The fractionator of FCC unit distillates the reaction oil and gas, and then draws out several streams as the products and sets up multiple middle sections to recover the heat of the reaction oil and gas. In the early stage, due to the low catalyst activity and high recycle ratio of the unit, a separate mid-pumparound for the fractionator would result in high liquid load in the trays near the middle section, thus increasing the diameter of the fractionator. In order to reduce the diameter of the fractionator and the investment, many existing units in operation are equipped with two mid-pumparounds, that is, light cycle oil (LCO) and heavy cycle oil (HCO). The simulation results of unit A in Case 1 and Case 2 show that the diameter of the fractionator can be reduced by about 300 mm after setting the HCO. In recent years, with the improvement of catalyst activity and the change in product plan of the unit, the recycle ratio of most FCC units has been reduced to about 0.1. At this point, it is possible to discuss canceling the HCO and reducing the operation difficulty of fractionator. The simulation results show that the diameters of fractionator in Case 1 and Case 3 are the same, which indicates that the existing fractionator can be used under the conditions of canceling the HCO and reducing the recycle ratio at the same time. Considering that such modification is usually carried out during overhaul and the time is limited, the utilization of the existing fractionator greatly shortens the construction period. At the same time, about 95% of the heat is used as the heat source of reboiler in the reasonably optimized heat exchange process of the LCO. In addition, the heat recovery ratio of the slurry system of fractionator is increased by about 10%. The above two measures can improve the energy utilization efficiency of the fractionator. This paper provides a reasonable and alternative modification idea for similar units.

In 2016, deep-cut revamping and heat exchanger network optimization were carried out on the 2.5 Mt/a atmospheric and vacuum distillation unit in Yumen refinery. The inlet temperature of crude furnace was increased from 260℃ to 310℃ after the integration and optimization of heat exchanger network. Through the deep-cut revamping of vacuum tower including the transformation from lubricating oil type to fuel type, the vacuum ejector system, the vacuum furnace and the vacuum transfer line, the TBP cut point of crude reached 565℃, the yield of VGO was improved by 6.47%, thus optimizing the feed to FCC unit. The yield of VR was decreased by 6.86%, reducing the load of DCU and improving the economic benefit of the refinery.

The flow rate and pressure of the primary leakage gas dropped to zero during the dry gas seal operation of high pressure cylinder of pressurized hydrogen compressor in the reforming unit at SINOPEC Zhenhai Refining and Chemical Company. This paper makes an in-depth analysis on the sealing structure, installation data, static test situation, condition monitoring, process data and other aspects to identify the root causes of the sealing failure and puts forward some corresponding countermeasures, providing theoretical basis and practical experience for preventing similar problems from appearing again.

In residue hydrocracking process, the unconverted oil easily agglomerates and deposits when its temperature or flow velocity is reduced, leading to the plugging of heat exchangers. Through heat transfer calcultation of spiral plate steam generator, the impact of different process parameters on oil side outlet temperature and flow velocity is investigated. The results show that the total heat transfer coefficient of spiral plate steam generator is restricted by oil side heat transfer coefficient. The outlet temperature and flow velocity of unconverted oil will reduce with the increase in heat exchanger design margin and improve with the increase in fouling resistance, heat duty or water side operating pressure. In pracitce, the oil side outlet temperature and flow velocity can be effectively regulated by adjusting water side operating pressure.

EPCC (Engineering-Procurement-Construction-Commissioning) or LSTK (Lump-Sum Turn Key) is an execution mode of overseas project. This paper introduces the commissioning management of an overseas EPCC project undertaken by SINOPEC Engineering Incorporation, and introduces the scope of commissioning work, the organization of commissioning team, the preparation of commissioning documents and the management and execution of job-site commissioning work. The commissioning management practice of this project shows that there are many uncontrollable risks that may affect the EPCC project schedule.

To solve the problem of delayed project schedule during EPC project execution, the optimizable items of Time, Cost, Quality and Scope are analyzed through Project Management Triangle model based on the definition of project management to obtain an expectation model. On this basis, the principle of information gathering, information analysis and information processing are discussed, and its necessity for project execution is obtained. Finally, it is expected that the original intention of improving project schedule control can be realized through the combination of purposefulness, methodology and executive ability.

 In view of the increase in internal pressure and respiratory loss of oil and gas storage tanks under high temperature, the cooling effect of radi-cool coating applied to the surface of absorption tower kettle of petrochemical storage tank was studied and an experiment was carried out in the plant of Ningbo Zhongjin Petrochemical Co., LTD. The results showed that the radi-cool coating takes advantage of high solar reflectivity, high emissivity and low thermal conductivity index to achieve self-cooling. While the surface of the oil and gas storage tank was sprayed with radi-cool paint, the tank wall temperature dropped by 15℃, effectively reducing the internal pressure of the tank and reducing the respiratory loss.

