Table of Content

12 December 2025, Volume 56 Issue 12

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STUDY ON CATALYTIC CRACKING PROCESSING OF STYRENE TAR

2025, 56(12):  1-5. 

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In order to realize the resourceful utilization of styrene tar in catalytic cracking unit, the properties and hydrocarbon composition characteristics of styrene tar were analyzed, the product distribution of styrene tar through catalytic cracking and the influence of feeding methods and blending ratios on the product distribution were investigated. The results show that styrene tar has high density, high carbon residue and high aromatics content. The molecular structure of aromatics in styrene tar is dominated by monocyclic aromatics and non-dense polycyclic aromatics. Main products of different styrene tar are gasoline and diesel, with low gas yield and high coke yield, and the aromatics content in gasoline is more than 80%. Based on the influence of product distribution and product quality requirements, styrene tar is suitable for processing by mixing it with catalytic feed and with a blending ratio of less than 5%.

INDUSTRIAL EXPERIMENT ON DESALINATION OF HIGH SALT HEAVY CRUDE OIL

2025, 56(12):  6-14. 

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A heavy crude oil with high salt content is due to the high mineralization of its associated water. This crude oil also has high density, viscosity, asphaltene content, and solid particle content, which cause dehydration difficulties. As a result, the low-salinity water injected during the electric desalination process cannot be separated effectively, leading to high salt and water contents in the oil after electric desalination, which affects the enterprise's safe production.By analyzing the properties of this heavy crude oil, it was found that the high condensation degree of asphaltene and the existence of solid particles are the main factors hindering desalination. Accordingly, two demulsifiers, RPD-73X and RPD-73Y, were developed. Their industrial application reduced the salt and water contents in the oil after electric desalination. Industrial test results indicate that after three-stage electric desalination, the average salt mass concentration of the treated crude oil is 28.5 mgNaCl/L, a 41.4% decrease from the pre-test level, while the water mass fraction decreases by 20.1%. These results show that the developed demulsifiers are effective for desalination and dehydration.

ANALYSIS AND COUNTERMEASURES OF STARTUP AND SHUTDOWN ISSUES WITH FEEDSTOCK IN SOLVENT DEASPHALTING UNITS

2025, 56(12):  15-20. 

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The 0.8Mt/a solvent deasphalting unit of a refining and chemical company was shut down in October 2024, due to the change in the overall processing mode of the entire plant. Since then, the unit has been in a five-month shutdown with material remaining inside for static storage. Due to incomplete material withdrawal and thorough purging of the system, problems such as prolonged solvent purification time during shutdown and inability to conduct nitrogen gas tightness tests in stages during startup, resulting in numerous near-critical leakage points, and poor flow in the secondary solvent branch process occurred. Through regular and scheduled inspections, assistance from LDAR detection equipment, and staged steam purging, the smooth shutdown and startup of the solvent deasphalting unit were effectively ensured.

APPLICATION EFFECTS OF ENVIRONMENTALLY FRIENDLY LIQUID-PHASE HYDRODEOLEFINATION TECHNOLOGY FOR REFORMATE IN THE TRANSFORMATION OF REFINING AND CHEMICAL ENTERPRISES

2025, 56(12):  21-27. 

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Reformate contains a small amount of olefins, which can exert varying degrees of impacts on the equipment, adsorbents, catalysts, and other components of downstream units. Therefore, efficiently removing olefins from reformate has become an important research direction. The application of an environmentally friendly liquid-phase hydrotreating for olefin removal (HER) technology in reformate is introduced. The HER process offers significant advantages in multiple aspects, such as enabling light alkanes to be used as high-quality feedstocks for ethylene production; improving the quality of products like BTX,heavy aromatics,foaming agents,and solvent oils; enhancing environmental friendliness; and reducing equipment corrosion. This technology brings considerable social and economic benefits to petrochemical enterprises. Compared with traditional olefin removal processes such as industrial granulated clay, molecular sieve refining, and non-precious metal technologies, the HER process demonstrates outstanding performance in intrinsic safety, energy efficiency, environmental protection, and product quality enhancement, indicating promising development prospects.

