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2025 Vol.42 Issue.2,Published 2025-03-15

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2025 Vol. 42 (2): 0-0 [Abstract] ( 27 ) [HTML 1KB] [ PDF 918KB] ( 70 )
1 Performance of efficient Mn-N-C catalysts for the catalytic oxidation of Bisphenol A
JI Yongsheng, LI Yang, FAN Xiaobin, ZHANG Fengbao, ZHANG Guoliang, XIA Qing, PENG Wenchao
Advanced oxidation processes (AOPs) had received widespread attention as a simple and efficient means of treating pollutants, and its implementation relied on the activation of reliable catalysts. Based on this, we obtained two crystalline Mn-N-C materials in a simple way under the condition of only changing temperature. The results show that both Mn-N-C materials exhibit excellent catalytic oxidation performance and good stability in the process of activating NaIO4 to degrade bisphenol A(BPA). Furthermore, quenching experiments are conducted to demonstrate that the reactive oxygen species generated during the reaction process are superoxide radicals (O·-2) and singlet oxygen(1O2). This provides a feasible solution for further exploring the microstructure and reaction mechanism of M-N-C catalyst and solving the problem of difficult to degrade pollutants in water.
2025 Vol. 42 (2): 1-10 [Abstract] ( 25 ) [HTML 1KB] [ PDF 4899KB] ( 96 )
11 Effect of Nb doping on structure and electrochemical properties of LiNi0.9Mn0.1O2 cathode material
HE Zheng, LIU Jing, LEI Hailin, LI Wei, GUO Cuili
In this paper, the high temperature solid-phase reaction method is used, and Nb2O5 is mixed with LiNi0.9Mn0.1O2 precursor and LiOH·H2O in one step to prepare Nb2O5-doping LiNi0.9Mn0.1O2. The effect and mechanism of Nb2O5 doping amount on the crystal structure, morphology and electrochemical property were investigated. The experimental results show that Nb5+ doping can improve the order of layered structure, expand the spacing between transition metal layers, reduce cation mixing of Li+/Ni2+ and facilitate the de-intercalation of Li+ in the active material. At the voltage of 2.7—4.4 V and 1.0 C, NM-0.5Nb exhibited the capacity retention of 83.73% after 200 cycles, significantly higher than the retention rate (74.73%) of LiNi0.9Mn0.1O2. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) test results show that the electrochemical polarization and impedance of NM-0.5Nb cathode material decreases and the lithium ion diffusion rate increases, so the cycle performance and the rate performance of Nb2O5-doping LiNi0.9Mn0.1O2 cathode material are improved.
2025 Vol. 42 (2): 11-19 [Abstract] ( 29 ) [HTML 1KB] [ PDF 6368KB] ( 67 )
20 Highly selective synthesis of m-trifluoromethyl acetophenone by catalytic acylation based on solid acid catalyst
LI Bin, WANG Wenjun, JIANG Shuang, ZHANG Tianyong
m-Trifluoromethyl acetophenone(TFAP) is a key intermediate in the synthesis of trifloxystrobin, and also an important raw material for the synthesis of other chemicals such as pharmaceuticals and dyes. Most of the synthesis routes that have been reported presently suffer from complex processes, high environmental pollution and high risk. In this paper, we investigated the Friedel-Crafts acylation reaction for preparation of m-trifluoromethyl acetophenone from trifluorotoluene with acetyl chloride as the acylating agent in one step based on the loaded solid acid catalyst, which focused on the effects of catalyst loading, reaction temperature and reaction solvent on the catalytic preparation of trifluoromethy lacetophenone. The optimal process conditions were determined for the reflux reaction at 50 ℃ with FeCl3 as the active component, γ-Al2O3 as the carrier, dichloroethane as the solvent, and the catalyst addition of 10%. The selectivity of the target product trifluoromethyl acetophenone could reach 99%, and the one-way conversion of trifluorotoluene was 15.5%. The prepared FeCl3/γ-Al2O3 loaded solid acids were characterized by XPS, BET and NH3-TPD, and the possible catalytic reaction mechanism was proposed. The synthetic method is easy to operate, with low cost catalyst and environmentally friendly post-treatment process, which exhibiting good potential for industrial application.
