Table of Content

12 October 2024, Volume 55 Issue 10

Previous Issue    Next Issue

USING EQUILIBRIUM ADSORPTION METHOD TO STUDY THE EFFECT OF DIFFERENT ADDITIVES ON THE ADSORPTION BEHAVIORE OF MOLYBDENUM SPECIES ON THE SURFACE OF ALUMINA

2024, 55(10):  1-8. 

Asbtract ( 129 )  

Related Articles | Metrics

To study the competitive adsorption of various species on the surface of alumina carrier in metal impregnation solution, the corresponding equilibrium adsorption experiments were conducted by introducing different types of additives into the solution. The results showed that the addition of ammonium metatungstate into ammonium heptamolybdate solution could reduce molybdenum equilibrium adsorption capacity to a certain extent, and the competitive adsorption on the neutral hydroxyl groups of alumina was beneficial for weakening the strong interaction between tungsten species and alumina. Adding ammonium nitrate, ammonium chloride, ammonium sulfate, glycerol and polyethylene glycol into ammonium heptamolybdate solution had little effect on molybdenum equilibrium adsorption capacity, but adding phosphoric acid or its ammonium salt could significantly reduce molybdenum equilibrium adsorption capacity. The results showed that the molybdenum species could be adsorbed competitively, the interaction between molybdenum species and alumina was weakened, and the sulfidation of molybdenum species was promoted. The introduction of ammonium citrate could also significantly reduce molybdenum equilibrium adsorption capacity. In addition, molybdenum equilibrium adsorption capacity of the alumina carrier in the phosphomolybdic acid solution dominated by the [PMo₁₂O₄₀]^3- structure was significantly higher than that in the phosphomolybdic acid solution dominated by the [P₂Mo₅O₂₃]^6- structure. Furthermore, the molecular structure of molybdenum precursors and the amount of free phosphate and citrate ions could be changed by adjusting the P/Mo mole ratio in metal impregnation solutions containing citric acid. The molybdenum equilibrium adsorption capacity of the alumina carrier gradually decreased with the increase of the P/Mo mole ratio in the solution. The results provide the necessary theoretical and technical support for designing the composition of metal impregnation solution and developing high-efficiency hydrotreating catalyst.

HETEROGENEOUS OLIGOMERIZARION OF ETHYLENE OVER CATALYTIC CRACKING CATALYST

2024, 55(10):  9-14. 

Asbtract ( 81 )  

References | Related Articles | Metrics

The Y and ZSM-5 zeolite catalysts were characterized by N₂ physical adsorption-desorption, pyridine adsorption Fourier-transform infrared spectrum (Py-FTIR) and temperature-programmed desorption of ammonia (NH₃-TPD), and the effects of reaction temperature and pressure on catalytic performance in heterogenous oligomerization of ethylene were investigated. The results showed that the catalytic cracking catalyst was rich in mesoporous 3-4 nm and weak Lewis acid sites. At 500-550 ℃ and atmospheric pressure, ethylene was not easy to be converted, C₃-C₄ olefin was mainly produced by oligomerization and cracking, and the selectivity of propylene was higher than that of butylene. When the reaction temperature was higher than 550 ℃, the selectivity of coke was greatly increased by the cyclization dehydrogenation of propylene and butylene. Compared with the normal pressure, the catalytic cracking catalyst with weak Lewis acid sites could effectively catalyze ethylene oligomerization with the conversion higher than 70% at reaction pressure of 0.5-1.0 MPa. Increasing the reaction pressure was beneficial to the hydrogen transfer reaction of propylene and butylene, increasing the selectivity of propane and butane, but decreasing the selectivity of coke.

EFFECT OF pH IN PSEUDO-BOEHMITE AGING ON THE ALUMINA SUPPORT AND HYDRODESULFURIZATION PERFORMANCE OF HYDROGENATION CATALYST

2024, 55(10):  15-23. 