RESEARCH ON HYDRO-UPGRADING TECHNOLOGY SCHEMES FOR DIFFERENT CRUDE DISTILLATES TO PRODUCE HIGH-QUALITY ETHYLENE FEEDSTOCK

2025, 56(12):  28-34. 

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To address the structural market conflict between declining diesel demand and shortage of ethylene feedstock, technical schemes for converting different types of diesel fractions into high-quality ethylene cracking feedstocks via hydro-upgrading technology were investigated. The processing strategies for different fractions (kerosene, diesel) derived from paraffinic Saudi Lightcrude oil and intermediate-based Shengli crude oil were emphasized. The results show that for paraffinic Saudi Light crude oil, the light fraction with a final boiling point ＜200°C has high paraffin content (62%) and can be directly used as ethylene feedstock. For its 200—250°C jet fuel fraction, at a conversion rate of 10%, the BMCI value of the unconverted oil (UCO) decreases to 16.2 with paraffin content reaching 55.4%. For its 250—350°C diesel fraction, at a conversion rate ＞10%, the BMCI of UCOdecreases to below 21 and paraffin content exceeds 50%, becoming suitable ethylene feedstocks. For intermediate-based Shengli crude oil, <150℃ light fractions are more suitable for reforming feedstock. Its 150—250 °C jet fuel fraction achieves a UCO BMCI of 23.2 and paraffin content of 50.5% at conversion of 15%, becoming suitable ethylene feedstocks. Its 250—350 °C diesel fraction requires narrow fractionation (recommended initial boiling point of 220—240°C) of the UCO after 20% conversion; the resulting ＞220°C or ＞240°C fraction exhibits significantly reduced BMCI and increased paraffin content, meeting ethylene feedstock requirements.

COMMERCIAL APPLICATION OF LOW-TEMPERATURE FLEXIBLE AND RESIDUE FILTRATION DEASHING TECHNOLOGY FOR FCC SLURRY

2025, 56(12):  35-40. 

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To maximize the supply of slurry from catalytic cracking unit(FCC slurry) for advanced carbon materials, a combined low-temperature flexible and residue filtration deashing technology for FCC slurry was developed and implemented in SINOPEC Maoming Company.This technology employs flexible filter materials operating at 120—160 ℃, combined with back-blowing regeneration and adsorption processes using environmentally friendly composite filter materials, achieving efficient solid removal from both raw FCC slurry and residues. Operational results demonstrate that the low-temperature flexible deashing unit produces deashed FCC slurry with an average ash content below 0.01%, achieving an ash removal rate exceeding 98% and a FCC slurry yield of approximately 94%. The residue filtration deashing unit further reduces ash content to below 0.01% with an average ash removal rate of over 99%, while maintaining a dry residue yield below 1%. The integrated system achieves an overall purified FCC slurry recovery rate exceeding 99%, significantly enhancing resource utilization and reducing environmental burdens from solid waste. This technology provides stable feedstock for high-value carbon materials such as needle coke, characterized by low energy consumption and environmental benefits, demonstrating substantial industrial applicability and promotion value.

STUDY ON COUPLED REGULATION OFACID PROPERTIES AND PORE STRUCTURE IN HY ZEOLITE AND ITS CATALYTIC PERFORMANCE IN ALKYLATION OF NAPHTHALENE WITH 1-DODECENE

2025, 56(12):  41-49. 

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This work systematically investigates the influence of pressurized water-vapor treatment on the acidic properties and pore structure of HY zeolite, as well as its catalytic performance in the alkylation of naphthalene with 1-dodecene. Advanced analytical techniques, including SEM, NH₃-TPD,and Py-IR, are used to characterize the acid properties and pore structure of the catalysts. The results indicate that the mesopore volume of the zeolite catalyst treated with pressurized steam at 0.2 MPa is 0.120 cm³/g, with an average mesopore diameter exceeding 30 nm. The diffusion performance of reactant and product molecules within the zeolite is improved. The accessibility index of strong acid sites rises from 0.11 (for the untreated catalyst)to 0.32, while the acid-pore synergy index increases from 16.53 to 32.28, evidencing a synergistic optimization of acid properties and pore structure. The catalytic performance evaluation reveals that the conversion rate of 1-dodecene and the selectivity for long-chain alkylnaphthalenes on the zeolite catalyst treated with pressurized steam at 0.2 MPa reach 98.57% and 95.07%, respectively. This is primarily attributed to thelarger mesopore volume and higher accessibility of strong acid sites of the catalyst achieved through coupled regulation.

