A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indi...A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indicated that the pre-reduction sintering process(PSP)can effectively remove 58.02%of K and 30.68%of Na from raw mixtures and improve yield and tumbler index to 74.40%and 68.69%,respectively.Moreover,PSP was conducive to reducing NO_(x) and SO_(2)emissions and simultaneously increasing CO content in flue gas.Circulating CO-containing flue gas to sintering bed effectively recycled CO and further improved K and Na removal ratio to 74.11%and 32.92%,respectively.Microstructural analysis revealed that the pre-reduced sinter mainly consisted of magnetite,wustite and a small quantity of metallic iron,and very few silicate glass phase was also formed.This process can simultaneously realize alkali metal elements removal as well as flue gas emission reduction from the integrated ironmaking process.展开更多
With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can re...With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].展开更多
Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley a...Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment measures.First,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction model.The effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions.The operating parameter combination was then pushed.The flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.展开更多
Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.C...Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.展开更多
Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated wi...Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.展开更多
Sintering is the process that emits the most pollutants in ironmaking,including CO,SO_(2),NO_(x),and dioxins.Flue gas circulation sintering technology can not only reduce the emissions of various pollutants but also d...Sintering is the process that emits the most pollutants in ironmaking,including CO,SO_(2),NO_(x),and dioxins.Flue gas circulation sintering technology can not only reduce the emissions of various pollutants but also decrease the consumption of solid fuels.Therefore,it is necessary to summarize and discuss the research status of flue gas circulation technology.Firstly,the research status,advantages,and disadvantages of five typical flue gas circulation processes and their effects on the emission of different pollutants were analyzed.Then,the impact of O_(2),CO,SO_(2),and temperature in the circulating gas during the sintering flue gas circulation process on the quality of sinter and their reasonable ranges was summarized,and the formation mechanisms of CO_(x),NO_(x),SO_(2),and dioxins during the sintering process were discussed.Furthermore,the optimization and improvement of flue gas circulation technology in recent years were introduced.Finally,issues related to element enrichment,equipment improvements,and fine particulate matter emissions in the flue gas circulation process were reviewed,providing a reference for the optimal application of flue gas circulation sintering technology in the future.展开更多
Mercury(Hg)pollution has been a global concern in recent decades,posing a significant threat to entire ecosystems and human health due to its cumulative toxicity,persistence,and transport in the atmosphere.The intense...Mercury(Hg)pollution has been a global concern in recent decades,posing a significant threat to entire ecosystems and human health due to its cumulative toxicity,persistence,and transport in the atmosphere.The intense interaction between mercury and selenium has opened up a new field for studying mercury removal from industrial flue gas pollutants.Besides the advantages of good Hg^(0) capture performance and lowsecondary pollution of the mineral selenium compounds,the most noteworthy is the relatively low regeneration temperature,allowing adsorbent regeneration with low energy consumption,thus reducing the utilization cost and enabling recovery of mercury resources.This paper reviews the recent progress of mineral selenium compounds in flue gas mercury removal,introduces in detail the different types ofmineral selenium compounds studied in the field ofmercury removal,reviews the adsorption performance of various mineral selenium compounds adsorbents on mercury and the influence of flue gas components,such as reaction temperature,air velocity,and other factors,and summarizes the adsorption mechanism of different fugitive forms of selenium species.Based on the current research progress,future studies should focus on the economic performance and the performance of different carriers and sizes of adsorbents for the removal of Hg^(0) and the correlation between the gas-particle flow characteristics and gas phase mass transfer with the performance of Hg^(0) removal in practical industrial applications.In addition,it remains a challenge to distinguish the oxidation and adsorption of Hg^(0) quantitatively.展开更多
With the rapid development of adsorbents for removal of elemental mercury (Hg0) from coal combustion flue gas,the preparation of adsorbents with superior performance,lower cost and environmental friendliness remains a...With the rapid development of adsorbents for removal of elemental mercury (Hg0) from coal combustion flue gas,the preparation of adsorbents with superior performance,lower cost and environmental friendliness remains an important challenge.An incipient wetness impregnation method followed by in-situ selenization was used to load copper selenide(CuSe) onto the surface of optimal magnetic biochar (OMBC).The results showed that CuSe significantly enhanced the Hg0removal performance of the OMBC,and CuSe loading ratio of 10%(10CuSe/OMBC) had the best Hg0removal performance.10CuSe/OMBC maintained its Hg0removal efficiency above 95% for 150 min at 30-150℃,and it had a good resistance to SO2.The equilibrium adsorption capacity of 10CuSe/OMBC could reach up to 8.73 mg/g,which was close to the theoretical value 12.99 mg/g,and the adsorption rate was up to 20.33μg/(g·min) Meanwhile,10CuSe/OMBC had strong magnetism that is not permanently magnetized,which could be separated from desulfurization gypsum and recycled many times.Characterization results demonstrated that Se22-,Cu2+and Oβplayed essential roles in the oxidation of Hg0,and Se22-and Se2-can immobilize Hg2+to HgSe.10CuSe/OMBC has important guiding significance for practical application because of its low cost,high performance and low mercury leaching characteristic to form HgSe.展开更多