Asbtract ( 78 )  

References | Related Articles | Metrics

The effect of aging pH on the preparation of pseudo-boehmite by stepwise continuous neutralization with NaAlO₂-Al₂(SO₄)₃ method was investigated, the corresponding Ni-Mo-P/Al₂O₃ catalysts were prepared, and the hydrodesulfurization performance was evaluated by using 4,6-dimethyldibenzothiophene (4,6-DMDBT) as the reactant. The results showed that the aging pH had a significant effect on the properties of pseudo-boehmite. The content of sulfate in the product was too high at pH 8.6, and the mass fraction of alumina trihydrate and Na₂O in the product was too high at pH 10.0. The proposed pseudo-boehmite with lower content of impurities could be obtained at the aging pH of 9.0-9.5. The aging pH also affected the growth of different crystalline surfaces, and high aging pH was conducive to increasing the growth rate of (020) crystalline surfaces. The pore volume and specific surface area of Al2O3 support were larger at the aging pH of 9.0 and 9.5, and the most probable pore diameter was about 9.1 nm. The aging pH significantly affected the distribution ratio of different types of hydroxyl groups in the supports, thus, the reduction temperature at the low temperature reduction peaks of the active metals and the proportion of hexa-coordinated 2D polymers were affected. The order of hydrodesulfurization activity of the catalysts was consistent with the order of the low temperature reduction peak temperature of the active metal supported on the carries and the proportion of hexa-coordinated 2D polymers of molybdenum. The preparation of pseudo-boehmite for high activity hydrodesulfurization catalyst support was most favorable when the aging pH was 9.0.

MODELING OF CARBON EMISSION FROM GASOLINE UTILIZATION AT MOLECULAR LEVEL BASED ON VIRTUAL SAMPLE GENERATION

2024, 55(10):  24-31. 

Asbtract ( 63 )  

References | Related Articles | Metrics

Under the strategic background of carbon peaking and carbon neutrality, gasoline, as a member of the high carbon emission ranks, faces the challenge of emission reduction. Based on the gasoline molecular composition data obtained by gas chromatography and the gasoline CO₂ emission data obtained by the New European Driving Cycle,a priori model for the relationship between gasoline and the CO₂ emission per kilometer by categorizing the gasoline components was established according to the PONA composition, the number of carbon atoms and the number of substituents, and using hierarchical clustering method to cluster the gasoline molecular composition data, and dividing the training set and test set according to the clustering result, in order to provide data support for the production of low carbon emission gasoline. The priori model of gasoline and CO₂ emission per kilometer was established, aiming to provide data support for the production of low-carbon emission gasoline. Due to the small and concentrated range of data samples, the priori model has poor applicability in predicting CO₂ emissions. Therefore, the multi-distribution overall trend diffusion technique based on radius nearest neighbor classification (RNC-MD-MTD) was proposed and virtual samples were generated by this method. The calculation results showed that the prediction accuracy of the model was effectively improved with the addition of virtual samples generated by the RNC-MD-MTD method, which proved the validity of the method, and the final prediction model for CO₂ emission running per kilometer had a decision coefficient of 0.98, a mean absolute percentage error of 0.29% and a root-mean-square error of 792.6 mg/km.

ADSORPTION AND DIFFUSION CHARACTERISTICS OF EICOSANE, ANTHRACENE AND p-DIBUTYLCYCLOHEXANE IN CALCIUM OXIDE

2024, 55(10):  32-40. 

