Table of Content

12 December 2014, Volume 45 Issue 12

Previous Issue    Next Issue

muci

STUDY ON METHANE FORMATION IN THERMAL AND CATALYTIC CRACKING OF 2,5-DIMETHYLHEXANE

2014, 45(12):  1-5. 

Asbtract ( 605 )   PDF  

Related Articles | Metrics

The thermal and catalytic cracking reactions of 2,5-dimethylhexane were carried out at 550—650 ℃ at low conversion (x < 15%) in a pulse micro-reactor over quartz and ZRP zeolite，respectively. Formation mechanism of methane was analyzed. The results show that methane, propylene and i-butylene are the primary products in thermal cracking. There are three reaction pathways that contribute to the methane formation during chain propagation through the hydrogen extraction from C—H bond by methyl radical. The C—H bond attached to the tertiary carbon shows higher reactivity and accounts for more than 90% of methane selectivity during thermal cracking. The conversion and product distribution are clearly influenced by shape-selective catalysis and the methane is produced by protolytic cracking reaction during the catalytic cracking of 2,5-dimethylhexane over ZRP zeolite. The comparison of the contribution to methane between thermal and protolytic cracking pathways reveals that methane is mainly formed by thermal cracking, which gradually enhances along with the increase of reaction temperature.

SYNTHESIS AND THERMAL DECOMPOSITION BEHAVIOR OF POLYSULFIDE OLEFINS

2014, 45(12):  6-10. 

Asbtract ( 583 )   PDF  

Related Articles | Metrics

Polysulfide olefins were synthesized and purified using 60~140 ℃ distillation range of FCC gasoline and industrial grade sulfur as raw materials in the presence of various basic catalysts. The possible synthesis and purification reaction processes were discussed. The synthetic reaction conditions were optimized and the thermal decomposition behavior of polysulfide olefins was studied. The results show that the sulfur content of polysulfide olefins is 30.03% with a density of 0.953 g/cm using sodium hydroxide catalyst under the reaction conditions of 170 ℃, the reaction time of 3 h, the sulfur and FCC distillate gasoline mass ratio of 0.45:1 and the basic catalyst and distillate mass ratio of 0.15:1. The Polysulfide olefins has a good oil solubility and a wide range of decomposition temperature (190-260 ℃) and can be applied to the presulfurization of hydrogenation catalyst.

INFLUENCE OF MICROWAVE ON INTERACTION BETWEEN CRUMB RUBBER AND ASPHALT

2014, 45(12):  11-16. 

Asbtract ( 766 )   PDF  

References | Related Articles | Metrics

Modified asphalts by crumb rubber powder with different microwave treating time were prepared. The molecular weight distribution of toluene extract of the crumb rubber microwave treated was determined by gel permeation chromatography. The crumb rubber and asphalt in modified asphalt were separated by solvent extraction to further investigate the crosslinking degree of the crumb powder and rubber hydrocarbon content changes using TG-DTA. Results show that the property of the modified asphalt has significant relations with its solubility in toluene. The crumb powder treated with microwave 5min has the highest degree of degradation in asphalt, and forms banded structures. The crosslinking of part of the macromolecular are decomposed, producing medium-sized molecules. The modified asphalt by crumb powder treated 5 min has the highest ductility and penetration but slightly lower in softening point. However, if the microwave treatment time prolongs to 6 min, the crosslinking of the medium-sized molecules formed at 5 min treatment occurs again. It is discovered that the extent of crossliking of powder in modified asphalt first decreases and then increases as the microwave treating time prolongs, the lowest crosslinking appears at 4 min treatment. While the rubber hydrocarbon content presents a trend of first decrease and then increase, with 5 min treatment, the content is down to the lowest. Decreasing the crosslinking is advantageous for the light components in asphalt swelling into the powder inside, raising the heavier components content, and thus helpful to harden the modified asphalt. The small molecules produced by degradation can enter into and soften the asphalt and form an interface layer between powder and asphalt that enhances the interaction of them..

COMPARISON OF HYDRODYNAMIC CHARACTERISTICS IN BUBBLE COLUMN AND AIRLIFT LOOP REACTORS

2014, 45(12):  17-22. 

Asbtract ( 650 )   PDF  

Related Articles | Metrics

Numerical simulations of different slurry bed hydrocracking reactors were carried out using Euler-Euler multiphase model and RNG k-ε turbulence model. In the simulations, bubble column reactor and airlift loop reactors with different diameter of draft tube were chosen to investigate the similarities and differences in gas holdup and axial liquid velocity. The results demonstrate that liquid circulation flow is formed in all three kinds of reactors. The draft tube divides the whole flow field into riser and downcomer, located in and out of the tube, respectively and at the same time, can increase the liquid velocity both in riser and downcomer, rising gas holdup both in the downcomer and the entire reactor. A conclusion can be drawn that airlift loop reactor is better than bubble column reactor for slurry bed hydrocracking process.

