Combined with synchronized monitoring techniques, purification processes for active constituent of alkylbenzene sulfonate have been optimized, and the total alkylbenzene sulfonate, mono-alkylbenzene sulfonate and di-alkylbenzene sulfonate can be obtained with purity over 90%. With the above active constituents as standard substances respectively, the determination of alkylbenzene sulfonate content in the original samples was carried out by high performance liquid chromatograph. The results showed the sample contained mono- and di-alkylbenzene sulfonate simultaneously, and the content of mono-alkylbenzene sulfonate was much higher than that of di-alkylbenzene sulfonate. They had maximum absorption at the wavelength of 224 nm, and the absorption coefficients of total alkylbenzene sulfonate and mono-alkylbenzene sulfonate were similar, higher than that of di-alkylbenzene sulfonate. With total, mono- and di-alkylbenzene sulfonate as standard substances respectively, the limits of quantitation were 5 mg/L, 5 mg/L and 10 mg/L, respectively. The determination result of active constituent was about 3% lower with total alkylbenzene sulfonate as standard substance than that with mono- and di-alkylbenzene sulfonate as standard substances simultaneously, owing to the weaker absorption coefficient of di-alkylbenzene sulfonate.
In this work, the Bi2O3 samples were synthesized via a liquid precipitation method with a precursor of Bi(NO3) 3•5H2O. The structure and morphology of the samples obtained at different pH values (3 and 8) of reacting solution were investigated using XRD and SEM, respectively. The results suggested that the Bi5O7NO3 was obtained from the precursor, then transformed to β-Bi2O3 and α-Bi2O3 at pH=3. The higher pH range (pH=8) could further improve phase transformation process. Thus, the pH value of reacting solution strongly affected the phase composition and transformation process. Furthermore, the photocatalytic activity of the obtained samples was evaluated by degradation of RhB. The results indicated that the Bi5O7NO3 exhibited the higher photocatalytic activity than α-Bi2O3.
The Y-type zeolites (REY ) with different contents of rare earth ions were prepared by the traditional liquid-phase ion exchange method. The mass transfer kinetics of benzene on the REY zeolite was studied by using frequency response (FR) technique and intelligent gravimetric analyzer (IGA). The effects of the concentration of rare earth ions on the adsorption and diffusion process were studied, and the samples were characterized by XRD, physical analyzer and other characterization methods. The results show that the adsorption capacity decreases with the introduction of rare earth, and the introduction of appropriate rare earth can improve its mass transfer performance, but excessive mass of rare earth decreases the mass transfer performance. The adsorption process of benzene on REY zeolite has different adsorption process. The introduction of rare earth can improve the selectivity of zeolite to adsorbate in the process of catalytic and adsorption separation, so as to improve the efficiency of catalysis and separation.
Y zeolites with different pore structural and acid properties were studied by XRD, N2 physical adsorption, NH3-TPD and PyFTIR. The adsorption and diffusion properties of benzene in hierarchical pore Y zeolites were investigated by using intelligent gravimetric analyzer (IGA). It was found that there was no obvious change in the crystal structure of the Y zeolites in the process of modification, while the pore structure, acid type, acidity and acid strength were changed. The mass transfer performance of benzene molecules in the pore level Y zeolite molecular sieve was mainly decided by pore structure. The larger of pore volume Y molecular sieve was, the faster diffusion rate was. It was more conducive to the diffusion of benzene molecule. The amount of saturated adsorption of benzene molecule was depended on the type and intensity of acid type of Y zeolite.
In this article, low temperature pyrolysis upgrading experiment was conducted with the low rank coal from Shanyin, Shanxi. The influence of temperature and holding time on the product yield and properties was investigated by tube furnace. The results showed that the optimized pyrolysis temperature of the experiment was 500~550 ℃，and holding time was 60 minutes. The semi-coke yield of the low rank coal was high, the sulfur content decreased significantly, and the desulfurization rate was up to 55%. The volatile matter, high ash content and higher heating value can meet the requirements of clean coal quality index in Beijing-Tianjin-Hebei region, and it can be used as clean fuel for heating, heating and so on. The tar yield was high, the density of tar was low, and the light oil component content was high. So, high quality fuel oil can be obtained through hydrogenation. The gas yield was high, and H2 can be gotten using the produced gas as raw material by pressure swing adsorption technology.
The stability of emulsion of Shengli crude oil and variation of drop size were investigated using LUMisizer-LS610. At the same time, the influences of the emulsifier concentration，the wateroil ratio, temperature and electrolyte on the stability of emulsion and the drop size were also explored. The results show that the higher emulsifier concentration is, the smaller the drop size would be and the more stable crude oil emulsion is. The greater the proportion of oil phase in emulsion, the more stable the emulsion is. As the temperature increases, the good emulsified effect is obtained, however, the stability of the emulsion is reduced. The electrolyte can enhance the stability of the emulsion and reduce the drop size.
