Visbreaking of heavy petroleum oil catalyzed by SO42-/ZrO2 solid super-acid doped with Ni2+ or Sn2+

SO₄²⁻/ZrO₂ solid super-acid catalysts (SZ) doped with Ni²⁺ or Sn²⁺ (Ni²⁺/SZ, Sn²⁺/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field. The visbreaking reactions were carried out at 240°C and 3–4 MPa for 24 h using a heavy petroleum oil to catalyst mass ratio of 100 : 0.05. The effect of water content on viscosity of heavy petroleum oil was also investigated. Both catalysts can promote thermolysis of heavy petroleum oil and the viscosity was reduced from 0.319 Pa·s to 0.135 Pa·s for Ni²⁺/SZ and 0.163 Pa·s for (Sn²⁺/SZ) with visbreaking rates of 57.7% and 48.9%, respectively. After visbreaking, the saturated hydrocarbon content increased while aromatics, resin, asphaltene, sulfur and nitrogen content decreased. The presence of water was disadvantageous to visbreaking of heavy petroleum oil. __________ Translated from Petrochemical Technology, 2007, 36(3): 237–241 [译自: 石油化工]     

Production of Saponin Biosurfactant from <Emphasis Type="Italic">Glycyrrhiza glabra</Emphasis> as an Agent for Upgrading Heavy Crude Oil

Saponins are the main group of phytogenic biosurfactants extracted from plants. One of the significant applications of these compounds is upgrading and viscosity reduction of heavy crude oil water in oil (W/O) emulsions. In this research, use of saponin extracted from Glycyrrhiza glabra was investigated for viscosity reduction of heavy crude oil and upgrading its API properties. The extracted saponin was characterized using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Phase behavior analysis demonstrated a reduction in initial viscosity and improved API gravity of the heavy oil from 2350 mPa·s and 19 to 900 mPa·s and 27, respectively. In addition, the emulsification index (E ₂₄) was found to be 98 % at a saponin concentration of 8 % w/v. It was observed that the emulsions were stable in the pH range of 5.5–13, temperature from 30 to 80 °C and salinity up to 6 % w/v of NaCl solution. Average diameter of W/O droplets evaluated by dynamic light scattering (DLS) were in the range of 10–15 µm. The results obtained from the present research revealed that the extracted saponin improved the physical characteristics of heavy crude oil. We propose the use of saponin as a potential alternative to conventional emulsifiers for upgrading heavy crude oil in petroleum industry.     

稠油注空气催化氧化采油催化剂的制备与评价

注空气催化氧化采油技术是一项提高稠油采收率的创新技术,因其气源丰富、成本低,越来越受到人们关注。该文针对SZ36-1稠油,制备了5种油溶性催化氧化催化剂——过渡金属环烷酸盐,并加以筛选,得到环烷酸铜催化效果最佳。对稠油注空气催化氧化条件进行了初步评价。在催化剂用量为原油质量的0.2%,反应温度100℃,反应时间3 d的条件下,稠油酸值从3.96 mg KOH/g上升至13.50 mg KOH/g,黏度由2.004 Pa.s上升到11.48 Pa.s,尾气中φ(O2)由21.0%降至10.0%。向氧化油中分别加入氧化油质量1.2%的助剂SW-1和质量分数40%的水,保温50℃搅拌,生成大量表面活性剂,形成O/W乳化油,黏度最终降至0.067 Pa.s,总降黏率达到96.66%。     

Gas hold‐up in bubble columns: Operation with concentrated slurries versus high viscosity liquid

The hydrodynamics of bubble columns with concentrated slurries of paraffin oil (density, ρ_L = 790 kg/m³; viscosity, μ_L = 0.0029 Pa·s; surface tension, σ = 0.028 N·m¹) containing silica particles (mean particle diameter d_p = 38 μm) has been studied in columns of three different diameters, 0.1, 0.19 and 0.38 m. With increasing particle concentration, the total gas hold‐up decreases significantly. This decrease is primarily caused by the destruction of the small bubble population. The hold‐up of large bubbles is practically independent of the slurry concentration. The measured gas hold‐up with the 36% v paraffin oil slurry shows remarkable agreement with the corresponding data obtained with Tellus oil (ρ_L = 862 kg/m³; μ_L = 0.075 Pa·s; σ = 0.028 N·m^?1) as the liquid phase. Dynamic gas disengagement experiments confirm that the gas dispersion in Tellus oil also consists predominantly of large bubbles. The large bubble hold‐up is found to decrease significantly with increasing column diameter. A model is developed for estimation of the large bubble gas hold‐up by introduction of an wake‐acceleration factor into the Davies‐Taylor‐Collins relation (Collins, 1967), describing the influence of the column diameter on the rise velocity of an isolated spherical cap bubble.     