2025 Vol. 42 (2): 20-27 [Abstract] ( 35 ) [HTML 1KB] [ PDF 2883KB] ( 84 )
28 Study on fluorinated modified solid methylaluminoxane supported metallocene catalysts
DENG Xiuyuan, WANG Lijuan, JIANG Tao, LI Jian
In the field of metallocene catalyst polymerization of olefins, methylaluminoxane (MAO) is a common cocatalyst. Curing methylaluminoxane to form solid methylaluminoxane (sMAO) can play a dual role as a cocatalyst and carrier. In this study, sMAO is modified by adding different fluoroalkanes and fluoroaromatic compounds. Simultaneously, bis (1-butyl-3-methylcyclopentadienyl) zirconium dichloride was loaded onto a modified carrier as the active component of the metallocene to obtain a supported metallocene catalyst, which was used for ethylene slurry polymerization. Among them, using decafluorobiphenyl, perfluorohexane, and 1-hydroperfluorohexane as modifiers, and the activity of the prepared modified catalyst was 1.58×106,1.42×106 and 1.46×106 g·mol-1, showing 17% to 30% increase in activity compared to that before modification.
2025 Vol. 42 (2): 28-34 [Abstract] ( 34 ) [HTML 1KB] [ PDF 9094KB] ( 45 )
35 Study on the process of macroporous resin-C18 column separation and purification of β-caryophyllene and its antioxidation properties
HE Weigang, SUN Chengjun, Lü Shijun, TAO Yuheng, YAN Shenghu, WANG Liqun, QING Qing
The crude extract of β-caryophyllene was obtained from the transgenic microalgae culture solution by reduced pressure concentration combined with ethanol extraction process, and the products were further concentrated and purified by establishing a macroporous resin combined with C18 spherical column separation method. Six different types of macroporous resin were investigated, and HPD-100 macroporous resin was selected as the optimal adsorbent for β-caryophyllene. The separation and purification conditions of crude extract were optimized respectively under static and dynamic adsorption-desorption conditions. Through the optimization of temperature, pH, time and desorption agent during static adsorption and desorption, the static adsorption and desorption rates reached 87.8% and 80.8% respectively. In the dynamic adsorption and desorption experiment, the initial loading flow rate was 2 BV·h-1, the loading volume was 28 BV, the adsorption rate was 98.0%. The desorption rate reached 64.8% using ethanol as eluent at a flow rate of 1.5 mL·min-1 with the elution volume of 7 BV. Subsequently, 5 mL eluate was loaded to a C18 column with methanol as the mobile phase and the elution flow rate of 1.0 mL·min-1. The purity of β-caryophyllene in the collected sample reached 99.0% which increased 63.2% compared with the crude extract, indicating the efficiency of this method. In vivo and in vitro antioxidant capacity tests were conducted using the purified β-caryophyllene. The clearance capacity for DPPH, ABTS, and ·O-2 was 82.2%, 76.7%, and 82.4%, respectively, at 1 000 μmol·L-1 and 40.75% reduction in PC12 cells at the addition of 10 μmol·L-1. Moreover, molecular docking simulations indicated that β-caryophyllene had excellent affinity to SOD, CAT, POD and GPX.
