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A pressurized drop tube furnace was used to study the pyrolysis behavior of bituminous and lignite coal at elevated pressure. Experiments were conducted at the pressure range from 1 to 10 atm in 100% N2 or 100% CO2 atmosphere. The volatile yields, char morphology, swelling ratio, and pore structure were discussed in detail. The results show that the pressure, atmosphere and coal rank could effect on the volatile releasing and char evolution significantly. In N2 atmosphere, the total volatile yields of YL and NM coal decrease as the pressure elevated, while in CO2 atmosphere, the mass release of NM coal increases at high pressure contributed by the reaction of CO2 with organic macromolecule inside the particles; different with bituminous coal, no significant swelling behavior is found with the increase of pressure; the BET surface area of YL char decreases as the pressure increases, while for lignite coal, in N2 atmosphere and at high pressure, less macro pores are formed, which could contribute to the BET surface area. While in CO2 atmosphere, the CO2-macromocular organic reaction would promote the volatile releasing, and the BET surface area decreases significantly at high pressure.
Jiaye Zhang; Chongming Chen; Ao Zhou; Zia Ur Rahman; Xuebin Wang; Dragoslava Stojiljković; Nebojsa Manić; Milan Vujanović; Houzhang Tan. Morphology of char particles from coal pyrolysis in a pressurized entrained flow reactor: Effects of pressure and atmosphere. Energy 2021, 238, 121846 .
AMA StyleJiaye Zhang, Chongming Chen, Ao Zhou, Zia Ur Rahman, Xuebin Wang, Dragoslava Stojiljković, Nebojsa Manić, Milan Vujanović, Houzhang Tan. Morphology of char particles from coal pyrolysis in a pressurized entrained flow reactor: Effects of pressure and atmosphere. Energy. 2021; 238 ():121846.
Chicago/Turabian StyleJiaye Zhang; Chongming Chen; Ao Zhou; Zia Ur Rahman; Xuebin Wang; Dragoslava Stojiljković; Nebojsa Manić; Milan Vujanović; Houzhang Tan. 2021. "Morphology of char particles from coal pyrolysis in a pressurized entrained flow reactor: Effects of pressure and atmosphere." Energy 238, no. : 121846.
There is a growing research interest in tidal current energy, as it is more predictable when compared to wind and solar. Most past studies on tidal current energy focused on assessing the potential resource of sites with known fast tidal currents. Regions with less energetic tidal currents, but shallow waters for easy installation of energy infrastructure, have not been investigated. One potential tidal current energy location, which fits this categorization, is the strait of Novsko Ždrilo that connects the Novigrad Sea with the Adriatic Sea. In this study a high resolution 3D hydrodynamic model SCHISM was used to estimate the tidal current energy resource potential of this strait. The model results show that tidal current velocities are up to ten times higher than in the outer sea and vary spatially within the strait. However, the obtained velocities in the strait are not sufficient for viable energy exploitation with present tidal energy converter technology level. It is therefore important to further develop turbine type energy converters that could exploit these low tidal current energy resource locations. The applied model can be applied elsewhere for enhanced assessment of tidal energy potential, micro sitting of turbines and environmental impact. Since the current tidal energy potential estimates have been performed mainly with low resolution models, using high resolution models for assessment could lead to overall increase of tidal energy potential.
Melita Burić; Sanja Grgurić; Hrvoje Mikulčić; Xuebin Wang. A numerical investigation of tidal current energy resource potential in a sea strait. Energy 2021, 234, 121241 .
AMA StyleMelita Burić, Sanja Grgurić, Hrvoje Mikulčić, Xuebin Wang. A numerical investigation of tidal current energy resource potential in a sea strait. Energy. 2021; 234 ():121241.
Chicago/Turabian StyleMelita Burić; Sanja Grgurić; Hrvoje Mikulčić; Xuebin Wang. 2021. "A numerical investigation of tidal current energy resource potential in a sea strait." Energy 234, no. : 121241.
Pressurized oxy-combustion is an emerging and more efficient technology for carbon capture, utilization, and storage than the first generation (atmospheric) oxy-combustion. NOx is a major conventional pollutant produced in pressurized oxy-combustion. In pressurized oxy-combustion, the utilization of latent heat from moisture and removal of acid gases (NOx and SOx) are mainly conducted in an integrated direct-contact wash column. Recent studies have shown that NOx particular inlet concentration should be maintained before direct contact wash column to remove NOx and SOx efficiently. As a result, minimizing NOx for environmental reasons, avoiding corrosion in carbon capture, utilization, and storage, and achieving effective NOx and SOx removal in direct contact wash columns are crucial. Reburning is a capable and affordable technology for NOx reduction; however, this process is still less studied at elevated pressure, particularly in pressurized oxy-combustion. In this paper, the kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion was conducted. First, the most suitable mechanism was selected by comparing the results of different kinetic models with the experimental data in literature at atmospheric and elevated pressures. Based on the validated mechanism, a variety of parameters were studied at high pressure, i.e., comparing the effects of oxy and the air environment, different reburning fuels, residence time, H2O concentration, CH4/NO ratio, and equivalence ratio on the NO reduction. The results show that de-NOx efficiency in an oxy environment is significantly enhanced compared to the air environment. Improvement in the de-NOx efficiency is considerably higher with a pressure increase of up to 10 atm, but the effect is less prominent above 10 atm. The formation of HCN is significantly reduced while the N2 formation is enhanced as the pressure increases from 1 to 10 atm. The residence time required for the maximum NO reduction decreases as the pressure increases from 1 atm to 15 atm. At the higher pressure, the NO reduction rises prominently when the ratio of CH4/NO increases from 1 to 2; however, the effect fades after that. At higher pressure, the NO reduction by CH4 reburning decreases as the H2O concentration increases from 0 to 35%. The optimum equivalence ratio and high pressure for maximum NO reduction are 1.5 and 10 atm, respectively. This study could provide guidance for designing and optimizing a pressurized reburning process for NOx reduction in POC systems.