EFFECT OF SYNTHESIS METHOD ON PROPERTIES OF Ce0.9Zr0.1O2 SOLID SOLUTIONS AND ITS PERFORMANCE IN SULFUR TRANSFER CATALYSTS

2014, 45(12):  23-28. 

Asbtract ( 549 )   PDF  

Related Articles | Metrics

Ce0.9Zr0.1O2 solid solutions were prepared by co-precipitation, modified sol-gel (CGS), inverse microemulsion and hydrothermal synthesis method, respectively. The corresponding sulfur transfer catalysts containing Ce0.9Zr0.1O2 solid solutions were made by acid process. The Ce0.9Zr0.1O2 solid solutions was characterized by X-ray diffraction (XRD), N2 adsorption-desorption, oxygen storage capacity test (OSC) and temperature-programmed reduction (H2-TPR). The corresponding sulfur transfer catalysts were evaluated under conditions similar to those in the typical FCC unit. The results indicate that Ce0.9Zr0.1O2 solid solution prepared by CSG method shows a relative higher thermostability, better redox behavior and larger OSC value which contribute to a better desulfurization rate of the corresponding sulfur transfer catalysts under the conditions of lean oxygen.

APPLICATION OF THE THIRD GENERATION OF RHT SERIES CATALYSTS IN VRDS UNIT

2014, 45(12):  29-33. 

Asbtract ( 782 )   PDF  

Related Articles | Metrics

The commercial application of the third generation of RHT series catalysts developed by Research Institute of Petroleum Processing in the 2.0 Mt/a VRDS unit of SINOPEC Maoming Company was introduced. The operation results show that this new generation of RHT series catalysts exhibits higher HDS/HDM and residue carbon reduction activity, but a similar activity of HDN compared with the reference catalysts.

muci

INFLUENCE OF COUPLED BETA AND USY ON PERFORMANCE OF HYDROUPGRADING CATALYST

2014, 45(12):  34-37. 

Asbtract ( 678 )   PDF  

Related Articles | Metrics

A series of Ni-W/Beta-USY-Al2O3 hydro-upgrading catalysts using USY and different amount of Beta zeolite as acid components were prepared by co-impregnation. The catalysts were characterized by BET, Py-IR and NH3-TPD. The hydro-upgrading performance of the catalysts was investigated in a 100 mL high pressure trickle-bed reactor. The effect of Beta zeolite addition on the acidity of the catalysts with the same amount of USY and the hydroupgrading performance were tested. The results show that the Bronsted/Lewis ratio and total acidity of the catalysts increase with the adding amount of β zeolite rising. Ni-W/Beta-USY-Al2O3 catalysts reveal a high hydroupgrading activity. Under the conditions of 10.0 MPa, H2/oil ratio of 700: 1 and 380 ℃ in upgrading zone, the diesel yield is about 90%, density is lowered 0.1 g/cm3, sulfur content is less than 10 μg/g, cetane number increases 19-22 units and condensation point declines dramatically.

EFFECT OF ALKALI METAL MODIFICATION ON SELECTIVE HYDROGENATION OF ISOPRENE ON Pd-Au/AL2O3 CATALYSTS

2014, 45(12):  38-42. 

Asbtract ( 637 )   PDF  

Related Articles | Metrics

A series of Pd-Au/Al2O3 catalysts modified by different amount of alkali metal K or Li were prepared by incipient wetness impregnation and characterized by low temperature nitrogen adsorption, FT-IR and H2-TPR techniques. The isoprene was used to evaluate the selective hydrogenation performance of the modified catalysts. The FT-IR results show that only Lewis acid sites exist on the catalysts, no Bronsted acid is found. The acid strength of K-modified catalyst is weaker than Li-modified catalyst. The H2-TPR results indicate that Pd-Au binary alloy is formed, the reduction peaks of catalysts shift to higher temperature after modified by alkali metals. The reaction results of isoprene selective hydrogenation on the modified Pd-Au/Al2O3 catalysts show that the isoprene conversion and isopentenes selectivity increase when addition of K2O. The LiO modification reduces the conversion of isoprene but isopentenes selectivity increases. At 70 ℃, isoprene conversion reaches 90.0%, isopentenes selectivity is 86.0% on the catalyst Pd-Au/Al2O3 with 1.2% K2O.

DEACTIVATION AND REGENERATION OF NON-MERCURY CATALYST AuCl3-CuCl2/γ-Al2O3

2014, 45(12):  43-46. 