The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon ...The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon emissions in reservoirs with interlayers.Currently,there is limited research on the low-carbon strategy of coupling exhaust gas from steam boilers with the VH-SAGD technique.Herein,considering heterogeneity,a series of flue gas-assisted VH-SAGD experiments were conducted employing a high-performance 2D visualization model.The mechanism of enhanced recovery of flue gas in VH-SAGD and the effect of its injection methods were studied,with a focus on steam chamber development and oil saturation distribution.Crucially,the interlayer length was optimized to enhance oil recovery,providing a new perspective for well location design in heavy oil reservoirs with interlayers.The results showed that flue gas,as an additive,could fully exploit the well-type advantage of VH-SAGD.By supplementing energy at the reservoir top,flue gas effectively promoted steam chamber development,expanded the oil drainage area of VH-SAGD,and increased the oil recovery from 58.9%to 71.7%.The flow channels formed by pre-injection flue gas accelerated the early-stage expansion of the steam chamber while also inducing lateral migration of steam,slowing steam rise,and consequently increasing the heating range within the low-permeability layer.When the distance between the vertical and horizontal wells was set to twice the interlayer length,the negative effects of the interlayer were more effectively turned into advantages.Because when the lateral development distance of the steam chamber in the low-permeability layer slightly exceeds the interlayer,enhanced heating of the lower part of the reservoir occurred through vertical convection of rising steam and returning condensate.The research results contribute to reducing carbon emissions from steam-based heavy oil extraction while advancing the maturity of VH-SAGD.展开更多
In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the instal...In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the installation height of the first catalyst layer,on the flow field and the overall denitration efficiency of a cement kiln’s SCR(Selective catalytic reduction)denitrification reactor.It is shown that accurate numerical results can be obtained by fitting the particle size distribution function to the actual cement kiln fly ash and implementing a non-uniform particle inlet boundary condition.The relative error between denitration efficiency derived from experimental data,numerical simulation,and real-time system pressure drop ranges from 4%to 9%.Optimization of the SCR reactor is achieved when the rectifier grid thickness ratio k/H≥0.030,the rectifier grid height ratio h/H=0.04,and the spacing between the rectifier grid and the first catalyst layer l/H=0.10.Under these conditions,airflow distribution and particle dispersion upstream of the catalyst result in increased denitration efficiencies of 3.21%,3.43%,and 3.27%,respectively,compared to the least favorable operating conditions.展开更多
For the treatment of the mixed flue gas desulfurization wastewater with high salinity by the biological fluidized bed process,the optimum temperature was 25-35℃,and the optimum hydraulic retention time was 10 h.When ...For the treatment of the mixed flue gas desulfurization wastewater with high salinity by the biological fluidized bed process,the optimum temperature was 25-35℃,and the optimum hydraulic retention time was 10 h.When the influent quality was stable,the average concentration of COD,NH_(4)^(+)-N and TN in the inlet water was 210,11 and 16.3 mg/L,respectively,and their average concentration in the effluent was 54,0.32 and 4.09 mg/L,respectively.The treatment effect was good.When the incoming water quality of flue gas desulfurization wastewater fluctuated greatly,the effluent quality was still relatively stable after being treated by the biological fluidized bed,indicating that the biological fluidized bed process had a good ability to resist the impact of water quality in the treatment of high-salinity flue gas desulfurization wastewater.At the same time,the biological fluidized bed process provides a reference for high-salinity wastewater that is difficult to be biologically treated.展开更多
Currently,as environmental pollution becomes increasingly severe,flue gas denitrification has emerged as a significant area of research.With the advancement of modern industry and the improvement of living standards,a...Currently,as environmental pollution becomes increasingly severe,flue gas denitrification has emerged as a significant area of research.With the advancement of modern industry and the improvement of living standards,air pollution has gained growing attention.Sulfur dioxide and nitrogen oxides(NO_(x))have become major contributors to air pollution,posing serious harm to the environment.Consequently,flue gas desulfurization and denitrification technologies have become key research focuses in industrial development.This paper explores the selection of agricultural waste carbon sources and their pretreatment methods.It provides an in-depth analysis of the significance of agricultural waste carbon sources in flue gas denitrification,focusing on their performance and mechanisms.The study also discusses the role of agricultural waste carbon sources in flue gas denitrification,aiming to offer new research perspectives for relevant stakeholders.展开更多