Zia Ur Rahman; Jiaye Zhang; Lan Zhang; Xuebin Wang; Zhiwei Yang; Houzhang Tan; Richard L. Axelbaum. A kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion. Journal of Environmental Management 2021, 290, 112690 .
AMA StyleZia Ur Rahman, Jiaye Zhang, Lan Zhang, Xuebin Wang, Zhiwei Yang, Houzhang Tan, Richard L. Axelbaum. A kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion. Journal of Environmental Management. 2021; 290 ():112690.
Chicago/Turabian StyleZia Ur Rahman; Jiaye Zhang; Lan Zhang; Xuebin Wang; Zhiwei Yang; Houzhang Tan; Richard L. Axelbaum. 2021. "A kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion." Journal of Environmental Management 290, no. : 112690.
Shaerhu (SEH) coal in Xinjiang province of China, with a reserve of 90 billion tons, is one of the most representative high-chlorine-alkaline coal. However, the chlorine content in coal exceeding 1% easily leads to severe problems of ash deposition and hot corrosion on tubes, which are closely related to the evolution of fine particles. In this study, the formation of fine particle from the combustion of two types of SEH coal (#1 and #2) are investigated in the temperature range of 900–1300 °C. Their results are compared with Xinjiang Tianchi (TC) coal (high-sodium but low-chlorine). In order to demonstrate the formation mechanism of fine particles, the particle size distribution, elemental composition and morphology of fine particles, as well as chlorine- and sulfur-containing gas products, are characterized. The results show that the particle size distribution of PM10 present a bimodal distribution. Fine-mode particles (PM0.4) from SEH#1 coal combustion mainly consist of NaCl since the molar ratio of Na/Cl is about 1.0, while fine-mode particles from TC coal combustion could be Na2SO4 and CaSO4. Coarse-mode particles (PM0.4-10) mainly consist of silicon, aluminum, calcium and magnesium, whose compositions are not significantly affected by combustion temperature, and calcium accounts for the largest proportion in coarse-mode particles. As the temperature increased to 1150 °C, the chlorine and sulfur in SEH coal were fundamentally associated to solid ashes, while for TC coal extra sulfur existed as the gaseous form of SO2.
Daoyang Ma; Renhui Ruan; Yingdian Li; Lan Zhang; Xuebin Wang; Jingbin Zi; Yibin Wang; Hao Li; Hongbo Wen; Houzhang Tan. Characteristics of fine particle formation during combustion of Xinjiang high-chlorine-sodium coal. Fuel 2021, 297, 120772 .
AMA StyleDaoyang Ma, Renhui Ruan, Yingdian Li, Lan Zhang, Xuebin Wang, Jingbin Zi, Yibin Wang, Hao Li, Hongbo Wen, Houzhang Tan. Characteristics of fine particle formation during combustion of Xinjiang high-chlorine-sodium coal. Fuel. 2021; 297 ():120772.
Chicago/Turabian StyleDaoyang Ma; Renhui Ruan; Yingdian Li; Lan Zhang; Xuebin Wang; Jingbin Zi; Yibin Wang; Hao Li; Hongbo Wen; Houzhang Tan. 2021. "Characteristics of fine particle formation during combustion of Xinjiang high-chlorine-sodium coal." Fuel 297, no. : 120772.
Pyrolysis is the key step in biomass thermochemical conversion process. The network model can accurately predict the pyrolysis process but generally cannot incorporate the combustion and gasification sub-models due to its complexity. This paper used the Bio-CPD model to predict the pyrolysis products of softwood and hardwood respectively; based on the predicted results, two empirical-simple forms of pyrolysis models were further optimized. The ultimate kinetic parameters obtained are suitable for biomass pyrolysis at high heating rate. For softwood, after being optimized, the apparent frequency factor and E/R of single rate are 4.3106e + 07 s−1, 10042 K respectively. While for two-competing rates model, the parameters are, α1 = 0.75, α2 = 0.89, A1 = 7992 s−1, E1/R = 7000 K, A2 = 8.3e + 09 s−1, E2/R = 14520 K, respectively. The numerical simulation of biomass pyrolysis and combustion process were performed by using CFD code Ansys Fluent. The results reveal that the release of volatile predicted by the default parameters have a delay compared with the actual process and is not appropriate for biomass simulation, while the optimized parameters in two simple models are accurate enough to simulate the biomass pyrolysis at high heating rate (103–105 K/s).
Jiaye Zhang; Shijie Zheng; Chongming Chen; Xuebin Wang; Zia Ur Rahman; Houzhang Tan. Kinetic model study on biomass pyrolysis and CFD application by using pseudo-Bio-CPD model. Fuel 2021, 293, 120266 .
AMA StyleJiaye Zhang, Shijie Zheng, Chongming Chen, Xuebin Wang, Zia Ur Rahman, Houzhang Tan. Kinetic model study on biomass pyrolysis and CFD application by using pseudo-Bio-CPD model. Fuel. 2021; 293 ():120266.
Chicago/Turabian StyleJiaye Zhang; Shijie Zheng; Chongming Chen; Xuebin Wang; Zia Ur Rahman; Houzhang Tan. 2021. "Kinetic model study on biomass pyrolysis and CFD application by using pseudo-Bio-CPD model." Fuel 293, no. : 120266.