Asbtract ( 66 )  

References | Related Articles | Metrics

In the temperature range of 823.15-923.15 K, the adsorption and diffusion properties of eicosane (C₂₀H₄₂), anthracene (C₁₄H₁₀) and p-dibutylcyclohexane (C₁₄H₂₈) in 5 nm pore channels of calcium oxide were studied by Monte Carlo and molecular dynamics methods. The adsorption isotherm, molecular diffusion kinetics, probability density distribution and radial distribution function of the three molecules in the calcium oxide pore channels were analyzed. The analysis of adsorption isotherm showed that the adsorption capacity of C₁₄H₁₀ in calcium oxide pore was the highest, the adsorption capacity of C₁₄H₂₈ was the lowest at 923.15 K, and the adsorption capacity of C₂₀H₄₂ was the lowest at 823.15 K; C₂₀H₄₂ and C₁₄H₁₀ were multi-layer adsorption, while C₁₄H₂₈ was mono-layer adsorption. Molecular diffusion dynamics analysis showed that the diffusion coefficient of C₂₀H₄₂ was the largest, followed by that of C₁₄H₂₈, and that of C₁₄H₁₀ was the smallest. The diffusion performance is mainly affected by temperature and molecular configuration. According to the activation energy of diffusion, the diffusion of C₁₄H₁₀ is most affected by temperature, followed by that of C₁₄H₂₈, and that of C₂₀H₄₂ is the smallest. The analysis of probability density distribution and radial distribution function showed that there were three adsorption layers of C₁₄H₁₀ near the surface at distances of 0.4, 0.7 and 1.1 nm, while C₂₀H₄₂ and C₁₄H₂₈ had three adsorption layers at 0.5 nm from the surface.

RESEARCH ON THE MECHANISM OF CO₂ METHANATION CATALYZED BY Ni/ZrO₂

2024, 55(10):  41-47. 

Asbtract ( 53 )  

References | Related Articles | Metrics

The methanation of CO₂ exhibits significant positive implications in multiple dimensions, including environmental protection, energy utilization and economic benefit enhancement. However, the intermediate species in the CO₂ methanation process of ZrO₂-supported Ni catalyst are not clear, which hinders the development of new high efficient catalysts. The adsorption and activation mechanisms of CO₂ at the Ni/ZrO₂ surface and the elementary reactions of the CO₂ methanation process were studied by first-principles calculation, the roles of Ni, ZrO₂ and their interface in the process of CO₂ hydrogenation were clarified, and specific reaction paths in the process of CO₂ methanation were proposed. This laid a solid foundation for the further development of efficient catalysts.

STUDY ON CATALYTIC PERFORMANCE OF HMCM-22 ZEOLITE FOR PROPYLENE OLIGOMERIZATION

2024, 55(10):  48-59. 

Asbtract ( 99 )  

References | Related Articles | Metrics

The propylene oligomerization catalyzed by HMCM-22 zeolite was studied and compared with HZSM-5, HY, HMOR and Hβ zeolite. The relationship between pore structure, acid properties and propylene oligomerization performance of 5 kinds of zeolites were investigated by a series of physical characterization methods and propylene oligomerization evaluation. The results showed that the topological structure and acidity of HMCM-22 zeolite had significant effects on the activity, selectivity and stability of propylene oligomerization. HMCM-22 zeolite has multi-dimensional pore structure, moderate acidity, good product diffusion performance and excellent carbon accumulation resistance, and the activity and stability of propylene oligomerization reaction are the best. It was found that HMCM-22 zeolite with high acid content of B acid and total acid had high initial activity and was easy to produce high carbon number products, but the zeolite with low selectivity of C_3n and moderate mesoporous ratio had better stability. The results of stability evaluation of HMCM-22 zeolite showed that the conversion rate of propylene was over 85% and the selectivity of C_3n reached 77.6% within 300 h, which indicated excellent propylene oligomerization activity, selectivity and stability.

RESEARCH ON PRODUCTION TECHNOLOGY OF LOW SULFUR HEAVY MARINE FUEL BY FCC SLURRY AND RESIDUE

2024, 55(10):  60-67. 