STUDY ON ENHANCEMENT MECHANISM OF ETHANE ADSORPTION BY NITROGEN/OXYGEN HETEROATOM-DOPED ACTIVATED CARBON

2025, 56(12):  50-60. 

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This study systematically investigates the adsorption mechanism of ethane (a critical component of volatile organic compounds, VOCs) on heteroatom-modified activated carbon, aiming to address the dual challenges of efficient ethane recovery in petrochemical industries and greenhouse gas emission reduction. To overcome the limitations of conventional activated carbon, such as restricted specific surface area and suboptimal pore structure, an innovative surface doping strategy was developed by introducing hydroxyl, carbonyl, pyridinic nitrogen, and amino functional groups. Through combined quantum chemical calculations and grand canonical Monte Carlo (GCMC) simulations, the regulatory effects of these functional groups on binding energy, weak intermolecular interactions, and electrostatic potential distribution in the activated carbon-ethane system were elucidated at the molecular level. Key findings reveal that amino-group doping achieves the highest binding energy in planar adsorption configurations, with an ethane adsorption capacity of 153.9 mL/g, representing a 10.2% enhancement over pristine activated carbon. Conversely, carbonyl-group doping exhibits optimal performance in lateral adsorption configurations, achieving a 74.0% increase in ethane adsorption capacity. Electrostatic potential analysis demonstrates that nitrogen/oxygen heteroatom doping modulates adsorption performance by redistributing surface charge density. The microscopic mechanism of ethane adsorption by activated carbon is revealed through simulation calculations, which provides a theoretical basis and design strategy for the development of high-efficiency VOCs adsorption materials.

MP-PIC SIMULATION OF THE EFFECTS OF DISTRIBUTOR CONFIGURATIONS ON REGENERATED CATALYST SHORT-CIRCUITING AND DILUTE-PHASE PARTICLE ENTRAINMENT IN AN MTO UNIT

2025, 56(12):  61-66. 

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There is a short-circuit problem of regenerated catalyst particles during the operation of a fluidized bed reactor in an industrial methanol-to-olefin (MTO) unit, accompanied by abnormal catalyst loss. In this study, the Multi-Phase Particle-in-Cell (MP-PIC) model was used to simulate the hydrodynamic behavior of the reactor in equal proportion and analyzed together with field data. The results show that the two distributors in the reactor, especially the distributor near the outlet of spent catalyst, are prone to short circuit of regenerated catalyst particles. After the installation of three overflow buckets, the short circuit of regenerated catalyst particles can be suppressed to a certain extent. Under normal conditions, the catalyst loss in the reactor mainly come from the extremely small particle size fine powder (particle size below 10 μm) produced by particle wear. In the MTO unit, the probabilities of abnormal catalyst loss from the reactor and the regenerator are 18.19% and 54.51%, respectively; the much higher probability in the regenerator is attributed to its higher dense bed level and to the cyclone wing valves being located below the bed level. Through simulation, the possibility of short circuit of regenerated catalyst particles and the necessity of installing overflow buckets were clarified, and follow-up improvement suggestions were proposed to mitigate abnormal catalyst loss in the unit.

SIMULATION OF DYNAMIC ADSORPTION PERFORMANCE OF ACTIVATED CARBON-BASED OIL DECHLORINATOR

2025, 56(12):  67-73. 