Visbreaking of heavy petroleum oil catalyzed by SO/ZrO solid super-acid doped with Ni or Sn

SO₄^2-/ZrO₂ solid super-acid catalysts (SZ) doped with Ni²⁺ or Sn²⁺ (Ni²⁺/SZ, Sn²⁺/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field. The visbreaking reactions were carried out at 240°C and 3–4 MPa for 24 h using a heavy petroleum oil to catalyst mass ratio of 100 : 0.05. The effect of water content on viscosity of heavy petroleum oil was also investigated. Both catalysts can promote thermolysis of heavy petroleum oil and the viscosity was reduced from 0.319 Pa·s to 0.135 Pa·s for Ni²⁺/SZ and 0.163 Pa·s for (Sn²⁺/SZ) with visbreaking rates of 57.7% and 48.9%, respectively. After visbreaking, the saturated hydrocarbon content increased while aromatics, resin, asphaltene, sulfur and nitrogen content decreased. The presence of water was disadvantageous to visbreaking of heavy petroleum oil.     

Viscosity Reduction of Indian Heavy Crude Oil by Emulsification to O/W Emulsion Using Polysorbate-81

Pipeline transportation is the most convenient means of transportation of crude oil continuously and economically from production site to refinery. However, transportation of heavy crude oil (HCO) through pipelines is difficult due to its high viscosity. The high viscosity of heavy crude oil is mainly due to the presence of poly-aromatic compounds like resins and asphaltenes. Emulsification of HCO using surfactant is believed to be the most favorable technique to reduce the viscosity of HCO for efficient pipeline transport. In the present study, oil-in-water (O/W) emulsion has been formulated using a non-ionic surfactant Polyoxyethylene (5) sorbitan monooleate (PS-81) at different pH, surfactant concentration, and oil content. Box–Behnken response surface method has been used to optimize two responses, apparent viscosity and emulsion stability index (ESI). The optimal values of the parameters found are 75%v/v oil content, 2.5%w/v surfactant concentration, and pH value of 7 at which experimental value of emulsion viscosity is 0.2162 Pa·s, at 150 RPM, with a reduction of viscosity by 95.8% and having ESI of 98.16 after 24 h at 30°C.     

输油管线内气液固三相流中沙粒沉积规律的数值模拟研究

以苏丹油田Palouge油区的输油管线参数为研究对象,基于多相流混合模型,采用Fluent软件对输油管线内的气液固三相流中的沙粒沉积过程进行了数值模拟,研究了流速、含沙量、含水量、压力和原油粘度对沙粒沉积规律的影响。结果表明:沙粒在输油管线中的沉积分为起始沉积段、过渡段和稳定段。平均沉沙量随流速、含水量的增大而减小,随含沙量的增大而增加,压力为0.2MPa和原油粘度为0.1 Pa.s时,分别达到51.80%和45.76%极小值。沉沙量最大位置随流速、含水量而右移,随含沙量增大而左移,随着压力和原油粘度增大存在一临界值(0.2MPa时4.28m和0.1Pa.s时3.68m)。过渡段宽度随流速和压力增大存在一临界值,随含沙量、含水量和原油粘度的增大存在极值(8%时22.56m,20%时21.80m和0.1Pa.s时22.19m)。过渡段压差直接影响了过渡段的宽度。流速和含沙量对其沉积规律的影响最大。     

Treatment of Oily Waste Water Using Low-Cost Ceramic Membrane: Flux Decline Mechanism and Economic Feasibility