Asbtract ( 98 )  

Related Articles | Metrics

By analyzing the properties and solid particle size distribution of seven typical FCC slurries, it was found that the properties of slurry from different sources were quite different, the particle size of most solid particles in the slurry was less than 50μm, and the volume fraction of particles with diameter of 1-10μm was more than 50%. Three generations of flexible filter materials were used for FCC slurry desolidification experiments. The results showed that the third generation filter material had the highest desolidification rate for FCC slurry, (Al+Si) removal rate was over 97%, and the filter material regeneration performance was good. Under the condition of hydrogen partial pressure of 3.0 MPa, the desulfurization process of slurry under low pressure was studied. The results exhibited that the process has good adaptability of feedstocks and stable product quality. The blending of low sulfur heavy marine fuel oil with desulfurized and desolidified slurry as well as hydrogenated residue as components was carried out. Most of properties indexes of the blending accord with the linear law, and the mass ratio of FCC slurry in the economic blending formula is higher than 30%.

ANALYSIS AND TREATMENT MEASURES FOR THE INCREASE OF PACKING LAYER PRESSURE DIFFERENCE IN CDAlky^R ALKYLATION REACTOR

2024, 55(10):  68-72. 

Asbtract ( 66 )  

References | Related Articles | Metrics

Alkylation technology is an important oil processing technology for producing clean fuels, which usually adopts sulfuric acid alkylation of CDAlky^R static mixing reactor technology. However, there are still some problems in the process of sulphuric acid alkylation, for example,the increase of the pressure difference of the packed bed in the reactor leads to the decrease of the operating load of the unit, which seriously affects the production capacity of the unit. In view of this probleum, the factors which might affect the increase of the pressure difference of the packing layer were investigated from four aspects:the initial pressure difference of the packing layer, the impurity content in raw materials, theprecision of thecirculating acid filter and the impurity content in the machine-sealed white oil.The treatment measures were put forward accordingly, which could effectively solve the problem of the increasing pressure difference of CDAlky^R alkylated packing layer, and provide technical reference for other unites.

OPERATION ANALYSIS OF S Zorb UNIT IN CHINA

2024, 55(10):  73-78. 

Asbtract ( 105 )  

References | Related Articles | Metrics

The distribution of S Zorb units in China and the operation data of 28 industrial units in 2023 were introduced. By comparing the 2023 operation data of different S Zorb units, it was found that although there were significant differences in the sulfur and olefin content of raw material, main operating parameters, octane loss and adsorbent activity, all the units could stably produce gasoline that met the China VI standard, which indicated that the S Zorb unit has a good adaptability. Based on the summarized operation data of SINOPEC S Zorb units since 2011, it was found that sulfur content in raw material of SINOPEC S Zorb plant fluctuated greatly, and the olefin content was decreasing year by year, however, the desulfurization rate of the units was basically unchanged, and the olefin saturation reaction and octane number loss changed greatly.

PREPARATION OF NYLON 6 AND ε-POLYLYSINE COMPOSITE MATERIAL USING SOLVENT METHOD AND THEIR THERMAL PROPERTIES

2024, 55(10):  79-83. 

Asbtract ( 42 )  

Related Articles | Metrics

The dispersion of nylon 6 (PA6) and ε-polylysine (ε-PL) solution was achieved by controlling the solubility of PA6 and ε-PL in trifluoroethanol and water, the concentration of trifluoroethanol and the mixing order, and then PA6 series composites with different ε-PL content were prepared by rotary evaporation and vacuum drying. The thermal properties of commercial PA6, ε-PL and a series of samples were investigated by thermal gravimetric analyzer and differential scanning calorimeter. The results showed that commercial PA6 was purified and recrystallized by solvent treatment, and the crystallization temperature of PA6 was increased by 9℃, and the melting point was increased by 7 ℃. The addition of ε-PL affected the regularity of PA6, so that the melting point and crystallization temperature of PA6 decreased slightly, but the decrease was less than 3℃, which did not affect its processing performance.

EFFECT OF CONCENTRATION OF CARRIER PORE SIZE DISTRIBUTION ON PYRENE HYDROGENATION REACTION OVER Ni-Mo CATALYST

2024, 55(10):  84-93. 