This research has focused on the treatment of zinc flue dust by an acid leach process, combining an environmentally suitable impurity removal process to recover cadmium. Optimum conditions were found as follows: H2SO...This research has focused on the treatment of zinc flue dust by an acid leach process, combining an environmentally suitable impurity removal process to recover cadmium. Optimum conditions were found as follows: H2SO4 concentration 90 g/L, liquid/solid ratio 6:1, leaching temperature 60 ℃ and leaching time 1.0 h. Under these conditions, 95.8% cadmium was recovered. FeAsO4 and Fe(OH)3 precipitates with FeCI3 are found to be highly effective to obtain a high degree of separation of heavy metals and the oxyanions of arsenic from the leachate. The overall separation of arsenic and other heavy metals and precipitate settling rates are optimum at n(Fe)/n(As) ratio of 3:l and pH 6. The removal rates ofFe, Pb and Cu from the solution were greater than 98.9%, and As removal rate was 99.6%. A solvent extraction with P204 was used for the separation of zinc and cadmium. Optimum conditions are obtained as follows: 20% P204 (volume fraction) diluted with kerosene at room temperature, pH 3.0, and varying organic/aqueous (O/A) phase ratio 1:1. The extraction rate of zinc is 99.2% under these conditions. Spherical cadmium particles showing nearly uniform size were produced by hydrogen reduction at 310 ℃ and the crystal structure was cubic. In addition, the purity of the recovered cadmium powder is more than 99.99%.展开更多
The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM...The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM) consistent with American standard test methodtogether with the semi-continuous emissions monitoring (SCEM) system as well as a mobile laboratoryfor mercury monitoring. The mercury and its speciation concentrations including participate mercuryat three locations of before air preheater, before electrostatic precipitator (ESP) and after ESPwere measured using the OHM and SCEM methods under normal operation conditions of the boiler systemas a result of firing a bituminous coal. The vapor-phase total mercury Hg(VT) concentration declinedwith the decrease of flue gas temperature because of mercury species transformation from oxidizedmercury to particulate mercury as the flue gas moved downstream from the air preheater to the ESPand after the ESP. A good agreement for Hg°, Hg^(2+) and Hg( VT) was obtained between the twomethods in the ash-free area. But in the dense particle-laden flue gas area, there appeared to be abig bias for mercury speciation owing to dust cake formed in the filter of OHM sampling probe. Theparticulateaffinity to the flue gas mercury and the impacts of sampling condition to accuracy ofmeasure were discussed.展开更多
Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (HSN 1) in chicken. Crude extraction from Cochinchina momordica seed (ECM...Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (HSN 1) in chicken. Crude extraction from Cochinchina momordica seed (ECMS) was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine (HSN1) alone or combined with ECMS (5, 10, 20, 40 and 80 μg/dose). Serum IgG antibody levels (by ELISA) as well as effects on dally weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 μg/dose groups significantly (P〈0.05) enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 μg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 μg/dose ECMS and antibody titer was measured through hemagglutination inhibition (HI). It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.展开更多
Flue gas fooding is one of the important technologies to improve oil recovery and achieve greenhouse gas storage.In order to study multicomponent fue gas storage capacity and enhanced oil recovery(EOR)performance of f...Flue gas fooding is one of the important technologies to improve oil recovery and achieve greenhouse gas storage.In order to study multicomponent fue gas storage capacity and enhanced oil recovery(EOR)performance of fue gas water-alternating gas(fue gas-WAG)injection after continuous waterfooding in an oil reservoir,a long core fooding system was built.The experimental results showed that the oil recovery factor of fue gas-WAG fooding was increased by 21.25%after continuous waterfooding and fue gas-WAG fooding could further enhance oil recovery and reduce water cut signifcantly.A novel material balance model based on storage mechanism was developed to estimate the multicomponent fue gas storage capacity and storage capacity of each component of fue gas in reservoir oil,water and as free gas in the post-waterfooding reservoir.The ultimate storage ratio of fue gas is 16%in the fue gas-WAG fooding process.The calculation results of fue gas storage capacity showed that the injection gas storage capacity mainly consists of N_(2) and CO_(2),only N_(2) exists as free gas phase in cores,and other components of injection gas are dissolved in oil and water.Finally,injection strategies from three perspectives for fue gas storage,EOR,and combination of fue gas storage and EOR were proposed,respectively.展开更多
The tests of flue gas desulfurization were carried out on a circulating fluidized bed reactor in which the flue gas had different velocities at different sections. The SO 2 removal efficiency could be as high as 80% ...The tests of flue gas desulfurization were carried out on a circulating fluidized bed reactor in which the flue gas had different velocities at different sections. The SO 2 removal efficiency could be as high as 80% when Ca/S molar ratio was 1 1 and a small amount of water was sprayed into the reactor by a two phase (gas liquid) system nozzle.展开更多
