Mechanism of the inhibiting effect of diphenylamine in the oxidation of hydraulic oils

The mechanism of the inhibiting effect of diphenylamine during the oxidation of two base stocks of hydraulic oils were studied at 120, 130, and 140°C. The key reactions in the mechanism of the action of the inhibitor were identified, and the values of the kinetic parameters and their activation energies were determined. The kinetic parameters were calculated, and the salient kinetic features of the inhibited oxidation of the two specimens were compared at 70°C, the temperature of accelerated testing of hydraulic oils. The results of this prediction were analyzed, and the reasons for differences in the oxidation stability of the samples examined were established.     

Effect of Severity on Hydrotreating of Demetallized Oil Monitored by 1H-NMR Spectroscopy

Abstract

A study on aromatic hydrogenation of demetallized oil has been carried out using a commercial catalyst under pilot plant reaction conditions similar to those found in industrial processes. The feedstock was contacted with the catalysts in a trickled bed reactor unit at 330°C, 350°C, and 370°C. A combination of physicochemical characterization of feed and products and ¹H-NMR spectra was used to monitor changes in the aromatic fractions caused by variation in reaction temperature. Analysis of the ¹H-NMR spectra, along with the quantitative variation in the areas of the resonance lines, showed that the diaromatics with relatively long alkyl changes present in the lightest distillation cuts of the products were highly hydrogenated. In contrast, smaller changes in aromaticity in the heaviest fractions were observed under the same conditions. A limit of about 2 wt% of the integrals corresponding to the diaromatic+ species suggests a thermodynamical limitation of hydrogenation under the studied reaction conditions.     

Sulfur compounds in the fuel range fractions from different crude oils

A gas chromatograph coupled with sulfur chemiluminscence detector (GC-SCD) has been used for the speciation of individual sulfur compounds in fractions of different crude oils. The crude oil fractions characterized were light naphtha (C5-90°C), heavy naphtha (90–140°C), kerosene (140–240°C), and gas oil (240–370°C) fractions obtained from true boiling point distillation process. Low boiling fractions (up to 140°C) were analyzed by existing ASTM D5623 (American Society for Testing and Materials, 2009a) method for sulfur compound speciation. As there is no standard method for the distribution of sulfur compounds in high boiling samples (up to 370°C), therefore, a methodology has been developed for the diesel range samples. The identification of individual sulfur compounds were carried out by using reference sulfur compounds. The results show that type of sulfur compounds depends upon the boiling range of the fraction and source of crude oil. The major changes in the sulfur compounds profiles of different fractions are discussed. The results of this study can be used to predict the suitability of crude oil for the production of Euro-IV and V gasoline and diesel fuels.     

Production of aviation fuel by bioethanol conversion on zeolite catalysts

The catalytic process of two-stage conversion of ethanol into jet fuel, wherein the second step is the hydrogenation of aromatic hydrocarbons obtained in the first step, has been studied. It has been shown that at 400°C and an ethanol space velocity of LHSV = 2 h^–1, aromatic hydrocarbons are produced, which are hydrogenated on a Pt/C catalyst in an autoclave at 80–100 atm and T = 200–250°C for 1.5 h with a final yield of naphthenic hydrocarbons on a fed ethanol basis of 15–20%.     

Determination of the functional groups and the melting point of iraqi asphaltenes

A qualitative analysis study of n-C5 asphaltene of Iraqi crude oil from (Al-Dura, Kirkuk and Basra) oil fields was done using Fourier transform infrared spectroscopy (FT-IR). The melting points of the three oil derived asphaltenes were determined using Hot stage polarizing microscope at 180?°C for Al-Dura, 125?°C for Kirkuk and 140?°C for Basra asphaltenes. The FTIR spectrum shows an aromatic behavior of the asphaltene samples at a wavelength of 3049?cm^?1 and aliphatic chains were found at wavelengths 2924?cm^?1.     

