Effects of Bio-Syngas Blends on Combustion Characteristics of Coal: Kinetic Analysis

2021 ◽  
Vol 15 (3) ◽  
pp. 269-277
Author(s):  
Ailing He ◽  
Zaifeng Li ◽  
Jingping Li ◽  
Xin Wang ◽  
Liya Zhang ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Combustion Mechanism ◽  
Exponential Factor ◽  
Maximum Reaction Rate ◽  
Heating Value ◽  
Renewable Biomass ◽  
Reasonable Description

The coupled combustion of biomass and coal can utilize large amounts of renewable biomass and reduce the emission of pollutants during power generation. In this study, the coal combustion characteristics were analyzed at different heating value-based biomass blending ratios and temperatures in the coupled combustion of bio-syngas and coal. The kinetic reaction mechanism of coal combustion was investigated by Micro-fluidized Bed Reaction Analyzer (MFBRA). The results indicated that the reaction time decreased with increasing the heating value-based biomass blending ratio and temperature in the coupled combustion process of bio-syngas and coal. The major conversion process of coal combustion usually took 15 s at 1273 K and the maximum reaction rate was usually below 0.14 at 873 K to 1273 K and decreased with increasing reaction temperature. The nucleation and growth model offered a most reasonable description of the coal combustion process. The activation energy was about 121.04 kJ/mol and the pre-exponential factor was of the order of 5.01 × 104 s−1 in the combustion of coal. These data are important to the understanding of the coupled combustion mechanism of bio-syngas and coal, which is beneficial for improving combustion efficiency as well as operating a combustion furnace.

Impacts of the Heating Value and CO/H2 Ratio on Syngas Diffusion Flame Structure

2012 ◽  
Author(s):  
Chong Feng ◽  
Haiying Qi ◽  
Junzong Zhu ◽  
Dapeng Bi
Keyword(s):  
Flame Structure ◽  
Initial Pressure ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Normal Operation ◽  
Diffusion Combustion ◽  
Heating Value ◽  
No Formation ◽  
Two Factors ◽  
Wobbe Index

Syngas with CO/H2/N2 as the primary ingredients is the main fuel for the gas turbine in the IGCC system, but changes of the heating value and CO/H2 ratio frequently cause great impacts on the normal operation of the combustor, which is a challenge to the design of the syngas combustor. In this paper based on the Sandia/ETH-Zurich CO/H2/N2. Flame A, numerical simulations and predictions of the impacts of these two factors on the flame structure and diffusion combustion characteristics are carried out, and the main results are as follows. The heating value and CO/H2 ratio both have important impacts on the diffusion combustion characteristics. Most of the impacts have regularity such as changes of the axis velocity and temperature distribution, the highest temperature of the whole temperature field, the combustion efficiency and the NO formation with the heating value and CO/H2 ratio. However, the most important one is that the relationship between the flame size and the Wobbe Index is linear, for it has established connections between the structure size of the combustor and the characteristics of the fuel and the linear relationship can be used to provide reference for the combustor design. So the Wobbe Index is not only an important parameter to judge whether different fuels can be exchanged or not under the same initial pressure and heat load of a combustion equipment, but also an important parameter for syngas combustor design.

Study of Combustion Characteristics of Ethanol at Different Dilution With the Carrier Gas

2014 ◽  
Author(s):  
Binash Imteyaz ◽  
Mohamed A. Habib
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Carbon Capture ◽  
Liquid Fuel ◽  
Flame Temperature ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Conventional Combustion ◽  
Gas Volume