Asbtract ( 913 )   PDF  

References | Related Articles | Metrics

A non-mercury AuCl3-CuCl2/γ-Al2O3 catalyst was prepared by impregnation method using γ-Al2O3 as support. The catalytic properties for acetylene hydrogen chloride reaction were explored in a fixed bed reactor. The catalyst was characterized by SEM-EDS, FT-IR, inductively coupled plasma atomic emission spectrum and BET analysis to see the reason for catalyst deactivation. The results show that acetylene conversion reaches more than 97% and the vinyl chloride selectivity is more than 99% under the conditions of 150 ℃, 0.1 MPa, 120 h-1 ,V(HCl) : V(C2H2) = 1.05:1. However, the high activity can only keep for 3h. The analysis found that the carbon deposit on the catalyst surface is the main reason for the deactivation. It proved that the catalyst activity can be recovered to the fresh level after regeneration in air for 1h at 500 ℃.

NEW PROCESS FOR RECOVERING ETHYLENE FROM FCC DRY GAS

2014, 45(12):  47-49. 

Asbtract ( 614 )   PDF  

Related Articles | Metrics

A novel process was introduced about ethylene recovery from catalytic cracking dry gas. The commercial application in Yangzhou Petrochemical Co. Ltd., SINOPEC was disclosed. The results show that the conversion of ethylene is over 95.41%. The sulfur in gasoline fraction is about 6 μg/g and RON is as high as 114. The deficiency of this technology is that the gasoline selectivity is on the low side, only about 37.64%. In view of the present operation status, some proposals for improving the performance of catalyst are suggested.

muci

OPERATION OPTIMIZATION OF S Zorb GASOLINE REFINING UNIT

2014, 45(12):  50-53. 

Asbtract ( 677 )   PDF  

Related Articles | Metrics

There were some problems in S Zorb gasoline refining unit of Yan’an Petrochemical Factory in operation, such as low yield of stabilized gasoline, mismatch of heat removal system of the regenerator and catalyst regeneration. By optimizing the operating parameters of stabilization system, the emission of fuel gas from stabilization tower is reduced and the yield of gasoline is improved by 0.7%. The modifications of revamping the regenerator heat removal system and adding N2 heat removal system effectively protect the regenerator heat removal coil and reduce operation difficulty. Then the hot nitrogen is used as a heat source for fresh N2. The purpose of saving consumption and energy is achieved.

OPERATION OPTIMIZATION FOR PROCESSING COKER GAS OIL IN HYDROCRACKING UNIT

2014, 45(12):  54-58. 

Asbtract ( 598 )   PDF  

Related Articles | Metrics

In order to improve the quality of FCC gasoline and increase the economic profit，SINOPEC Guangzhou Company, tried the hydrocracking of feedstock blending with coker gas oil. The results indicated that when processing the blending feed, the tail oil BMCI was increased and ethylene cracking furnace operation cycle was shortened. To solve these problems, we used KBC's Petro-SIM software to optimize the operation conditions of the hydrocracking unit. The optimized conditions are: hydrogen partial pressure of 13.31 MPa and the cut-point of fractionation tower of 375 ℃. After optimization, the tail oil BMCI decreases from 13.01 to 11.03, the cracking furnace coke cleaning cycle extend from 28 days to 52 days.

COMPARISON OF TWO PROPANE DEASPHALTING UNITS ON YIELD AND PROPERTIES OF DEASPHALTED OIL

2014, 45(12):  59-62. 

Asbtract ( 549 )   PDF  

Related Articles | Metrics

The process flowsheets and technical features of the core equipment of two different propane deasphalting units of a petrochemical company.were analyzed and compared in terms of DAO yield and its quality under the conditions of the same feed and solvent. No large difference in properties of DAOs was found for the two devices. However, the temperature at the top of the extractor and solvent-oil ratio are all needed to be adjusted to get good balance of quality and yield. On the other aspect, the commercial results indicate that the device adopting ROSE technology from US KBR Company has a higher yield, as the ROSE technology uses high efficiency structured packing components, two stage process and larger solvent to oil ratio.

INFLUENCE FACTORS ON DELAYED COKING FURNACE OPERATION CYCLE AND IMPROVEMENT MEASURES

2014, 45(12):  63-68. 

Asbtract ( 668 )   PDF  

References | Related Articles | Metrics

Heating furnace is the core of the coking unit, which plays a vital role in production. In view of the gradually shortened coking furnace operation cycle, the influence factors of feed property, furnace temperature, operation load, terminal temperature fluctuations of the heat exchanger and heating condition adjustment range were analyzed. It is concluded that all the above mentioned factors can significantly affect the furnace cycle. Based on the discussion, some improvement measures are proposed, like the adding material buffer tanks and mixers, strengthening the cold slag property analysis, constanting the terminal temperature, controlling the production load and smoothing the operation. After the implementation of above measures, the rate of coke formation effectively slows down and the furnace operation cycle is prolonged. The economic benefits of about 6.09 million Yuan per year are realized.