Crude distillation unit, hydrotreating unit, olefin plant and polymer plant are usually installed in refinery and petrochemical complex. Central laboratory is responsible for the analysis of feedstock, intermediate efflux, products and by-products. Gas Chromatography (GC) is one of the most important means of analyzing the composition of streams in petrochemical industry. GC is the equipment with the largest number in the central laboratory. In the engineering design stage, it is particularly important to configure GCs correctly and reasonably. Based on the experience of engineering design, this paper takes a refinery and petrochemical complex as an example to give some suggestions on the configurations of GC in central laboratory.

This article introduces the temperature anomalies at the second stage exit of flash gas compressor. Based on the working principle of reciprocating compressor and valve volume regulating mechanism, the airtightness of compressor air valve, the wear of piston rings, the ovality of cylinder liner and the scale of cylinder water jacket were checked. The effect of air valve scaling on temperature was eliminated, and the relative dimensions of the valve assembly were measured. It was determined that the pneumatic valve stem at the second stage inlet restricted the movement of valve plate, so that the air valve plate could not be closed normally. The position change of valve volume regulating mechanism was the fundamental cause of the abnormal temperature rise in the second stage. The corrosion of valve cage and the excessive tightening force of valve gland bolts caused the deformation of valve cage, resulting in the position change of valve volume regulating mechanism. The failure was removed by changing the thickness of gasket between valve cage and air valve, replacing the valve plate, cleaning the water jacket and repairing the internal circulating water pump, and some solutions were put forward to prevent the deformation of valve cage.

Combined with the feedstock data and process flow of a sulfur recovery unit in China, the simplified modeling and calculation for thermal reaction was carried out with the equilibrium constant method based on the Engineering Data Book published by Gas Processors Suppliers Association. Also the CLAUS split flow process was simulated by ProMax. The results were compared and analyzed. The influence of key operating parameters of split flow process was studied to provide guidance for the design and operation of sulfur recovery unit.

The Aspen Plus simulation software is used to study the product quality optimization of FCC unit. The influence of the type and amount of stripping medium, the dry point of stabilized gasoline and the pumparound flowrate of main fractionator on the product quality of crude gasoline and light diesel, the output of stablized gasoline and the inlet flowrate of wet gas compressor is studied. Based on the study, the product quality of FCC unit is optimized, the output of high-value product stabilized gasoline is increased, and the energy consumption of unit is reduced. The results show that using low-low pressure steam or low pressure steam as the stripping medium, controlling the stripping steam flowrate within 3% ~ 4% of diesel flowrate and controlling the dry point of stabilized gasoline at about 200℃ are beneficial to controlling product quality, stabilizing gasoline output and reducing the energy consumption of FCC unit.

 Based on a 80/280 kt/a EO/EG plant in China, this research conducted a process modeling for the EO purification unit via Pro II in order to develop a revamping scheme. Combining the data obtained from the simulation with its counterpart collected from the actual operation, this article studied the influence of reflux ratio, EO concentration in feed, tower internal, energy utilization scheme and other factors on the output and quality of EO product, and determined a reasonable revamping scheme. Without increasing EOE (EO Equivalents) capacity, the optimized revamping scheme can increase the EO design capacity up to 180% of the original design within a short design and construction time, with the lowest energy consumption and the highest profit. What presented herein can provide valuable reference for the EO capacity expansion of EO/EG plants.

Two isothermal shift technologies used in HT-L pulverized coal pressure gasification for methanol production, including total shift and partial shift, are introduced. Through the simulation calculation of the two isothermal shift technologies, comparison and analysis ae made from the aspects of process scheme, process flow, equipment configuration, utilities consumption and side reaction. When selecting process routes, the users should give overall consideration and select the most suitable isothermal shift technology according to their needs.

Alkylate production has become an inevitable trend for refineries. In consideration of the high energy consumption of alkylation unit, it’s necessary to optimize the operation of alky unit in combition with the energy supply conditions of the whole refinery. A refinery has a 300 kt/a sulfuric acid alkylation unit with 135 kgoe/t alkylate consumption, and a large amout of low-temperature hot water is available. An energy-saving revamping scheme is designed to save 1.0 MPag steam (27.0 t/h) by using low-termperature hot water as much as possible. The energy consumption of the unit can be reduced by 30.3 kgoe/t alkylate after the revamping.

In this paper, the UOP process for phenol-acetone production by isopropyl benzene oxidation was simulated using Aspen Plus. Based on the simulation results, a pinch analysis of the distillation tower involved in the process was carried out, and a heat integration scheme was proposed. Subsequently, the feasibility of heat integration between the tower system and the background process was analyzed, and the possibility of matching the heat exchange between the tower system and the background process was pointed out, which provided a basis for the extraction of logistics data in the design of heat exchanger network. Finally, the theoretical maximum heat exchange recovery network was obtained based on the pinch design principle. Compared with the initial process, in the final energy-saving plan, cold utilities reduced from 96.69 MW to 70.98 MW, saving energy by 26.59%, and heat utilities reduced from 55.41 MW to 29.71 MW, saving energy by 46.38%. Good energy-saving results were achieved.