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Oil dechlorination is a key step in petroleum refining and processing, and the selection of appropriate dechlorinator is the core issue of this step. The dynamic adsorption process of HCl from oil was simulated using Aspen Adsorption on the basis of the static adsorption data of AC/Ca-Cu activated carbon-based dechlorinator. The results show that the time from the start of dynamic adsorption to complete breakthough for the dechlorinator is basically equal to the saturation duration of static adsorption,with a relative error of 2.5%. It is favorable for increasing the dynamic saturation adsorption capacity of the adsorption bed by increasing the HCl concentration in the feed or decreasing the feed flow-rate, but it will cause the breakthrough point to occur earlier. When the mass transfer coefficient is greater than or equal to 0.1 s^-1, it has almost no effect on the adsorption process. With the increase of bed voidage, the starting point of bed breakthrough is significantly advanced, requiring frequent regeneration of the dechlorinator during production. Using the AC/Ca-Cu activated carbon-based dechlorinator with a feed flow rate of 4 m³/h, a feed concentration of 0.001 mol/L, a mass transfer coefficient of 0.1 s^-1 ,and a bed voidage of 0.4, the elapsed time from the start of adsorption until the bed layer reaches complete breakthrough is approximately 3.9 h.

STUDY ON PREPARATION OF HIERARCHICAL SILICA GEL ADSORBENT AND ITS ADSORPTION AND SEPARATION PERFORMANCE FOR AROMATICS

2025, 56(12):  74-81. 

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By employing microporous silica gel powder and silica sol binder in different proportions, hierarchical silica gel adsorbents A–Dwere prepared with the method molding by rolling.The adsorbent mechanical strength and sintered bulkdensity were measured. The pore structure of adsorbent was characterized by gas adsorption method and mercury intrusion method. The adsorption and separation characteristics of the adsorbents for alkanes, aromatics and sulfur-containing compounds were studied by static adsorption and dynamic pulse methods. The research results indicated that the adsorbent obtained microporous, mesoporous, and macroporous structures simultaneously. With the increase of binder content, the mechanical strength of the adsorbent increased and the sintered bulk density decreased. The static adsorption results showed that hierarchical pores in adsorbent would not affect the selectivity of the adsorbent towards aromatic components. With the increase of the binder content, the adsorption capacity of aromatics decreased gradually. The selectivity of adsorbents with different pore structures for aromatics decreased as follows: dibenzothiophene>methyl naphthalene>monocyclic aromatic hydrocarbons>non aromatic hydrocarbons. The dynamic pulse test results showed that the separation resolution of adsorbent B and adsorbent C for aromatic components is comparable to or slightly higher than that of microporous silica gel spheres. Additionally, the mass transfer rates for each component increased by 44.7%–51.5% and 26.1%–32.5%, respectively.. The hierarchical material formed by microporous material obtained a high aromatics adsorption capacity and a large specific surface area, while the mass transfer characteristics were improved and the separation performance of aromatic components was enhanced, which was beneficial for better adsorption and separation performance in simulated moving bed processes.

COMMERCIAL APPLICATION OF Min-Coke: A LOW COKE-FORMING CATALYST FOR EFFICIENT HEAVY OIL CRACKING

2025, 56(12):  82-90. 

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SINOPEC Research Institute of Petroleum Processing Co., Ltd. has developed a novel hierarchical pore catalyst named Min-Coke for efficient cracking of heavy oil with low coke formation. The catalyst demonstrates exceptional properties, such as a high specific surface area, elevated meso- and macro-pore ratios, and robust resistance to metal contamination. These characteristics enhance feedstock and product diffusion while improving accessibility to active sites, leading to significantly improved heavy oil cracking performance. Industrial trials of Min-Coke were carried out on the No. 2 fluid catalytic cracking (FCC) unit at SINOPEC Jinan Company. Benchmarking results revealed notable improvements compared to baseline data: gasoline yield increased by 1.35 percentage points, combined gasoline and liquefied petroleum gas (LPG) yield rose by 2.44 percentage points, and total liquid product yield improved by 1.99 percentage points. Light olefin yields (ethylene, propylene, and butylene) increased by 1.18 percentage points—a gain exceeding 10%. Most strikingly, coke yield decreased by 1.92 percentage points, representing a reduction of over 15%. Statistical analysis further indicated that, even with a 1 percentage point increase in feedstock carbon residue, higher proportions of graded-pore catalyst in the inventory correlated with marked improvements in gasoline yield. Simultaneously, diesel yield declined, dry gas production trended downward, and coke yield decreased by nearly 1 percentage point. Additionally, the olefin content in gasoline was substantially reduced. These findings conclusively demonstrate Min-Coke’s superior ability to optimize product distribution, particularly through enhanced gasoline yield and reduced coke formation, thereby advancing heavy oil cracking efficiency.