2025 Vol. 42 (2): 35-44 [Abstract] ( 34 ) [HTML 1KB] [ PDF 3794KB] ( 71 )
45 Support effects of Ru based catalysts for CO catalytic oxidation
ZHENG Xiwen, JIN Shishan, ZENG Xin, HAN Jiao, HU Shaozheng, ZHANG Lei, GAO Zhixian
CeO2, pseudo boehmite [AlO(OH)], γ-Al2O3 and ZrO2 were used as the carriers, and Ru was the active component, Ru based catalysts with different carriers were prepared using a deposition precipitation method. The prepared catalytic materials were characterized by XRD, H2-TPR, BET, XPS, etc, and the influence of carrier on the catalytic CO oxidation was also explored. The results indicated that different carriers mainly affected the interaction between Ru species and the carrier, showing obvious support effects. Among them, the Ru species on Ru/CeO2-BM catalyst exhibited good dispersion and could generate oxygen vacancies, thus exhibiting excellent low-temperature catalytic performance. Under the conditions of an oxygen excess coefficient of 5, a space velocity of 60 000 h-1, and the reaction temperature of 147 ℃, the outlet CO concentration decreased to less than 1×10-5, and the CO conversion reached 99.9%.
2025 Vol. 42 (2): 45-54 [Abstract] ( 33 ) [HTML 1KB] [ PDF 5121KB] ( 35 )
55 Research progress on lithium-ion conductive solid polymer electrolytes
ZHANG Yating, MA Shuo, ZHANG Yanan, LI Xuan, CHEN Mingming
The combined advantages of good safety, excellent interfacial compatibility, low cost, and ease of processing make solid-state polymer electrolytes the most desirable candidates for next-generation batteries. However, the low ionic conductivity of these electrolytes limits their application in solid-state batteries. Therefore, an in-depth understanding of the lithium ion conduction mechanism in solid-state polymer electrolytes can help to design electrolytes that conduct lithium ions more efficiently. Typical solid-state polymer electrolytes and their lithium ion conduction mechanisms are reviewed, including 'salt-in-polymer' electrolytes, 'polymer-in-salt' electrolytes, and single-ion-conducting polymer electrolytes. Based on the above understanding, three major strategies to improve the ion transport performance and the latest research progress are described, and an outlook on the enhancement of lithium ion conduction in solid polymer electrolytes is presented.
2025 Vol. 42 (2): 55-67 [Abstract] ( 35 ) [HTML 1KB] [ PDF 4889KB] ( 84 )
68 Electrochemical recovery of lithium from brine by highly stable truncated octahedral LiAl0.1Mn1.9O4
LI Jiaming, MENG Xiaorong, WU Zhenpeng
LiMn2O4-based electrochemical lithium extraction systems have become a highly promising lithium extraction technology due to their high lithium extraction efficiency, good selectivity, and green and non-polluting advantages. However, the lack of stability limits its further development. In this study, an aluminum-doped LiAl0.1Mn1.9O4 lithium extraction electrode material was prepared, and the doping of Al3+ effectively enhanced the diffusion rate of Li+ and suppressed the Jahn-Teller effect. In the continuous constant current charge/discharge test, the LiAl0.1Mn1.9O4 electrode achieved 67% capacity retention compared to 42% for the LiMn2O4 electrode, indicating that LiA10.1Mn1.9O4 has better electrochemical stability. The simulated electrochemical lithium extraction LiAl0.1Mn1.9O4 electrode exhibited high lithium extraction capacity (25.17 mg·g-1), stable cyclic lithium extraction performance (90.58%), and low energy consumption (15.52 Wh·mol-1). Finally, the LiAl0.1Mn1.9O4 electrode maintained a high lithium extraction capacity (19.75 mg·g-1) and lithium-magnesium separation performance (αLi-Mg=118.74) in 10 consecutive lithium extraction experiments in the brine of East Taijiner Brine with a Mg-lithium ratio of 46.31, and the lithium extraction capacity retention rate reached 90.2% over 10 cycles. These excellent properties make the LiAl0.1Mn1.9O4 electrode valuable for practical applications in electrochemical lithium extraction.