Asbtract ( 69 )  

References | Related Articles | Metrics

Pseudo-boehmite was prepared by the NaAlO₂-Al(SO₄)₃ method, the grain size of the pseudo-boehmite was adjusted by controlling the aging time of the pseudo-boehmite, and four carriers with different pore structures were obtained with the same specific surface area, pore volume and pore size, but the pore size distribution was different. Pyrene was used as a model compound to investigate the hydrogenation saturation properties of the catalysts prepared by these four carriers on a high-pressure microreaction device. BET, XRD, XPS, TEM and GC-MS were used to characterize the pseudo-boehmite, support and catalyst. The results showed that with the increase of aging time, the crystallinity and grain size of the pseudo-boehmite increased, the specific surface, pore volume and maximum pore size of the support were similar, the pore size distribution concentration increased, the number of total hydroxyl groups on the surface and the proportion of basic hydroxyl groups decreased gradually, the interaction force between the oxidized metal and the support decreased, and the sulfidation degree of the catalyst and the proportion of class Ⅱ multilayer active phases increased after sulfidation. The hydrogenation evaluation results of pyrene displayed that the hydrogenation conversion rate of pyrene increased with the increase of the concentration of carrier pore size distribution. The results also indicated that the increase of sulfidation degree and the proportion of type Ⅱ active phase was conducive to improving the hydrogenation performance of the catalyst. With the increase of the concentration of pore size distribution, the effective specific surface of the 8-10 nm pores was obviously increased, which was more conducive to the molecules diffusion into the pores to contact active site.

PREPARATION OF Pt-Pd/MnCo₂O₄ COMPOSITE CATALYST AND ITS CATALYTIC COMBUSTION PERFORMANCE FOR LOW CARBON HYDROCARBONS AND OTHER ORGANIC COMPOUNDS

2024, 55(10):  94-101. 

Asbtract ( 84 )  

References | Related Articles | Metrics

Chemical reduction reaction between potassium permanganate and manganese nitrate was employed to directly generate MnCo₂O₄ spinel on a monolith coated with alumina, and two kinds of Pt-Pd/MnCo₂O₄ composite combustion catalysts, named MnCo-2 and MnCo-3, were prepared. MnCo-2 had approximately 44% less noble metal content than the foreign reference sample, and about 16% less than the domestic reference sample. Its activity in the oxidation of low carbon hydrocarbons such as ethane was comparable to that of the foreign reference sample. The oxidation conversion temperature T99 for ethane, T99 for propane, and T90 for methane were 440, 380 and 460 ℃, respectively, which were approximately 60 ℃ lower than that of the domestic reference sample, and the performance was stable in the cumulative 800 h test. MnCo-3 had approximately 61% less noble metal content than the foreign reference sample and about 41% less than the domestic reference sample. Its total reagent cost was approximately 38% lower than that of the domestic reference sample, and the ethane T99 conversion temperature was 475 ℃, which was 25 ℃ lower than that of the domestic reference sample.

MODIFICATION OF ZSM-5 ZEOLITE BY CHEMICAL LIQUID DEPOSITION AND ITS CATALYTIC PERFORMANCE

2024, 55(10):  102-108. 

Asbtract ( 95 )  

References | Related Articles | Metrics

ZSM-5 zeolitewas modified by chemical liquid deposition with silane coupling agent KH540, methyl silicone oil and tetraethyl orthosilicate (TEOS). X-ray diffraction, scanning electron microscopy, NH₃ temperature-programmed desorptionand N₂ adsorption-desorption were used to characterize the morphology, acidity and pore structure of the modified catalysts.In order to evaluate the catalytic performance, the cracking reaction of 1,3,5-triisopropylbenzene (TIPB) was used as a probe reaction to determine the acid density on the outer surface of the modified catalyst, and the modified catalyst was used for the ethylbenzene isomerization. The results showed that the TIPB conversion of the modified catalyst decreased, which indicated tha tthe acid content on the surface of the modified catalyst decreased. The conversion of ethylbenzene was increased and the isomerization activity was decreased by adjusting the modification conditions. The optimum mass fraction of TEOS was 30%, the TIPB conversion was approximately 30%,the ethylbenzene conversion, isomerization activity and xylene yield were 98%, 5% and 100%, respectively, and benzene selectivity was around 89%.