RESEARCH ON DIGITAL INTELLIGENT MANAGEMENT PLATFORM FOR DAMAGE IDENTIFICATION OF PETROCHEMICAL PLANT

2025, 56(12):  91-96. 

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As a key link in energy supply, the safety and stable operation of the petrochemical industry's facilities are of vital importance. In view of the deficiencies of traditional petrochemical plant damage identification accuracy, the timeliness of risk early warning and the scientific nature of decision-making, a digital intelligent management platform for petrochemical plant damage identification was established by using modern information technology and intelligent models. Its design architecture, functional interface, identification mechanism and description mode were analyzed, and then the actual application effect in enterprises was studied. The analysis results show that the platform architecture framework consists of four layers, namely,the display layer, business logic layer, data layer, and service support layer. This platform has achieved visual management of dynamic process factories, damage penetration management, standardized description of damage mechanisms and patterns, dynamic update of the knowledge base, and data-driven control throughout the entire life cycle of the equipment. The practical application effect shows that the application of this platform has improved the accuracy and timeliness of damage identification in petrochemical plants, achieved equipment damage prediction and intelligent early warning, and provided reference technology and intelligent management framework for the digital transformation of equipment management in the petrochemical industry.

TRIBOLOGICAL PROPERTIES OF STRAIGHT CHAIN PERFLUOROPOLYETHER GREASE

2025, 56(12):  97-105. 

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Perfluoropolyether (PFPE) grease was prepared by using different types of polytetrafluoroethylene (PTFE) and anti-wear additives. Based on the detection techniques of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption, the structure and microscopic morphology of PTFE thickener were characterized and analyzed.Two standardized test platforms, namely the four-ball friction testing machine and the SRV friction and wear testing machine, were used to explore the tribological behavior characteristics of PFPE grease.Meanwhile, the detection techniques of SEM, energy dispersive spectrometer (EDS), three-dimensional profilometer(micro-XAM-3D),andX-ray photoelectron spectrometer (XPS) were comprehensively employed to deeply analyze the composition and morphological characteristics of the friction pair surface and infer the lubrication mechanism of different greases.The results show that the P3-type PTFE micropowder with large pore structure has good thickening ability, and the prepared grease has the best wear reduction and wear resistance, which the minimum friction coefficient is only 0.101, the wear volume is only 7.29×10⁵ μm³. The grease with borate added exhibits more outstanding anti-friction and anti-wear properties, specifically manifested as a reduction of approximately 14% in the coefficient of friction and a decrease of approximately 50% in the volume of wear. Borate additives form a solid solution structure to construct a complex permeable protective film at the friction interface. This special protective film can effectively reduce the coefficient of friction and enhance the surface's anti-wear ability.

EFFECTS OF ANTIOXIDANTS AND AGING DEGREE ON THE ADHESION OF ASPHALT AND LIMESTONE INTERFACE

2025, 56(12):  106-113. 

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In order to explore the influence mechanism of antioxidants and aging on the adhesion of asphalt-limestone interface, the adhesion of antioxidants (Irganox 1010 and Irgafos 168) at the interface between asphalt and limestone aggregate at different aging stages was investigated by quantitatively analyzing the mass loss rate and solution absorbance of asphalt-aggregate mixtures before and after aging. Furthermore, combined with molecular dynamics simulation, the changes of adhesion work and diffusion coefficient of asphalt at the aggregate interface before and after aging were calculated. The results show that with the deepening of aging, the adhesion of asphalt on the surface of the aggregate gradually decreases and the mass loss rate increases. Antioxidants can inhibit the oxidation reaction of asphalt, and the adhesion between modified asphalt and aggregate at the same aging stage is better than that of unmodified No.70 asphalt. The addition of antioxidants can significantly improve the adhesion and diffusivity of asphalt at the aggregate interface, because oxidation enhances the polarity of asphalt, improves the fluidity of asphalt, and makes it react with highly active ions on the aggregate surface to form stable chemical bonds. The adhesion between modified asphalt and aggregate was significantly better than that of No.70 asphalt, and the modification effect of Irganox 1010 was better than that of Irgafos 168.