2025 Vol. 42 (2): 68-79 [Abstract] ( 27 ) [HTML 1KB] [ PDF 7627KB] ( 58 )
80 Preparation and properties of hollow fiber membrane for MABR
JI Qingyuan, XIE Lixin, WU Yixuan, XU Shichang
The polypropylene hollow fiber membranes were prepared by the thermally induced phase separation method and the effect of preparing conditions on the properties of membranes was investigated in this paper. The resulted hollow fiber membranes have the advantage of narrow pore size distribution and high bubble point pressure. We also modified the membranes by the co-deposition of catechol (CCh) and polyethyleneimine (PEI). After the modification, the membranes have lower contact angle and higher Zeta potential. Membrane aerated biofilm reactor (MABR) experiments reveal that the modified membranes take less time to complete bioadhesion and the total oxygen transfer coefficient increases by about 3 times, with a COD degradation rate of 89.0% and an ammonia nitrogen degradation rate of 89.3%. The modified membranes also show good anti-fouling ability. After the continuous operation for 20 d, the decrease of modified membranes in total oxygen transfer coefficient is 4.6%, much less than that of the original membranes (27.9%).
2025 Vol. 42 (2): 80-88 [Abstract] ( 33 ) [HTML 1KB] [ PDF 5358KB] ( 59 )
89 Impact of enhancer of low rank pulverized coal in the process of preparation of formed coke
WANG Chaofan, SONG Yonghui, YIN Ning, SHEN Xiaorui, LI Liang, LAN Xinzhe
In order to solve the problem of low strength of formed coke products prepared from low-rank pulverized coal, this paper takes low low-rank pulverized coal (HL) as raw material, coal pitch (LQ) binder, and addition of benzene homologues as the main fortifying agent (AC). The formed coke was prepared using cold pressing molding pyrolysis technology, and the optimum process conditions for formed coke preparation were determined. The formed coke was analyzed and characterized by FT-IR and four component extraction, and the strengthening mechanism of AC addition on the formed coke compressive strength was discussed. The results showed that under the conditions of LQ addition ratio of 35%, pyrolysis temperature of 900 ℃ and retention time of 120 min, when AC addition ratio of 3%, the formed coke compressive strength could be increased from 20.00 MPa to 26.22 MPa. AC can reduce the repulsive force between raw materials to make them more closely combined, and undergo substitution reactions with functional groups such as —CH3 and —OH, resulting in an increase in the relative contents of aliphatic —CH, aromatics C=C and C—O by 429.52%, 186.56% and 119.00%, respectively. Meanwhile, the activities of aliphatic hydrocarbon and aromatic hydrocarbons were enhanced and more aromatic compounds were generated during pyrolysis process. The asphaltene and pre-asphaltene contents increased by 3.5% and 2.0% respectively, which led to an increase in the colloidal body content, enhanced coking performance, and improved the formed coke compressive strength.
2025 Vol. 42 (2): 89-96 [Abstract] ( 32 ) [HTML 1KB] [ PDF 3543KB] ( 74 )
97 Hydrothermal method for efficient impurity removal and calcination repair of spent graphite
HUA Weiming, CHEN Xiangping, JI Shaowen, LI Futao
Graphite materials occupy an important position in lithium-ion batteries (LIBs), and if spent graphite (SG) can be recycled and reused, the shortage of graphite resources will be alleviated, which is beneficial to the sustainable development of the new energy industry. For the restoration and regeneration process of SG, this study focuses on the application of different removal methods for different metal impurities. Efficient removal of Cu and Li under hydrothermal conditions, efficient removal of Co, Mn and Ni simultaneously under water bath conditions, and finally the effect of different temperature and time on the removal of organic impurities from the surface of SG was investigated. For the above obtained regenerated graphite (RG), it was characterized and analyzed by XRD and SEM. Finally, the graphite was prepared into button cells and tested for its electrochemical properties. The results show that the leaching rates of Cu, Li, Co, Mn and Ni exceed 96% under the suitable conditions. The capacity retention of RG was 97.99% at a current density of 0.1 C. This method achieved the restoration and regeneration of waste graphite.