The emulsions stabilized by a betaine amphiphilic polymer were prepared by shearing emulsification under high salt conditions. The effect of salt concentration on the stability of the emulsions was analyzed by using stability analyzer and laser particle size analyzer. The influence mechanism was discussed by using rheometer. The results show that O/W emulsions can be formed through the addition of the polymer under high salt conditions. The higher the salt concentration, the smaller the average particle size of the oil droplets and the narrower its distribution. The increase of the viscosity of the dispersion medium and the enhancement of the interfacial strength will lead to improvement of the stability of the emulsions.
According to the mechanism of associative polymers forming large-size congeries through association of hydrophobic side chains, the association degree of the associated polymer was controlled using β-cyclodextrin with the amphiphilic structure, and the association degree of the associating polymer in porous media was indirectly calculated by the viscosity of polymer solution. Viscosity was used for evaluation of association degree of polymer in porous media indirectly. The paper provided a detailed experimental study of association behavior in porous media, including effect of β-cyclodextrin concentration on the polymer viscosity, congeries form, and association degree under different permeability. The results showed that β-cyclodextrin was only wrapped on the hydrophobic side chains of the associative polymer, but had no effect on the molecular backbone of associative polymer and the molecular structure of linear polymer. The contribution rate of association viscosity to apparent viscosity was more than 94%. The association degree of associative polymer in the porous medium increased with the increase of the permeability. The size of the aggregates formed by the association polymer was more compatible with the pore size of the core due to the presence of the association. The degree of association of the polymer in the core with permeability below 4 000 × 10-3 μm2 was less than 10%.
According to geological characteristics of high liquid content and high water content wells in Chaoyang Trench oil field. A new chemical water shutoff agent with strong strength and strong stability was selected through the determination of gelling strength, gelling time, stability time, type and concentration of shutoff agents and additives. The optimum formula of water plugging (mass fraction) is as follows: 0.7%HPAM+2%Ca-Ls+0.3%organic chromium+0.15%NaHCO3+0.005% thiourea. The viscosity in 24 h is less than 2 000 mPa•s, the gelling time is more than 48 h，the gelling max viscosity is more than 20 000 mPa•s, and the viscosity reservation in 30 days is more than 80%. According to the cores of different permeability, the water plugging rate of plugging agent is more than 80%, and the plugging oil rate is less than 20%, which has good selectivity. It has been used on 3 wells in Chaoyang Trench oil field in 2016. The increase production of cumulative oil is 2 225.3 t, and the cut of cumulative water is 11 631.2 t, which has good sealing performance.
In order to evaluate the influence of the construction parameters of the plugging agent on the plugging removal effect, the plugging sequence and the displacement optimization of the polymer flooding wells were studied with the plugging removal rate as the evaluation index. The core experiment was carried out through the displacement of injection plugging agent and the injection order of three main chemicals, and the best construction parameters (including the best displacement and the injection sequence) were obtained. Experimental results showed that polymer injection well plugging agent were higher than 70% by changing injection order of chemical. When the organic scale corrosion agent, polymer degradation agent and solid blocking agent were injected sequentially, the plugging removal rate was the highest, and the plugging removal effect was better than other injection combinations. For the permeability of core 300 mD, when the displacement of plugging agent is larger than 0.1 mL/min, the displacement had little influence on the plugging removal effect, and the blockage removal rate was above 90%. In order to speed up the construction schedule and shorten the cycle, large displacement injection should be used. when the core permeability is 100 mD, plugging rate was less than 90%. With the increase of displacement, the rate of plug removal decreased. In order to achieve good plugging removal effect, it was advisable to choose the lower injection displacement. The higher the permeability, the better the final solution. The plugging effect of polymer flooding can be further improved by optimizing the injection sequence and displacement of the plugging agent, which can provide the basis for improving the quality of plug removal.
The viscosity of heavy oil is high, the pipeline transportation is difficult, and the viscosity decreases greatly after dissolved gas. Thus researching viscosity-reducing properties of dispersion system of heavy oil with dissolved gas is of great significance to the actual pipeline operation. The viscosity-reducing mechanisms, viscosity models and influence factors of heavy oil with dissolved gas are summarized. The research indicates that dilution micelle damage, swelling, molecular force and micro-bubbles effect can reduce the viscosity of dispersion system. Viscosity models are mainly established by Shu, Abivin and so on, and the defects in the model are presented. The property of oil and gas, temperature, pressure, the amount of dissolved gas and micro-bubbles have different effects on the system's viscosity, and the direction of the heavy oil with dissolved gas is proposed.