EFFECT OF ETHANOL-GASOLINE BLENDING RATIO ON COMBUSTION AND EMISSION CHARACTERISTICS IN GASOLINE ENGINE

2025, 56(12):  114-122. 

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Ethanol gasoline, as a low-carbon and sustainable alternative fuel to gasoline, has untapped potential for energy conservation and emission reduction. Select 8 representative operating conditions to study the effects of blending different proportions of ethanol (E10—E100) on the combustion and emission performance of direct injection gasoline engines according to the national ⅥB emission standard. The results show that blending low proportion ethanol gasoline (E10—E50) can improve combustion performance, increase heat release rate, significantly increase combustion speed, and reduce equivalent fuel consumption; Mixing high proportion ethanol gasoline (E85—E100) has poor compatibility with existing gasoline engine technology, resulting in delayed combustion process, significant decrease in combustion temperature and heat release rate, and reduced thermal efficiency. As the proportion of blended ethanol increases, the overall CO and THC emissions show a decreasing trend, while NOx emissions show an increasing and then decreasing trend. Under some operating conditions, the THC emissions of E100 significantly increase, and ethanol gasoline also has high potential for reducing particulate matter emissions.

ENERGY-SAVING OPTIMIZATION SCHEME OF ATMOSPHERIC AND VACUUM DISTILLATION UNIT BASED ON EXERGY ANALYSIS AND ITS COMMERCIAL APPLICATION

2025, 56(12):  123-132. 

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To reduce energy consumption in refineries, an exergy analysis model was established for an 8.0 Mt/a atmospheric and vacuum distillation unit. The model systematically studied the exergy efficiency and exergy losses of the main equipment and heat exchange network within the unit, identifying the energy utilization bottlenecks as the underutilization of high-temperature heat sources such as vacuum residue, atmospheric third-side cut, and atmospheric second-middle cycle oil. By calculating exergy losses and exergy efficiency, an energy-saving optimization retrofit plan was determined. Industrial results showed that after implementing the optimization plan for the atmospheric and vacuum distillation unit based on exergy analysis, the final temperature of the heat exchange network increased by 13℃. The unit could save 8.47 kt/a of fuel gas, reducing energy consumption by 1.15 kgOE/t（1 kgOE=41.8 MJ）. The project could save approximately 18.6 million yuan/a in fuel gas costs and reduce CO₂ emissions by about 18.8 kt/a, with an investment payback period of about 1.5 a.

ENERGY CONSUMPTION ANALYSIS AND ENERGY-SAVING OPTIMIZATION MEASURES FOR ETHYLENE PLANT

2025, 56(12):  133-139. 

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The energy consumption status of a 1 Mt/a ethylene plant and the energy-saving measures that have been taken are introduced. Six energy-saving optimization measures have been adopted, including the application of a new energy-saving and viscosity-reducing technology for quench oil, the addition of a heat exchange process for process condensate and desalinated water, the modification of the demethanizer overhead process to a vertical CIV condenser form, the waste heat utilization of boiler continuous blowdown, the conversion of the ethylene machine turbine from extraction-condensing type to backpressure type, and the collaborative optimization of electrification. These measures can reduce the energy consumption of the plant by 1734.28 MJ/t in total, and the energy-saving effect is remarkable. Combined with the actual situation of the plant, six next-step energy-saving optimization suggestions are put forward, including achieving the theoretical ratio combustion of the cracking furnace, adding a secondary air preheater to the cracking furnace, installing frequency converters for high-power pumps, carrying out temperature and pressure reduction operations for the debutanizer tower, and applying full-process intelligent control technology at an appropriate opportunity. This has good guiding and reference significance for the energy-saving and consumption reduction work of similar plants.