Characterization and Kinetics of Siberian and Tatarstan Regions Crude Oils Using Differential Scanning Calorimetry

In this study, nonisothermal kinetics and thermal analysis of Siberian and Tatarstan regions crude oils is studied by differential scanning calorimetry (DSC) at different heating rates. DSC curves revealed two reaction regions in the temperature range of 20–600°C, known as low and high temperature oxidation, respectively. Three different kinetic methods (ASTM, Borchardt and Daniels, and Roger and Morris) were used to determine the kinetic parameters of the samples and it was observed that the activation energy values are varied.     

RESIDUUM HYDROTREATING/APPLICATION OF LIQUID- SOLID CHROMATOGRAPHY FOR THE STUDY OF HYDROTREATED PRODUCTS.

ABSTRACT

Iraqi reduced crude (above 350^°C) was hydrotreated in a fixed-bed reactor with commercial Ni-Mo-alumina catalyst. Reaction temperature varied from 320 to 400^°C over liquid hourly space velocity ranging from 0.82 to 2.6 h^?1. Hydrogen pressure was kept constant throughout all the experiment at 6.1 MPa with hydrogen/ oil ratio about 30D NL/L. Asphaltenes were precipitated from the reduced crude and hydrotreated products with 15 parts of n-pentane (by volume) to 1 part of sample. Then, the deasphaltened products were fractionated by liquid- solid chromatography for saturates, aromatics and polar- aromatics separation. The kinetic study of aromatics and polar- aromatics hydrogenation indicates that these reactions are well correlated with a second-order kinetics. The rate constants of aromatics and polar-aromatics hydrogenation were calculated. Finally, the apparent activation energy (Ea), enthalpy of activation (?H)^? and entropy (?S)^? were calculated for hydrogenation of aromatics and polar-aromatics of reduced crude during hydrotreating.     

Compositional Analysis of Waxy Distillate Fractions by 1H and 13C NMR Spectroscopy

Abstract

Distillate fractions having boiling ranges of 270–320°C and 320–370°C derived from Heera and Panna crudes are characterized for their average structural parameters using n-d-M method as well as ¹h and ¹³C NMR spectroscopy. It is observed that these fractions contain predominantly saturated carbons. Aromatic carbons in them decreases with the increase in boiling range. Methyl substituents are predominant compared with other alkyl substituents in these distillate fractions.     

THE EFFECT OF ANTIOXIDANT ADDITIVE ON THE THERMOXIDATION STABILITY OF DISTILLATES FROM MEDIUM CRUDE OIL

ABSTRACT

Fractions 100-150, 150-200, 200-250°C were distilled from medium Iraqi crude oil. The thermo-oxidation stability experiments were carried out on original and inhibited (with Topanol 0) distillate fractions using the Alcor Jet Fuel Thermal Tester, over a temperature range 516-573 k. It was found that the antioxidant (Topanol 0) efficiency depends on the fractions composition and the oxidation temperature. Only 30 PPM of Topanol 0 stabilizes fraction 100-150°C to a considerable extent. Also, an inhibition effect is obtained in fraction 150-200°C but at a higher antioxidant concentration (90 PPM). Only, slight inhibition effect was observed in fraction 200-250°C at low oxidation temperature (below 551 K), while effect will be of no value at higher oxidation temperatures.     

CONTRIBUTION TO THE SEPARATION OF ACIDIC COMPONENTS FROM COAL LIQUEFACTION OIL

ABSTRACT

The naphtha fractions of coal hydrogenation products (IBP-130^°C) were separated by successive extraction with potassium hydroxide solution. Basic oil was also separated from the residue. The extracted fractions were analyzed by H-NMR and FI mass spectroscopy. It is concluded that the consecutive extraction with dilute potassium hydroxide solution should be capable of fractional separation of acidic oil from coal oil and further separation of individual component may be done by increasing the consecutive extraction steps.     

Production of white oil bases by hydrogenation of olefin oligomers

It was shown that iodine numbers of less than 1 g I₂/100 g are obtained during hydrogenation of olefin oligomers on a platinum-containing catalyst with optimum parameters. This ensures obtaining white oil stocks that satisfy all current requirements. Stock for hydraulic, aviation, cable, compressor, and other oils can be separated from the hydrogenated products.     