Abstract

This work addresses the applicability of different membrane pore blocking models for the prediction of flux decline mechanisms during dead end microfiltration (MF) of stable oil-in-water (o/w) emulsions using relatively low-cost ceramic membranes. Circular disk type membranes (52.5 mm diameter and 4.5 mm thickness) were prepared by the paste method using locally available low-cost inorganic precursors such as kaolin, quartz, calcium carbonate, sodium carbonate, boric acid, and sodium metasilicate. Characterization of the prepared membrane was done by SEM analysis, porosity determination, and pure water permeation through the membrane. Hydraulic pore diameter, hydraulic permeability, and hydraulic resistance of the membrane was evaluated as 0.7 µm, 1.94 × 10^?6 m³/m²·s·kPa and 5.78 × 10¹¹ m²/m³, respectively. The prepared membrane was used for the treatment of synthetic stable o/w emulsions of 40 and 50 mg/L crude oil concentration in batch mode with varying trans-membrane pressure differentials ranging from 41.37 to 165.47 kPa. The membrane exhibited 96.97% oil rejection efficiency and 21.07 × 10^?6 m³/m²·s permeate flux after 30 min of experimental run at 165.47 kPa trans-membrane pressure for 50 mg/L oil concentration. Different pore blocking, models such as complete pore blocking, standard pore blocking, intermediate pore blocking and cake filtration were used to gain insights into the nature of membrane fouling during permeation. The observed trends for flux decline data convey that the decrease in permeate flux was initially due to intermediate pore blocking (during 1 to 10 minutes of experimental run) followed with cake filtration (during 10 to 30 minutes of experimental run). Based on retail prices of the inorganic precursors, the membrane cost was estimated to be 130 $/m². Finally, preliminary process economic studies for a single stage membrane plant were performed for the application of the prepared membrane in industrial scale treatment of o/w emulsions. A process economics study inferred that the annualized cost of the membrane plant would be 0.098 $/m³ feed for treating 100 m³/day feed with oil concentration of 50 mg/L.     

Separation of Heavy Crude Oil Emulsions Using Microwave Radiation for Further Crude Oil Analysis

Microwave radiation in closed vessels was used for the separation of heavy crude oil emulsions for further oil characterization. Operational conditions were studied and the following parameters were evaluated: water content, density, viscosity, N, S, V, Ni, and Cl. Using the proposed procedure it was possible to reduce the water and Cl content in crude oil to values lower than 1% and 300 µg g^?1, respectively. It was possible to determine important crude oil properties without interferences caused by excessive water and salt concentrations. The proposed procedure is relatively fast and it was possible to obtain a suitable condition for water and salt removal from heavy crude oil emulsions without using demulsifiers or toxic reagents.     

［(MoO2)(acac)2］/t-BuOOH/H3PO4催化氧化体系对稠油中重组分的降解作用

针对稠油的重组分，探讨了催化氧化稠油降解反应体系中稠油黏度、平均分子量随反应时间、催化剂及氧化降解体系的变化规律.研究了各种条件下油层矿物在反应中的作用.实验结果表明，［(MoO₂)(acac)₂］催化剂对稠油的氧化降黏是非常有效的，其催化降解反应与氧化剂、氢质子供体以及油层矿物有关.在［(MoO₂)(acac)₂］/t-BuOOH/H₃PO₄/油层矿物体系中，稠油沥青质降解率达到81%，稠油黏度由原始的117.2 Pa·s下降到55.8 Pa·s，下降率为52.4%，平均相对分子质量下降了100.TLC-FID分析证明，稠油中的沥青质减少主要生成胶质、芳烃和饱和烃，这种理化性质的改变促进了稠油体系的稳定，对稠油开采、运输以及后处理工艺将起到推动作用.     

Effect of Different Drying Methods on Rheological and Textural Properties of Balangu Seed Gum

The purpose of the present study was to investigate the effect of different drying methods on the rheological and textural properties and color changes in Balangu seed gum. Three drying methods, including air drying (40–80°C), freeze drying, and vacuum drying, were used. The apparent viscosity decreased from 0.161 to 0.056 Pa s with increasing temperature from 40 to 80°C (shear rate = 60 s^?1) and freeze-dried gum exhibited the highest viscosity among all dried gums (0.203 Pa s). Different time-independent rheological models (power law, Bingham, Herschel-Bulkley, Casson, and Vocadlo) were used to fit the experimental data and the results revealed that the Herschel-Bulkley model was the most suitable to describe the flow behavior of Balangu seed gum over the whole experimental range (r > 0.98). The hardness values of air dried Balangu seed gum gels varied from 33.1 to 40.4 g and were significantly lower compared to the freeze-dried and vacuum-dried gums (46.9 and 46.6, respectively). The consistency of samples decreased from 386.27 to 245.33 g · s when the drying air temperature increased from 40 to 80°C. The results indicated that the freeze-dried gum exhibited the highest hardness and consistency. The color of air-dried gum was darker (lower L* value) compared to the freeze- and vacuum-dried samples.     