2025 Vol. 42 (2): 97-106 [Abstract] ( 27 ) [HTML 1KB] [ PDF 6658KB] ( 64 )
107 Microwave heating behaviors and drying characteristics of mercury catalyst
LIU Chao, LUO Wei, WANG Zixiao, ZHANG Libo, ZHNAG Bin
The conventional drying process of mercury catalyst has disadvantages such as low efficiency and poor quality, so the microwave drying method of mercury catalyst is proposed. The dielectric properties of the main components activated carbon, mercury chloride and mercurous chloride were compared. The results show that microwave heating of mercury catalyst is a selective heating process, moisture and activated carbon can selectively absorb microwave, but the microwave absorption abilities of mercury chloride, mercurous chloride are poor, which can effectively avoid heat volatilization. The microwave multi-stage constant temperature drying process was compared. The results show that the drying times of two-stage drying method (80 and 120 ℃) and three-stage drying method (80, 100 and 120 ℃) are 74 min, while that of two-stage drying method (100 and 120 ℃) is only 50 min, which can save 77.3% drying time. Compared with conventional drying, the maximum drying rate and average drying rate of microwave drying were 7 times and 4 times respectively. The higher the moisture content, the more obvious the advantage of microwave drying. Microwave drying of mercury catalyst has the advantages of high efficiency and good quality.
2025 Vol. 42 (2): 107-115 [Abstract] ( 33 ) [HTML 1KB] [ PDF 4093KB] ( 66 )
116 Pyrolysis behavior and product characteristics of apple branches
YIN Ning, SONG Yonghui, WU Lei, DONG Ping, WANG Chaofan, ZHANG Xinwei
Pyrolysis technology is one of the most important means for the efficient utilization of biomass resources, and research on the pyrolysis process and its products is of great significance. The pyrolysis behavior of apple tree branches (AB) and its product properties were investigated based on thermogravimetric-infrared spectroscopy (TG-FTIR), pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy (Raman) techniques. The results showed that the volatile compounds of AB pyrolysis were mainly released within the range of 178.6—459.9 ℃, and the weight loss rate was 53.12%. The gaseous products produced by AB pyrolysis corresponded to TG-DTG curves and were dominated by CO, CO2, and C=O-containing substances, while the absorption intensity of aliphatic and aromatic hydrocarbons was extremely weak. The volatile products consisted of substances with C≤10, accounting for 86.57%. The liquid products were mainly aldehydes and ketones, alkanes, acids, and aromatics, with 27.66%, 22.79%, 14.75%, and 12.50%, respectively. Among them, the aldehydes and ketones were mainly 4,4-dimethyl-2-oxetane and acetone. Alkanes were mainly cyclopropane and long-chain alkanes. The acid components were mainly acetic acid. The aromatic components were benzene, toluene and 2-methylindene. AB pyrolysis process is mainly the decomposition of oxygen-containing functional groups, in which the intensity of the vibrations decreases with the increase in pyrolysis temperature. Raman spectra showed that the proportion of aromatic side chains in ABC decreased, the concentration of aromatic rings with a benzene ring number greater than 6 increased, and the graphitization degree increased.
2025 Vol. 42 (2): 116-124 [Abstract] ( 32 ) [HTML 1KB] [ PDF 4702KB] ( 61 )
125 Influence of DTB crystallizer structure on flow characteristics
CHEN Zhirong, XIANG Yanting, YUAN Shenfeng, YIN Hong
DTB crystallizer (draft tube baffled) can be used to produce methionine as a continuous industrial crystallization equipment. There are few studies have focused on the flow characteristics of industrial-scale DTB crystallizer at present. Computational fluid dynamics (CFD) technology and Euler-Euler model were used to describe the macroscopic flow characteristics of industrial DTB crystallizer. The rationality of increasing the guide vane to improve circulation in the crystallizer was investigated, and the effect of draft tube length and baffle length on fluid flow and particle suspension state was studied. The simulation results show that increasing the guide vane improves the axial flow effect of the crystallizer. When the draft tube length is 2.8 m, the DTB crystallizer can maintain a good internal circulation effect without unstable flow field due to high velocity reaching the boiling liquid level. The baffle length determines the size of the settling zone, and long baffle is unfavorable for eliminating fine crystals and stabilizing the operation of the crystallizer.
