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Particle attrition is commonly existed in gas-solid two-phase flow process. A novel CFD-DEM particle attrition model is developed, a series of experiments/simulation studies are performed to quantitatively investigate the attrition mechanism of particles in fluidized beds. The particle attrition process could generally be divided into unstable attrition stage and stable attrition stage, while the results show that unsteady attrition stage should be subdivided into high-speed attrition phase and low-speed attrition phase. Both wear and fragmentation become more intense with increasing height-diameter ratio and superficial gas velocity. The wear ratio decreases with increasing particle size, while the fragmentation ratio firstly decreases and then increases. Particle attrition mechanism also presents spatial ununiformity, particles reaching the bottom are worn most significantly, while the proportion of fragmentation based on this study for the sidewall areas, the bottom area and the center area is about 69%, 22% and 9% respectively. [Display omitted] • A CFD-DEM model of particle attrition is developed. • The attrition characteristics and mechanism of particles are quantitatively analyzed. • Unsteady attrition stage is subdivided into high-speed and low-speed attrition phases. • The influence of three operating parameters on attrition mechanism are revealed. • The spatial ununiformity of attrition mechanism is discussed in detail. [ABSTRACT FROM AUTHOR]

Replacing the steam Rankine cycle with the supercritical CO 2 Brayton cycle (sCO 2 cycle) has been demonstrated to be an effective way to improve the efficiency of oxy-coal power plants. The present work focuses on the optimal design of the sCO 2 oxy-coal circulating fluidized bed (CFB) power generation systems which so far has not received much attention in the research field. A novel triple recompression sCO 2 cycle and a new sCO 2 oxy-coal CFB boiler configuration with medium-temperature and high-temperature flue gas recirculation have been proposed and evaluated. With the novel boiler configuration and triple recompression cycle, the system efficiency can be increased by about 1.4% points in comparison to the basic system using the basic recompression cycle and the basic boiler configuration. The influences of the cycle minimum temperature, recuperator pinch temperature difference, furnace inlet oxygen concentration, flue gas recirculation flow distribution and coal itself on the sCO 2 oxy-coal CFB power generation system performances were thoroughly investigated. The results show that increasing the minimum cycle temperature and the recuperator pinch temperature difference reduces the system efficiency while increasing the oxygen concentration at the furnace inlet and reducing the proportion of the recirculating flue gas as the primary oxidizing gas can boost the system efficiency. Coal itself also has an impact on the system efficiency due to its properties affecting the cycle efficiency, boiler efficiency and auxiliary equipment power consumptions. • A novel supercritical CO 2 cycle with three recompression stages was proposed. • A new oxy-coal CFB boiler configuration was integrated with the cycle. • Thermodynamic performances of various system configurations were modelled. • The integrated novel supercritical CO 2 cycle with the boiler has higher efficiency. • Effects of key parameters on the system thermodynamic performance were investigated. [ABSTRACT FROM AUTHOR]

Artificial heart valve replacement is recognized as the most effective method for treating valvular heart disease. Presently, the bileaflet mechanical heart valve is the predominant type utilized. Nonetheless, complications are known to arise following valve replacement surgery, mostly attributable to deviations in the left ventricular blood flow pattern instigated by the dysfunction of the bileaflet mechanical valve. However, the impact of mitral valve leaflet dysfunction on left ventricular hemodynamics has not been studied in depth. Hence, to approximate the physiological conditions of the left ventricular flow and pressure, a left heart circulation pulsatile flow system was devised. The time-resolved particle image velocimetry method was employed to evaluate the left ventricular blood flow under standard working conditions of the bileaflet mechanical valve and in the case where one of the valve leaflets is determined to be functionally impaired. The experimental results reveal that the normally functioning bileaflet valve manifests a tri-jet flow pattern, with intense jets on both sides generating two expansive vortices. Conversely, when one of the valve leaflets is impaired, the tri-jet flow metamorphoses into a bi-jet flow, coupled with augmented velocity. In both instances, the jets traverse along the ventricular model wall and alter their direction subsequent to passing the apex. Consequently, the employment of bileaflet valves culminates in a multifaceted left ventricular blood flow pattern. Furthermore, the valve leaflet dysfunction escalates shear stress, a condition that could potentially instigate damage to blood cells. The insights gained from this study can potentially guide the improved design of the mechanical bivalve. [ABSTRACT FROM AUTHOR]

Plastic products containing high levels of hydrogen can act as hydrogen donors during coal pyrolysis to promote the production of light tars such as alkanes, olefins, and aromatic hydrocarbons. In this study, metal loaded HZSM-5 was applied to enhance the yields of light aromatics such as benzene, toluene, ethylbenzene, xylene, naphthalene and methylnaphthalene (BTEXNM) in the catalytic co-pyrolysis of lignite and HDPE/waste plastic. The effect of HZSM-5 catalysts on the preparation of BTEXNM under different metal loadings (Cu, Fe, Co, Mo, Ga), different loadings (1 wt%, 3 wt%, 5 wt%, 7 wt%) and bimetallic (Ga, Mo) loadings was studied by using Py-GC/MS. The results showed that the highest content of light aromatics was achieved at a pyrolysis temperature of 600 °C and a lignite to plastic mix ratio of 3:1. After metal loaded HZSM-5, Ga and Mo increased the content of aromatic products, with 3 wt%Ga being the most effective. In the Ga and Mo bimetallic modification experiments, the 1 wt%Mo2wt%Ga/HZSM-5 combination was the most effective, with a significant increase in the content of monocyclic aromatic hydrocarbons such as benzene, toluene and xylene, and a relative decrease in the content of polycyclic aromatic hydrocarbons such as naphthalene and methylnaphthalene. [Display omitted] • Co-pyrolysis of lignite and plastics has a synergistic effect. • Metal Ga-modified HZSM-5 catalysts can effectively increase the yield of BTEX. • Appropriate metal loading facilitates co-pyrolysis of lignite and plastics. • Metal Ga and Mo have a synergistic effect in increasing the yield of light aromatics. [ABSTRACT FROM AUTHOR]

Crustacean waste has great potential as fossil fuel substitution and efficient desulfurization to reduce pollutant emissions, but high moisture and poor quality restrict broad-scale utilization. This study used microwave radiation on crayfish shell to investigate the combustion characteristics and desulfurization effect in different atmospheres/pulse microwave cycle. Meanwhile, the structure evolution mechanism and molecular reaction pathways were revealed. The results show that crayfish shell derived fuel has a pleasurable combustion performance and sulfur fixation ability after microwave radiation in flue gas. The heat release of derived fuel increased by 29.9 % after five microwave cycle in flue gas, and activation energy decreased by 3.7 %. By contrast, the heat release increased by 17.4 % after five microwave cycle in inert gas, and activation energy increased by 39.3 %. Subsequently, the effect of microwave cycle times in flue gas on crayfish shell combustion and desulfurization performance was studied. The results show that the heat release of derived fuel gradually increases with microwave cycle. After seven microwave cycle, the derived fuel heat release and SO 2 removal efficiency increased by 34.9 % and 44.4 %, respectively. The results establish the foundation for expanding the utilization pathway of crustacean waste and realizing the low-carbon energy transition. [Display omitted] • Prepared crayfish shell derived fuel use microwave radiation in flue and inert gas. • The effect mechanism of pore structure on combustion performance was elucidated. • Proposed the two reaction pathways of functional groups under microwave radiation. • Microwave radiation in flue gas increased exotherm by 35 % and reduced SO 2 by 44 %. • Crayfish shell derived fuel sync realized the fuel substitution and SO 2 reduction. [ABSTRACT FROM AUTHOR]