DEVELOPMENT OF GEAR OIL FOR GAS TURBINE OF NAVAL VESSEL

2014, 45(12):  69-74. 

Asbtract ( 634 )   PDF  

References | Related Articles | Metrics

To localize gas turbine gear oil for main retarder of naval vessel, alternative gas turbine gear oil was developed. The developed gear oil composes of PAO6, VHVI4, esters and appropriate antioxidant, antirust and anticorrosive, extreme pressure abrasion resistance additive and the quality of the gear oil meets the provisional qualification standard. The developed oil has an excellent performance in viscosity-temperature, oxidation stability, antirust and anticorrosion, anti-high temperature corrosion, hydrolytic stability and a suitable extreme pressure abrasion resistance.

INFLUENCE OF EMULSION FORMULA AND WATER QUALITY ON STABILITY OF COLD-ROLLING EMULSION

2014, 45(12):  75-78. 

Asbtract ( 567 )   PDF  

Related Articles | Metrics

A simple evaluation criterion was established to compare the influence of dosage of oiliness agents，antirust agent and emulsified oil on the stability of emulsion prepared with fresh water, deionized water, or water placed for a long time. It is found that for the poor stable emulsified oil with more interference components, the emulsion prepared with the long placed water containing more impurities is more stable than the one prepared with other two waters. However, for the emulsified oil with optimized formula and with less interference impurities, the more clean water used, the more stable emulsion is. Formula optimization for emulsified oil is not only beneficial to strengthen the stability of the emulsion and can improve its lubricity and extreme pressure properties.

CASCADE HEATING METHOD FOR GAS FRACTIONATOR EFFLUENT USING FIRST TYPE ABSORPTION HEAT PUMP

2014, 45(12):  79-83. 

Asbtract ( 713 )   PDF  

References | Related Articles | Metrics

Aiming at large heat transfer temperature difference and serious mismatch of heating energy level in conventional gas fractionation process, a cascade heating method using first type absorption heat pump for gas fractionation column effluent was proposed. By the method the exergy efficiency of gas fractionation process is greatly improved through diminishing heat dissipation in the top of fractionating tower, reducing steam consumption and recovering waste heat. After revamping the gas fractionation system in a refining &chemical company in Yinchuan, the steam consumption can be reduced by 22.0%, and save the operating cost about 3.98 million Yuan annually.

PREDICTION OF NAPHTHA COMPOSITION BASED ON CONVENTIONAL PHYSICAL PROPERTIES

2014, 45(12):  84-87. 

Asbtract ( 651 )   PDF  

Related Articles | Metrics

A method for predicting naphtha composition based on the conventional physical properties was established. Based on the data base of RIPP, 54 real components were chosen to represent the composition of naphtha, which is divided into 4 groups: N-paraffins, iso-paraffins, naphthenic and aromatics. A set of simulation equations were built using conventional properties of density, refractive index，group composition，and Engler distillation curve of 4 groups to get the mass fractions of 54 components and then compared with the measured results. The results show that the calculated compositions agree well with the measured results. The calculation average error for corresponding normal alkanes, iso-alkanes, cyclanes is 6.6%, 8.5%, 5.9%, respectively. The error of alkanes, iso-alkane and cyclanes contents in C6-C11 is 3.2%, 5.2%, 4.4%, respectively. The above results demonstrate that the established model equations can reflect well the hydrocarbon distribution of straight-run naphtha.

DEVELOPMENT AND APPLICATION OF METHEMATIC MODEL FOR PROCESS CALCULATION OF DELAYED COKING HEATER TUBES

2014, 45(12):  88-93. 

Asbtract ( 546 )   PDF  

Related Articles | Metrics

The fluid flow and reaction of vacuum residue in Delayed coking heater was investigated. Based on the balance of mass, heat and momentum, a mathematic model for process calculation in delayed coking heater tube was established. The temperature, pressure, composition and vaporizing fraction along axial direction of the tubes were calculated by the model. The results of calculation agree well with the data of actual operation on some delayed coking heater and are in accordance with the experience knowledge. The model can be used in different working conditions of steam injection and furnace feed fluctuation and provide theoretical guidance for the optimized design and operation of delayed coking furnace.

REVIEW ON STANDARD TEST METHODS FOR DETERMINATION OF HYDROCARBON COMPOSITIONS OF GASOLINE

2014, 45(12):  94-100. 

Asbtract ( 600 )   PDF  

Related Articles | Metrics

The contents of olefins, aromatics and benzene are the important quality specifications of gasoline. The determination of olefins, aromatics and benzene can be measured by different methods. The characteristics of these methods are compared and analyzed through robin tests. A new method for determination of hydrocarbon types and benzene by multi gas chromatography developed by Research Institute of Petroleum processing （RIPP）is introduced in detail. This method is adopted and published as an international ASTM standard, which is the first international standard set by China in the field of oil and petroleum products.