Time is running out, while it is becoming obvious that many countries may fail to meet Paris Agreement goals. More intensive efforts should be invested with a strong emphasis on emissions decarbonisation of all sectors and energy transition towards more renewable energy sources. This work provides an overview of the impact of the energy transition on the environment, energy and water systems and the need for integration of these systems. Reduction of carbon-related emissions has been identified as the common topic through reliance on the circular economy concept, taking into account the economic dimension in an attempt to decouple economic growth from emissions. Advanced control concepts, mathematical modelling and integration of renewable energy sources with carbon capture and storage and sewage sludge treatment can be recognised as dominant topics through the recognition that energy transition offers a solution to emission problem, but raises further challenges by introducing disbalance between supply and demand side of energy systems. It is expected that present contribution will identify dominant trends under the common divisor of the energy transition and foster discussion among the experts for future studies.
Hrvoje Mikulčić; Jakov Baleta; Jiří Jaromír Klemeš; Xuebin Wang. Energy transition and the role of system integration of the energy, water and environmental systems. Journal of Cleaner Production 2021, 292, 126027 .
AMA StyleHrvoje Mikulčić, Jakov Baleta, Jiří Jaromír Klemeš, Xuebin Wang. Energy transition and the role of system integration of the energy, water and environmental systems. Journal of Cleaner Production. 2021; 292 ():126027.
Chicago/Turabian StyleHrvoje Mikulčić; Jakov Baleta; Jiří Jaromír Klemeš; Xuebin Wang. 2021. "Energy transition and the role of system integration of the energy, water and environmental systems." Journal of Cleaner Production 292, no. : 126027.
Pressurized oxy-combustion is emerging to be one of the best technologies for significantly decreasing the energy penalty for CO2 capture in coal-fired power plants. However, the higher pressure boosts the formation of acid gases, including SO3 and NO2, which could increase the risk of corrosion. The synergistic promotion of SO3 and NO2 formation in pressurized oxy-combustion is kinetically evaluated under representative conditions (1 ~ 30 atm, 600 ~ 1200 °C, NO/SO2 = 0.1 ~ 5). We begin with a comprehensive mechanism (72 species and 428 reactions), covering nitrogen and sulfur chemistry, relying on GRI-Mech 3.0. This analysis shows that the interaction of SOX and NOX enhances the conversion rates of SO2 → SO3, and this effect is more apparent at elevated pressures and lower temperatures. Mechanism analyses indicate that at elevated pressures, the formation pathways of SO3 through HOSO2 + O2 = SO3 + HO2, and NO2 through HO2 + NO = NO2 + OH, are promoted due to the strong interaction between SOX and NOX. The intermediate between these two reactions is SO2 + OH + M = HOSO2 + M, resulting in a strong cycle, that can be expressed by the global reaction NO + SO2 + O2 = NO2 + SO3. Finally, a nine-step reduced chemistry is developed and validated to accurately predict the formation of SO3 in the post-flame region at elevated pressures.
Xuebin Wang; Gregory S. Yablonsky; Zia Ur Rahman; Zhiwei Yang; Pan Du; Houzhang Tan; Richard L. Axelbaum. Assessment of sulfur trioxide formation due to enhanced interaction of nitrogen oxides and sulfur oxides in pressurized oxy-combustion. Fuel 2021, 290, 119964 .
AMA StyleXuebin Wang, Gregory S. Yablonsky, Zia Ur Rahman, Zhiwei Yang, Pan Du, Houzhang Tan, Richard L. Axelbaum. Assessment of sulfur trioxide formation due to enhanced interaction of nitrogen oxides and sulfur oxides in pressurized oxy-combustion. Fuel. 2021; 290 ():119964.
Chicago/Turabian StyleXuebin Wang; Gregory S. Yablonsky; Zia Ur Rahman; Zhiwei Yang; Pan Du; Houzhang Tan; Richard L. Axelbaum. 2021. "Assessment of sulfur trioxide formation due to enhanced interaction of nitrogen oxides and sulfur oxides in pressurized oxy-combustion." Fuel 290, no. : 119964.
Green development of energy, water and environment systems is essential as these three systems represent the basic life needs of humankind. Therefore, environmental problems arising from each of these three systems need to be carefully addressed to preserve the energy, water and environment resources for future generations. This paper discusses some of the latest developments in three main areas of sustainability themes, namely energy, water and environment, that emerged from the 14th Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conference held in 2019. As such, it acts as an editorial paper for the virtual special issue of the Journal of Environmental Management, dedicated to the SDEWES 2019 conference.
Hrvoje Mikulčić; Jakov Baleta; Xuebin Wang; Neven Duić; Raf Dewil. Green development challenges within the environmental management framework. Journal of Environmental Management 2020, 277, 111477 .
AMA StyleHrvoje Mikulčić, Jakov Baleta, Xuebin Wang, Neven Duić, Raf Dewil. Green development challenges within the environmental management framework. Journal of Environmental Management. 2020; 277 ():111477.
Chicago/Turabian StyleHrvoje Mikulčić; Jakov Baleta; Xuebin Wang; Neven Duić; Raf Dewil. 2020. "Green development challenges within the environmental management framework." Journal of Environmental Management 277, no. : 111477.
Liang Wang; Lorenzo Riva; Øyvind Skreiberg; Roger Khalil; Pietro Bartocci; Qing Yang; Haiping Yang; Xuebin Wang; Dengyu Chen; Magnus Rudolfsson; Henrik Kofoed Nielsen. Effect of Torrefaction on Properties of Pellets Produced from Woody Biomass. Energy & Fuels 2020, 34, 15343 -15354.