In this paper, a multi-core@shell catalyst LDH@SiO 2 was fabricated by coating a silica layer over hexagonal Ni–Mg–Al LDH nanoplates. After calcination and H 2 -reduction, Ni nanoparticles were well dispersed on the support, as well as encapsulated within the mesoporous silica shell. The multi-core@shell catalyst was then tested in low temperature dry reforming of methane (DRM) at 600 °C and showed a stable CH 4 conversion of 27% for 16 h time on stream. Characterizations of the spent catalyst indicated that there was almost no carbon formation and the multi-core@shell structure was well preserved. While the pristine layered double hydroxide (LDH) catalyst exhibited a severe carbon formation as 68%. The confinement effect conveyed by the unique multi-core@shell structure effectively suppressed metal sintering and carbon deposition. Besides, the thickness of the silica shell was tuned and it made a great difference to the catalytic activity due to the diffusion resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficient synergistic removal of NO and VOCs under low temperature. • The synergistic effect of Mn and Ce can promote the generation of oxygen vacancies. • High oxygen vacancy content greatly improves simultaneous removal of NO and VOCs. • Potential mechanisms for the simultaneous abatement of NO and VOCs were made. Coal-fired power plants are known for emitting substantial amounts of nitrogen oxides (NO x) and volatile organic compounds (VOCs) during operation. In this study, the utilization of Mn–CeO x catalysts for the simultaneous removal of these pollutants was explored. The catalysts were synthesized through the co-precipitation technique, and their material structure and active sites were analyzed through XRD, TEM, NH 3 -TPD, XPS, and in-situ DRIFTs characterization methodologies. The DFT calculations indicated that VOCs and NO x were efficiently adsorbed and activated on the catalyst surface and then converted into less harmful substances (CO 2 , N 2 , and H 2 O). Additionally, the potential reaction pathways occurring on the catalyst surface were investigated. Furthermore, the effectiveness of the Mn–CeO x catalyst in simultaneously reducing NO x and VOCs under low-temperature conditions was assessed. The experimental results validated the exceptional performance of the Mn–CeO x catalyst in eliminating both NO x and VOCs. Furthermore, the underlying mechanisms governing the catalytic process were comprehensively investigated. [ABSTRACT FROM AUTHOR]

Pressurised circulating fluidized bed oxy-fuel combustion (PCFB-OFC) is a promising technology for CO 2 capture because of its high carbon capture efficiency and net efficiency. However, there is a lack of comprehensive experimental studies on PCFB thermal state experimental devices due to the complexity of their design, construction, and operation. In this study, a 100 kWth PCFB-OFC experimental device was developed, and a series of coal combustion experiments were conducted under 0.1 to 0.6 MPa at an average oxygen concentration of 30% with a fixed peroxygen coefficient β (1.1–1.3). The effect of combustion pressure was investigated to determine the influence of pressure on coal combustion efficiency, furnace temperature distribution, gaseous pollutant emissions, and fly ash chemical composition. The experimental results showed that the increase in pressure increased the particle concentration in the dilute phase zone and increased the temperature at the top of the furnace, with a more uniform temperature distribution. The carbon content in the fly ash and the CO emissions in the flue gas were gradually reduced, and the combustion efficiency increased to 97.3%. The emissions of NO and N 2 O gradually decreased with the increase in load, and the NO emissions reduced by approximately 70% at 0.6 MPa. The emission of SO 2 showed a downward trend as the pressure increases. Affected by the increase in pressure, the self-desulfurization capability of fly ash was improved. In addition, lower K 2 O and Na 2 O contents may reduce the deposition of fly ash in the furnace. • The experiments of coal oxy-fuel combustion were conducted via a 100KWth PCFB system. • The concentration of particles in dilute phase zone increases with the increase of pressure. • Higher pressure promotes more uniform temperature distribution in the furnace. • Combustion efficiency is significantly improved compared to traditional combustion methods. • The emission of NO, N 2 O and SO 2 decreases with increasing pressure. [ABSTRACT FROM AUTHOR]

In this paper, a multiple-image encryption method is proposed based on authenticable phase and phase retrieval under structured light illumination. In the encryption process, each plaintext image is firstly encrypted into two phase masks by using phase retrieval algorithm under structured light illumination with the help of encryption authenticable phase, and then the final ciphertext is generated by using phase mask multiplexing technology, overcoming the trade-off relationship between encryption capacity and decryption quality, thereby the decryption quality is improved meanwhile the encryption capacity is expanded. Furthermore, the optical parameters of structured phase mask in the structured light illumination are introduced as supplementary digital keys, expanding the key space and enhancing the security of encryption method. In the decryption process, the decryption authenticable phase needs to pass authentication before it is used to decrypt the ciphertext, leading to a further improvement for the level of security of encryption method. Numerical simulations are performed to demonstrate the feasibility of the proposed multiple-image encryption method, and the simulation results show that the proposed method exhibits high feasibility and security as well as strong robustness and large capacity. • A multiple-image encryption with high security and large capacity is proposed. • The high security is beneficial from an expanded key space. • The large capacity depends on high quality of decrypted images. • The proposed method exhibits high robustness against various attacks. [ABSTRACT FROM AUTHOR]

Background: The TIFY gene family is a group of plant-specific transcription factors involved in regulation of plant growth and development and a variety of stress responses. However, the TIFY family has not yet been well characterized in kiwifruit, a popular fruit with important nutritional and economic value. Results: A total of 27 and 21 TIFY genes were identified in the genomes of Actinidia eriantha and A. chinensis, respectively. Phylogenetic analyses showed that kiwifruit TIFY genes could be classified into four major groups, JAZ, ZML, TIFY and PPD, and the JAZ group could be further clustered into six subgroups (JAZ I to JAZ VI). Members within the same group or subgroup have similar exon-intron structures and conserved motif compositions. The kiwifruit TIFY genes are unevenly distributed on the chromosomes, and the segmental duplication events played a vital role in the expansion of the TIFY genes in kiwifruit. Syntenic analyses of TIFY genes between kiwifruit and other five plant species (including Arabidopsis thaliana, Camellia sinensis, Oryza sativa, Solanum lycopersicum and Vitis vinifera) and between the two kiwifruit species provided valuable clues for understanding the potential evolution of the kiwifruit TIFY family. Molecular evolutionary analysis showed that the evolution of kiwifruit TIFY genes was primarily constrained by intense purifying selection. Promoter cis-element analysis showed that most kiwifruit TIFY genes possess multiple cis-elements related to stress-response, phytohormone signal transduction and plant growth and development. The expression pattern analyses indicated that TIFY genes might play a role in different kiwifruit tissues, including fruit at specific development stages. In addition, several TIFY genes with high expression levels during Psa (Pseudomonas syringae pv. actinidiae) infection were identified, suggesting a role in the process of Pas infection. Conclusions: In this study, the kiwifruit TIFY genes were identified from two assembled kiwifruit genomes. In addition, their basic physiochemical properties, chromosomal localization, phylogeny, gene structures and conserved motifs, synteny analyses, promoter cis-elements and expression patters were systematically examined. The results laid a foundation for further understanding the function of TIFY genes in kiwifruit, and provided a new potential approach for the prevention and treatment of Psa infection. [ABSTRACT FROM AUTHOR]

Pressurized oxy-coal combustion has received wide attention recently due to its potential of high efficiency and low cost in CO 2 capture. However, there is still a significant knowledge gap on the effects of pressure on the oxy-coal and oxy-char combustion behaviors. In this study, oxy-char combustion experiments were carried out in a pressurized fluidized bed combustor, and the effects of pressure and oxygen concentration on the burnout time, reactivity and temperature of the char particles were investigated. The experimental results showed that the burnout time of the char particles decreased significantly with an increase in pressure from 0.1 MPa to 0.5 MPa. Besides, an increase in either the combustion pressure (within the range of 0.1 – 0.5 MPa) or the oxygen concentration (within the range of 10 – 30% O 2 in CO 2) led to increases in the reactivity and temperature of the char particles, while the promotional effects of the pressure increase were weaker at the higher pressures. In order to better interpret the experimental results, a combustion model considering reaction kinetics, mass and heat transfer, and energy balance was developed and validated by the experimental results. The model simulation results showed that an increase in pressure would reduce the burnout time of char particles only when the combustion was kinetically controlled or combined kinetic-diffusion controlled. Once the combustion became diffusion-controlled, a further increase in pressure would have an insignificant effect on the char burnout time. Although the values of kinetic constants were different when different kinetic models, the global power-law model and Langmuir-Hinshelwood model, were adopted, the simulation results of the burnout time of the char particle under the pressurized fluidized bed combustion conditions were almost the same since the char combustion was mainly diffusion-controlled. The elevated combustion pressure accelerated both the char combustion rate and the char-CO 2 gasification rate, while the carbon consumption ratio by gasification increased with pressure. Moreover, the enhanced gasification reaction had a great impact on the particle temperature especially under the higher oxygen concentration combustion conditions. [ABSTRACT FROM AUTHOR]