[Objective] This study aimed to compare the effects of Chinese quality-improving fragrunce-increasing tobacco flue-curing technology, Chinese three- stage tobaeeo flue-curing technology and Zimbabwean tobaceo flue-eur...[Objective] This study aimed to compare the effects of Chinese quality-improving fragrunce-increasing tobacco flue-curing technology, Chinese three- stage tobaeeo flue-curing technology and Zimbabwean tobaceo flue-euring technology on microscopie structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method ] Middle leaves of tobacco cultivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the microscopic structure of flue-cured tobaceo leaves. [ Result] During three flue-curing processes, leaves, palisade tissues and sponge tissues shrank gradually. Three flue-euring processes exhibited significant differ- ences in the peak of tissue shrinkage : microscopic structure of flue-cured tobacco leaves in Chinese three-stage tobacco flue-curing process shrank earliest, follower by Chinese quality-improving fragrance-increasing tobacco flue-curing process; flue-eured tobacco leaves in Zimbabwean tobacco flue-curing process presented the latest shrinkage. At 84 h post-curing, leaf thickness in three flue-curing processes showed a descend order of Chinese three-stage tobacco flue-curing process 〉 Chinese quality-improving fragrance-increasing tobacco flue-curing process 〉 Zimbabwean tobacco flue-curing process. Upper and lower epidermal cells in Zimb- abwean tobacco flue-curing process ruptured earlier than other two flue-curing processes; eventually, the majority of cells ruptured and mixed with palisade tissues and sponge tissues. In Chinese quality-improving fragranee-increasing tobacco flue-curing process, only a small number of epidermal cells in dried leaves ruptured. Among three flue-curing technologies, Zimbabwean tobacco flue-curing technology exhibited the greatest damage to epidermal cells, followed by Chinese three-stage tobaceo flue-curing technology; Chinese quality-improving fragrance-increasing tobacco flue-curing technology had the minimum damage to epidermal cells. Mese- phyll cross-section exhibited significant morphological changes in stomata. To be specific, at 0 - 12 h post-curing, stomata of tobacco leaves closed with slightly prominent stamatal apparatuses on upper and lower epidermis; at 24 -72 h post-curing, stomata of tobaceo leaves changed gradually from opening to closure with significantly prominent stomatal apparatuses on upper and lower epidermis; at 84 h post-curing, stomata of tobacco leaves closed, and the majority of stomatal appa- ratuses were significantly prominent. In Chinese quality-improving fragrance-increasing tobacco flue-curing process, only a small number of epidermal ceils ruptured at 84 h pest-flue-curing; palisade tissues and sponge tissues shrank almost simultaneously. Significant gaps were observed between palisade tissues and between pal- isade tissues and sponge tissues. Chinese quality-improving fragrance-increasing tobacco flue-curing technology exhibited lower disorder level compared with other two flue-curing technologies. [ Conclusion] Chinese quality-improving fragrance-increasing tobacco flue-curlng technology was conducive to maintaining the micro- scopic structure integrity of flue-cured tobacco leaves and obtaining high-quality flue-cured tobacco leaves.展开更多
[ Objective] This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology, moderate-temperature moderate- humidity tobacco flue-curing technology and moderate-temperature high...[ Objective] This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology, moderate-temperature moderate- humidity tobacco flue-curing technology and moderate-temperature high-humidity tobacco flue-curing technology on submicroscopic structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method] Middle leaves of tobacco cuhivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the submicroscopic structure of flue-cured tobacco leaves. [ Result] Morphology changes and structural rupture of chloroplasts occurred at different time during three flue-curing proces- ses. In low-temperature low-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred late but rapidly; in moderate-tempera- ture moderate-humidity flue-curing process and moderate-temperature high-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred early but slowly. Among these three flue-curing processes, the speed of changes in mitochondria morphology, cristae number and membrane rupture pres- ented an upward order of low-temperature low-humidity flue-curing process 〈 moderate-temperature high-humidity flue-curlng process 〈 moderate-temperature moderate-humidity flue-curing process. In low-temperature low-humldity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 36 -48 h ; in moderate-temperature moderate-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 24 - 36 h; in moderate-temperature high-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 12 - 24 h. [ Conclusion ] Using low-temperature low-humidity flue- curing technology could prolong the maintenance duration of the submicroscopic structure integrity of flue-cured tobacco leaves, which was conducive to fully decom- posing and transforming substances in tobacco leaves and obtaining high-quality flue-cured tobacco leaves.展开更多
基金Project(52274290)supported by the National Natural Science Foundation of ChinaProject(72088101)supported by the Basic Science Center Project for National Natural Science Foundation of China。
文摘A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indicated that the pre-reduction sintering process(PSP)can effectively remove 58.02%of K and 30.68%of Na from raw mixtures and improve yield and tumbler index to 74.40%and 68.69%,respectively.Moreover,PSP was conducive to reducing NO_(x) and SO_(2)emissions and simultaneously increasing CO content in flue gas.Circulating CO-containing flue gas to sintering bed effectively recycled CO and further improved K and Na removal ratio to 74.11%and 32.92%,respectively.Microstructural analysis revealed that the pre-reduced sinter mainly consisted of magnetite,wustite and a small quantity of metallic iron,and very few silicate glass phase was also formed.This process can simultaneously realize alkali metal elements removal as well as flue gas emission reduction from the integrated ironmaking process.