AMA StyleLiang Wang, Lorenzo Riva, Øyvind Skreiberg, Roger Khalil, Pietro Bartocci, Qing Yang, Haiping Yang, Xuebin Wang, Dengyu Chen, Magnus Rudolfsson, Henrik Kofoed Nielsen. Effect of Torrefaction on Properties of Pellets Produced from Woody Biomass. Energy & Fuels. 2020; 34 (12):15343-15354.
Chicago/Turabian StyleLiang Wang; Lorenzo Riva; Øyvind Skreiberg; Roger Khalil; Pietro Bartocci; Qing Yang; Haiping Yang; Xuebin Wang; Dengyu Chen; Magnus Rudolfsson; Henrik Kofoed Nielsen. 2020. "Effect of Torrefaction on Properties of Pellets Produced from Woody Biomass." Energy & Fuels 34, no. 12: 15343-15354.
Pressurized Oxy-combustion is one of the most promising technologies for carbon capture, utilization, and storage (CCUS) of coal utilization. In pressurized oxy-combustion, the removal of acid gas pollutants and the latent heat of moisture condensation are mainly carried out by an integrated direct-contact wash column (DCC). Recent studies have shown that the inlet concentration of NOx in the column is important for the combined removal of NOx and SOx, therefore, it is essential to control the NOx emissions before the DCC. Selective non-catalytic reduction (SNCR) is a promising and economical technology of NOx reduction; however, no study has been conducted on SNCR at elevated pressure, especially in pressurized oxy-combustion. In this paper, kinetic modeling is carried out to explore and optimize the NOx reduction by SNCR in pressurized oxy-combustion. First, the detailed mechanism used in this study is validated by the experimental results in literature. Based on the validation of the detailed mechanism, the effects of different parameters including temperature, oxygen concentration, moisture content, NH3 concentration, and SO2 concentrations on the SNCR performance are analyzed at higher pressures in oxy-combustion atmosphere. The modeling results show that by increasing the pressure from 1 atm to 15 atm, the SNCR de-NOx efficiency increased by 2–3%. The width of the optimum temperature window for maximum De-NOx is broadened from 1250K to 1450K with increasing the pressure from 1 atm to 10 atm. The increase of pressure has no significant effect on thermal de-NOx efficiency with increasing the NH3/NO ratio. At higher pressure (10 atm) the increase in O2 concentration from 1 to 20% the de-NOx efficiency decreases almost twice as much as at 1 atm. The increase of SO2 and moisture contents at high pressure have no significant effect on the de-NOx efficiency. Rate of production (ROP) and sensitivity analysis are performed to determine the dominant reaction paths of de-NOx in pressurized-oxy SNCR process. This study can provide guidance for the process optimization of de-NOx by SNCR in pressurized oxy-combustion.
Zia Ur Rahman; Xuebin Wang; Jiaye Zhang; Jakov Baleta; Millan Vujanović; Houzhang Tan. Kinetic study and optimization on SNCR process in pressurized oxy-combustion. Journal of the Energy Institute 2020, 94, 263 -271.
AMA StyleZia Ur Rahman, Xuebin Wang, Jiaye Zhang, Jakov Baleta, Millan Vujanović, Houzhang Tan. Kinetic study and optimization on SNCR process in pressurized oxy-combustion. Journal of the Energy Institute. 2020; 94 ():263-271.
Chicago/Turabian StyleZia Ur Rahman; Xuebin Wang; Jiaye Zhang; Jakov Baleta; Millan Vujanović; Houzhang Tan. 2020. "Kinetic study and optimization on SNCR process in pressurized oxy-combustion." Journal of the Energy Institute 94, no. : 263-271.
Coal gasification fine ash (CGFA) having high carbon content is produced in large quantity as a by-product from coal gasifiers in China. CGFA is usually disposed of by landfill as a solid waste, which is not only detrimental to environment, but also a loss of an enormous energy that renders the process inefficient. Therefore, it is very crucial to make use of the high-carbon content in the CGFA with an economic and environmentally friendly method. In this study, the ignition and burnout behavior of CGFA was investigated by thermogravimetric analyzer (TGA), flat-flame burner (FFB) and drop-tube furnace (DTF) respectively. Further, the co-firing of CGFA was numerically studied in a tangentially fired pulverized coal boiler burning anthracite with various co-firing ratio (0%, 10%, 20% and 30%). The TGA results show the similar oxidation reactivity, oxidation kinetics and ignition behavior of CGFA with the anthracite. In the FFB atmosphere with practical heating rates, the CGFA and anthracite are both heterogeneously ignited with an ignition time of 8.1 ms and 7.6 ms, respectively. The particle size significantly affected the ignition time of CGFA, as the particle size decreased from 125-135 μm to 45-63 μm, the ignition time of CGFA decreased from 10.1 ms to 5.6 ms. The burnout test in DTF indicates that the promising burnout performance in a pulverized coal furnace required a crucial oxygen concentration >10%, and the CFD simulation results are coincided well with the experimental data from DTF. The CFD modeling results of full-scale furnace show that the co-firing of CGFA is feasible in the pulverized coal furnace burning anthracite. Compared with the mode of pure anthracite combustion, under the co-firing mode with 10-30% CGFA as energy input, the central maximum temperature of main combustion zone increases by 50-90 oC, resulting in the slightly improved burnout for both anthracite and CGFA.
Xing Liu; Xuebin Wang; Hu Sheng; Jiaye Zhang; Chaoqiang Yang; Zia Ur Rahman; Lan Zhang; Houzhang Tan. Combustibility and Cofiring of Coal Gasification Fine Ash with High Carbon Content in a Full-scale Pulverized Coal Furnace. Energy & Fuels 2020, 34, 12972 -12983.