An emerging solution of poultry manure gasification for energy production is becoming attractive because of the enormous potential of livestock manure as renewable feedstock and environmental hazards by conventional disposal. As a novel technology, oxy-fuel gasification combines the advantages of biowaste gasification and potential for carbon capture and storage (CCS) and is expected to achieve negative carbon emissions. However, studies on the oxy-fuel gasification of poultry manure are lacking. This study developed a 3D Eulerian–Lagrangian model of poultry manure gasification in an industrial fixed-bed gasifier based on a power plant in Singapore. The feasibility of oxy-fuel gasification of poultry manure was explored, and the gas-solid flow, process mechanism, and gasification efficiency were investigated. The results indicate that the oxy-fuel gasification of poultry manure in an industrial-scale gasifier can operate stably at Oxy-21 (21 vol% O 2 /79 % CO 2) and Oxy-30. The heating value of syngas from Oxy-21 gasification is equivalent to that of air gasification, while the cold gas efficiency is slightly lower, and Oxy-30 gasification produces a higher energy yield as well as 20 % CO and 40 % CO 2 in syngas. The Nitrogen-free and CO 2 -rich fuel gas from oxy-fuel gasification facilitates subsequent CCS implementation. To analyze the practical application of the technology, a safety assessment was conducted on the dust hazards of this plant, which showed the explosion risk was the lowest class. This study offers a numerical simulation method for studying gasification processes and provides sustainable management of commercial-scale poultry manure gasification plants to achieve safe and carbon-negative waste-to-energy applications. • A 3D Eulerian–Lagrangian model for chicken manure gasification in an industrial fixed-bed gasifier is developed. • Oxy-fuel gasification of chicken manure in an industrial-scale gasifier can operate stably at Oxy-21 and Oxy-30 modes. • Oxy-30 gasification produces a higher energy yield due to simultaneously higher syngas yield and heating value. • The explosion risk of chicken manure dust collected from hazardous areas in the gasification plant is in the lowest class. [ABSTRACT FROM AUTHOR]

• The peel texture, cell wall-related substances and enzyme activity all affect the peelability of A. eriantha. • The good-peeling variety had a deeper saffron staining intensity in the outer pericarp than the poor-peeling variety. • Metabolome analysis showed that DAMs were mainly flavonoids, lipids and phenolic acids. • Eight DEGs that might associated with the peeling characters in A. eriantha were identified. • AeGAE6, AebHLH35-like and AeBGAL5 were the main genes affecting the peelability of A. eriantha. Actinidia eriantha is prone to peeling at the soft ripening stage, which is a unique characteristic that distinguishes it from other Actinidia species. However, the mechanism underlying the formation of peelability in A. eriantha is still not very clear. In this study, two A. eriantha varieties with contrasting peeling behavior were used as materials and the peel cell wall metabolism-related substances and enzyme activities were detected during fruit development. The peel cell structures were observed and the transcriptome and metabolome analysis were performed. The results indicated that the firmness and toughness of the fruit peel affect the peelability of A. eriantha. The increased activities of β-galactosidase, pectinase, and cellulase promoted the degradation of lignin, cellulose, hemicellulose, and total pectin, and ultimately affected the peelability. The anatomical structure showed that the staining intensity on the peel of the two varieties did not change much at different stages. The differential metabolites were mainly flavonoids, lipids, and phenolic acids. Eight genes that may be related to fruit peeling traits of A. eriantha were identified, three of which (AeGAE6, AebHLH35-like, and AeBGAL5) may be the main genes affecting the peelability of A. eriantha. These candidate genes may affect the peelability of A. eriantha by influencing the metabolism of cell wall components such as galactose, mannose, arabinose, and glucuronic acid. [ABSTRACT FROM AUTHOR]

The CO 2 gasification of biomass and waste plastics is one of the essential ways to utilize solid waste resources, and it is also potential negative carbon emission technology. The complex interactions in the co-gasification of biomass and waste plastics affect the quality of syngas and the efficient conversion of solid waste. In this study, sawdust, PE and PVC were selected for CO 2 gasification. Firstly, the interaction and gasification characteristics were investigated by thermogravimetric experiments. Then, the impact of interaction on syngas generation and quality was studied through fluidized bed experiments. The results indicated that PE, PVC, and sawdust co-gasification exhibits both inhibitory and synergistic. PE inhibits the release of volatiles in sawdust, while PVC promotes the volatiles release. In short, PVC improves the gasification reactivity of sawdust, and PE enhances syngas quality. Adding 75 % PE, the syngas Low Heating Value by 415 % up to 30.05 MJ/kg, and Cold Gas Efficiency by 147 %. The synergistic of the sawdust/PE-PVC was manifested as the superposition and amplification of the synergistic in sawdust/PE and sawdust/PVC. Adjusting the PE and PVC proportion, syngas quality can be targeted to control. The study results exhibit new perspectives on classifying waste plastics for gasification and regulating syngas quality. [Display omitted] • Experimental study on CO 2 co-gasification characteristics of biomass and plastic. • PE, PVC, and sawdust co-gasification exhibit both inhibitory and synergistic. • PVC improves the sawdust gasification reactivity and PE enhances syngas quality. • Adding 75 % PE, the syngas Low Heating Value by 415 % up to 30.05 MJ/kg. • Adjusting PE and PVC proportion, syngas quality can be targeted to control. [ABSTRACT FROM AUTHOR]

[Display omitted] • Membrane reactor coupling dehydrogenation and methanation reactions is feasible. • High hydrogen permeance is prerequisite to positive effect of methanation reaction. • Enhancing methanation catalyst activity is not so beneficial limited by diffusion. • Increasing pressure is not promotional due to unfavorable thermodynamics. In this work, a novel hydrogen-membrane reactor coupling cyclohexane (CLH) dehydrogenation and CO 2 methanation was proposed. A 2D model was built up and the effects of hydrogen permeance, methanation rate and reaction pressure were examined with CFD simulation. It turned out that high hydrogen permeance was prerequisite to the positive effect of methanation reaction. And increasing hydrogen permeance of the membrane was able to promote both CLH and methanation reactions. While boosting methanation reaction could increase methane production yield at permeate side, but did not show much positive effect towards CLH conversion due to the limitation of radial diffusion of hydrogen molecules. Increasing pressure at retentate side even decreased CLH conversion slightly due to the negative thermodynamic effect. This work well proves the feasibility and advantage of the membrane reactor that integrates CLH dehydrogenation and CO 2 methanation reactions. [ABSTRACT FROM AUTHOR]

• A CFD-DEM study of gas–solid heat transfer process in fluidized bed is presented. • Bed temperature and heat flux distribution are provided at particle-scale. • Heating rate and temperature uniformity in the bed are quantitatively analysed. • Tracer particle study under thermal condition is developed. In this paper, the hydrodynamics and gas–solid heat transfer characteristics during bed material heating process are investigated using the CFD-DEM approach, and the heating rate and bed temperature uniformity are quantitatively analysed. After model validation, gas–solid heat transfer characteristics in a typical case is analysed. On this basis, the effects of operating conditions is further discussed. The results show that overheating phenomenon at bed bottom is weakened obviously by solid internal circulation behavior in fluidized bed. As time marches, bed temperature uniformity is effectively improved with increasing mean bed temperature. Specially, a temperature drop at particle scale is captured by tracer particle method. A simplified energy balance model is developed to explain the relationship between bulk heating rate and operating conditions, and qualitatively consistent between simulation results and model analytical solutions is captured. Furthermore, the temperature uniformity under different operating conditions is qualitatively discussed by standard deviation of particle temperature. [ABSTRACT FROM AUTHOR]

