FCC plays a key role in the process of resid cracking to light hydrocarbons. In this study, HYSYS software was employed to set up FCC mechanism model, and the model was calibrated by plant data. The influence of reactor size, feed properties, catalysts and operation conditions on product yield was analyzed systematically, and the maximum or minimum product yields were taken as the target for variable optimization. The results show that the four key parameters influencing the product yield are feed characterization factor, conradson carbon residue (CCR) content, catalyst micro-activity and reaction temperature. LPG yield is positively correlated with feed characterization factor, catalyst micro-activity and reaction temperature and negatively correlated with CCR content. The relation between diesel yield and multiple variables is just the opposite. The relation of gasoline yield and total liquid yield with the variables is the same as that of LPG yield except that the gasoline yield and total liquid yield increase firstly and then decrease with the incrase of the reaction temperature. For gasoline yield, diesel yield and total liquid yield, feed characterization factor shows the highest optimization degrees of 18.91%, -41.23% and 4.85%, respectively. For LPG yield, reaction temperature shows the highest optimization degree of 23.19%. Catalyst micro-activity presents the lowest optimization degrees for gasoline, LPG and diesel yields, which are 1.59%, 1.77% and -3.25%, respectively. For total liquid yield, reaction temperature presents the lowest optimization degree of 0.26%. The obtained results could provide theoretical basis for the optimization of process design and the operation adjustment in refinery plant

Based on China's rich coal resources, coal-based ethylene glycol technology has developed rapidly in China in recent years. Henan Energy and Chemical Group has the coal-based ethylene glycol technology with independent intellectual property rights, and has completed the construction of five sets of ethylene glycol plants with an annual output of 200,000 tons. The cooling system after carbonylation is an important node of the process system, but during the long-term operation of the unit, it is found that the design and selection of circulating pump deviate from the actual operation. Through this technical transformation, the circulating pump of the cooling system is optimized to ensure the stable operation of the system and to achieve energy saving and consumption reduction. The comparison of the operation conditions before and after the type change shows that the energy consumption is reduced by 47% after the type change.

In construction projects of new petrochemical plant, an 110kV main substation can provide reliable guarantee for the power supply of the whole plant. In order to guarantee that the units and supporting facilities completed in advance can be put into operation smoothly as scheduled, the design and construction of the main substaion is always the landmark control point of the project. In this paper, by analyzing the practical engineering examples of 110kV main substation in construction projects of new petrochemical plant in recent years, the engineering experience accumulated in architectural design is summerized to provide reference for the standardization design of main substation, and some thoughts and suggestions are put forward for design optimization in the future, so as to ensure the smooth progress of the construction projects of petrochemical plant.

Due to the unsaturated double bond, butadiene is easy to polymerize, especially at higher temperatures and in the presence of oxygen. Polymers may cause blockage or explosion of equipment and pipes, thus affecting the large-scale storage of butadiene. Aiming at the actual storage problems of spherical tanks, this paper analyzes in detail the problems of the system from the aspects of process, equipment, control, safety and environmental protection, and proposes a new large-scale semi-refrigerated vertical storage process, which can reduce not only polymerization risk but also equipment investment and floor area. The actual operation of the industrial plant shows that the storage system has good stability and low generation of polymer, so it can be applied to the large-scale storage of butadiene

The process scheme of crude distillation unit (CDU) was discussed based on the properties of a light mixed crude oil and the requirements of refinery block flow diagram (BFD), and the pre-distillation CDU process scheme with high operation pressure was proved suitable for the given mixed crude oil. The process simulation of the process scheme was carried out through Simsci PRO/II 8.2, the pre-fractionator operation pressure was optimized, the total CDU off-gas flowrate was significantly reduced and the SGP feedstock gas compressor load was cut down.

The flue gas waste heat recovery system is to recover flue gas waste heat, improve the thermal efficiency of heating furnace, and reduce flue gas temperature. Air preheater is one of the important equipment in the waste heat recovery system of heating furnace. When the exhaust gas temperature drops to a certain point, there will be a large amount of condensate at the cold flue gas outlet of the preheater. When the wall temperature of flue gas side of heat exchange plate is lower than the dew point temperature of water, the moisture in flue gas will condense on the wall of heat exchange plate, and the dew will gradually converge into water drops, forming flowing condensate. The lower the wall temperature of flue gas side of heat exchange plate is, the more water drops. This problem can be solved by installing pre-stage preheater, hot air circulation and cold air bypass. Among them, hot air circulation is the most flexible, practical and effective method.

Due to the compact space on offshore platform, the equipment needs to be designed as a skid, and even double-layer platform is used for skidding design. Limited by the load-bearing capacity per unit area of platform deck, more stringent weight control is proposed for the skid-mounted equipment on double-layer platform. The finite element model of six different lifting lugs is established for analysis and calculation. Based on the general finite element analysis software ANSYS, this paper optimizes the design of double-layer platform to achieve the lightweight of the whole skid while meeting the strength requirement, and provides reference for engineering practice.