基金the support of the National Natural Science Foundation of China(Nos.22205207 and 22378369).
文摘With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].
基金supported by the General Program of the National Natural Science Foundation of China(No.52274326)the China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202109)the Seventh Batch of Ten Thousand Talents Plan of China(No.ZX20220553).
文摘Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment measures.First,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction model.The effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions.The operating parameter combination was then pushed.The flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.
基金supported by the National Key R&D Program of China(No.2023YFC3709500).
文摘Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.
基金supported by the National Natural Science Foundation of China(22278066,21776039)the National Key R&D Program of China(2023YFB4103001)The Fundamental Research Funds for the Central Universities(DUT2021TB03).
文摘Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.
基金the financial support provided by the National Natural Science Foundation of China(52204335,52374319,52174291)the National Youth Talent Support Program(GJRC2023008)+2 种基金the Beijing New-Star Plan of Science and Technology(Z211100002121115)the Central Universities Foundation of China(06500170)Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities)(FRF-IDRY-22-004).
文摘Sintering is the process that emits the most pollutants in ironmaking,including CO,SO_(2),NO_(x),and dioxins.Flue gas circulation sintering technology can not only reduce the emissions of various pollutants but also decrease the consumption of solid fuels.Therefore,it is necessary to summarize and discuss the research status of flue gas circulation technology.Firstly,the research status,advantages,and disadvantages of five typical flue gas circulation processes and their effects on the emission of different pollutants were analyzed.Then,the impact of O_(2),CO,SO_(2),and temperature in the circulating gas during the sintering flue gas circulation process on the quality of sinter and their reasonable ranges was summarized,and the formation mechanisms of CO_(x),NO_(x),SO_(2),and dioxins during the sintering process were discussed.Furthermore,the optimization and improvement of flue gas circulation technology in recent years were introduced.Finally,issues related to element enrichment,equipment improvements,and fine particulate matter emissions in the flue gas circulation process were reviewed,providing a reference for the optimal application of flue gas circulation sintering technology in the future.
基金supported by the Basic Research Business Fund Grant Program for University of Science and Technology Beijing (No.06500227)the Fundamental Research Funds for the Central Universities (No.FRF-TP-22-091A1).
文摘Mercury(Hg)pollution has been a global concern in recent decades,posing a significant threat to entire ecosystems and human health due to its cumulative toxicity,persistence,and transport in the atmosphere.The intense interaction between mercury and selenium has opened up a new field for studying mercury removal from industrial flue gas pollutants.Besides the advantages of good Hg^(0) capture performance and lowsecondary pollution of the mineral selenium compounds,the most noteworthy is the relatively low regeneration temperature,allowing adsorbent regeneration with low energy consumption,thus reducing the utilization cost and enabling recovery of mercury resources.This paper reviews the recent progress of mineral selenium compounds in flue gas mercury removal,introduces in detail the different types ofmineral selenium compounds studied in the field ofmercury removal,reviews the adsorption performance of various mineral selenium compounds adsorbents on mercury and the influence of flue gas components,such as reaction temperature,air velocity,and other factors,and summarizes the adsorption mechanism of different fugitive forms of selenium species.Based on the current research progress,future studies should focus on the economic performance and the performance of different carriers and sizes of adsorbents for the removal of Hg^(0) and the correlation between the gas-particle flow characteristics and gas phase mass transfer with the performance of Hg^(0) removal in practical industrial applications.In addition,it remains a challenge to distinguish the oxidation and adsorption of Hg^(0) quantitatively.
基金supported by the Basic Research Business Fund Grant Program for University of Science and Technology Beijing(No.06500227)the Fundamental Research Funds for the Central Universities(No.FRF-TP-22-091A1)+1 种基金National Natural Science Foundation of China(No.52200121),Chinese Universities Scientific Fund(No.00007713)the Guide special project(No.40103322).
文摘With the rapid development of adsorbents for removal of elemental mercury (Hg0) from coal combustion flue gas,the preparation of adsorbents with superior performance,lower cost and environmental friendliness remains an important challenge.An incipient wetness impregnation method followed by in-situ selenization was used to load copper selenide(CuSe) onto the surface of optimal magnetic biochar (OMBC).The results showed that CuSe significantly enhanced the Hg0removal performance of the OMBC,and CuSe loading ratio of 10%(10CuSe/OMBC) had the best Hg0removal performance.10CuSe/OMBC maintained its Hg0removal efficiency above 95% for 150 min at 30-150℃,and it had a good resistance to SO2.The equilibrium adsorption capacity of 10CuSe/OMBC could reach up to 8.73 mg/g,which was close to the theoretical value 12.99 mg/g,and the adsorption rate was up to 20.33μg/(g·min) Meanwhile,10CuSe/OMBC had strong magnetism that is not permanently magnetized,which could be separated from desulfurization gypsum and recycled many times.Characterization results demonstrated that Se22-,Cu2+and Oβplayed essential roles in the oxidation of Hg0,and Se22-and Se2-can immobilize Hg2+to HgSe.10CuSe/OMBC has important guiding significance for practical application because of its low cost,high performance and low mercury leaching characteristic to form HgSe.