SELECTIVE PRODUCTION OF BUTENE FROM γ-VALEROLACTONE DECARBOXYLATION OVER FAU ZEOLITE

2024, 55(10):  109-117. 

Asbtract ( 109 )  

References | Related Articles | Metrics

The decarboxylation of biomass-based γ-valerolactone (GVL) provides a new pathway for the sustainable production of butene. However, due to the low acidity of the commonly used amorphous SiO₂-Al₂O₃ catalyst, this reaction could only be operated at low weight hourly space velocity (WHSV) condition, which limited its industrial scale-up. An efficient NaY catalyst was developed to address this challenge, which could achieve 100% GVL conversion and 99.6% butene selectivity at high WHSV. After 1 320 minutes on stream, the yield of butene remained at 99.4%. In addition, the yield of butene remained at 99.2% after 5 cycles of regeneration. Furthermore, LiY, KY and CaY were prepared by ion exchange to investigate the effect of metal cations on catalytic performance. The results indicated that NaY showed the best performance due to its balanced acid and base sites, and CaY exhibited poor performance due to the existence of strong Br?nsted acid sites.

SURFACE MODIFICATION OF WOLLASTONITE AND ITS APPLICATION IN BUTADIENE RUBBER

2024, 55(10):  118-123. 

Asbtract ( 59 )  

References | Related Articles | Metrics

Stearic acid (SA) was used to modify wollastonite, and the effects of wollastonite size and the amount of wollastonite before and after modification on the mechanical properties, vulcanization performance and slip resistance of butadiene rubber (BR) were investigated. The results of infrared spectroscopy and contact angle tests showed the hydrophobicity of wollastonite was obviously improved by the reaction between stearic acid and hydroxyl groups on the surface of wollastonite. The results of mechanical and vulcanization performance tests indicated that the tensile strength and elongation at break of BR composite material with modified wollastonite were significantly improved under the same dosage, while the vulcanization rate decreased. The results of antislip performance test showed that adding modified wollastonite could significantly improve the friction coefficient of BR composite materials on ice and oil surfaces. The scanning electron microscope indicated that the interface gap between unmodified wollastonite and rubber was clear, but the interface gap was blurred after modification. Under the conditions of formula, the tensile strength of BR composite with 40% modified wollastonite was 10.77 MPa, the elongation at break was 803%, and a friction coefficient between oil surface and ice surface was 0.48, which had good mechanical and slip resistance properties.

TREATMENT OF ORGANIC AMINE WASTEWATER CONTAINING TEMPLATE AGENT BY CATALYTIC WET AIR OXIDATION

2024, 55(10):  124-128. 

Asbtract ( 46 )  

References | Related Articles | Metrics

Catalytic wet air oxidation (CWAO) process was used to treat wastewater containing organic amines with high chemical oxygen demand (COD). The effects of different types of catalysts and reaction temperature on the treatment effect were investigated. The experiment results showed that when precious metals were used as catalyst, the COD decreasing rate was the highest, reaching 96%, and when the reaction temperature was 270 ℃, the volume fraction of oxygen in tail gas and the decreasing rate of COD were about 13.1% and 96% respectively; while the energy consumption was lower, and the treatment effect was better. Under the optimal conditions of a temperature of 270 ℃ and a pressure of 7.6 MPa, using precious metal catalyst, the average decreasing rate of COD in the produced water was above 96% after 140 h continuous operation of the CWAO equipment. At the same time, the equipment material corrosion test and accelerated oxidation small-scale test were carried out, and the equipment corrosion problem was solved by adjusting the pH of the reaction water. Considering the treatment effect and operation cost, the CWAO process is competitive in treating wastewater with high COD containing organic amines.

