Chemistry and Technology of Fuels and Oils最新文献

Oil shale, as an unconventional energy source, has attracted much attention in countries worldwide. The traditional way of extracting oil shale from the open pit is not only costly but also polluting to the environment. Sufficient understanding of the relationship between subsurface fractures and temperature fields is important for the extraction of oil shale and is of great significance for the actual in-situ extraction of oil shale. The study of fracture initiation and expansion in oil shale formations is based on the effect of fractures on convective heating efficiency in oil shale in situ conversion technology. In view of the objective situation that hydraulic fracturing can enhance the rate of the permeability and heating efficiency of oil shale formations, and hence the oil yield, the effect of single fractures with different fracture heights (2 mm, 4 mm, 8 mm) on the temperature field of oil shale; and the effect of multiple fractures (two, three and four fractures) on the temperature field of oil shale are investigated under convective heating methods.

The feasibility of obtaining a modified lignosulfonate reagent derived from acrylic and lignosulfonate components is examined. The completeness of the reaction yielding a modifier derived from acrylamide and citric acid to be used for subsequent dispersion in sodium lignosulfonate was monitored by HPLC. A comparative analysis of the surface tension data was carried out by the stalagmometric drop counting method. In order to study the effect of electrolytes on the surface activity of a complex reagent with acrylic and lignosulfonate components, the surface tension of aqueous solutions of NaCl and CaCl₂ of different concentrations was determined upon the introduction of from 0.1% to 2% reagent. The assessment of the adsorption activity was carried out by constructing an isotherm of surface tension at the liquid‑liquid interface under static conditions over time with constant reagent concentration. Feasibility was established for the use of this lignosulfonate reagent for effective reduction of the conditional viscosity of clay drilling mud at from 20°C to 180°C.

East Inner Mongolia region is rich in renewable energy and is an important power station. The aim of this study was to further enhance the development and utilization of wind power and photovoltaic in the East Inner Mongolia region, and help build a new type of power system in the region. Based on the research targets in Chifeng, Tongliao, Xing’an and Hulunbuir in the East Inner Mongolia region, Study of load characteristics, wind power and photovoltaic output characteristics and optimal ratios throughout the year, and study the scale and mode of operation of energy storage in the banner county seats. Research shows that wind power, photovoltaic monthly output during the year as a whole shows the law of “winter big summer small, spring big winter small”, applies. Taking into account the operating costs and the average standard deviation of slow regions, the optimal ratio of wind and photovoltaic power in Chifeng should be 4.7:1, in Tongliao 4.8:1 and in Hulunbuir and Xing’an 4.4:1; Compared with the adjustment of the before energy storage method, the combined power formed by the power storage of grid is relatively gentle, with a low peak valley difference, and the overall performance of the grid side storage is better than that of the supply side storage. Therefore, research on the ratio of wind and photovoltaic power and the energy storage analysis of these regions can effectively promote the development of power and accelerate the realization of strategic goals such as “dual carbon”, as well as providing a reference for the future planning of the East Inner Mongolia region power network.

Oil shale is an unconventional energy source with abundant reserves. However, the global oil shale resources have not been fully exploited. In-situ oil shale extraction technology based on electric heating has gradually become a research focus in this field. In this study, the construction of a numerical simulation model for the in-situ extraction of oil shale by electric heating and the results of the numerical simulation study are summarized. By summarizing the research progress and current status of numerical simulation of electrically heated in-situ oil shale extraction, the core issues, main challenges, progress made, and bottlenecks to be solved in the current numerical simulation research are analyzed.

Because of their small particle size, excellent stability, high temperature tolerance, and salt tolerance, polymer nanoparticles are attracting a lot of attention in low-permeability reservoirs. In this study, SiO2, acrylamide (AM), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were used to synthesize novel copolymer-grafted nano-silica particles (HPGN). HPGN’s overall performance in low-permeability reservoirs was evaluated. The results demonstrate that the viscosity of a 2000 mg/L HPGN solution at 50 °C is 75.8 mPa·s, with high stability under high temperature, high salt, and shear conditions. More notably, the displacement experiment proved that under the condition of 18450 mg/L, a 2000 mg/L HPGN solution enhanced the recovery rate by 21.89%. This research indicates that HPGN has great applicability potential in low-permeability reservoirs with high temperatures and salinities.