AMA StyleXing Liu, Xuebin Wang, Hu Sheng, Jiaye Zhang, Chaoqiang Yang, Zia Ur Rahman, Lan Zhang, Houzhang Tan. Combustibility and Cofiring of Coal Gasification Fine Ash with High Carbon Content in a Full-scale Pulverized Coal Furnace. Energy & Fuels. 2020; 34 (10):12972-12983.
Chicago/Turabian StyleXing Liu; Xuebin Wang; Hu Sheng; Jiaye Zhang; Chaoqiang Yang; Zia Ur Rahman; Lan Zhang; Houzhang Tan. 2020. "Combustibility and Cofiring of Coal Gasification Fine Ash with High Carbon Content in a Full-scale Pulverized Coal Furnace." Energy & Fuels 34, no. 10: 12972-12983.
The conversion of KCl to K2SO4 (potassium sulfation process) significantly affects ash deposition and corrosion in biomass-fired furnaces. The potassium sulfation has been previously estimated by a detailed gas-reaction chemistry with a simple hypothesis that potassium vapor condensed in single-step. In this study, a detailed aerosol dynamics model is proposed to replace the single-step model of potassium vapor condensation, which is coupled with the detailed gas-reaction chemistry of K-S-Cl to predict the potassium sulfation, particle size distribution, and K2SO4/KCl ratio of different particle size. The improved model shows a good consistency on the sulfation rate and aerosol formation. The comparison between the calculated and experimental results approves the non-negligible promotion of aerosol formation on KCl(g) sulfation. The sulfation and aerosol formation are calculated at varied SO2 concentrations (100-1000 ppm) with other initial compositions of 100 ppm KCl(g), 5% O2, 10% H2O, 12% CO2 and balanced N2. The modeling results show that the mass-based particle size distributions under different cases are generally unimodal. With the increase of SO2 concentration, the particle size distribution shifts toward larger scale because of the intensified conversion from KCl to K2SO4. The increase of K2SO4(g) partial pressure in flue gas advances the homogeneous nucleation at a higher temperature, consequently causing a longer time for particle growth. Furthermore, the nucleation and condensation of K2SO4(g) significantly promote the transformation from KHSO4(g) to K2SO4(g), causing an accumulation of K2SO4 in solid phase and thereby an increased sulfation rate.
Zhongfa Hu; Xuebin Wang; Houzhang Tan; Yuegui Zhou. A Coupling Study of Potassium Sulfation Chemistry and Aerosol Dynamics for a KCl/SO2/O2/H2O System. Energy & Fuels 2020, 34, 12951 -12959.
AMA StyleZhongfa Hu, Xuebin Wang, Houzhang Tan, Yuegui Zhou. A Coupling Study of Potassium Sulfation Chemistry and Aerosol Dynamics for a KCl/SO2/O2/H2O System. Energy & Fuels. 2020; 34 (10):12951-12959.
Chicago/Turabian StyleZhongfa Hu; Xuebin Wang; Houzhang Tan; Yuegui Zhou. 2020. "A Coupling Study of Potassium Sulfation Chemistry and Aerosol Dynamics for a KCl/SO2/O2/H2O System." Energy & Fuels 34, no. 10: 12951-12959.
Understanding the conversion of particulate matter (PM) in the post-combustion zone is important for controlling the emissions and ash deposition from coal combustion. In this study, the evolution of PM in the post-combustion zone of coal was investigated experimentally and numerically. The air combustion of three Zhundong lignite was performed in a drop tube furnace. PM was sampled at different flue gas temperature from 473K to 1273K. Low pressure impactor, X-ray fluorescence, scanning electron microscope, and scanning mobility particle sizer were applied to analyze mass-based particle size distribution (MPSD), elemental compositions, morphology, and number-based particle size distribution (NPSD) of PM. The results show that when the flue gas temperature decreases from 1273K to 473K, the MPSD and compositions of PM0.4-10 remain stable, while PM0.4 moves towards larger particle size. The reduction of NaCl concentration in the flue gas between 1073K and 1273K may be due to the sulfation of NaCl. The critical condensation temperature of NaCl in flue gas is between 843K and 902K. When the flue gas was sampled beyond the critical condensation temperature, NaCl vapors is converted to PM0.4 through nucleation and condensation during the cooling of the sampling system. The particle size distribution of submicron particles in the post-combustion zone is well described by an aerosol dynamics model with moment method. In the post-combustion zone of Zhundong lignite, coagulation is the dominate mechanism controlling the evolution of PM0.4 from 1273K to 473K.
Renhui Ruan; Houzhang Tan; Xuebin Wang; Zhongfa Hu. Evolution of particulate matter in the post-combustion zone of Zhundong lignite. Fuel 2020, 281, 118780 .
AMA StyleRenhui Ruan, Houzhang Tan, Xuebin Wang, Zhongfa Hu. Evolution of particulate matter in the post-combustion zone of Zhundong lignite. Fuel. 2020; 281 ():118780.
Chicago/Turabian StyleRenhui Ruan; Houzhang Tan; Xuebin Wang; Zhongfa Hu. 2020. "Evolution of particulate matter in the post-combustion zone of Zhundong lignite." Fuel 281, no. : 118780.