KINETICS OF HYDROCARBON GAS GENERATION FROM MARINE KEROGEN AND OIL: IMPLICATIONS FOR THE ORIGIN OF NATURAL GASES IN THE HETIANHE GASFIELD, TARIM BASIN, NW CHINA

In this paper we derive kinetic parameters for the generation of gaseous hydrocarbons (C_1‐5) and methane (C₁) from closed‐system laboratory pyrolysis of selected samples of marine kerogen and oil from the SW Tarim Basin. The activation energy distributions for the generation of both C_1‐5 (Ea = 59‐72kcal, A = 1.0×10¹⁴ s^?1) and C₁ (Ea = 61‐78kcal, A = 6.06×10¹⁴ s^?1) hydrocarbons from the marine oil are narrower than those for the generation of these hydrocarbons from marine kerogen (Ea = 50‐74kcal, A = 1.0×10¹⁴ s^?1 for C_1‐5; and Ea = 48‐72kcal, A=3.9×10¹³ s^?1 for C₁, respectively). Using these kinetic parameters, both the yields and timings of C_1‐5 and C₁ hydrocarbons generated from Cambrian source rocks and from in‐reservoir cracking of oil in Ordovician strata were predicted for selected wells along a north‐south profile in the SW of the basin. Thermodynamic conditions for the cracking of oil and kerogen were modelled within the context of the geological framework. It is suggested that marine kerogen began to crack at temperatures of around 120°C (or 0.8 %Ro) and entered the gas window at 138°C (or 1.05 %Ro); whereas the marine oil began to crack at about 140 °C (or 1.1 %Ro) and entered the gas window at 158 °C (or 1.6%Ro). The main geological controls identified for gas accumulations in the Bachu Arch (Southwest Depression, SW Tarim Basin) include the remaining gas potential following Caledonian uplift; oil trapping and preservation in basal Ordovician strata; the extent of breaching of Ordovician reservoirs; and whether reservoir burial depths are sufficiently deep for oil cracking to have occurred. In the Maigaiti Slope and Southwest Depression, the timing of gas generation was later than that in the Bachu Arch, with much higher yields and generation rates, and hence better prospects for gas exploration. It appears from the gas generation kinetics that the primary source for the gases in the Hetianhe gasfield was the Southwest Depression.     

Selective hydrogenation on palladium-containing catalysts of byproduct phenylacetylene present in industrial fractions of styrene

The process of liquid-phase hydrogenation of the phenylacetylene byproduct in the industrial styrene fractions formed in different styrene manufacture stages at OAO Salavatnefteorgsintez was studied on specimens of the palladium-containing G-58E, APKGS-20E2, and KSVK catalysts. It was found that the KVSK catalyst, which is a silica glass-fiber matrix containing 0.2 wt % of dispersed palladium, was the most effective in the selective hydrogenation at atmospheric pressure and temperatures of 20–30°C of phenylacetylene present in the industrial fractions of styrene. It was shown that the minimal loss of styrene is attained in the case of phenylacetylene hydrogenation in the hydrocarbon condensate fraction.     

Cu-Zn-Al-Zr浆状催化剂二甲醚合成宏观动力学

在压力3MPa～7MPa,温度220℃～260℃,空速0.4 L.g-1.h-1～1.2 L.g-1.h-1,气体摩尔分率yH20.75～0.65,yCO 0.14～0.20,yCO2 0.04～0.08,搅拌转速1000 r.min-1的反应条件下,于500mL高压搅拌釜中进行了合成气在Cu-Zn-Al-Zr浆状催化剂上一步法合成二甲醚工艺过程的宏观动力学研究。基于CO加氢合成甲醇、CO2加氢合成甲醇及甲醇脱水为二甲醚三个独立反应,建立了Langmuir-Hinshelwood型宏观动力学模型。采用通用遗传算法和Levenberg-Marquardt优化算法相结合的方法对实验数据进行拟合、参数寻优,获得模型参数估值,经统计检验和残差分析证实了模型的可靠性。     

Development of a mathematical model and optimization of production of white oils

A mathematical model of oligomerization of propane–propylene cut with consideration of deactivation of the catalyst was developed. The optimum process parameters that allow obtaining the components of different brands of oil were determined. A kinetic model of hydrogenation of oligomers was formulated for production of white oils.     

