This paper introduces the modularization design concept for petrochemical plants, and discusses in detail some points for attention in the modularization design, including design principle, plant layout, modular partition, modular design and installation, providing reference for the modularization design of petrochemical plants.

By calculating the material balance and heat balance in EO catalytic hydration process, a simple mathematical model was established for reactor calculation, the effect of two heat removal methods using water and circulating material as cold media respectively in controlling the maximum temperature of reactor was analyzed, and the variations of temperature and reactant conversion with tube length during the reaction were calculated. The analysis on maximum temperature of reactor shows that in EO catalytic hydration process, the raw materials can be quickly converted with a conversion rate of 90% in the presence of catalyst, and a large amount of reaction heat can be released. At this time, the maximum temperature of heat removal by water is close to that of heat removal by circulating material. Taking energy utilization and the design, manufacture and operation of reactor into consideration, the heat removal by circulating material is recommended.

 Many petrochemical plants are flammable, explosive and corrosive. The corrosion protection design of petrochemical concrete buildings should strictly follow the national and industrial standards and the principle of prevention first and protection combined. The environmental category, corrosive grade and action type, corrosion resistance of protection materials, service life, importance of structure itself, construction operability, material supply and other factors shall be comprehensively considered. To ensure the strength, stability and durability of petrochemical buildings and the normal use of buildings and structures within design service life, effective basic corrosion protection measures for structures and additional corrosion protection measures for buildings should be adopted. The necessity of corrosion protection design, the appropriate corrosion protection, the characteristics of corrosive media, the structural measures and the architectural measures for the corrosion protection design of petrochemical buildings are discussed in this paper, and an example of corrosion protection design is given.

Deisobutanizer reboiler is one of the key equipment in alkylation unit. It is usually horizontal thermosiphon reboiler. For a 300 kt/a alkylation unit, the inner diameter of the reboiler shell is approximately 1500mm under the condition that hot oil or low-pressure steam is the heat source. With the capacity expansion of the unit, the size of the reboiler will increase or several reboilers will be operated in parallel, which brings great difficulties to the piping design and field construction of equipment. Setting baffle in the column kettle can effectively reduce the inlet and outlet temperature of the reboiler shell side and improve the heat transfer temperature difference of the reboiler. The process simulation results show that after the baffle is set in the column kettle, the inlet and outlet temperature of the reboiler shell side decreases by 24.3℃ and 23.6℃ respectively, while the flow rates and specifications of the overhead and bottom products remain unchanged. The heat exchanger calculation results show that, after setting the baffle, the logarithmic average temperature difference increases by 47%, the heat exchange area decreases by 33%, and the inner diameter of the shell decreases by 300mm. In addition, the overflow of the baffle also provides a stable pressure head for the feed of the reboiler, which greatly improves the operational stability of the bottom reboiler system. For the effluent system of alkylation unit, there is no reboiler clogging problem in setting up the baffle due to the separation and removal of acid and alkali by coalescer before entering the deisobutanizer. This scheme can be regarded as a good optimization process for both new and modified alkylation units.

During the normal operation of cryogenic tank, the top flange of pump sump is subject to not only the periodic pressure and temperature changes but also the vibration load of pump in operation. Its unreasonable design may lead to the sealing failure of flange, the leakage of low temperature medium from flange seal and the local cold brittle cracking of tank roof near pump sump pipe, causing great hazard. This article analyzes the changes in temperature，pressure and load on the top flange of pump sump under various conditions, summarizes the possible causes of sealing failure of top flange, proposes some measures for avoiding the leakage at flange sealing face, and puts forward some suggestions for the reasonable design of top flange and fittings.

The development of the first-generation, second-generation and third-generation integrated heat tracing station technologies in petrochemical unit is introduced，and their advantages and disadvantages are summarized. The first-generation integrated heat tracing station technology has low investment, large floor area and easily corroded carbon steel pipeline. The second-generation technology has high integration, corrosion resistance, close to zero maintenance cost and high engineering cost. The third-generation technology has small floor area, low engineering cost, corrosion resistance and low maintenance cost. The status quo of integrated heat tracing station technology is analyzed, and its future development is forecasted.

Sulfuric acid, a kind of harmful medium, exists in a variety of forms in sulfuric acid alkylation unit and its supporting acid treatment unit by incineration, and its pipeline materials are complex and diverse, setting strict requirements for the piping design. This paper mainly introduces the characteristics of acid medium pipeline from the types of acid medium and the types of acid medium pipeline materials, and discusses the design of acid medium pipeline from the aspects of the drainage and venting design of acid medium pipeline, the priority design of special material pipeline, the type selection of pipe supports and hangers, and the leakage protection of pipeline.

Taking the construction technology of the inlet and outlet pipeline of flue gas turbine in the 4.8 Mt/a FCCU of a refinery as the example, this paper introduces the pipeline construction process, the key points of pipeline installation technology, the expansion joint installation and the support and hanger installation, and summarizes the key points in the installation of inlet and outlet pipeline, expansion joint and support and hanger of flue gas turbine, providing reference for the construction of similar pipelines in the future.

This paper introduces the application and preparation method of ethylene glycol (EG) in industry, discusses the process flow of multi-effect evaporation system in EG plant by EO hydration, and analyzes its equipment layout. According to the minimum NPSH of the pump, the installation height of the final vacuum effect reboiler condensate tank is obtained. In combination with the requirements of the process installation height between the condensate tanks, the installation height of the previous several effect condensate tanks is calculated, and then the minimum installation height of the reboiler and the multi-effect tower is further calculated. Thus, the structure height of multi-effect tower skirt and equipment frame can be reduced as much as possible while meeting the process conditions and piping requirements, so as to optimize the design of multi-effect evaporation system in EG plant.