RESEARCH ON ENERGY-SAVING OPTIMIZATION OF LARGE-SCALE n-BUTANE OXIDATION PROCESS FOR PRODUCING MALEIC ANHYDRIDE

2025, 56(12):  140-147. 

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A large integrated refining and chemical enterprise extends its industrial chain by using the self-produced n-butane raw material and adopting the n-butane oxidation to produce maleic anhydride (maleic anhydride) process route to produce BDO (1,4-butanediol). In order to improve its competitive advantage with the alkyne aldehyde process, further reduce the operating cost of the device, and tap the potential for energy saving and consumption reduction of the device, a low-grade hot water preheating scheme is proposed to save 25.35 t/h of steam consumption in the rear heater. A n-butane staged vaporization scheme is also proposed to reuse the hot water from the isobutane refining unit's deisobutane tower reboiler, saving 4.07 t/h of n-butane vaporization steam consumption. A deep coupling scheme for oxidation incineration is proposed, which uses the waste heat of the incineration system to preheat boiler feedwater and superheated high-pressure steam separately, increasing high-pressure steam production by 13.8%. The comprehensive energy consumption has been reduced to -900.55 kgCE/t (maleic anhydride,1 kgCE = 29.3 MJ)), achieving good economic benefits. At the same time, the acid hydrolysis oxidation wastewater treatment process has been proposed, and it is estimated that the comprehensive energy consumption per unit product can be reduced by 55.3 kgCE/t (maleic anhydride), while reducing the difficulty of treating high chemical oxygen demand wastewater and promoting the green transformation of degradable materials.

DEEP HEAT INTEGRATION BETWEEN MAIN FRACTIONATING COLUMN AND ABSORPTION-STABILIZATION SYSTEM IN A HYDROCRACKING UNIT

2025, 56(12):  148-154. 

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There are two main problems in hydrocracking unit with a processing capacity of 3.16 Mt/aina petroleum refinery: the surplus heat of the main fractionating column is only used by 19.2%, resulting huge cooling duty; debutanizer consumes 16.5 t/h of 2.2 MPa steam as its reboiler heat. With the help of total process simulation to the main fractionating column and absorption-stabilization system, a deep heat integration is suggested, where a new pumparound with No.9 withdrawing and No.8 returning is established, its heat is sent to deethanizer as reboiler heat; the original pumaround heat is transferred to the debutanizer replacing the 2.2 MPa steam. At the same time, the top pressure of the main fractionating column is increased to 0.25 MPa from 0.2MPa and the top pressure of the debutanizer is dropped to 0.60 MPa from 0.90 MPa. The simulation result shows that the integrated case achieves a benefit of 2.9731×107Yuan/a and a drop by 238.5 MJ/t for the comprehensive energy consumption.

RESEARCH PROGRESS OF ADSORPTION MATERIALS FOR CARBON DIOXIDE DIRECT CAPTURE FROM AIR

2025, 56(12):  155-166. 

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To address climate change caused by carbon emissions, CO₂ solid adsorbents have entered a peak development period. To compare the application potential of various adsorbents in carbon dioxide direct air capture technology(DAC), the modification and properties of carbon-based adsorbents, metal-based adsorbents, metal-organic framework(MOFs) adsorbents, molecular sieve adsorbents, as well as resin and sepiolite adsorbents are analyzed. The study reveals that carbon-based adsorbents feature simple synthesis and wide-ranging raw materials. After modification, they can exhibit favorable adsorption performance, but their service life needs improvement. Metal-based adsorbents show high adsorption capacity and rapid reaction kinetics, yet their high adsorption/desorption temperatures lead to substantial energy consumption. MOFs adsorbents are adaptable to various active substances, demonstrating good modification effects, but they are constrained by process difficulties and raw material costs, hindering large-scale application. Molecular sieve adsorbents can efficiently treat low-concentration CO₂, with mature synthesis and regeneration technologies. Comprehensively, molecular sieve adsorbents show the greatest application potential in DAC. Through optimizing the synthesis and modification technologies of molecular sieves and investigation the adsorption-regeneration process flow, high-benefit large-scale application of DAC can be achieved.