Steady rheological behaviors of UV-curable waterborne hyperbranched polyurethane acrylate dispersions

A rotational rheometer was used to investigate the steady rheological behaviors of UV-curable waterborne hyperbranched polyurethane acrylate dispersions (WHBPUADs). The flow curves of WHBPUADs were fitted mathematically using the Cross model. The effects of many factors including solid content, concentration of hydrophilic groups, and degree of neutralization on the rheological behaviors were studied and discussed. It was found that the viscosity of WHBPUAD decreased with increasing shear rate, indicating that WHBPUAD was pseudoplastic. On the other hand, at the same shear rate, the viscosity of WHBPUAD increased with increasing solid content and degree of neutralization but decreased with increasing concentration of hydrophilic groups. The Cross model could describe the flow curve of WHBPUAD accurately, with square of correlation coefficient (R ²) above 0.9. Moreover, most of the zero-shear viscosity values (η ₀) obtained by the Cross model were located in the range of 0.2–10 Pa·s, which could fully meet the practical application requirement.     

Sugars and Fructans Separation by Nanofiltration from Model Sugar Solution and Comparative Study with Natural Agave Juice

The fructan separation from a model sugar solution and natural agave juice was studied using a stirred-cell nanofiltration unit operated in concentration mode. Hydrophilic cellulose membrane with MWCO of 1000 Da was used. The experimental conditions were varied to predict the influence of pressure (0.14–0.350 MPa) and feed concentration (0.15–0.25 g/mL) on the initial permeate flux and solute retained fraction (SRF) values of the process. Response surface plots (p < 0.05) showed that the permeate flux and SRF increased significantly with the pressure and decreased with feed concentration. The permeate flux varied from 0.5 to 4.1 L · h^?1 · m^?2. The fructan retained fraction in model sugar solution varied from 0.85 to 0.97 whereas fructose, glucose and sucrose presented similar SRF values ranging from 0.38 to 0.65. Promising results were obtained when natural agave juice was used.     

Highly soluble phenylethynyl terminated oligoimides derived from 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane, 4,4′-oxydianiline and mixed thioetherdiphthalic anhydride isomers

Novel highly soluble phenylethynyl-endcapped oligoimides derived from mixed thioetherdiphthalic anhydride isomers (m-TDPA) and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane (DAPI), 4,4′-oxydianiline (4,4’-ODA) with 4-phenylethynylphthalic anhydride (PEPA) as a reactive endcapping agent were synthesized. The calculated molecular weights of all the oligoimides were 2500 g·mol^?1.The effect of the mole ratio of DAPI/4,4’-ODA on solubility and melt viscosity of oligoimides as well as the thermal and mechanical properties of cured polyimide films was investigated. Experimental results indicated that DAPI greatly improved the solubility (>30 wt.%) of the oligoimides in low boiling points solvents when the content of DAPI was more than 10 mol% per total diamine. All the oligoimides exhibited very good processability with minimum melt viscosity lower than 60 Pa·s at about 330 °C. Tough and brown films were obtained after thermally cured at 370 °C for 1 h and dynamic mechanical analysis (DMA) showed that glass transition temperatures of the cured films increased up to 340 °C with the increasing content of DAPI. However, the thermal stability and mechanical properties decreased with the increase of DAPI content. The temperature of 5% weight loss was higher than 470 °C in both air and N₂ atmosphere obtained by thermogravimetric analysis (TGA). And the tensile strengths of the cured films were about 60 MPa.     

Experimental studies of liquid flow maldistribution in a random packed column

Liquid flow distribution has been a major concern when scaling up random packed columns. This study concerns the measurements of liquid flow distribution in a large scale column packed with 25.4 mm stainless steel Pall rings. The liquid flow distribution was studied with packed bed height from 0.9 to 3.5 m, liquid flow rate from 2.91 to 6.66 kg/m²·s, and gas flow rate from 0 to 3.0 kg/m²·s. In addition, three systems, water/air, aqueous detergent solution/air and Isopar/air, were used to study the effect of liquid physical properties on liquid flow distribution, and two different liquid distributors were employed to test the effect of liquid distributor design. It was found that liquid flow distribution was strongly influenced by liquid distributor design, packed bed height, gas flow rate and liquid viscosity, slightly influenced by liquid flow rate, but not by liquid surface tension.     