• U mf of different PSD particles was measured at elevated pressures and temperatures. • Effects of pressure, temperature, and PSD on U mf were investigated. • A new predicting correlation of U mf of the different PSD particles was proposed. This paper presents a detailed investigation into the effect of pressure, temperature and particle size distribution (PSD) on the minimum fluidization velocity (U mf). A series of measurement of U mf were carried out under the pressure from 0.1 MPa to 0.5 MPa and the temperature from 300 °C to 850 °C on a lab-scale pressurized fluidized bed reactor for three narrow PSD and three wide PSD (binary, uniform, and Gaussian-type) silica sand particles. The results showed that the U mf for narrow and wide PSDs both decreased with increasing temperature and decreased slightly with rising pressure. Besides, the Gaussian-type mixtures had almost the same U mf as the reference narrow PSD particle, while the U mf of binary and uniform PSD mixtures was larger than these two. Based on the experimental data, a new simple relationship for predicting U mf of the different PSD particles at elevated pressures and temperatures was developed. [ABSTRACT FROM AUTHOR]

• SO 2 emissions are almost independent of combustion pressure. • The SO 2 emissions are lower in oxy-coal combustion than in air combustion. • The elevated pressure improves the direct desulfurization efficiency of limestone. • Temperature increase improves the desulfurization efficiency under high pressures. • SEM images and BET analysis show the surface morphology of limestone products. Pressurized oxy-fuel combustion (POFC) has attracted wide attention due to its potentials of high efficiency and low cost in CO 2 capture. Compared with numerical simulation and system analysis, there are few experimental studies about POFC. In order to investigate the SO 2 emissions and desulfurization behaviors of limestone under continuous fuel-feeding POFC conditions, a series of oxy-coal combustion experiments were conducted with a 30 kW th pressurized fluidized bed combustor. The results showed that the SO 2 emission was almost independent of combustion pressure and excess oxygen coefficient, while it was higher in air than in O 2 /CO 2 atmosphere because less sulfur was retained by the coal ash. Although the higher CO 2 partial pressure caused by an increase in combustion pressure from 0.1 MPa to 0.4 MPa had negative effects on the calcination of limestone and inhibited the indirect desulfurization, the higher combustion pressure was beneficial to improve the direct desulfurization efficiency. An increase in combustion temperature from 850 °C to 950 °C significantly improved the desulfurization efficiency of limestone with both atmospheric and pressurized oxy-coal combustion. SEM images were obtained and used to show the surface morphology of limestone products under different combustion conditions, which was helpful to the understanding of the desulfurization behaviors of limestone. [ABSTRACT FROM AUTHOR]

As one of the most promising carbon capture technologies for coal-fired power plants, oxy-coal combustion has attracted wide interests during the last two decades. In comparison to atmospheric oxy-fuel combustion, pressurized oxy-fuel combustion has the potential to further reduce the energy penalties caused by the carbon capture and storage and improve the net power plant efficiency. Although many researchers have investigated the NO x emissions of atmospheric oxy-coal combustion, the NO x emission behaviors under pressurized oxy-coal combustion conditions are much less understood and further comprehensive experimental investigations with continuous fuel-feeding pressurized oxy-coal combustion systems are needed in order to fill this knowledge gap. In the present study, a series of oxy-coal combustion experiments were conducted in a 30 kW th pressurized fluidized bed combustor. The effects of combustion pressure, bed temperature and excess oxygen on the NO x emissions were investigated systematically. The experimental results have shown that an increase in combustion pressure from 0.1 MPa to 0.4 MPa leads to a significant reduction in NO x emissions. An increase in bed temperature or excess oxygen results in higher NO x emissions under the higher combustion pressure conditions, which is consistent with what is observed under the atmospheric pressure combustion condition. Besides, it is found that the promoting effect of temperature increase on NO x emissions under the higher combustion pressures is weaker than that under the atmospheric pressure. • The NO x emissions of pressurized oxy-coal combustion are investigated. • An increase in pressure reduces the NO x emissions of oxy-combustion significantly. • An increase in temperature or excess oxygen leads to the higher NO x emission. • The promoting effect of temperature increase on NO x is weaker under high pressures. • The NO x emissions are closely related to the CO concentration in the flue gas. [ABSTRACT FROM AUTHOR]

• The oxy-fuel combustion in S-CO 2 CFB was simulated by a Eulerian-Lagrangian model. • Particle Size Distribution (PSD) was introduced in the current models. • Gas-solid flow and combustion characteristics for two power cycles were revealed. • Effects of operating conditions on the combustion in S-CO 2 CFB were studied. The supercritical CO 2 (S-CO 2) power cycle CFB with oxy-fuel combustion is considered as a perspective carbon capture technology with high net efficiency. A three-dimensional (3D) CFD simulation using MP-PIC method was developed to predict oxy-fuel combustion in a 12 MW th S-CO 2 CFB. This model couples the gas-solid flow, the heat transfers with combustion reactions, and takes into account of the particle size distribution. The effects of the different thermal wall boundary conditions and various O 2 concentration on the particle motion, combustion characteristics and gaseous pollutant emissions were systemically studied in this work. Results show that the combustion efficiency and the emission of CO, NO and SO 2 in the S-CO 2 boiler were higher than those in the conventional steam boiler. The increase in the inlet O 2 concentration increased the temperature of gas phase, the combustion efficiency and the desulfurization efficiency in the S-CO 2 boiler. [ABSTRACT FROM AUTHOR]

• An optimization method for coal-fired power plant desulfurization systems is proposed. • The optimization method can effectively reduce the desulfurization cost. • An enhanced FCM clustering method is developed. Desulfurization systems in coal-fired power stations often suffer the problem of high operating costs caused by a rule-of-thumb control strategy, which implies great potential for optimization of the operation. Due to the complex desulfurization mechanism, frequently fluctuating unit load, and severe disturbance, it is challenging to determine the optimal operating parameters based on the traditional mechanistic models, and the operating parameters are closely related to the operational efficiency of the flue gas desulfurization system. In this paper, an operation strategy optimization method for the desulfurization process is proposed based on a data mining framework, which is able to determine online the optimal operating parameter settings from a large amount of historical data. First, Principal Component Analysis (PCA) is used to reduce data redundancy by mapping the data into a new vector space. Based on the new vector space, an enhanced fuzzy C-means clustering (Enhanced-FCM) is developed to cluster the historical data into groups sharing similar characteristics. Taking sulfur dioxide emission concentration as a constraint condition, the system is optimized with economic benefits and desulfurization efficiency as the objective function. When performing optimization, the group that current operating conditions belong to is determined first, then the operating parameters of the best performance are searched within the group and provided as the optimization results. The method is validated and tested based on the data from a wet flue gas desulfurization (WFGD) system of a 1000 MWe supercritical coal-fired power plant in China. The results indicate that the proposed operation strategy can appropriately obtain operating parameter settings at different conditions, and effectively reduce the desulfurization cost under the constraint of meeting emission requirements. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composites were successfully prepared by doping alkali metals in Mg/DOBDC for the first time. • The novel composites were tested for CO 2 adsorption in a laboratory fixed-bed adsorption system. • The obtained 0.5 K-Mg/DOBDC showed high dynamic CO 2 uptake of 14.93 mmol g−1. • The CO 2 adsorption process of the materials was simulated using various models. In this paper, novel M−Mg/DOBDC (M = Li, Na, K) composites (a MOF built of Mg(OAc) 2 ·4H 2 O and MOAc (M = Li, Na, K) linked by 2,5-dioxido-1,4-benzenedicarboxylate (DOBDC) ligands) were prepared for the first time by doping alkali metals in Mg/DOBDC MOF. The CO 2 dynamic adsorption performance of the novel synthesized composite was experimentally investigated, including different alkali metal doping amounts and alkali metal species. The structural morphology and CO 2 adsorption of the composites were characterized by XRD, FT-IR, SEM, EDX, BET, CO 2 -TPD and TGA. Ten cycles of adsorption–desorption tests were performed on the M−Mg/DOBDC after doping with alkali metals. In addition, the CO 2 adsorption process of the materials was simulated using various models. The results showed that the introduction of the alkali cation M+ would coordinate with the active site of the metal center and had high affinity and activation ability for CO 2. The composite with the best dynamic CO 2 uptake after the modification of Li, Na and K alkali metals was 0.5 K-Mg/DOBDC with an adsorption capacity of 14.93 mmol g−1 (0.1 MPa, 25 °C), which was 3.44 times higher than that of the parent material Mg/DOBDC. That was higher than the previously reported CO 2 capture performance. [ABSTRACT FROM AUTHOR]