2025 Vol. 42 (2): 125-134 [Abstract] ( 20 ) [HTML 1KB] [ PDF 5455KB] ( 38 )
135 Cutting diameter for solid particles and flow field in cyclones with different cylinder-cone height ratio
LI Shengnan, WU Bin, CHEN Kui, JI Lijun, WU Yanyang
Geometric configuration of a cyclone separator has an important influence on its pressure drop and particle separation performance. In separation of dust-laden tail gas, accurate understanding of the impact of configuration parameters and operating conditions of a cyclone separator on separation efficiency for solid particles is the premise for optimized structure and operation. RSM-DPM model was used to simulate and investigate the variation of particle cutting diameter, pressure and tangential velocity profile in the cyclone separator under different cylinder-cone ratios while maintaining a constant total height. It has been established that pressure drop between the inlet and outlet tends to decline with the increase of cylinder-cone ratio. Profiles for tangential velocity exhibit slight deviation from symmetric centerline of cyclones with changes of the cylinder-cone ratio. The effect of cylinder-cone ratio on cutting diameter for solid particles exhibits different mode under different range of inlet gas velocity. When inlet gas velocity is less than 12 m·s-1, a smaller cylinder-cone ratio is more conducive to separation. When inlet gas velocity is greater than 12 m·s-1, for a configuration with a small cylinder-cone ratio (less than 2.50), an appropriate increase in the cylinder-cone ratio is more favorable to separation, and when the cylinder-cone ratio is greater than 3, the cutting diameter barely changes with the cylinder-cone ratio. Aiming at different inlet flow rates, proper choice of the cylinder-cone ratio will help to obtain higher separation efficiency. For high and a low inlet gas flowrate, cylinder-cone ratio of 2.50 and 0.85 are suitable configuration options respectively.
2025 Vol. 42 (2): 135-144 [Abstract] ( 20 ) [HTML 1KB] [ PDF 5865KB] ( 63 )
145 Prediction of methanol to aromatics products based on virtual sample generation technology
GAO Tun, YANG Chen, YU Feng, ZHANG Wei, ZHANG Kan
Aiming at the difficulty of high data acquisition, high data repetition rate, small sample size, and large data information interval in two-stage methanol to aromatics (MTA) process, an extreme learning machine modeling method based on virtual sample generation technology and genetic algorithm (GA) optimization is proposed to predict the total yield of benzene, toluene and xylene (BTX), which are important products of the process. First, based on the data samples collected from the two-stage methanol to aromatics pilot plant, the input data for the model are expanded using the multi-distribution mega-trend-diffusion technology, and then the virtual sample set is obtained using the limit learning machine model optimized by GA. After verifying the rationality of the data, the BTX yield prediction model is established using the fusion of the original data set and the virtual data set. Through the verification of the MTA experimental data and the comparative analysis of the other two modeling methods, the results show that the modeling method based on virtual samples has the best precision performance, and the method has good stability, which is suitable for predicting BTX yield in methanol to aromatics process.
2025 Vol. 42 (2): 145-153 [Abstract] ( 34 ) [HTML 1KB] [ PDF 1845KB] ( 63 )
154 Simulation and prediction of the adsorption effect of space station condensate through activated carbon filled column
WU Kerong, LIANG Xiaoyi, ZHANG Xiaoyu, BAO Shiyuan
In the process of condensate water purification in the space station, the corresponding adsorption model can be established by measuring the actual penetration curve of the condensate water model and the adsorption isotherm of one-component organic matter. The adsorption of organic matter in the condensed water by activated carbon meets the Langmuir model and Freundlich model. Through further investigation, it is known that activated carbon has excellent adsorption performance for benzyl alcohol and caprolactam in condensed water, but weak adsorption performance for other organic matter. There is strong competitive adsorption between different organic matter in condensed water model, and the multi-component adsorption isotherm is consistent with IAS-Freundlich model and IAS-Langmuir model. By changing the initial concentration of benzyl alcohol and caprolactam in condensed water, it can be concluded that caprolactam has strong adaptability to the established models.