Molten salt heat storage system is the key point of solar thermal power station, which has important influence on the safety, reliability and operation cost of power generation system. Based on the analysis of the two element nitrate melt physicochemical properties, the material selection, corrosion resistance, thermal insulation, tank foundation insulation method of the high and low temperature molten salt tank were systematically studied. The optimum design scheme of molten salt tank was given from the angle of technical economy.
Dissolution of CO2 in crude oil can change its rheological properties notably, which makes it widely used in the fields of oil displacement, viscosity reduction, transportation and so on. In this study, a pressurized stirring-viscometric equipment was designed based on the stirring viscometry theory, and the corresponding viscometric method was also proposed, so that the viscosity of CO2 heavy oil mixture could be determined under the simulation conditions of pipeline transportation. On the basis of this equipment and method, the effects of pressure, shear rate and temperature on the viscosity of CO2 heavy oil mixture were probed. It was found that the viscosity of CO2 heavy oil mixture decreased exponentially with the increase of pressure. The viscosity of heavy oil system can be greatly reduced by dissolving gas pressure of 2 MPa. Meanwhile, the shear thinning feature became more obvious with increasing pressure of CO2. Moreover, the viscosity reducing rate became greater with decreasing temperature at the same pressure. The results of this study provide technical support for the feasibility of transporting viscosity-reduced heavy crude oil by CO2.
Due to the similarity of the routing between HVDC transmission lines and buried pipelines, the local pipelines inevitably enter the HVDC transmission interference zone. In order to study the law of interference and mitigation of HVDC grounding electrode on buried pipeline, boundary element software was used to calculate the effectiveness of various mitigation methods including anti-corrosion coating, the distance between the pipeline and the grounding electrode, insulating joints and zinc ribbon. The results indicated that the smaller the coating breakdown factor was, the more concentrated the interference current was , and the higher the local corrosion risk was. After installing the insulating joints, the strongest interfered section of pipe was alleviated, while the interference of the other section of pipe was aggravated. The protection range of the zinc ribbon was equivalent to the length of the zinc ribbon. Finally, the paper put forward the comprehensive protection measures which included insulating joints, cathodic protection and zinc ribbon.
According to the characteristics of aerostatic dry gas seals and the gas Reynolds equation, Galerkin method was used to derive the variational equations of pressure distribution of the gas film. Based on the gas film boundary conditions, the derivation process using the finite element method of the steadystate Reynolds equations was given. The pressure fitting curves of different thicknesses of the gas films were obtained by using polynomial fitting. In addition, the opening force was carried out. The fitting formula of the opening force and the film thinckness was obtained according to the opening force of the different film thicknesses.The relationship of the film stiffness and the film thickness was obtained by the derivation of the film thickness.The pressure distribution of the stationary seal ring end face was obtained. A parabolic decreasing trend is showed from the orifice to the inner and outer diameters in the radial direction of the stationary ring seal face. Pressure peak occurs at the orifice. With the increase of the gas film thickness, opening force and gas film stiffness decrease.
The ER5356 welded wire was welded under the TIG welding to 5 mm thick 7075-T6 super hard aluminum. The performance and microstructure of the welded joints obtained under different welding processes were analyzed, and the best welding parameters were determined. After solid solution treatment for the specimens, four solid solution temperature and three solid solution time were selected for the experiment. The change law of microstructure and properties of welded joints under different solid solution parameters was studied through macro morphology and metallographic observation, scanning electron microscope, X ray diffraction analysis, tensile test and hardness measurement. The results show that the best welding current is 110 A determined by welding technology, solid solution treatment temperature is 480 ℃, solid solution time is 45 min. At this time, the microstructure of welded joints is improved, and the mechanical properties of the welded joints are better. That is, the size of the grain structure is homogeneous, and the precipitates are dispersed in the matrix and grain boundaries. Thus, more elements are dissolved into the matrix and the grain boundary.
According to the theory of the spiral groove of the Muijderman,the MATLAB software is used to calculate the spring pressure of the dry gas seal.In this process,the gas film pressure equation is solved and a two-dimensional array about the radius and pressure is obtained. MATLAB curve fitting tool was used to fit the equation of radius and pressure.Combined with the classic example, the root pressure and the opening force of the spiral groove are calculated, and the relative error is compared with the literature, which verifies the reliability of inference calculation.The spring pressure of the working condition is obtained, which provides the basis for the design of the spring pressure and the maintenance of the spring.