The burner of outside vapor deposition (OVD) is of great significance for enhancing the yields and quality of the optical fiber preform. This study aims to numerically investigate the effects of the burner on silica particles formation and its corresponding deposition performance in the OVD process. This work is based on our recently developed integrated Eulerian-Eulerian multiphase OVD process model combined with a particle nucleation model. The effects of the distance between the burner and target, the horizontal offset of the target to the burner, the shape of burners, swirl burners as well as double burners are investigated. The results demonstrate that there exists an optimal value for the distance between the burner and target to yield the largest deposition efficiency. However, the deposition efficiency monotonically declines as the horizontal offset of the target to the burner increases. The elliptic burner potentially provides a better match with the target surface for particle deposition. An optimal number of helical vanes installed inside the O 2 –1 inlet is observed in the counter-swirling burner of O 2 –1 and H 2 inlets, which yields the largest deposition efficiency of 33.4%. Double burners could promote the deposition rate, but could not enhance the particle deposition efficiency. The results provide a deeper understanding of the burner design and OVD process optimization. [Display omitted] • Effects of burner on SiO 2 formation and deposition and OVD inner states are studied. • An optimal distance between the burner and target is identified. • Double burners promote deposition rate, but could not enhance deposition efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • 3D Eulerian-Lagrangian model on particle circulations in CLC DCFB was developed. • Particle Size Distribution (PSD) was introduced in the current models. • Flow patterns of particles with a wide size distribution in DCFB were revealed. • Effects of operating conditions on the particle circulation behaviors were studied. Abstract Understanding the particle dynamics is of paramount importance to the design, operation and optimization of looping combustion reactors. In this paper, a three-dimensional Eulerian-Lagrangian model was developed to study the particle flow in a dual circulating fluidized bed consisting of an air reactor and a fuel reactor. Based on the Multi-Phase Particle-In-Cell (MP-PIC) scheme, the turbulent gas motion was simulated by the large eddy simulation (LES) and the particle flow simulated by the discrete particle method, with the particle size distribution (d p = 0–108 μm) being fully taken into account. The effects of particle size, particle density, initial bed inventory and fluidizing gas flow rate were numerically studied. The results show that small particles mainly distribute in the fuel reactor while large particles tended to stay in the air reactor, leading to an unfavorable influence on the efficiency of metal oxide. The increase of particle density led to the increase of global and internal circulation rates. A high initial bed inventory would result in a high particle concentration and lower axial velocities of particles. When increasing the fluidizing gas flow rate in the fuel reactor, the internal particle circulation rate increased gradually; however, the global particle circulation rate decreased. The results should be useful for the design and control of dual circulating fluidized bed, looping combustion reactors. [ABSTRACT FROM AUTHOR]

This study proposes an optimization method for the supercritical carbon dioxide (S-CO 2 ) Brayton cycle in a 1000 MW single-reheat S-CO 2 coal-fired power plant based on the second law of thermodynamics. The effects of parameters and configurations on S-CO 2 cycle efficiencies and component irreversibility are studied. The analysis reveals that variations in parameters and configurations have more remarkable effects on the irreversibility of heat exchangers, particularly on the high-temperature recuperator (HTR) and cooler (COL), than on that of turbo machines. The results show that the optimum parameter of turbines provides a higher expansion ratio for the low-pressure turbine (LPT) than for the high-pressure turbine (HPT). The effects of split ratio to economizer (ECO) have contradicting results on cycle thermal and exergy efficiencies given that the irreversibility of HTR decreases with the increase in the split ratio to ECO. The minimum cycle pressure drastically affects the irreversible interaction between HTR and COL because of the nonlinear characteristics of CO 2 near its critical point. Double compression and the Case 2 of the ECO configuration is more reasonable for S-CO 2 power plants. The main differences between the S-CO 2 and traditional steam power plant are that exergy loss ratio of fuel combustion and exergy efficiency of the water wall, screen heaters, primary heaters are noticeably higher in the S-CO 2 boiler than those in the traditional steam boiler. The overall exergy efficiency of the innovative single-reheat 1000 MW S-CO 2 coal-fired power plant is 45.4%, which is approximately 3.5% higher than that of the traditional ultra-supercritical steam plant. [ABSTRACT FROM AUTHOR]

The methods of accurate measurement on the real-time solid mass flow rate are very limited, especially for non-intrusive measuring approaches. This paper presents a non-intrusive measurement system on solid mass flow rate. The measuring principle is based on microwave attenuation theory and microwave Doppler Effect. A series of experiments have been carried out to test the microwave measurement method. The effects of particle properties in terms of size and relative permittivity on the measuring results have been carefully discussed. The correlations between the output signal and the solid mass flow rate have been investigated. The experiment results show that the size and material of the measured solids can significantly influence the reflected microwave signal. To improve the measurement accuracy, the correlation related on the functions of particle diameter and permittivity is proposed for the solid mass flow rate. Furthermore, the experiments under the unsteady flow condition confirm that this method is promising to be applied in the actual industrial processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A 1000 MW S-CO 2 CFB boiler with the novel annular structure is proposed. • MP-PIC method is applied to simulate the gas-solid combustion process. • Unique gas-solid hydrodynamics are obtained by comparing with conventional steam CFB. • Combustion and pollutant characteristics under S-CO 2 boundary are studied. • Chemical reaction and heat transfer models are verified comparing to industrial data. Supercritical CO 2 (S-CO 2) power cycle has become one of the most efficient and low-pollution cycle schemes to improve thermal power generation efficiency and reduce energy consumption around the world. In this study, the 3D physical model of a 1000 MW S-CO 2 circulating fluidized bed (CFB) boiler with annular furnace is established to simulate the gas-solid combustion process based on the MP-PIC method under the Eulerian-Lagrangian framework. By comparing with the conventional water steam CFB boiler, the S-CO 2 CFB boiler has a smooth and stable gas-solid flow pattern with good uniformity of the particle concentration and velocity distribution, indicating that the annular structure and the layout of the heating surfaces is conducive to the gas-solid flow uniformity. The gas-solid phase temperature distributes uniformly basically without sudden rise or sudden drop, and the temperature difference between the solid phase and the gas phase is not large, which reflects the good combustion uniformity of the S-CO 2 CFB boiler. Compared with 300 MW and 600 MW S-CO 2 CFB boilers, the 1000 MW one shows a higher carbon conversion rate, lower desulphurization effect, and lower nitrogen removal performance with the CO, NO, and SO 2 outlet concentration of 0.002%, 5.8 mg/m3, and 125 mg/m3, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a randomly packed granular filtration model was built to investigate the mechanism of particle deposition on the granular surface, including the deposition positions, the backflow of particles and the relation with Stokes number. The deposition positions of particles of different size on the granular surface were exhibited, and the results showed that the diameters of particles deposited on the leeward side of the granule are smaller than 5 μm. The deposition area is larger and more uniform for smaller particle deposited on the windward side of the granule and it leads to a higher pressure drop. Besides, the concentrations of particles smaller than 5 μm linearly decrease with the height of the model between 50 mm–78 mm, and for the cases of lager than 15 μm, they dramatically drop between 50 mm–63 mm and the decline rate gradually reduces to zero with respect to 78 mm. Other cases of particle diameters between 5 μm–15 μm are between the above two situations. The Stokes number based on the inlet gas velocity versus the grade collection efficiency and the Stokes number based on the normal impaction velocity of particles versus the particle diameter are concluded to evaluate the filtration performance and the sticking probability of particles and they are expressed with two equations. [ABSTRACT FROM AUTHOR]