MICROWAVE SWING REGENERATION OF CO₂ IN BLENDED AMINE SOLUTION

2024, 55(10):  129-137. 

Asbtract ( 54 )  

Related Articles | Metrics

In order to solve the problem of high temperature(above 100 ℃) desorption of CO₂ captured by traditional process, based on the optimization of CO₂ absorption conditions, a low-temperature and efficient microwave swing regeneration method was proposed. The results showed that when the mass ratio of the N-methyl ethanolamine (MDEA), piperazine (PZ) and 2-(2-aminoethylamino) ethanol (AEEA) was 3:1:5,the CO₂ absorption efficiency of the mixed alcohol amine aqueous solution was the best. At an absorption temperature of 30℃, with the optimized blended alcohol amines as the absorption solution, whenthe mass fraction of the total amines was 20%, the CO₂ absorption capacity of the alcohol amine aqueous solution reached 1.15 mol/mol;the desorption equilibrium could be reached at 95 ℃ for 4 min, the desorption rate of CO₂ was 97.52%, and the desorption of CO₂ was almost complete. Compared with the conventional heating desorption method, the CO₂ desorption ratio of the microwave heating method at 95℃ increased by 62.25 percentage points, the desorption time was significantly shortened, and the high efficiency desorption of CO₂ at low temperature was realized.

ANALYSIS OF CARBON EMISSIONS AND CARBON REDUCTION IN A 10Mt/a REFINERY

2024, 55(10):  138-147. 

Asbtract ( 96 )  

References | Related Articles | Metrics

As the key enterprises of carbon emission, the “Double carbon” target puts forward higher requirements for the high-quality development of refining enterprises. Through the calculation of the carbon emission of the whole plant and the carbon emission of each device in a 10Mt/a refinery, the carbon emission of the whole plant were 2885.247 kt/a, of which the combustion emission accounted for 31.32%, the coke burning of the catalytic cracking unit accounted for 32.55%, the hydrogen production process accounted for 18.05 %, and the purchased electricity accounted for 17.99%. According to the actual situation of the refinery, the emission could be reduced by 38.3 kt/a by improving the thermal efficiency of the heating furnace, by 95.4 kt/a by reducing the carbon content of fuel, and by 60-120 kt/a by digitizing and intelligentizing the construction. The emission of condensing steam turbine could be reduced by 188.7 kt/a when it was driven by electric motor, the emission of hydrogen production unit could be reduced by 197.6 kt/a and the emission of catalytic cracking unit could be reduced by 318.4 kt/a when the processing structure was optimized and the sulfur content of crude oil was reduced. In the long term, the full use of green electricity and green hydrogen, as well as the maturity of electric heating furnace and carbon capture, utilization and storage (CCUS) technologies, can reduce the carbon emission of 10-million-ton refineries to less than 500 kt/a.

OPTIMIZED CONTROL OF PRODUCT QUALITY IN FRACTIONATOR OF DIESEL HYDROREFINING UNIT BASED ON MPC

2024, 55(10):  148-156. 

Asbtract ( 71 )  

Related Articles | Metrics

The stability time and control effect of traditional proportional integral (PI) control for fractionator of diesel hydrorefining unit with complex process and strong coupling of the system are not good. Based on the original PI scheme of fractionator of diesel hydrorefining unit in a domestic petrochemical enterprise, a model predictive control (MPC) co-PI control scheme was proposed. The results showed that the control scheme of MPC and PI could improve the dynamic performance of the device, and the oscillation frequency of PI control was similar to that of MPC control scheme when the feed rate and steam rate of stripper fluctuate, but the stability time and the control maximum deviation of MPC were smaller. For disturbances of ±10% feed rate, the maximum temperature relative deviation of PI control and MPC scheme was 3.48% and 0.07%, the stability time was 3.5 h and 1.5 h, and the value of absolute error integral (IAE) was 7.30 and 0.23, respectively, and the control effect of MPC was better than that of PI control. At the same time, the feasibility of MPC and PI control was verified, which showed that MPC combined PI control was more suitable for advanced control of fractionator of diesel hydrorefining unit.