基于空隙率的油气两相流流量测量的研究

利用文丘里管进行油气两相流流量测量的研究,在考虑了气液滑移比对流量测量的影响,对均相流流量测量模型进行了修正,得到了空隙率和文丘里管两端差压与两相流总质量流量及液相质量流量的关系式。实验结果表明利用这两个关系式,在干度小于2％,空隙率在15%～83％范围内,总质量流量测量和液相质量流量测量的均方根误差均小于5％。针对不同的流型,对关系式中的系数作了修正计算,进一步降低了测量误差。     

Influence of Gas Injection on the In‐Situ Oil Fraction of an Oil‐Water Flow in Horizontal Pipes

In this work, an experimental study was made on gas injection into an oil‐water flow in horizontal pipes with two unequal pipe diameters. Special attention was given to the influence of gas injection on the average in‐situ oil fraction. Measurements were made for input water flow rates of 1.25–5 m³/h, input oil flow rates of 0–8 m³/h and input gas flow rates of 0–9 m³/h. It was found that gas injection has a considerable influence on the in‐situ oil fraction. In general, a small increase in the rate of air injection leads to greatly decreasing in‐situ oil fractions. The in‐situ oil fraction with gas injection decreases to a greater extent than that without gas injection, at the same input liquid flow rates. At a given input water flow rate, the value of the in‐situ oil fraction in the pipe with the larger diameter is higher than that in the pipe with the smaller diameter. Furthermore, the drift flux models were extended to predict the average in‐situ fractions of the oil phase in the intermittent three‐phase flow regimes. A good agreement is obtained between theory and data, especially for the in‐situ oil fraction range of 0.2–1.0.     

A study of ionic transfer in electrodialysis process with laminar flow

The concentration profile in a laminar flow of the diluent of a parallel-plate electrodialysis stack is derived by assuming operation at the limiting current density. The Nusselt mass transfer number is found to depend on the Reynolds number, the Schmidt number and the dimensionless hydraulic equivalent diameter according to (Nu)_theo. = 3.7 · (Re · Sc · de/L)^1/3. An empirical correlation of the Reynolds number, the Schmidt number, and the shape factor of the electrodialysis cell, with the ionic mass transfer rate in ion exchange membrane electrodialysis is obtained by measuring the limiting current densities at various conditions. The resulting empirical mass-transfer correlation, (Nu)_exp. = 3.91 · Re^0.333 · Sc^0.328 · (de/L)^0.352, holds for sodium acetate as dialysate at concentrations ranging from 0.0106 to 0.0508 kmol/m³, viscosities ranging from 0.608 to 0.926 mPa · s, temperatures ranging from 15 to 55°C, axial velocities ranging from 0.341 to 4.55 cm/s, and for cell thicknesses of 0.32 and 0.94 cm, and is found to be in agreement with the equation obtained from theory. The effects of concentration, flow rate and temperature on the limiting current density are also studied. The relationship between the thicknesses of the diffusion layer and the Reynolds number has been analyzed.     

垂直上升管内气体扰动油水两相乳化液流动特性

气体 -油水乳化液的管内流动是原油开采、油气输运以及许多化工领域中经常遇到的工程现象 ,正确认识油水乳化液在气体扰动下的动力特性对圆管内油、气、水多相流的理论建模具有重要的工程应用和学术价值 .本文通过垂直上升管内油气水三相弹状流的实验研究 ,提出了垂直上升弹状流中油水乳化液黏度计算模型 .基于此模型 ,油水乳化液在气体掺入下的流动特性可表现为气体扰动变稠的非牛顿流体特性和气体扰动变稀的非牛顿流体特性 .     

加压下规整填料塔内气液两相流返混的实验研究:气相返混系数

规整填料因具有生产能力大、分离效率高、压降低、操作弹性大、持液量低等诸多优点 ,目前已被广泛应用于精馏、吸收及萃取等多种化工单元操作中 .通常只在常压或减压条件下操作 ,而在高压或大液相负荷下 ,因流体物性的变化及流动状态的改变 ,使塔内产生严重的返混 ,塔效率显著降低 .因此 ,研究加压下规整填料塔内流体的流动状态具有重要意义 .对于加压下填料塔内气相返混的研究 ,中国台湾的ＴａｎＣｈｕｎｇ -Ｓｕｎｇ[1] 在低实验气速 (0 .0 0 2～ 0 .1ｃｍ·ｓ- 1)下做过初步的研究 ,其实验填料为散堆填料 .Ｋｕｒｔｚ[2 ] 在这方面的研究…