Supercritical CO 2 (S-CO 2) circulating fluidized bed (CFB) boiler has broad prospects in the field of coal-fired power generation because of its high combustion efficiency, compact structure, and low pollution emission. Scale-up regularity research based on combustion characteristics of S-CO 2 CFB boiler is the key to make it a wide range of industrial applications. In order to simplify the complicated workload and save the huge time cost of numerical simulations, it is of great significance to accurately make the scale-up prediction according to the operating performance of the S-CO 2 CFB boiler. This study proposed a scale-up prediction model corresponding to the combustion characteristics of S-CO 2 CFB boiler based on adaptive particle swarm optimization support vector machine (APSO-SVM). The parameters of the particle swarm algorithm were processed adaptively firstly combined with the boiler characteristics, and then the adaptive particle swarm algorithm was integrated with the support vector machine to solve the precocious convergence problem of particles being easy to gather in a certain position in the process of pattern recognition. The novel method effectively predicts the boiler in the scaling process from the aspect of boiler capacity, optimizes the scale-up regularity expression by numerical simulations, greatly saves time cost and applicability of enlarge design by altering complex numerical simulations, and lays the application foundation of S-CO 2 CFB boiler in the industrial field with acceptable operation accuracy. [Display omitted] • 3D Eulerian-Lagrangian model computationally facilitated by the MP-PIC scheme. • Scale-up regularities are verified by simulation results of 1000 MW S-CO 2 CFB boiler. • A scale-up prediction model of S-CO 2 CFB boilers based on APSO-SVM is proposed. • Novel prediction model is compared with traditional ones to verify accuracy. • Scale-up fitting equations corresponding to boiler efficiency are optimized. [ABSTRACT FROM AUTHOR]

Background and Aim Propranolol is widely used to prevent gastroesophageal variceal bleeding; however, some patients could not benefit from propranolol. This study is to evaluate the relationship between CYP2D6 and β2-adrenergic receptor (β2-AR) gene polymorphisms and the hemodynamic response to propranolol in Chinese Han patients. Methods The clinical data of patients with gastroesophageal varices undergoing hepatic venous pressure gradient (HVPG) measurement before and 7 days after oral propranolol administration in our department were collected. Four single nucleotide polymorphisms of CYP2D6 and β2-AR genes were detected. The relationship was identified by logistic regression model. Results Thirty patients were involved in the analysis. Sixty milligram propranolol twice each day was well tolerated by all the patients. The initial and secondary average of HVPG was 17.4 ± 5.8 mmHg vs. 13.2 ± 4.8 mmHg, respectively ( t = 5.726, P < 0.001). Twenty patients responded to propranolol. The mean reduction value of HVPG was 6.6 ± 3.6 mmHg (range from 3 to 19). Genotype analysis showed: 20 homozygotes for C/C188 and 10 for heterozygous C/T188, 8 homozygotes for G/G4268 and 22 heterozygotes for G/C4268, 14 homozygotes for Gly16 and 10 heterozygotes, and 6 homozygotes for Arg16, 27 homozygotes for Gln27 and 3 heterozygotes. The multivariate logistic regression analysis indicated that CYP2D6 (188C>T) genotype was an independent predicting factor for HVPG response to propranolol ( P = 0.033). Conclusions CYP2D6 (188C>T) gene polymorphisms influence the hemodynamic response to propranolol in this population of Chinese Han patients with gastroesophageal varices. However, HVPG response cannot be completely predicted from CYP2D6 and β2-AR gene polymorphisms. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the influences of granular bed depth, gas velocity and granule diameter on the grade collection efficiency in a three-dimensional randomly packed granular filtration model. The simulation results and experimental results showed the effect of granular bed depth on the overall collection efficiency and pressure drop. It is found the pressure drop approximately linearly correlates with the granular bed depth. Then, the effects of granular bed depth, gas velocity and granule diameter on the grade collection efficiency were studied using simulation method, and the results indicated that increasing the gas velocity could improve the grade collection efficiency of particles greater than 7 μm while it is useless for the particles smaller than 5 μm. Increasing the granular bed depth makes the grade collection efficiency reaches the maximum earlier and it has equal promotion for the particles of all size. The grade collection efficiency is also approximately linearly correlates with the granule diameter and the granule diameter influences the position of the “turning point one” and “turning point two”. [ABSTRACT FROM AUTHOR]

The consequent lack of basic understanding of the cohesiveness of ash particles at high temperature is a major hindrance to advancing biomass combustion technology. This paper presents an investigation of the effect of temperature on tensile strength by a combined experimental and numerical method. Experimentally, tensile strength and fracture distance of palm residues combusted at 820 °C were measured as a function of temperature (25–800 °C). The results showed that the tensile strength is strongly dependent on temperature and the liquid bridge between particles may transform into partially solid bonds with increasing temperature. In numerical simulation by means of discrete element method (DEM), the cohesive force between particles was modelled using the so called Bonded Particle Model (BPM) and Capillary Force Model (CFM). The parameters of BMP and CFM models at different temperatures were determined by an empirical equation. Comparison with the existing test results showed that the model can reasonably describe the behaviour of biomass combustion ash under various temperatures. It was therefore confirmed that the proposed cohesive force model can be used in the DEM-based simulation of biomass ash deposition in the combustion devices, leading to better understand the phenomena of shedding and erosion in the future. [ABSTRACT FROM AUTHOR]

Wet particle fluidization is commonly applied in some industries such as catalytic cracking, pharmaceutical manufacturing, mineral processing, food drying, etc. Understanding the within fluidization characteristics is important for the scale-up, design and optimization of industrial process. This article reviews the recent studies on fluidization characteristics of wet particles in fluidized beds and spouted beds. Both physical experiment and numerical simulation results are included. For physical experiments, the focus is on the development of new measurement methods and the resulting findings. For numerical simulations, the focus is especially on the development of the discrete element method (DEM) which can lead to new insights for wet particle fluidization at particle scale. Finally, challenges and needs for future research on wet particle fluidization are discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Co-fluidization characteristics of irregular particles with bed material have been investigated. Experiments were carried out in a solid waste fluidized bed with cross section of 0.2m×0.2m and height of 2m. Four particles differing in shapes, sizes and densities were used as simulative solid waste, and silica sand was employed as fluidization medium. The pressure drop, flow pattern and minimum fluidization velocity (Umf) under different operating conditions were investigated by recording pressure differential signals and fluidization images. A correlation of Umf was also developed. The results showed that during the fluidization of irregular particles with the bed material of silica sand, the pressure drop curve measured with increasing fluidization gas flow rate was visibly fluctuant and always underestimated the Umf value; while the pressure drop curve measured with decreasing fluidization gas flow rate was smooth and adequate to determine the value of Umf. The Umf was found to be increased with increasing volume proportion and effective particle density, while the initial static bed height has no significant effect on the minimum fluidization velocity. By comparing the Umf values predicted by the developed correlation with the present experimental data and those from literature, it was found that the correlation was quite satisfactory on predicting the Umf value for the fluidization of irregular particles with the bed material of silica sand. The correlation was also found to be applicable to the prediction of Umf values of a solid waste fluidized bed with a single kind or multi-kinds of irregular particles. [Copyright &y& Elsevier]