裂解C9馏分加氢利用工艺研究

以沸程为155～220℃的裂解制乙烯装置副产的裂解C9馏分为原料,在实验室依次进行了蒸馏切割预处理、加氢催化剂的对比评价及加氢产品调合汽油试验,分别就C9馏分的原料油性质、加氢工艺技术、催化剂性能及加氢产品利用方案进行了研究。在200 L蒸馏装置上的切除了C9馏分中的重组分及有害杂物,其蒸馏切割产品可以做为较好的加氢原料;通过加氢评价试验的产品性质、入口温度、床层温升等方面对比分析可以看出,L系列C9馏分一二段加氢催化剂均比参比剂具有更好的加氢活性、选择性及稳定性,其整体性能超过了参比剂;C9馏分一段加氢产品可用于调合成品汽油,其调合比例可达10%,C9馏分二段加氢产品可经分离可生产高芳烃溶剂油。     

EFFECT OF INTER-MOLECULAR ASSOCIATION ON BITUMEN OXIDATION

ABSTRACT

The hypothesis that inter-molecular associations between species in petroleum bitumens affects the rate of air oxidation of the bitumens was examined using infrared spectroscopy, gel permeation chromatography and viscosity measurements. Experiments were carried out in which the rate of oxidation of two different bitumens and their fractions (maltenes, resins, asphaltenes) were measured in terms of carbonyl group formation. In THF solution at 30°C the rates of reaction of the maltene and asphaltene fractions were the same when oxidised separately or as a mixture. Although the presence of inter-molecular associations were confirmed by gel permeation chromatography, the results indicated that such effects were unimportant to the rate of the reaction. Further experiments were performed in which neat bitumen, resin and maltene (n-heptane) factors and reconstituted mixtures were oxidised under 2069 kPa of oxygen or air at 40°C or 60°C. Again, no evidence for the effect of inter-molecular association on oxidation rate was obtained. Another experiment in which a bitumen, rejuvenating oil (RO), and a mixture of the two was oxidised (2069 kPa air, 60°C) again showed that the reaction rate of the bitumen and RO were the same when oxidised separately or in the mixture. However, in contrast, the rate of increase of viscosity of the bitumen was significantly affected by the RO and was attributed to dispersal of polar oxidation products by the RO.     

A TWO PARAMETER CORRELATION FOR PETROLEUM BITUMENS

ABSTRACT

The viscosity data for a number of bitumen samples obtained from Russian crudes have been correlated. The model equation of viscosity with softening point contains two empirical parameters which were determined by linear regression method by the use of a computer. The viscosity of the 71 samples at 140°C varied from 37.6 to 80,000 mPa.s for the softening point range of 36 to 90°C respectively. The empirical equation gave a very good representation of the softening point -viscosity relationship for the range of bitumens of 40-60°C softening point. The average absolute deviation and the standard error were less than 8% over a wide softening point range.     

HYDROCRACKING OF ARABIAN MIX ASPHALTENES IN THE PRESENCE OF MODIFIED RED MUD

ABSTRACT

Asphaltenes precipitated from an Arabian Mix vacuum residue were hydro-cracked in a batch autoclave at 435 and 460°C for 5-90 min. Experiments without catalyst, with modified red mud and with an industrial Co Mo/Al₂0₃ catalyst were compared. The products were fractionated into gas, naphtha, oil, asphaltenes and coke. Feed asphaltenes and several product fractions were characterised by elemental analysis, by average molecular mass and by ¹H n.mr. Due to the hydrogenation activity, both catalysts caused - with similar efficiency - the decrease of coke formation and the increase of quantity and quality of oil.     

Thermogravimetric analysis and kinetic study of heavy oil pyrolysis

Pyrolysis, so-called devolatilization, is one of the first steps of all thermochemical processes occurring in an inert atmosphere. The authors discuss the main kinetic features of heavy oil pyrolysis, on the basis of the data derived m from a TGA analysis and by using a kinetic model. The samples were heated over a range of temperature from 400 K to 430°C at various heating rates between 10 and 80°C/min. Experimental results showed that the effect of time is considerable in the case of tar conversion, compared to char and gases.