Usage of traditional biomass raises serious concerns regarding its sustainability due to the inefficient combustion in household stoves and potential over-usage if the intention is to replace fossil fuels in power plants. Co-pyrolysis of biomass feedstock with different waste materials, especially plastics, might be a promising alternative for sustainable usage of enhanced biofuels. Even more, co-pyrolysis can help to integrate waste management schemes into the power production sector. Plastics materials have properties similar to those of fossil fuels in terms of heating value and the absence of oxygenated compounds; therefore, they could significantly improve the properties of biomass products, especially bio-oils. Especially interesting for this method is polystyrene (PS) since it yields a high share of liquid fraction, which is the most valuable pyrolytic product. In this work, co-pyrolysis was performed for a mixture of waste biomass sawdust (oak, poplar and fir wood) and waste polystyrene from dairy product packaging. Pyrolysis was carried out for sawdust and polystyrene alone, and their respective fuel blends (PS/SD 25-75%, PS/SD 50-50%, PS/SD 75-25%) from room temperature to 600 °C with a retention time of half an hour. The highest yield of liquid fraction was noticed for mixtures with 75% of PS, while the lowest one was for blends with 25% of PS, with a yield of 83.86% and 62.33%, respectively. Additionally, the mass spectrometric analysis was carried out to determine the chemical composition of the obtained oil.
H. Stančin; M. Šafář; J. Růžičková; H. Mikulčić; H. Raclavská; X. Wang; N. Duić. Co-pyrolysis and synergistic effect analysis of biomass sawdust and polystyrene mixtures for production of high-quality bio-oils. Process Safety and Environmental Protection 2020, 145, 1 -11.
AMA StyleH. Stančin, M. Šafář, J. Růžičková, H. Mikulčić, H. Raclavská, X. Wang, N. Duić. Co-pyrolysis and synergistic effect analysis of biomass sawdust and polystyrene mixtures for production of high-quality bio-oils. Process Safety and Environmental Protection. 2020; 145 ():1-11.
Chicago/Turabian StyleH. Stančin; M. Šafář; J. Růžičková; H. Mikulčić; H. Raclavská; X. Wang; N. Duić. 2020. "Co-pyrolysis and synergistic effect analysis of biomass sawdust and polystyrene mixtures for production of high-quality bio-oils." Process Safety and Environmental Protection 145, no. : 1-11.
The fine slag produced from the entrained flow gasifier in coal chemical industry contains a high amount of unburned carbon content, which can reach more than 40%. The coal gasification fine slag is dissipated just by land filling which occupies a lot of land. Consequently, it causes the pollution of soil, water and wastes the combustible carbon in coal gasification fine slag. It is crucial to develop an environmental friendly and economical scheme for the utilization of coal gasification fine slag. To achieve this aim, it is significant to investigate the combustibility of coal gasification fine slag and then propose a comprehensive utilization technology. In this study, the physical and chemical properties of the raw bituminous coal and the produced coal gasification fine slag, including proximate and ultimate analysis, particle size distribution, ash composition, morphology, and specific area were investigated. The combustion and co-combustion characteristics of coal gasification fine slag were analyzed by a thermo-gravimetric analyzer. A drop tube furnace and a fluidized bed reactor were employed to test the combustibility of coal gasification fine slag in a pulverized furnace and a fluidized bed furnace, respectively. Results show that the carbon content in dried coal gasification fine slag is >40% with a heating value > 16 MJ kg−1. Further, thermo-gravimetric analyzer test showed that the combustion property of coal gasification fine slag is worse than that of anthracite and close to that of high ash coal, and there is a non-negligible synergistic effect for raw bituminous coal and coal gasification fine slag co-firing. The combustibility test in drop tube furnace and fluidized bed reactor showed that coal gasification fine slag can be well burned in a pulverized furnace requiring combustion temperature >900 °C and oxygen concentration >10 vol%. However, the fluidized bed furnace was not appropriate for high efficiency coal gasification fine slag burning, because the unburned carbon content of fly ash after coal gasification fine slag combustion is still >14%, even at 900 °C, 21% oxygen concentration and a low fluidization number. It is suggested that coal gasification fine slag will be better to burned it in a pulverized furnace rather than fluidized furnace.
Gaofeng Dai; Shijie Zheng; Xuebin Wang; Yonghui Bai; Yongsheng Dong; Jie Du; Xiaowei Sun; Houzhang Tan. Combustibility analysis of high-carbon fine slags from an entrained flow gasifier. Journal of Environmental Management 2020, 271, 111009 .
AMA StyleGaofeng Dai, Shijie Zheng, Xuebin Wang, Yonghui Bai, Yongsheng Dong, Jie Du, Xiaowei Sun, Houzhang Tan. Combustibility analysis of high-carbon fine slags from an entrained flow gasifier. Journal of Environmental Management. 2020; 271 ():111009.
Chicago/Turabian StyleGaofeng Dai; Shijie Zheng; Xuebin Wang; Yonghui Bai; Yongsheng Dong; Jie Du; Xiaowei Sun; Houzhang Tan. 2020. "Combustibility analysis of high-carbon fine slags from an entrained flow gasifier." Journal of Environmental Management 271, no. : 111009.
The contents of chlorine and sodium in Xinjiang Shaerhu (SEH) coal are extremely high, leading to severe slagging. In this paper, the slag was sampled from a circulating fluidized bed (CFB) boiler purely burning SEH coal, to analyze the slagging mechanism based on the characterization of morphology and composition. The results show a three-layer structure for the slag sampled from the buried heat-exchanger in the dense-phase zone of the CFB boiler. The inner layer close to the heat-exchanger is NaCl, which enhances the adhesion of ash particles, while the middle layer and the outer layer are mainly composed of Ca2Al2SiO7 and other Si–Al materials. In comparison, the slag sampled from the refractory wall shows a molten state without a layered structure and mainly composed of NaCl, NaAlSiO4, Ca2Al2SiO7, and CaSiO3. The effect of mixing bed material, on the ash melting and release of chlorine and sodium was further conducted, which indicates that the mixing of bed material has no significant effect on the release of chlorine(Cl) and sodium(Na) but highly affects the melting temperature and compositions. The ash fusion temperature reaches the lowest with a 50% mixing ratio of bed material, which is 120 °C lower than that of SEH coal ash. This study can provide better guidance for controlling severe slagging, from the combustion of high Na and Cl coal in industrial furnaces.
