B. Shen

Palladium-Based Catalysts for the Hydrochlorination of Acetylene: Reasons for Deactivation and Its Regeneration

Abstract Palladium-based catalysts were prepared by an incipient wetness impregnation method, and the catalytic activity for the hydrochlorination of acetylene was studied in a fixed-bed reactor under normal pressure. Several analysis methods including scanning electron microscope (SEM), gas chromatography–mass spectrometry (GC-MS), N2-adsorption, thermogravimetry (TG), and inductively coupled plasma–atomic emission spectrometry (ICP-AES) analysis methods were combined to study the reasons for the deactivation of PdCl2/C catalyst in detail. On this basis, some attempts were made to improve catalyst stability and its regeneration.

An Au–Cu bimetal catalyst for acetylene hydrochlorination with renewable γ-Al2O3 as the support

The bimetal catalyst gold(III) chloride–copper(II) chloride (AuCl3–CuCl2) was prepared with several different gamma-aluminium oxide (γ-Al2O3) supports and its catalytic properties towards acetylene hydrochlorination were assessed in a fixed-bed reactor. The comparison indicated that one of the catalysts attained the highest activity with an acetylene conversion of 97%, which was far higher than the others. Catalysts were characterized using detailed X-ray diffraction, nitrogen-Brunauer, Emmett and Teller surface area analysis (N2-BET), ammonia temperature-programmed desorption, Fourier-transform infrared spectroscopy and carbon dioxide temperature-programmed desorption analysis. It is proposed that the base site contributed to its high catalyst activity compared with the other catalysts, instead of the acid site or the textural properties on the support, therefore, the activity and the life of the catalysts can be improved significantly by treating the supports with potassium hydroxide. In addition, the results of N2-BET, thermogravimetric analysis and scanning electron microscopy indicated that the catalysts deactivated rapidly because of carbon deposition, and the actual amount of coke deposition was 18.0% after the reaction. AuCl3–CuCl2/γ-Al2O3 was easily regenerated for reuse as a catalyst by burning off in an air atmosphere for 10 min. The activity of the regenerated catalyst nearly reached the level of the fresh catalyst.

A Study on the Performance and Storage Stability of Crumb Rubber-Modified Asphalts

Abstract Crumb rubber–modified asphalt (CRMA) with good storage stability was prepared using activated crumb rubber. The activation of crumb rubber was carried out by blending crumb rubber with polymeric compatibilizer in extruder to improve interaction between crumb rubber and asphalt. The softening point difference (SPD) and photomicrographs were used to reveal the storage stability of CRMA. The long-term storage stability test results indicate that the softening point difference of CRMA was below 2.5°C. The rheological characteristics of the binders were studied with a dynamic shear rheometer (DSR) and a bending beam rheometer (BBR). The results showed that the CRMA binders are possessed of the better resistance to permanent deformation at high temperature and cracking at low temperature than those SBS-modified and straight-run asphalts.

A Study on the Desulfurization Performance of Solvent UDS for Purifying High Sour Natural Gas

Abstract A desulfurization solvent called UDS was designed and developed based on the differences in desulfurization efficiencies of respective solvent components. The desulfurization performance of UDS was investigated in a simulated industrial unit and the thermal stability as well as the regeneration performance was evaluated using thermogravimetric analysis. The results indicated that the organosulfur removal performance of UDS was significantly enhanced by introducing the sulfur-containing heterocyclic compound and the cyclic amine compound. In the industrial pressure condition of 8.3 MPa, UDS showed around 30 percentage points higher organosulfur removal efficiency than methyldiethanolamine (MDEA). The contents of H2S and total sulfur were <0.5 and 81.6 mg · m−3, respectively, in purified gas when adsorption was conducted under gas–liquid volume ratio (Vg/Vl) of 169 and pressure of 1.5 MPa, using UDS. The quality of purified natural gas met first-class standards.

Biodegradation Potential and Influencing Factors of a Special Microorganism to Treat Petrochemical Wastewater

Abstract The objective of this study is to evaluate the potential ability of an active microorganism on the biodegradation of petroleum hydrocarbons in the petrochemical wastewater from Sinopec Shanghai Petroleum and Chemical Company Limited, China. In lab-scale batch experiments, by using this special functional microorganism to treat the pollutant, the wastewater was purified as one of the applications of the bioaugmentation technique. Results from this study showed that the biodegradation was quicker and more effective than the natural and physical degradation. The wastewater was analyzed by gas chromatography/mass spectrometry (GC-MS), and it indicated that the dominant pollutants of the wastewater were petroleum-based normal-alkanes (C15–C30). The concentration of microorganism, aeration time, and temperature of biodegradation all influence the potential biodegradation ability. Meanwhile, the biodegradation capability to biodegrade hydrocarbons by this microorganism is the average removal of total petroleum hydrocarbon and was approximately 85% with chemical oxygen demand about 65%. This study provides a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.