基金support for this work is received from the National Natural Science Foundation of China(Grant No.U22B20144).
文摘The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon emissions in reservoirs with interlayers.Currently,there is limited research on the low-carbon strategy of coupling exhaust gas from steam boilers with the VH-SAGD technique.Herein,considering heterogeneity,a series of flue gas-assisted VH-SAGD experiments were conducted employing a high-performance 2D visualization model.The mechanism of enhanced recovery of flue gas in VH-SAGD and the effect of its injection methods were studied,with a focus on steam chamber development and oil saturation distribution.Crucially,the interlayer length was optimized to enhance oil recovery,providing a new perspective for well location design in heavy oil reservoirs with interlayers.The results showed that flue gas,as an additive,could fully exploit the well-type advantage of VH-SAGD.By supplementing energy at the reservoir top,flue gas effectively promoted steam chamber development,expanded the oil drainage area of VH-SAGD,and increased the oil recovery from 58.9%to 71.7%.The flow channels formed by pre-injection flue gas accelerated the early-stage expansion of the steam chamber while also inducing lateral migration of steam,slowing steam rise,and consequently increasing the heating range within the low-permeability layer.When the distance between the vertical and horizontal wells was set to twice the interlayer length,the negative effects of the interlayer were more effectively turned into advantages.Because when the lateral development distance of the steam chamber in the low-permeability layer slightly exceeds the interlayer,enhanced heating of the lower part of the reservoir occurred through vertical convection of rising steam and returning condensate.The research results contribute to reducing carbon emissions from steam-based heavy oil extraction while advancing the maturity of VH-SAGD.
基金Anhui Province Key Research and Development Plan of the Ecological Environment Project(No.202104i07020016).
文摘In this study,Computational Fluid Dynamics(CFD)together with a component transport model are exploited to investigate the influence of dimensionless parameters,involving the height of the rectifier grid and the installation height of the first catalyst layer,on the flow field and the overall denitration efficiency of a cement kiln’s SCR(Selective catalytic reduction)denitrification reactor.It is shown that accurate numerical results can be obtained by fitting the particle size distribution function to the actual cement kiln fly ash and implementing a non-uniform particle inlet boundary condition.The relative error between denitration efficiency derived from experimental data,numerical simulation,and real-time system pressure drop ranges from 4%to 9%.Optimization of the SCR reactor is achieved when the rectifier grid thickness ratio k/H≥0.030,the rectifier grid height ratio h/H=0.04,and the spacing between the rectifier grid and the first catalyst layer l/H=0.10.Under these conditions,airflow distribution and particle dispersion upstream of the catalyst result in increased denitration efficiencies of 3.21%,3.43%,and 3.27%,respectively,compared to the least favorable operating conditions.
文摘For the treatment of the mixed flue gas desulfurization wastewater with high salinity by the biological fluidized bed process,the optimum temperature was 25-35℃,and the optimum hydraulic retention time was 10 h.When the influent quality was stable,the average concentration of COD,NH_(4)^(+)-N and TN in the inlet water was 210,11 and 16.3 mg/L,respectively,and their average concentration in the effluent was 54,0.32 and 4.09 mg/L,respectively.The treatment effect was good.When the incoming water quality of flue gas desulfurization wastewater fluctuated greatly,the effluent quality was still relatively stable after being treated by the biological fluidized bed,indicating that the biological fluidized bed process had a good ability to resist the impact of water quality in the treatment of high-salinity flue gas desulfurization wastewater.At the same time,the biological fluidized bed process provides a reference for high-salinity wastewater that is difficult to be biologically treated.
文摘Currently,as environmental pollution becomes increasingly severe,flue gas denitrification has emerged as a significant area of research.With the advancement of modern industry and the improvement of living standards,air pollution has gained growing attention.Sulfur dioxide and nitrogen oxides(NO_(x))have become major contributors to air pollution,posing serious harm to the environment.Consequently,flue gas desulfurization and denitrification technologies have become key research focuses in industrial development.This paper explores the selection of agricultural waste carbon sources and their pretreatment methods.It provides an in-depth analysis of the significance of agricultural waste carbon sources in flue gas denitrification,focusing on their performance and mechanisms.The study also discusses the role of agricultural waste carbon sources in flue gas denitrification,aiming to offer new research perspectives for relevant stakeholders.
