Chiral epichlorohydrin is obtained by kinetic resolution of racemic epichlorohydrin through hydrolysis. Chiral epichlorohydrin is a valuable intermediate which is widely used in the synthesis of medicine and material. Salen refers to a base formed by the condensation of two identical aldehyde molecules and a diamine molecule, and the complex formed by its combination with metals is called Salen metal complex, which is often used in the synthesis of chiral epichlorohydrin. In this paper, the development of Salen metal complex catalysts and their application in chiral epichlorohydrin synthesis are reviewed. At the same time, the deactivation mechanism of catalyst in the process of hydrolytic kinetic resolution was investigated and the application prospect of synthesis of chiral epichlorohydrin using Salen metal complex catalysts was prospected.

In recent years, the global market demand for pressure?sensitive adhesives has shown a steady growth trend. The market demand has reached about 3.5 million tons in 2021, and the estimated size of the global pressure?sensitive adhesive market in 2025 is ＄10 billion. Amid the development of pressure?sensitive adhesive technology and the increase in the application demand for pressure?sensitive adhesives, functionally modified pressure?sensitive adhesives have become a major trend in this field. Acrylate?based pressure?sensitive adhesive is the most widely used pressure?sensitive adhesive at present. Its performance has been improved after modification. Nevertheless, the modification process has some disadvantages, such as environmental pollution and low resource utilization. Since rubber has the advantages of low cost, superb mechanical properties, high and low temperature resistance, and environmental friendliness,and so on.Rubber?modified acrylate?based pressure?sensitive adhesives have become a development trend in this field. This paper summarized the development process of rubber?modified acrylate?based pressure?sensitive adhesives and outlined and compared the types of rubber and the advantages and disadvantages of modified products.

A high tide velocity makes it difficult for the riser to enter the borehole during its running after the riser section is drilled. A finite?element fluid?solid coupling model of fluid (seawater) and solid (casing) interaction is built with the finite?element analysis software ADINA. The following observations can be made from the analysis. A higher velocity results in a larger lateral offset in the final equilibrium state when the riser enters the borehole.Due to the flow blocking effect of the riser, seawater near the front end of the riser produces a strong detouring flow, while a local vortex is observed in the area near the back end of the riser.Under four working conditions of different tide velocities (0.60,0.70,0.80 and 0.90 m/s), both the Reynolds number and the equivalent flow resistance coefficient are in reasonable ranges.When the borehole diameter reaches 889.0 mm after borehole enlargement, a 508.0 mm riser is run in. No obstruction is encountered when the tide velocity is less than 0.59 m/s, whereas difficult borehole entering occurs when the tide velocity is higher than 0.83 m/s. It is suggested that the riser will be run in when the tide velocity reduces to below 0.59 m/s. The simulation analysis has a great guiding significance for the running of the riser during the drilling of offshore oil fields.

Mixing hydrogen into natural gas pipelines for transportation is an effective way to achieve large?scale,long?distance, and low?cost transportation of hydrogen.However, the mixing of hydrogen will have a great impact on the hydraulic characteristics and safety of natural gas pipeline during transportation.In this regard,SPS software was used to simulate the transportation and leakage conditions of natural gas pipelines with different hydrogen mixing ratios, in order to investigate the effects of hydrogen mixing on the hydraulic characteristics of natural gas pipelines,the operating characteristics of centrifugal compressors,and the pressure drop rate of block valve and leakage after leakage.The results show that adding hydrogen will reduce the gas transmission efficiency of the natural gas pipeline network and compressor performance,which can be compensated by increasing the pressure drop.The dynamic pressure amplitude decreases with the increase of hydrogen mixing ratio under the same natural gas output.When the hydrogen mixed natural gas pipeline leaks,the pressure drop rate and the leakage would increase as the increasing of hydrogen mixing,and the set value of the pressure drop rate threshold of the pipeline block valve also increases accordingly.In conclusion,the research results in this work can provide the basis for the research on determining the maximum of hydrogen mixing ratio in the natural gas pipeline and provide a reference for the determination of hydrogen mixing transportation technology in natural gas pipelines.

In view of the large fluctuation of the gas turbine load in the distributed energy system, the current researches on Organic Rankine Cycle (ORC) pay more attention to the comparison of the thermal performance of the same heat absorption with the initial parameters, but rarely consider the impacts of decrease in both flue gas temperature and mass flow rate on system performance causing by the gas turbine load reduction. Based on the characteristic model constructed by HYSYS platform, optimization scheme of the variable working condition ORC working medium was studied using the narrow⁃point temperature difference in the heat exchanger as the constraint condition. Under the variable load condition of gas⁃fired power plants, the operating parameters of the maximum net output power of the system are optimized. The cycle performances of varies working fluids with different compositions were compared of the characteristics of heat rate, mass flow and AP. The net output of R152a system shows obvious advantages on the heat rate and mass flow rate, compared with that in the mixed working medium in the selected working condition range, while the condenser AP value and the system heat recovery rate exhibit opposite performance. This work provides a reference database for the studying of the binary non⁃azeotropic mixture of ORC system.

The optimization of production and operation parameters of oil pipelines can effectively reduce operation energy consumption and improve the economic benefits of pipeline transportation. Aiming at the newly⁃built Qingha oil pipeline in the high and cold regions,the production energy optimization model was established with the constraints of the minimum energy consumption in production and operation,and the constraints of temperature constraints,pressure constraints,and oil pump operating characteristics constraints.In order to improve the solution efficiency,the hybrid PSO⁃Powell algorithm is used to solve the problem.The optimization results show that after optimization,the thermal energy loss is reduced by 38.3%,the pressure energy loss is increased by 90.3%,and the total energy loss is reduced by 26.3%.The energy saving effect is obvious.

With the implementation of the three oil recovery technology, although polymer flooding technology improves the oil recovery, it also brings new challenges to crude oil processing and gathering. High return pressure of oil gathering pipeline was caused by wax deposition of polymer flooding pipeline. Study was carried out on the heat cleaning of the polymer flooding gathering pipeline between the wellhead and the metering room after shutdown the well. The effects of heat washing water quantity, hot wash water temperature and different concentration of polymer on the dredging time were studied under different oil gathering radius. It was found that the hot wash water temperature was more obvious in the range of 65~70 ℃, which was calculated by the theoretical formula. When cleaning different polymer concentration pipelines, in the low water conditions, cleaning time of produced liquid with high concentration polymer was relatively longer. With the increase of heat washing water, there was no obvious change in the cleaning time of the sediment with different concentration.