Cumene hydroperoxide hydrogenation over Pd/C catalysts

Pd/C catalysts were prepared by wet impregnation using K(2)PdCl(4) as precursor and their performance in hydrogenation of cumene hydroperoxide (CHP) was investigated. The catalytic activity was examined on the formaldehyde-reduced and on the hydrogen-reduced Pd/C catalysts. Results from XRD, TEM and CO chemisorption showed that reduction methods have a significant impact on the palladium particles size of resulting catalysts. Formaldehyde-reduced Pd/C catalyst has larger palladium particles than hydrogen-reduced Pd/C catalyst. Consequently, higher activity but lower selectivity to alpha-cumyl alcohol (CA) was obtained on formaldehyde-reduced Pd/C catalyst. Moreover, hydrogenation of CHP over hydrogen-reduced Pd/C catalyst can give similar CA selectivity to Na(2)SO(3) reduction process, an industrial process for CA production. High rate of CHP conversion and CA selectivity can be obtained at an elevated temperature and H(2) pressure. Kinetics studies revealed that CHP hydrogenation is zero-order for CHP concentration and the activation energy was calculated to be 13.6 kJ/mol.

Refining Tahe Heavy Crude Oil to Increase Light Product Yield

Traditional processing technology is not suitable for Tahe crude oil due to its low light distillate yield and poor quality. A new process, atmospheric flash evaporation-solvent deasphalting combined process, was put forward. The appropriate operating conditions of solvent deasphalting process were as follows: iso-pentane solvent, temperature of 175°C, pressure of 3.7MPa, solvent volume ratio of 5.0. Compared with atmospheric distillation-delayed coking process, total liquid product yield by new process could reach 78.77%, increasing by 9.47%. The quality of deasphalting oil met the feed requirements for catalytic cracking and de-oiled asphalt could be used as asphalt mixture additives.

Distribution of Nickel and Vanadium in Venezuela Crude Oil

The distribution of nickel and vanadium in five fractions (saturated hydrocarbons, aromatic hydrocarbons, soft resin, hard resin, and asphaltene) of Venezuelan 380 crude oil was studied. The method of column chromatography separation was used two times. Furthermore, the UV-vis spectroscopy was used to characterize the role of metals in different fractions. Results showed that the content of vanadium in crude oil was much higher than nickel. The metals mainly existed in resins (~20%) and asphaltene (~70%). UV-vis spectroscopy had also confirmed the presence of vanadium porphyrins in resins and asphaltene.

Absorption Selectivities of Solvents for Organosulfurs in High Sour Natural Gas

In order to develop a solvent with satisfied organosulfur removal performance for high sour natural gas, the absorption process using UDS and MDEA as solvents was investigated and the absorption model was established to evaluate the selectivities of the two solvents for organosulfurs. The results indicate that both of the solvents, UDS and MDEA, have excellent absorption performance for H2S and CO2. The solvent, UDS, shows evident advantages when adsorbing high content COS and mercaptans. From the viewpoints of the solubility and the mass transfer performance, COS is the most easily absorbed. The methyl mercaptan and ethyl mercaptan come after. The isopropyl mercaptan and n-propyl mercaptan are hard to be absorbed. Compared with MDEA, the solvent UDS shows lower Henry constants and greater mass transfer factors for the organosulfurs; therefore, it has higher solubility and better mass transfer performance for the organosulfurs.

Soapstock Utilized for Producing Biofuels by the Delayed Coking Apparatus

Abstract Acidic oil made by acidification and extraction of soapstock was used to produce biofuel in delayed coking apparatus. Through two pre-heatings of acidic oil in delayed coking apparatus, when the temperature of the coking drum reached 460°C, the maximum yield of liquid oil (around 84%) was obtained, whereas the ratio of diesel and gasoline (about 5.3:1) was obtained. The liquid oil was separated by distillation to obtain the biofuel (205–360°C). By comparing the basic properties of the obtained biofuel with 0# diesel and analyzing the basic properties of the resulted biodiesel-diesel blends, the results showed that the performance of the product was almost close to 0# diesel standards; when biodiesel content reached up to 20% in the blend, its properties (such as viscosity, density, and CFPP) changed slightly by comparing with 0# diesel.