文摘This research has focused on the treatment of zinc flue dust by an acid leach process, combining an environmentally suitable impurity removal process to recover cadmium. Optimum conditions were found as follows: H2SO4 concentration 90 g/L, liquid/solid ratio 6:1, leaching temperature 60 ℃ and leaching time 1.0 h. Under these conditions, 95.8% cadmium was recovered. FeAsO4 and Fe(OH)3 precipitates with FeCI3 are found to be highly effective to obtain a high degree of separation of heavy metals and the oxyanions of arsenic from the leachate. The overall separation of arsenic and other heavy metals and precipitate settling rates are optimum at n(Fe)/n(As) ratio of 3:l and pH 6. The removal rates ofFe, Pb and Cu from the solution were greater than 98.9%, and As removal rate was 99.6%. A solvent extraction with P204 was used for the separation of zinc and cadmium. Optimum conditions are obtained as follows: 20% P204 (volume fraction) diluted with kerosene at room temperature, pH 3.0, and varying organic/aqueous (O/A) phase ratio 1:1. The extraction rate of zinc is 99.2% under these conditions. Spherical cadmium particles showing nearly uniform size were produced by hydrogen reduction at 310 ℃ and the crystal structure was cubic. In addition, the purity of the recovered cadmium powder is more than 99.99%.
文摘The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM) consistent with American standard test methodtogether with the semi-continuous emissions monitoring (SCEM) system as well as a mobile laboratoryfor mercury monitoring. The mercury and its speciation concentrations including participate mercuryat three locations of before air preheater, before electrostatic precipitator (ESP) and after ESPwere measured using the OHM and SCEM methods under normal operation conditions of the boiler systemas a result of firing a bituminous coal. The vapor-phase total mercury Hg(VT) concentration declinedwith the decrease of flue gas temperature because of mercury species transformation from oxidizedmercury to particulate mercury as the flue gas moved downstream from the air preheater to the ESPand after the ESP. A good agreement for Hg°, Hg^(2+) and Hg( VT) was obtained between the twomethods in the ash-free area. But in the dense particle-laden flue gas area, there appeared to be abig bias for mercury speciation owing to dust cake formed in the filter of OHM sampling probe. Theparticulateaffinity to the flue gas mercury and the impacts of sampling condition to accuracy ofmeasure were discussed.
基金Project(No.2004C32047) supported by the Department of Scienceand Technology of Zhejiang Province,China
文摘Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine (HSN 1) in chicken. Crude extraction from Cochinchina momordica seed (ECMS) was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine (HSN1) alone or combined with ECMS (5, 10, 20, 40 and 80 μg/dose). Serum IgG antibody levels (by ELISA) as well as effects on dally weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 μg/dose groups significantly (P〈0.05) enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 μg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 μg/dose ECMS and antibody titer was measured through hemagglutination inhibition (HI). It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.
基金This work was supported by the Department of Science and Technology of Sichuan Province(2019YFG0457)the National Natural Science Foundation of China(5183000045)+1 种基金the National Major Science and Technology Project of CNPC"Research and Application of Key Technologies for Beneft Development of Volcanic Rock Reservoirs”(2017E-04-05)the PetroChina Major Science and Technology Project(2018E-1805).
文摘Flue gas fooding is one of the important technologies to improve oil recovery and achieve greenhouse gas storage.In order to study multicomponent fue gas storage capacity and enhanced oil recovery(EOR)performance of fue gas water-alternating gas(fue gas-WAG)injection after continuous waterfooding in an oil reservoir,a long core fooding system was built.The experimental results showed that the oil recovery factor of fue gas-WAG fooding was increased by 21.25%after continuous waterfooding and fue gas-WAG fooding could further enhance oil recovery and reduce water cut signifcantly.A novel material balance model based on storage mechanism was developed to estimate the multicomponent fue gas storage capacity and storage capacity of each component of fue gas in reservoir oil,water and as free gas in the post-waterfooding reservoir.The ultimate storage ratio of fue gas is 16%in the fue gas-WAG fooding process.The calculation results of fue gas storage capacity showed that the injection gas storage capacity mainly consists of N_(2) and CO_(2),only N_(2) exists as free gas phase in cores,and other components of injection gas are dissolved in oil and water.Finally,injection strategies from three perspectives for fue gas storage,EOR,and combination of fue gas storage and EOR were proposed,respectively.
文摘The tests of flue gas desulfurization were carried out on a circulating fluidized bed reactor in which the flue gas had different velocities at different sections. The SO 2 removal efficiency could be as high as 80% when Ca/S molar ratio was 1 1 and a small amount of water was sprayed into the reactor by a two phase (gas liquid) system nozzle.