BLENDING AND OPTIMIZATION OF CRUDE OIL WITH MULTI-QUALITY AND MULTI-PROPERTIES BASED ON INTELLIGENT ALGORITHM

2024, 55(10):  157-164. 

Asbtract ( 98 )  

Related Articles | Metrics

Aiming at the problems of refineries relying on traditional experience to blend crude oil to meet the quality requirements of processed crude oil and the low profit of enterprises, a multi-objective optimization mathematical model based on the maximization of crude oil similarity and the maximization of production profit was established, and the Gray Wolf Algorithm , which combined the Levy Flight and Randomized Swimming Strategies(LRGWO), was chosen to solve the model after comparing the performance of five robust algorithms. The results showed that in LRGWO, Gray Wolf Algorithm (GWO), second-generation Non-dominated Sorting Genetic Algorithm (NSGA-II), third-generation Non-dominated Sorting Genetic Algorithm (NSGA-III) and Particle Swarm Algorithm (PSO), the coverage of the optimal solution set obtained from the LRGWO algorithm and the overall performance of algorithm were optimal. After optimization, the average similarity between the blended crude oils T1-T4 and the corresponding target crude oils W1-W4 reached 95.82%, which indicated that the blended crude oils with similar physical properties to the target crude oils could be obtained by using the constructed crude oil selection and blending model. According to the prices of the 10 kinds of crude, under the premise of the maximum purchasing quantity of 175 kt, the production profit maximization model optimizes the processing quantity of blended crude T1-T4 to be 50, 55, 40 and 30 kt, respectively. The maximum production profit of the enterprise is 33.5819 million Yuan.

RAPID DETERMINATION OF SILICON CONTENT IN DIESEL BY ICP-OES WITH ULTRASONIC ATOMIZATION DIRECT INJECTION SYSTEM

2024, 55(10):  165-170. 

Asbtract ( 57 )  

References | Related Articles | Metrics

In order to solve the problem that the emission intensity of the traditional temperature-controlled cyclone atomization system ICP-OES varies greatly for different forms of organosilicon compounds, the ultrasonic atomization direct injection system was adopted, which can send all the silicon elements in the sample into the ion chamber for detection. The influencing factors of the ultrasonic atomization direct injection ICP-OES method, such as instrument power, diluent, physical properties of blank diesel fuel, dilution ratio, etc., were tested and analyzed, and a suitable method for the detection of silicon content in diesel fuel was obtained. The recoveries of this method ranged from 93.3% to 108%, the detection limit was 0.16 μg/g, and the lower limit of the method was 0.64 μg/g. The results showed that the ultrasonic atomization direct injection ICP-OES method is suitable for the determination of silicon in diesel fuel.

ADVANCES IN LOW-CARBON ALKANE/ALKENE ADSORPTIVE SEPARATION TECHNOLOGY

2024, 55(10):  171-178. 

Asbtract ( 181 )  

References | Related Articles | Metrics

Ethylene and propylene are important basic chemical raw materials. In production process, the alkanes with the same carbon number as ethylene and propylene usually need to be removed. Their physical and chemical properties are similar, and the separation is difficult. At present, the main method is cryogenic separation with high energy consumption. In contrast, the adsorptive separation method using zeolites, MOFs and other adsorbent materials has the characteristics of low cost and low energy consumption. It is expected to become an alternative separation technology with low energy consumption. In this paper, the research progress of adsorptive separation methods for low-carbon alkanes and olefins at domestic and overseas in recent years was reviewed from the three aspects of adsorption mechanism, adsorbent materials,and desorption technology.The limitations and challenges of novel zeolites, MOFs adsorbent materials and their desorption technologies in the future were put forward, and the optimization direction was prospected.