentane dehydrogenation only releases two hydrogen atoms, which only allows 1-hexyne to hydrogenate to 1-hexene. Therefore, if the rate of alkene isomerisation and desorption is faster than that of pentane dehydrogenation, only alkenes will be observed. The latter proposal would suggest that the dehydrogenation/hydrogenation process is closely coupled and would be consistent with pentane influencing 1-hexyne surface chemistry. The effect of the potassium doping was to increase the yield of alkenes. The reason for this may be related to changes in the nature of the surface chromia species. The potassium also neutralised the acid sites on the alumina, reducing the extent of alkylation and hydrogenolysis, which suppressed the formation of other alkynes in the product mix.

Novel substituted series of aromatic copolymers was obtained by one-spot, metal-free super acid-catalyzed one-step polymerization of substituted isatin and phenothiazine. The polymerization reaction was performed at room temperature in the presence of Bronsted superacid (trifluoromethanesulfonic acid) and methylene chloride which condenses the compounds consists of carbonyl group (aldehydes and ketones) and aromatic rings to yield the polymers. Super acid catalyst has several advantages including the reaction proceeding at room temperature and great synthetic versatility. The obtained polymers have good solubility in common organic solvents. The polymers were purified by repeated precipitations with methanol. Polymers (P1–P3) were completely characterized by FT-IR, ¹H NMR, TGA, and UV–visible, fluorescence and cyclic voltammetry techniques. Polymers (P1–P3) possessed excellent thermal stability up to 300?°C and have absorbance and emission maximum at 557 and 630?nm, respectively. The optical and electrochemical properties of these polymers revealed that it could be one of the capable materials for applications in optoelectronic device and in the area of proton exchange membrane fuel cell.

Wax deposition is a common problem in oil pipelines and production systems. In this study, impact of water cut, mixing rate, chemical inhibitor, and time on wax deposition were investigated in a cold finger setup. Effect of different chemical inhibitors on wax appearance temperature (WAT) was studied using viscometry and differential scanning calorimetry techniques. Results suggested that WAT reduced with increasing inhibitor concentration, with 800?ppm being the optimum. Also, chloroform–toluene–ethylene vinyl acetate (EVA) mixture with 30, 30, and 40 wt% had the highest performance and reduced the WAT to 16.7?°C. Mixtures of toluene—EVA with acetone, p-xylene, and disulfide oil (DSO), followed next. Moreover, deposition decreased with increasing temperature difference between oil and pipe at constant cold surface temperature and increased upon increasing temperature difference at constant oil temperature. Wax deposition in two-phase system was lower than in single-phase system, but increased by increasing water cut. EVA–toluene, 2 wt% DSO, 2 wt% acetone, and 2 wt% p-xylene mixtures reduced the deposition to 23.33, 21.71, 32.14, and 12.5%, but addition of 2 wt% of EVA–DSO–acetone mixture reduced deposition to 35.74%. At similar operating conditions, flow turbulence has greater impact on reducing wax deposition, and its effect is enhanced using a proper inhibitor.

The adipic acid (AA) production was carried out in two stages: oxidation of cyclohexanone (-one) by Keggin-type polyoxometalate (POM), followed by oxidation of this latter by hydrogen peroxide. The process lasts 20?h and the temperature is maintained at 90?°C. AA is then recovered by cold crystallization (4?°C). The POMs have as formula HMPMo₁₂O₄₀ (M:Co, Ni, Mn, Cu or Zn). The materials were characterized by FT-IR and UV–Vis spectroscopies and by thermogravimetric analysis. The purity of adipic acid was confirmed by FT-IR and ¹³C and ¹H NMR analysis. The effects of POM composition, catalyst/-one molar ratio and the cyclohexanol addition to -one on adipic acid yield were examined. The whole catalysts were found to be effective toward cyclohexanone oxidation and the highest yield (53%) was obtained with HZnPMo₁₂O₄₀ system for a catalyst/-one molar ratio of 1.89?×?10^?3. The alcohol addition to -one has a negative effect on adipic acid formation.

Vanadium catalysts supported on Al(Zr)-MCM-41-type materials were prepared by impregnation. Textural and structural properties, elemental composition and electronic structure were determined by N₂ physisorption, small-angle XRD, SEM–EDX and UV–vis DRS, respectively. Al-containing materials showed mostly of Al framework and a small fraction of Al extra-framework species. Zr-containing materials presented almost exclusively small clusters of Zr_xO_y covering the MCM-41 matrix. Vanadium catalysts, showed the presence of isolated V⁵⁺ species and to a lesser extent polymeric chains likely as small crystallites of V₂O₅. The catalytic results revealed that VAlM30 catalyst, characterized by a Si/Al atomic ratio of 30, was the most active in thiophene hydrodesulfurization, which could be associated to better textural properties and high dispersion of the vanadium species.

Oligomerization of isobutene to produce high-quality fuel distillates in the range of gasoline, jet fuel and diesel free of sulfur, nitrogen and aromatic hydrocarbons has been investigated over a new environmental-friendly, clean and long-lifetime supported phosphoric acid on H-Zeolite-Y catalyst with SiO₂/Al₂O_3?mol ratio of 60. The catalyst was obtained by acid impregnation and ultrasonic vibration technique with successive heating at different temperatures and under atmospheric pressure. The catalysts were characterized by several techniques (BET, SEM, XRD, TDA, TGA and XPS). The oligomerization reactions were carried out in a gas phase using fixed-bed flow reactor at variable temperature ranges between 50 and 100?°C under atmospheric pressure with a space velocity (WHSV) of 176?h^?1.The fuel distillates were identified by GC/MS and quantified by gas chromatography. The results showed that the conversion of isobutene into distillates ranges between 97 and 100%. The maximum selectivity to C ⁼₈ isomers is about 65%, and a flow rate of isobutene 5.0?ml/min. and temperature 50?°C were obtained. Research octane number under the above-mentioned conditions ranges between 85 and 96, and Reid pressure ranges between 27 and 125?Pa.

In the present work, we have made attempts to prepare petroleum pitches from paraffinic-rich clarified oil (CLO) by giving thermal treatment at 370?°C in the presence of Cu and Cr catalysts. The feed CLO is predominantly paraffinic in nature, so it takes fairly large thermal soaking time (21?h) to convert into pitch having mesophase content below countable limits. To increase the mesophase content in the pitch or to make mesophase pitch, 3 wt?% transition metal catalysts (Cu and Cr) were added to CLO. Addition of transition metal catalysts not only enhances mesophase formation but also helps to reduce thermal treatment time by promoting polymerization and condensation reactions at a faster rate. The mesophase formation pattern reveals that Cu and Cr catalysts increase the mesophase content from below countable limit to 12 and 9 vol?%, respectively. This indicates that Cu and Cr showed better catalytic activity for mesophase formation growth. The effect of transition metal catalysts on physico-chemical properties (softening point, coking value, toluene insolubles and quinoline insolubles) as well as the optical texture and physical properties of mesophase pitches were investigated by optical microscope, FT-IR, SEM, NMR, TG/DTG and XRD.