基金Supported by General Program of Science and Technology Project of China National Tobacco Corporation[ZYB(2012)No.122]Science and Technology Project of Chongqing Branch of China National Tobacco Corporation(NY20110601070010)
文摘[Objective] This study aimed to compare the effects of Chinese quality-improving fragrunce-increasing tobacco flue-curing technology, Chinese three- stage tobaeeo flue-curing technology and Zimbabwean tobaceo flue-euring technology on microscopie structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method ] Middle leaves of tobacco cultivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the microscopic structure of flue-cured tobaceo leaves. [ Result] During three flue-curing processes, leaves, palisade tissues and sponge tissues shrank gradually. Three flue-euring processes exhibited significant differ- ences in the peak of tissue shrinkage : microscopic structure of flue-cured tobacco leaves in Chinese three-stage tobacco flue-curing process shrank earliest, follower by Chinese quality-improving fragrance-increasing tobacco flue-curing process; flue-eured tobacco leaves in Zimbabwean tobacco flue-curing process presented the latest shrinkage. At 84 h post-curing, leaf thickness in three flue-curing processes showed a descend order of Chinese three-stage tobacco flue-curing process 〉 Chinese quality-improving fragrance-increasing tobacco flue-curing process 〉 Zimbabwean tobacco flue-curing process. Upper and lower epidermal cells in Zimb- abwean tobacco flue-curing process ruptured earlier than other two flue-curing processes; eventually, the majority of cells ruptured and mixed with palisade tissues and sponge tissues. In Chinese quality-improving fragranee-increasing tobacco flue-curing process, only a small number of epidermal cells in dried leaves ruptured. Among three flue-curing technologies, Zimbabwean tobacco flue-curing technology exhibited the greatest damage to epidermal cells, followed by Chinese three-stage tobaceo flue-curing technology; Chinese quality-improving fragrance-increasing tobacco flue-curing technology had the minimum damage to epidermal cells. Mese- phyll cross-section exhibited significant morphological changes in stomata. To be specific, at 0 - 12 h post-curing, stomata of tobacco leaves closed with slightly prominent stamatal apparatuses on upper and lower epidermis; at 24 -72 h post-curing, stomata of tobaceo leaves changed gradually from opening to closure with significantly prominent stomatal apparatuses on upper and lower epidermis; at 84 h post-curing, stomata of tobacco leaves closed, and the majority of stomatal appa- ratuses were significantly prominent. In Chinese quality-improving fragrance-increasing tobacco flue-curing process, only a small number of epidermal ceils ruptured at 84 h pest-flue-curing; palisade tissues and sponge tissues shrank almost simultaneously. Significant gaps were observed between palisade tissues and between pal- isade tissues and sponge tissues. Chinese quality-improving fragrance-increasing tobacco flue-curing technology exhibited lower disorder level compared with other two flue-curing technologies. [ Conclusion] Chinese quality-improving fragrance-increasing tobacco flue-curlng technology was conducive to maintaining the micro- scopic structure integrity of flue-cured tobacco leaves and obtaining high-quality flue-cured tobacco leaves.
基金Supported by General Program of Science and Technology Project of China National Tobacco Corporation[ZYB(2012)No.122]Science and Technology Project of Chongqing Branch of China National Tobacco Corporation(NY20110601070010)
文摘[ Objective] This study aimed to compare the effects of low-temperature low-humidity tobacco flue-curing technology, moderate-temperature moderate- humidity tobacco flue-curing technology and moderate-temperature high-humidity tobacco flue-curing technology on submicroscopic structure of flue-cured tobacco leaves to provide theoretical basis for tobacco flue-curing. [ Method] Middle leaves of tobacco cuhivar K326 were collected in Pengshui County of Chongqing City for flue-curing experiment using three flue-curing technologies. Leaf samples were collected regularly in the flue-curing process, to investigate the submicroscopic structure of flue-cured tobacco leaves. [ Result] Morphology changes and structural rupture of chloroplasts occurred at different time during three flue-curing proces- ses. In low-temperature low-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred late but rapidly; in moderate-tempera- ture moderate-humidity flue-curing process and moderate-temperature high-humidity flue-curing process, morphology changes and structural rupture of chloroplasts occurred early but slowly. Among these three flue-curing processes, the speed of changes in mitochondria morphology, cristae number and membrane rupture pres- ented an upward order of low-temperature low-humidity flue-curing process 〈 moderate-temperature high-humidity flue-curlng process 〈 moderate-temperature moderate-humidity flue-curing process. In low-temperature low-humldity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 36 -48 h ; in moderate-temperature moderate-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 24 - 36 h; in moderate-temperature high-humidity flue-curing process, starch granules in chloroplasts ruptured after flue-curing for 12 - 24 h. [ Conclusion ] Using low-temperature low-humidity flue- curing technology could prolong the maintenance duration of the submicroscopic structure integrity of flue-cured tobacco leaves, which was conducive to fully decom- posing and transforming substances in tobacco leaves and obtaining high-quality flue-cured tobacco leaves.