Jingbin Zi; Daoyang Ma; Xuebin Wang; Zia Ur Rahman; Hao Li; Shengming Liao. Slagging behavior and mechanism of high-sodium–chlorine coal combustion in a full-scale circulating fluidized bed boiler. Journal of the Energy Institute 2020, 93, 2264 -2270.
AMA StyleJingbin Zi, Daoyang Ma, Xuebin Wang, Zia Ur Rahman, Hao Li, Shengming Liao. Slagging behavior and mechanism of high-sodium–chlorine coal combustion in a full-scale circulating fluidized bed boiler. Journal of the Energy Institute. 2020; 93 (6):2264-2270.
Chicago/Turabian StyleJingbin Zi; Daoyang Ma; Xuebin Wang; Zia Ur Rahman; Hao Li; Shengming Liao. 2020. "Slagging behavior and mechanism of high-sodium–chlorine coal combustion in a full-scale circulating fluidized bed boiler." Journal of the Energy Institute 93, no. 6: 2264-2270.
Transition and decarbonization of the energy sector require the utilisation of new technologies and energy sources. Higher penetration of intermittent renewable energy sources implies the installation of energy storage, to store electricity excess and enhanced system efficiency. These electricity surpluses that will occur more often in the future energy system could be effectively utilized for the production of alternative fuels. Most of the alternative fuels that are considered for future applications are already known chemicals or products, nowadays used for other purposes. Another great advantage of some alternative fuels lies in their possibilities to act as an energy carrier. This feature might be crucial while discussing their utilisation potential and further development. Fuels which can simultaneously be used for power generation and as an energy carrier will have a more important role in the future and are likely to be utilized on a greater scale. Renewable energy source like biomass, on the other hand, is already widely used, and their role in the future system is not questionable. Even though significant increment in biomass consumption raises serious concerns about its sustainability, and seeks for new approaches. In this work, the authors tried to review alternative fuel characteristics, alongside their utilisation and production opportunities. To come up with the optimal solutions, the authors compared various proposed alternative fuels, alongside their advantages and drawbacks with an aim to find the most appropriate role for each fuel.
H. Stančin; H. Mikulčić; X. Wang; N. Duić. A review on alternative fuels in future energy system. Renewable and Sustainable Energy Reviews 2020, 128, 109927 .
AMA StyleH. Stančin, H. Mikulčić, X. Wang, N. Duić. A review on alternative fuels in future energy system. Renewable and Sustainable Energy Reviews. 2020; 128 ():109927.
Chicago/Turabian StyleH. Stančin; H. Mikulčić; X. Wang; N. Duić. 2020. "A review on alternative fuels in future energy system." Renewable and Sustainable Energy Reviews 128, no. : 109927.
The utilization of biomass energy is attracting worldwide attention due to the worsening energy crisis and the concerns on carbon dioxide emission. However, the rapidly development of biomass-fired power plants generate enormous amount of slag and ash. At present, the main treatment method of biomass slag and ash is landfill, which not only requires high cost, but also causes a series of environmental issues. Aiming at this problem, the slag and fly ash from four biomass power plants were sampled and characterized. The major/trace element composition and leaching characteristics of slag and fly ash are analyzed, and the effect of volatile mineral in these solid residues on furnace efficiency is also evaluated. The results indicate that for biomass-fired grate furnaces, in the generated solid residues, the slag accounts 60 ~ 70% while the fly ash accounts for 30 ~ 40%. The volatile elements in slag are much lower than those in fly ash, and the unburned carbon content of fly ash is generally lower than that of slag. Due to the enrichment of volatile minerals in fly ash, instead of 815 °C, 550 °C is suggested to measure the unburned carbon content in fly ash. When the measuring temperature of unburned carbon decreases from 815 °C to 550 °C, the measured energy loss from the incomplete combustion of solid fuels decreases by one third, which affords a more reasonable evaluation on combustion efficiency. The contents of cadmium and lead in certain fly ash samples exceed the standard, however, all fly ash samples have a high leaching rate of potassium but low leaching rates of copper, zinc, cadmium, lead, chromium and arsenic. It indicates that the fly ash from biomass-fired grate furnace is suitable for producing potassium fertilizer by leaching instead of direct soil fertilization or landfill. The leaching rate of most minerals in slag is much lower than that in fly ash and the contents of heavy metals are far below the prescribed upper limit in standard, which indicates that the slag from biomass-fired grate boiler is more suitable for direct use in soil improvement due to the low contents of hazardous elements.
Xuebin Wang; Yiming Zhu; Zhongfa Hu; Lan Zhang; Shunzhi Yang; Renhui Ruan; Shengjie Bai; Houzhang Tan. Characteristics of ash and slag from four biomass-fired power plants: Ash/slag ratio, unburned carbon, leaching of major and trace elements. Energy Conversion and Management 2020, 214, 112897 .
AMA StyleXuebin Wang, Yiming Zhu, Zhongfa Hu, Lan Zhang, Shunzhi Yang, Renhui Ruan, Shengjie Bai, Houzhang Tan. Characteristics of ash and slag from four biomass-fired power plants: Ash/slag ratio, unburned carbon, leaching of major and trace elements. Energy Conversion and Management. 2020; 214 ():112897.