2025 Vol. 42 (2): 154-165 [Abstract] ( 21 ) [HTML 1KB] [ PDF 5707KB] ( 71 )
166 Simulation study of the susceptor assisted microwave high-temperature reactor heating based on fully coupled electromagnetic thermal fluid
WANG Xianfeng, SHANG Xiaobiao, WANG Wenbo, FAN Huili, ZHANG Qun, ZHOU Jiashen
Microwave heating is widely used in the industrial field because of its high efficiency, fast and uniform characteristics. However, due to the selective heating characteristic, the coupling effect between microwave and weak microwave absorbing material is not obvious, which limits the application of microwave in industrial field. Therefore, the external susceptor (SiC) was introduced into the microwave reactor, and a finite element simulation model was established based on the electromagnetic-thermal-fluid coupling theory to explore the influence of different receptor configuration on the microwave heating of weak absorbing materials. The results show that the design of the external susceptors should not only consider the influence of the external susceptors on the electric field distribution of materials, but also consider the energy transfer between materials and susceptors, so as to achieve the optimal energy conversion balance between the susceptors assisted heating and the microwave volume heating material; When the susceptor is placed on both sides of the material and parallel to the waveguide side, the assisted heating effect is the best, the average temperature at 500 s is 918.86 ℃, and the COVT is 0.133 6; In high-temperature microwave reactor, thermal radiation is the main heat transfer mode, and the higher the temperature, the more intense the heat transfer.
2025 Vol. 42 (2): 166-176 [Abstract] ( 23 ) [HTML 1KB] [ PDF 5504KB] ( 72 )
177 Numerical simulation of pulverized coal combustion and calcium carbonate decomposition coupling and NOx generation in swirl precalciner
LI Quanliang, HE Feng, MEI Shuxia, XIE Junlin, ZHANG Chao, DENG Yuhua
Aiming at a new type of swirl precalciner, numerical simulations were carried out for the pulverized coal combustion, raw meal decomposition coupling, and NOx generation processes. In Euler coordinate system gas phase was expressed with the Realizable k-ε two-equation model, in Lagrange coordinate system solid phase was expressed with the discrete phase model(DPM),pulverized coal combustion and raw meal decomposition was expressed with the species transport model,radiation was expressed with the P-1 model, NOx generation was expressed with the pollutant model. Thermal NOx and fuel NOx generation are considered. The results show that the tertiary air mainly moves upward along the wall spiral, while the flue gas mainly moves the central axis spiral in the precalciner. When the pulverized coal enters the precalciner, the volatiles are rapidly released and burned, and then the char continues to burn, and its main combustion area is near the shell. When the pulverized coal enters the precalciner, the volatiles are rapidly released and burned, and then the char continues to burn, and its main combustion area is near the shell, and the combustion residence time is approximately 5.9 s. The raw meal decomposes rapidly after entering the precalciner. When reaching a height of 50 m in the precalciner, the decomposition rate of CaCO3 reaches 90%. At this point, the decomposition times for the lower and upper raw meal are approximately 6.5 s and 4.7 s, respectively. 92.32% decomposition of calcium carbonate at the outlet. Due to the poor coupling between pulverized coal combustion and raw meal decomposition at the shell, local high temperatures are formed at the wall, which makes the NOx generation rate larger, and the NOx at the outlet reaches 1.251×10-3, which needs to be improved.
2025 Vol. 42 (2): 177-186 [Abstract] ( 28 ) [HTML 1KB] [ PDF 5640KB] ( 68 )
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