This paper briefly introduces the structure and working principle of rotary drum vacuum filter which is the core equipment of acetone-benzol dewaxing and deoiling unit, analyzes the reasons for the problems including the failure of unloader knife, the vibration of high vacuum tube, the moisture absorption of bearing box and the damage of filter cloth based on the operation of filter, and puts forward some reasonable solutions. Part of the structures are improved to ensure the normal operation of equipment and to prolong its service life.

This paper introduces an optimization method for the design of prestressing system for the outer wall of large-scale reinforced concrete LNG storage tank under the condition of inner tank leakage, including the finite element model of outer tank, the computing method and the analysis of results. The influence of prestressing system on the internal force distribution, reinforcement and liquid tightness of outer tank wall under the condition of inner tank leakage is studied in detail.

The feed position and temperature of the absorption and desorption tower in hydrocracking unit are usually designed according to the undercooled liquid feed to the absorption and stabilization system, but the liquid feed is actually saturated. Therefore, the optimization of absorption and desorption tower can greatly influence the material consumption and energy consumption of the unit. The effects of liquid feed position and stripping tower reflux temperature on material loss, energy consumption and operating cost are studied using Pro/II, and some optimization methods are proposed. The optimization results of the absorption and stabilization system in a 1.0 Mt/a hydrocracking unit show that the loss of heavy components in dry gas can be reduced by 37%, the energy consumption can be reduced by 23%, and the benefit can be increased by 1.64 million CNY per year.

The characteristics of ultra-high operating pressure of LDPE (EVA) plant determine the particularity and specialty of the design and installation of its pipelines and equipment. The application of modern three-dimensional laser scanning technology and three-dimensional model plays an important role in optimizing the design and reconstruction of such plants and improving the design efficiency and installation accuracy. Combined with the application experience of this technology in the reconstruction of a domestic EVA plant, this paper introduces the application method of 3D laser scanning technology, and analyzes and summarizes the advantages and disadvantages before and after the application, providing reference for the later construction and reconstruction of such plants.

This paper analyzes the causes of dry gas seal failure during the start-up of centrifugal recycle hydrogen compressor, and concludes that the liquid entrainment in recycle hydrogen and the fast speedup of compressor unit are the direct causes of dry gas seal failure. The liquid entrainment in recycle hydrogen does not necessarily damage the dry gas seal. When the unit runs at a low speed, the liquid in the recycle hydrogen does not gain enough energy to enter the seal chamber due to the obstruction in labyrinth seal and first-stage seal gas, so the dry gas seal is not affected. Only when the rotation speed is high enough, the liquid in the recycle hydrogen can enter the compressor outlet seal chamber, causing damage to the dry gas seal. Therefore, if the dry gas seal is not affected after the naphtha enters the centrifuge, it is not necessary to dismantle the machine for repair.

Methyl tert-butyl ether (MTBE), as an important oil blending component, can effectively improve the octane number of gasoline. In order to meet the requirements of national V gasoline blending standards, the sulfur content of MTBE products must be reduced to less than 10 mg/L. Extractive distillation process is generally used in the industry for the deep desulfurization of MTBE, but gumming often occurs due to the enrichment of organic sulfur in the bottom of distillation column, the colloid will seriously affect the heat transfer efficiency at the tower bottom, and the unit has to be shut down intermittently for cleaning up. The variation of sulfur content in the top and the bottom of distillation column, the gumming conditions and the trend of sulfur content and its effect on distillation at different reflux ratios were explored by simulated distillation experiment, and new cost-effective antigum inhibitor for distillation desulfurization was developed

The naphtha product separation processes of hydrocracking unit mainly include light naphtha effluent from fractionator overhead and full-range naphtha effluent from fractionator overhead. Taking a 2.0 MMTA hydrocracking unit as an example, this article analyzes the differences between the two processes, and compares them in operating cost, investment and product properties through process simulation. The advantages of light naphtha effluent from fractionator overhead process are the low operating cost and low investment, while the advantage of full-range naphtha effluent from fractionator overhead process is the clear cutting of light naphtha and heavy naphtha. Refineries can select appropriate process according to the actual conditions.

Restricted by regional conditions, a proposed crude oil pipeline has to pass through Dawu groundwater enrichment area. This paper discusses the technical prevention measures for pipeline passing through groundwater enrichment area from the aspects of pipeline body, anti-corrosion, line block valve chamber, leakage detection, optical fiber early warning, groundwater monitoring well and anti-seepage scheme, and puts forward some environmental protection requirements for construction period and operation management, so as to improve the intrinsic safety of pipeline, reduce the environmental risk of pipeline leakage and ensure the safety of groundwater environment

This paper introduces the characteristics of multi-way plunger valve and its configuration design from the perspective of piping design combined with the design experience and examples of slurry pipeline in a residue hydrocracking unit. There is no fixed configuration for multi-way plunger valve. The process flow requirements, equipment layout, installation and operation space and piping flexibility should be considered comprehensively in the piping design, the configuration of main plunger should be designed based on piping system on the premise of meeting the valve manufacturing requirements, and the design of valve support, flushing plunger valve and draining plunger valve should be perfected. Piping design and the configuration design of multi-way plunger valve influence each other and should be carried out synchronously.