Aerosol Infrared Stealth Technology is a novel method to suppress the infrared by releasing aerosol particles around the hot exhaust plume. However, the Infrared Radiation (IR) suppression rate is much lower in flight tests, which is caused by the unclear particle dispersion mechanism in high-speed non-isothermal shear flow. Hence, the large eddy simulation (LES) and particle discrete phase model (DPM) are coupled to solve the turbulent shear flow and the aerosol particle motion. The effects of aircraft flight speed on the turbulent flow characteristics and particle motion behaviors are systematically studied. It is found that the Mach rings appear in flight conditions, and they are getting blurry when increasing the flight speed. Both γ-like vortex and horseshoe-like vortex are observed when Ma < 1, and the horse-like could disappear when Ma > 1. The aerosol particle distribution is closely related to the turbulent gas vortices. The particle lateral dispersion is obviously restricted with the rising flight speed. Besides, the drag force plays a dominant role, the Saffman force and the thermophoretic force are of the same order of magnitude, all of these three forces are much greater than the gravity. The particles dispersion in turbulent vortices under different flight speeds. [Display omitted] • LES coupled with DPM is applied to solve the high-speed non-isothermal gas-particle flow. • The effects of flight speed on particle dispersion are studied. • The influences of flight speed on vortex structure and evolution are studied. • The forces on the dispersed particles in aircraft plume are discussed. [ABSTRACT FROM AUTHOR]

Boiler is one of the critical equipment to realize supercritical carbon dioxide coal-fired (SCDC) power, but there is a lack of cost evaluation method. In this study, an improved global optimization model which is composed of genetic algorithm, thermal calculation and levelized cost of electricity (LCOE), was designed to obtain the optimal design of SCDC boilers. The cost curve of boilers with different capacity (350–1000 MW), temperature (600–650 °C) and pressure (300–330 bar) was analyzed and a new correlation of boiler cost was given. Due to the influence of heat transfer and material, the boiler cost firstly decreases and then increases with the increase of thermal power. For a single boiler, thermal power of 1000-2000 MW th is a suitable choice. Temperature affects boiler cost through thermal power and material strength, which are reflected by " r 2 t " and " r 7 t + r 8 ". Furthermore, double/multiple boiler design and positive matching principle were proposed to ensure the cost was in optimal range. These two schemes can provide the basis for selecting boiler parameters. The SCDC boiler cost increases by 32 % compared with the traditional steam boiler. SCDC units that meet the positive matching principle can achieve lower LCOE. This study can provide reference for the design of SCDC system. • An improved global optimization model of S–CO 2 boiler was established. • A new semiempirical cost correlation of S–CO 2 boiler was designed. • There is a minimum value for the boiler cost, which is determined by temperature. • Double/multiple boiler design and positive matching principle were proposed. [ABSTRACT FROM AUTHOR]

Abstract: Preparation of activated carbon from chicken waste is a promising way to produce a useful adsorbent for Hg removal. A three-stage activation process (drying at 200°C, pyrolysis in N2 atmosphere, followed by CO2 activation) was used for the production of activated samples. The effects of carbonization temperature (400–600°C), activation temperature (700–900°C), and activation time (1–2.5 h) on the physicochemical properties (weight-loss and BET surface) of the prepared carbon were investigated. Adsorptive removal of mercury from real flue gas onto activated carbon has been studied. The activated carbon from chicken waste has the same mercury capacity as commercial activated carbon (Darco LH) (Hgv: 38.7% vs. 53.5%, Hg0: 50.5% vs. 68.8%), although its surface area is around 10 times smaller, 89.5 m2/g vs. 862 m2/g. The low cost activated carbon can be produced from chicken waste, and the procedure is suitable. [Copyright &y& Elsevier]

• Transition from conventional blast furnace (CBF) to oxygen BF is studied. • This is done using the recently developed CFD process model. • In-furnace-state analysis elucidates changes in fuel rate and energy consumption. • Roles of blast temperature and top pressure are also clarified. Oxygen blast furnace (OBF) ironmaking promises to realize "zero carbon footprint" production via high oxygen enrichment in the blast. This paper presents a comprehensive study of the inner states and overall performance of the BF under such an operation. This is done by means of our recently developed multi-fluid process model, covering the oxygen content of the blast from 21% to 100%, with fixed hot metal temperature, bosh gas volume and blast temperature. The results show that with increasing oxygen enrichment, the fuel rate or coke rate increases initially to a minimum and then increases. This trend agrees with published experimental observations. On this basis, the flow and thermochemical behaviors are analyzed in detail. It shows that the cohesive zone becomes lower as the oxygen enrichment increases; meanwhile, the heat loss through reactions increases, but that through walls and top gas decreases. These opposite trends control the coke rate variation and explain the presence of the minimum coke rate. Some wide ore cohesive layers featured with long horizontal length appear at high oxygen enrichments, contributing to the high pressure drop in the lower part of the BF. Also, the dependence of OBF operations on blast temperature and top pressure is examined. It is shown that the increase in blast temperature or top pressure can both lead to a lower coke rate and higher productivity. The influence of blast temperature is less significant at higher oxygen enrichments. This is not the case for top pressure, whose effect on coke rate and productivity becomes more significant as the oxygen content increases. The analysis of reactions reveals that the coke reduction is caused by the increased indirect reduction rate and prolonged reaction time at a higher top pressure, but the enlarged indirect reduction zone for a hotter blast. [ABSTRACT FROM AUTHOR]

Hydrogen is regarded as one of the promising sustainable energy carriers for human society. Methane reforming is crucial to hydrogen energy industry since it is the main route to obtain hydrogen. Ni-based catalyst has been extensively explored because of its low price and good catalytic activity. However, it suffers from fast deactivation caused by carbon deposition. Perovskite with its unique structure, has been a popular candidate for catalyst precursors and lots of related literature is published. In this review, the application of perovskite catalysts for methane reforming is discussed in details. Typical LaNiO 3 has shown its superb carbon-resistance due to the strong interaction between La 2 O 3 and CO 2. The substitution of A and B sites could modify the structure and improve the catalytic performance further. Recent advances on this topic are presented as well. It is beneficial to increase the surface area by preparation supported and porous perovskite. Finally, a summary with future outlooks is raised for the future development of perovskite catalysts. Image 1 • Basic LaNiO 3 catalysts for methane reforming. • Substitution of A and B sites to modify perovskite structure. • Explored supported and porous perovskite catalysts. • Emerging sulphur-tolerance of perovskite catalysts. • Summary of current work and outlooks for future development. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide (S–CO 2) coal-fired power generation technology is considered as the transformative technology in the energy sector due to its high efficiency, simple turbomachinery and high power density though the concept design of S–CO 2 boiler is still in the infancy stage. This study constructs a modified combustion and heat transfer thermodynamic calculation method of the S–CO 2 boiler adapted for multi-zone furnace. The effects of parameters and configurations on the characteristics of the S–CO 2 boiler are compared and analyzed. The results show that the increase in the separated over-fired air ratio can effectively equalize the heat duty distribution. And the increasing of the furnace wall temperature will affect the furnace radiation heat transfer performance, which increases the flue gas average temperature. The boiler configurations including the flue gas recirculation, double furnace strategy, thermal insulation strategy and boiler local expansion strategy have the positive effects on decreasing the furnace heat duty to ensure the boiler safety. Finally, the novel S–CO 2 boiler configurations are proposed and the comprehensive evaluations are conducted on the boiler combustion, heat transfer and burnout characteristics, which show that the novel S–CO 2 boiler performance is promising and can provide a basis for the design of S–CO 2 boiler. • Modified thermodynamic calculation method of S–CO 2 boiler is constructed. • Effects of parameters and configurations on boiler characteristics are analyzed. • Combined strategies of FGR, DBS, TIS, BLES are for lowering the furnace heat duty. • Novel S–CO 2 boiler configuration adapted for S–CO 2 cycle is proposed and evaluated. [ABSTRACT FROM AUTHOR]