Chicago/Turabian StyleXuebin Wang; Yiming Zhu; Zhongfa Hu; Lan Zhang; Shunzhi Yang; Renhui Ruan; Shengjie Bai; Houzhang Tan. 2020. "Characteristics of ash and slag from four biomass-fired power plants: Ash/slag ratio, unburned carbon, leaching of major and trace elements." Energy Conversion and Management 214, no. : 112897.
The high sodium and high iron contents induce severe ash deposition in pulverized coal boiler. Additive injection technology is deemed as an effective solution to solve these problems. This work is to evaluate the effect of aluminum ash on alleviating the ash deposition of high-sodium and high-iron coal. Results show that sodium vapor volatilizes, condenses and forms a viscous bottom layer, then the co-melting behavior of sodium-containing mineral and calcium aluminosilicate causes the ash deposition of high-sodium coal, and the co-melting behavior of Fe2O3 and calcium aluminosilicate causes the ash deposition of high-iron coal. When the addition ratio of aluminum ash reaches 4%, ST (softening temperature) and FT (flowing temperature) of mixed ash sample are close to and exceed 1773 K, meanwhile, slag types of ash deposit are transformed from molten slag and viscous slag to attached ash. Al2O3 and MgAl2O4 in aluminum ash can inhibit the interaction between sodium, iron and calcium aluminosilicate, making the particles less sticky. The optimum temperature of aluminum ash for sodium capture is 823 K. Aluminum ash has a better sodium capture ability for high-sodium coal than high-iron coal. Based on the above analysis, this work also provides the blending strategies of additives due to the different ash deposition mechanisms of coal.
Shangkun Zhou; Meng Wang; Houzhang Tan; Xuebin Wang; Wenjun Yang; Xiaohe Xiong; Fuxin Yang. Evaluation of aluminum ash in alleviating the ash deposition of high-sodium and high-iron coal. Fuel 2020, 273, 117701 .
AMA StyleShangkun Zhou, Meng Wang, Houzhang Tan, Xuebin Wang, Wenjun Yang, Xiaohe Xiong, Fuxin Yang. Evaluation of aluminum ash in alleviating the ash deposition of high-sodium and high-iron coal. Fuel. 2020; 273 ():117701.
Chicago/Turabian StyleShangkun Zhou; Meng Wang; Houzhang Tan; Xuebin Wang; Wenjun Yang; Xiaohe Xiong; Fuxin Yang. 2020. "Evaluation of aluminum ash in alleviating the ash deposition of high-sodium and high-iron coal." Fuel 273, no. : 117701.
Sulfur trioxide (SO3) is not only environmentally harmful but also highly corrosive, taking a great threat to the safe operation of coal-fired power plants. A dominant pathway of SO3 formation in coal-fired power plant is through the catalytic oxidation of SO2 (SO2+1/2O2→SO3) on the surfaces of ash particles containing Fe2O3. The catalytic formation of SO3 could be affected by complex atmosphere, where the effect from H2O is still debatable. In this paper, density functional theory (DFT) is employed to explore the reaction pathway of SO3 formation catalyzed by α-Fe2O3 in complex atmosphere containing O, O2, SO2 and H2O. In order to get the stable adsorption sites of these species, the adsorption energy of potential adsorption configurations on the α-Fe2O3 (001) surface is calculated. The dissociations of O2 molecule on complete and defect α-Fe2O3 (001) surfaces with O vacancy are calculated, and the Langmuir-Hinshelwood and Eley-Rideal mechanisms for the O(ads) reaction with SO2(ads) or SO2 are compared. The effect of H2O besides of SO2 and O2 on the formation of SO3 is especially discussed. The DFT calculation results show that for the formation of SO3 in gas phase, the energy barrier of ‘SO2+1/2O2→SO3’ is 436.75 kJ mol−1, in contrast, for the catalytic formation of SO3 on α-Fe2O3 surfaces, this energy barrier becomes an order of magnitude smaller, 24.82 kJ mol−1. O2 molecules can dissociate on the defect α-Fe2O3 (001) surface with O vacancy spontaneously, indicating that the defect α-Fe2O3 is favorable for the dissociation of O2, thereby promotes the formation of SO3. The energy barrier of ‘SO2(ads)+O(ads)→SO3(ads)’ through Langmuir-Hinshelwood mechanism is much higher than that of ‘SO2+O(ads)→SO3(ads)’ through Eley-Rideal mechanism. The adsorption energy on the α-Fe2O3 (001) surface of H2O is much smaller than that of SO2 and O2, indicating that H2O has little effect on the adsorption of O, O2, SO2 and eventually the heterogeneous formation of SO3. The DFT analysis results in this study provide a deep understanding on the reaction pathway of SO3 catalytic formation by Fe2O3.
Gaofeng Dai; Xuebin Wang; Hongjun You; Yongbing Wang; Zhiliang Shan; Houzhang Tan. Catalytic function of ferric oxide and effect of water on the formation of sulfur trioxide. Journal of Environmental Management 2020, 264, 110499 .
AMA StyleGaofeng Dai, Xuebin Wang, Hongjun You, Yongbing Wang, Zhiliang Shan, Houzhang Tan. Catalytic function of ferric oxide and effect of water on the formation of sulfur trioxide. Journal of Environmental Management. 2020; 264 ():110499.
Chicago/Turabian StyleGaofeng Dai; Xuebin Wang; Hongjun You; Yongbing Wang; Zhiliang Shan; Houzhang Tan. 2020. "Catalytic function of ferric oxide and effect of water on the formation of sulfur trioxide." Journal of Environmental Management 264, no. : 110499.