Tight oil has become one of the important energy sources for increasing reserves and production in China’s oil and gas field. Chang 8 Member of Ordos Basin shows great exploration potential, and the classification and evaluation of tight reservoirs are critical to reservoir optimization and reserve evaluation. However, the classification and evaluation of tight reservoirs in Chang 8 Member of Ordos Basin have not been unified. Therefore, on the basis of previous research results, this paper systematically studied the petrological characteristics, physical properties and microscopic pore throat structure characteristics of tight sandstone reservoirs by means of rock slice observation, overburden porosity and permeability test and high-pressure mercury injection test. On this basis, the weight coefficient of the correlation between the key parameters and the oil-bearing property of the reservoir is determined by screening the key parameters, and the mathematical model of reservoir classification evaluation is established by using the analytic hierarchy process. The research results show that the reservoir composition maturity of Chang 8 Member in Ordos basin is medium, and the lithology is mainly lithic arkose and feldspathic lithic sandstone. The physical property of Chang 8 reservoir is poor, and it belongs to low porosity, low permeability ultra-low permeability reservoir as a whole. The reservoir space is dominated by intergranular pores and dissolution pores, and micro fractures are developed locally. The pore throat structure of the reservoir is fine, and the pore type is smaller than 10 μm, and the throat and micro throat are dominant with 0.2 μm. Considering porosity, permeability, displacement pressure, average pore throat radius and other parameters comprehensively, normalize each parameter, and determine the weight of each parameter according to its correlation with oil saturation. The reservoir classification and evaluation model were established by using the analytic hierarchy process (AHP), and the reservoir quality index (RMI) is used to classify the reservoirs of Chang 8 Member in Ordos Basin into 4 types. This study can provide a basis for efficient exploration and development of tight oil.

A complete analysis of the existing methods of synthesis of polyhydroxylated fullerenes using direct chemical interaction, as well as alternative methods of creation has been carried out in order to identify the optimal methods of obtaining, for their implementation in various technological and biomedical fields. The scientific literature on this field of research is summarized and classified, and a comparative assessment of the efficiency and feasibility of practical implementation of the developed synthesis methods is given on the basis of a comprehensive review of literature and patent documents.

Molecular dynamics modelling was carried out for polyethylene terephthalate and composite materials derived from this polymer with different single‑walled carbon nanotubes as a filler. The effect of the supramolecular structure of this polymer composite material on some of its physicochemical and mechanical properties was studied. The interphase intermolecular interaction of the polymer matrix‑filler system was found to be the major factor determining the physicochemical and mechanical properties. Therefore, consideration of this interaction is necessary for predicting the properties of such materials.

The article discusses the special features of operation of hydroejector vacuum-creating systems. The flow diagram of a two-stage hydroejector vacuum-creating system is described and a calculation algorithm is given. The dependence of the yield of the components of the vapor-gas mixture on the temperature of the working fluid was analyzed and the required heating temperature of the working fluid was determined. A two-stage hydroejector vacuum-creating system was calculated and the dependence of the flow rate of the working fluid on the pressure and power consumption of the pumps was determined.

On the basis of the characteristics of low-density polyethylene determined experimentally from the geometric dimensions of the extruder parts and COMSOL MULTIPHYSICS software a digital model of the apparatus was created, and the flow rate of the polymer melt from the extruder nozzle was calculated hydrodynamically. The agreement between the experimentally measured polymer flow rate and the value obtained from the model lies within the permissible error. This establishes the adequacy of the digital twin model, which will be used to predict the viscosity characteristics of composite materials based on low-density polyethylene and the technological regimes of their production by blending in the extruder.