• The conversion characteristics of lignite char were experimentally investigated in a MFBRA reactor. • Significant differences in char combustion between O 2 /Ar and O 2 /CO 2 were measured. • The isotopic tracing provided a perspicuous approach to clarity CO 2 gasification in oxy-fuel combustion. • The transfer of 18O originating from C18O18O to C18O16O was detected. • The heterogeneous C-CO 2 and C-O 2 reactions took place simultaneously in O 2 /CO 2 atmosphere. In this work, the conventional combustion in O 2 /Ar and O 2 /CO 2 atmospheres at temperatures of 700–1000 °C and isotopic tracing experiments at 700–800 °C were conducted respectively in a micro fluidized bed reactor to clarify the conversion characteristics of lignite char and influence mechanism of elevated CO 2 concentrations. The isotopic method employing C18O18O provides an intuitive insight into the CO 2 gasification behavior by tracking the evolution of the 18O atom throughout the oxy-fuel combustion. The results reveal that char conversion rate significantly reduces when the atmosphere is switched from O 2 /Ar to O 2 /CO 2 at low temperature range (e.g. 700–800 °C), primarily caused by thermo-physical properties of CO 2. However, at higher temperature range (e.g. 950–1000 °C), the C-O 2 reaction is limited by the external O 2 diffusion and the C-CO 2 reaction contributes to the carbon consumption, resulting in a higher combustion rate, especially at O 2 -deficient conditions. The presence of the atomic 18O in the product C18O16O originating from C18O18O confirms that CO 2 is indeed involved in the whole oxy-fuel combustion process and the overall reaction could be described as C + C18O18O+16O16O → 2C18O16O. Besides, total contributions to carbon conversion by the C-CO 2 reaction decrease as O 2 concentrations and particle sizes increasing. [ABSTRACT FROM AUTHOR]

Gaze estimation is an important fundamental task in computer vision and medical research. Existing works have explored various effective paradigms and modules for precisely predicting eye gazes. However, the uncertainty for gaze estimation, e.g., input uncertainty and annotation uncertainty, have been neglected in previous research. Existing models use a deterministic function to estimate the gaze, which cannot reflect the actual situation in gaze estimation. To address this issue, we propose a probabilistic framework for gaze estimation by modeling the input uncertainty and annotation uncertainty. We first utilize probabilistic embeddings to model the input uncertainty, representing the input image as a Gaussian distribution in the embedding space. Based on the input uncertainty modeling, we give an instance-wise uncertainty estimation to measure the confidence of prediction results, which is critical in practical applications. Then, we propose a new label distribution learning method, probabilistic annotations, to model the annotation uncertainty, representing the raw hard labels as Gaussian distributions. In addition, we develop an Embedding Distribution Smoothing (EDS) module and a hard example mining method to improve the consistency between embedding distribution and label distribution. We conduct extensive experiments, demonstrating that the proposed approach achieves significant improvements over baseline and state-of-the-art methods on two widely used benchmark datasets, GazeCapture and MPIIFaceGaze, as well as our collected dataset using mobile devices.

The development of a new and efficient supercritical carbon dioxide (S-CO 2 ) power cycle system is one of the important technical ways to break through the bottleneck of coal power development, improve the efficiency of power generation, and realize energy saving and emission reduction. In order to simplify the complicated workload and save the huge time cost of numerical simulations on combustion characteristics, it is of great significance to accurately make the combustion characteristic prediction according to the operating performance of the S-CO 2 CFB boiler. This study proposed a combustion characteristic prediction model corresponding to the S-CO 2 CFB boiler based on the adaptive gray wolf optimizer support vector machine (AGWO-SVM). The parameters of the gray wolf optimizer algorithm were processed adaptively first combined with the boiler characteristics, and then the adaptive gray wolf optimizer algorithm was integrated with the support vector machine to solve the imbalance of local and global search problems of particles being easy to gather in a certain position in the process of pattern recognition. The novel method effectively predicts the boiler in the scaling process from the aspect of boiler capacity, optimizes the combustion characteristic expression by numerical simulations, greatly saves time cost and applicability of enlarged design by altering complex numerical simulations, and lays the application foundation of the S-CO 2 CFB boiler in the industrial field with acceptable operation accuracy., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Actinidia eriantha is a unique germplasm resource for kiwifruit breeding. Genetic diversity and nutrient content need to be evaluated prior to breeding. In this study, we looked at the metabolites of three elite A. eriantha varieties (MM-11, MM-13 and MM-16) selected from natural individuals by using a UPLC-MS/MS-based metabolomics approach and transcriptome, with a total of 417 metabolites identified. The biosynthesis and metabolism of phenolic acid, flavonoids, sugars, organic acid and AsA in A. eriantha fruit were further analyzed. The phenolic compounds accounted for 32.37% of the total metabolites, including 48 phenolic acids, 60 flavonoids, 7 tannins and 20 lignans and coumarins. Correlation analysis of metabolites and transcripts showed PAL ( DTZ79&#95;15g06470 ), 4CL ( DTZ79&#95;26g05660 and D TZ79&#95;29g0271 ), CAD ( DTZ79&#95;06g11810 ), COMT ( DTZ79&#95;14g02670 ) and FLS ( DTZ79&#95;23g14660 ) correlated with polyphenols. There are twenty-three metabolites belonging to sugars, the majority being sucrose, glucose arabinose and melibiose. The starch biosynthesis-related genes ( AeglgC , AeglgA and AeGEB1 ) were expressed at lower levels compared with metabolism-related genes ( Ae a myA and AeamyB ) in three mature fruits of three varieties, indicating that starch was converted to soluble sugar during fruit maturation, and the expression level of SUS ( DTZ79&#95;23g00730 ) and TPS ( DTZ79&#95;18g05470 ) was correlated with trehalose 6-phosphate. The main organic acids in A. eriantha fruit are citric acid, quinic acid, succinic acid and D-xylonic acid. Correlation analysis of metabolites and transcripts showed ACO ( DTZ79&#95;17g07470 ) was highly correlated with citric acid, CS ( DTZ79&#95;17g00890 ) with oxaloacetic acid, and MDH1 ( DTZ79&#95;23g14440 ) with malic acid. Based on the gene expression, the metabolism of AsA acid was primarily through the L-galactose pathway, and the expression level of GMP ( DTZ79&#95;24g08440 ) and MDHAR ( DTZ79&#95;27g01630 ) highly correlated with L-Ascorbic acid. Our study provides additional evidence for the correlation between the genes and metabolites involved in phenolic acid, flavonoids, sugars, organic acid and AsA synthesis and will help to accelerate the kiwifruit molecular breeding approaches.

The co-combustion of biomass and coal has both environmental and economic benefits in terms of pollutants and greenhouse gas emissions. However, one of the key factors affecting the feasibility of this technology is the ash deposition and corrosion caused by the high alkali metal content of biomass, especially K. After the addition of elemental S to corn stalk/Xiaolongtan lignite blended fuel and Al 2 O 3 to corn stalk/Datong lignite, combustion experiments were carried out in a tubular furnace to explore the effects of S and Al in coal on K migration and transformation. The experimental results show that when S/K < 6, an increase in the S/K ratio inhibited the release of K. When S/K > 6, the sulfation become saturated, and an increase in S promoted the release of K. When S/K = 6, the higher the temperature was, and the more obvious the inhibitory effect on the release of K was. Increasing the S/K ratio not only increased the CaSO 4 content of the ash but also increased the content of water-soluble K compounds, such as K 2 SO 4 , and decreased the contents of acid-soluble K compounds and insoluble K compounds, such as KAlSi 3 O 8 . After Al 2 O 3 was added, as the Al/K ratio increased, the K release rate gradually decreased. When the sample with Al/K = 2.5 and the original samples were burned at 600-700 °C, the difference in the K release rates of the two samples was relatively small. When the temperature was higher than 700 °C, the higher the temperature was, and the greater the difference in the K release rates of the samples was, which indicates that a high temperature promotes the formation of aluminosilicates containing K., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

A comprehensive three-dimensional numerical model is developed to simulate forestry residues gasification in a fluidized bed reactor using Eulerian-Lagrangian approach. The complex granular flow behaviors and chemical reaction characteristics are addressed simultaneously. The model uses an Eulerian method for fluid phase and a discrete particle method for solid phase, which takes particle contact force into account. Heterogeneous and homogenous reaction rates are solved on the Eulerian grid. The numerical model is employed to study the gasification performance in a lab-scale pine gasifier. A series of simulations have been performed with some critical parameters including temperature, equivalence ratio and steam to biomass ratio. The model predicts product gas composition and carbon conversion efficiency in good agreement with experimental data. The formation and development of flow regimes, profiles of particle species, and distributions of gas compositions inside the reactor are also discussed., (Copyright © 2012 Elsevier Ltd. All rights reserved.)