 In order to prevent the strong and weak electromagnetic signal interference and ensure the safe and reliable operation of weak current system in electronically controlled pry, the electromagnetic shielding performance of 2.5-mm-diameter wire mesh shielding test box under different electromagnetic radiation distances and frequencies was studied using experimental methods. The experimental results show that the shielding effectiveness of wire mesh shielding test box decreases gradually with the increase of distance but the frequency of electromagnetic wave has less impact on the shielding effectiveness of wire mesh shielding test box when the frequency of electromagnetic wave is 900～2400 MHz. When the frequency of electromagnetic wave is less than 900 MHz, the electromagnetic shielding effectiveness of wire mesh shielding test box increases with the frequency of electromagnetic wave. The electromagnetic shielding effectiveness of wire mesh shielding test box is greatly affected by the electromagnetic radiation distance, and increases as the radiation distance decreases. The higher the frequency of electromagnetic wave is, the better the shielding performance of wire mesh is. The research results provide experimental basis for the shielding design of strong/weak electromagnetic signals in electronically controlled pry with wire mesh.

International advanced petrochemical projects attach great importance to the concept of safety first and people-oriented, so the establishment of a complete traffic sign and marking system for plant area is required. However, domestic project is still in its infancy in this field, and uniform design regulations and practices are lacked. As many world-class plants were put into production, China has attached more and more importance to safety and human culture. It is urgent to find out a simple and easy design method for road traffic sign and marking system in plant area of domestic projects. Based on the engineering practice of overseas projects, this paper discusses how to use the practical experience of international projects in this field for reference in domestic petrochemical projects.

This paper mainly introduces the application of high pressure PSA technology developed by Haohua Chemical Technology Group Co., Ltd. in the hydrogen recovery from methanol gas. It is characterized by advanced technology, desorption under high pressure, high degree of automation, excellent performance of program-controlled valve and adsorbent, and trouble-free long-term operation. The 9-year operation results of the plant show that the hydrogen yield of product is more than 5 percentage points higher than the design yield, and the methanol yield increases by 8-10%. The product gas pressure can reach 4.5 MPa (G), and the desorption gas pressure can reach 0.25 MPa (G). It can be directly sent to the natural gas reformer for combustion without pressurization. The energy consumption is much lower than that of ordinary PSA, of which the product gas pressure is 3.2 MPa (G) and the desorption gas pressure is 0.02 MPa (G), and the economic benefit is remarkable.

Both the process simulations by ASPEN PLUS and the combustion and heat transfer simulations of top-fired steam reformer by REFORM-3PC are carried out for the CO₂ emission reduction of hydrogen production unit with steam reforming process. The simulation results show that for the existing hydrogen production unit with top-fired steam reformer, the optimum CO₂ removal rate is no more than 60%, but 100% CO₂ removal rate can be achieved by decreasing the turndown ratio of the unit. After CO₂ removal, the hydrogen recovery rate in hydrogen purification section will be increased, and the consumption of feedstock and makeup fuel will be reduced. The rise of tube wall temperature of reformer, the rise of combustion temperature and the decrease in flame length are the main risk factors after CO₂ removal, and the preliminary solutions are put forward.

China is a country lack of water resources, and water resource is an important basic raw material for petrochemical production. Under this situation, the shortage of water resources severely restricts the development of China's petrochemical industry and affects the development direction and operating cost of petrochemical enterprises. By analyzing the current situation and existing problems in the water saving and sewage reduction of domestic petrochemical enterprises, some targeted improvement measures and methods are proposed in combination with the latest water saving and sewage reduction theories and methods, so as to improve the water use efficiency of the entire petrochemical enterprise and promote the energy saving and consumption reduction in the industry.

 The accuracy of process calculation of LPG loading pump is related to the efficient operation of LPG loading facilities. However, there are deviations both in the calculated pump head and the NPSHa based on the existing process calculation model, thus affecting the actual production of LPG loading facilities. Therefore, it is important to modify the process correlations of loading facilities to reduce the adverse impact of calculation deviation on actual production. Taking the LPG loading facilities of a factory in northwestern China as the example, this paper corrects the process correlations of LPG loading facilities and optimizes the process calculation model and process parameters of LPG loading pump based on theoretical analysis and practical operation experience.  The results show that the operation effect of the loading pump is improved in actual production after optimization.

With the increase of plant-wide projects in recent years, the importance of interface management is growing. Although its role in design achievements is not obvious, interface management plays a major part in improving the design quality and the work efficiency of plant-wide projects. This paper makes a simple comparison between the interface management of a foreign and a domestic plant-wide projects from software application to workflow, so that the engineers and the management can learn the experience, gradually attach importance to interface management, improve interface management level, and improve design quality and efficiency through the continuous standardization of interface management process, thus letting interface management better serve the engineering design.

Under the Belt and Road Initiative, adhering to the going global strategy and contracting large-scale overseas EPC projects is conducive to the integration of relevant enterprises and the utilization of domestic and foreign resources, thus promoting the growth of the national economy and the continuous progress of enterprises. Facing the severe international situations such as the slowdown of global economic growth, the cut in investment of overseas projects and the aggravation of trade tension, all the engineering construction enterprises in China attach great importance to the development of projects in central and west Asia. Coordinating market development, strengthening risk control and exploring the road of reform and innovation are the key factors for China to open up overseas market and promote the steady and healthy development of international projects. However, the international situation is changing rapidly, and central and west Asia has always been the center of the game between various political forces, so it is necessary to scientifically analyze and grasp the national conditions and the world situations to make reasonable prediction, so as to help relevant engineering construction enterprises better compete with and learn from foreign counterparts on the world stage.