With the ever rising concern of global warming, carbon capture is gaining the reputation of one of the most challenging fields of research. A very promising technology to capture CO2 is oxy-combustion. Oxy-combustion offers several advantages over conventional combustion technologies, such as flue gas volume reduction, high combustion efficiency, low fuel consumption and significant reduction in NOx emissions. Liquid fuel is available and it is the most widely used source of energy in the world. Easy handling and transportation, less storage volume and higher flame temperature are some of the features of liquid fuel which give it an upper hand over other sources. In this study, an experimental work on oxygen enriched combustion of ethanol in a vertical reactor by Lacas F. et. al. has been modeled numerically. Non-premixed model using Probability Density Function has been incorporated to simulate the combustion process of ethanol droplets. Predicted combustion characteristics are found to be in good compliance with the experimental data. In addition to this, effects of dilution of carbon-dioxide in oxygen on the flame properties have also been presented. Combustion of ethanol in oxygen-carbon dioxide environment has been compared with that of the conventional air environment.

Study of Combustion Characteristics of Ethanol at Different Dilution With the Carrier Gas

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Binash Imteyaz ◽  
Mohamed A. Habib
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Carbon Capture ◽  
Liquid Fuel ◽  
Flame Temperature ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Gas Volume ◽  
Probability Density Function Pdf

With the ever-rising concern of global warming, carbon capture is gaining the reputation of one of the most challenging fields of research. A very promising technology to capture CO2 is oxy-combustion. Oxy-combustion offers several advantages over conventional combustion technologies, such as flue–gas volume reduction, high combustion efficiency, low fuel consumption, and significant reduction in NOx emissions. Liquid fuel is available and it is the most widely used source of energy in the world. Easy handling and transporting, less storage volume and higher flame temperature are some of the features of liquid fuel which give it an upper hand over other sources. In this study, an experimental work on oxygen enriched combustion of ethanol in a vertical reactor by Lacas et al. (2005, “Experimental Study of Air Dilution in Oxy-Liquid Fuel Flames,” Proc. Combust. Inst., 30(2), pp. 2037–2045) has been modeled numerically. Nonpremixed model using probability density function (PDF) has been incorporated to simulate the combustion process of ethanol droplets. Predicted combustion characteristics are found to be in good compliance with the experimental data. In addition to this, effects of dilution of carbon dioxide in oxygen on the flame properties have also been presented. Combustion of ethanol in oxygen–carbon dioxide environment has been compared with that of the conventional air environment.

Experimental Study on the Combustion Characteristics of Municipal Solid Waste

2011 ◽  
Vol 204-210 ◽  
pp. 1351-1356 ◽  
Author(s):  
Yong Hua Li
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Combustion Process ◽  
High Water ◽  
Combustion Characteristics ◽  
High Water Content ◽  
Element Analysis ◽  
Ignition Point ◽  
Heating Value ◽  
Two Stages

In China, municipal solid waste (MSW) of low heating value and high water content are always burnt in their original forms. Based on the constituent of Shijiazhuang City’s MSW, nine typical constituent of wastes were blended as actual MSW. In this paper, MSW were chosen to carry out element analysis, industrial analysis and thermogravimetric analysis. Analysis combustion characteristics of MSW and the mixture of MSW and coal adopt WCT-2 High Temperature Computer Differential Thermal Balance. The kinetic parameters of MSW and the mixture of MSW and coal were obtained through the law of Arrhenius and the thermogravimentric curve. The final result indicates that ignition point and activation energy of MSW are obviously lower than those of the coal, and the ignition point of the mixture of MSW and coal are not high. It can be combusted completely below 850°C. And the combustion process of MSW or the mixture of MSW and coal can be separate into two stages, the first stage is water in the MSW evaporated, the second stage is combustion of combustible. There are four stage of weightlessness in the combustion of combustible, it shows that there are influence between each constituent of MSW. All this will offer help for incineration MSW of low-heating-valued.

scholarly journals Numerical Investigation on Coal Combustion in Ultralow CO2 Blast Furnace: Effect of Oxygen Temperature

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 877 ◽  
Author(s):  
Zhenfeng Zhou ◽  
Qiujie Yi ◽  
Ruihao Wang ◽  
Guang Wang ◽  
Chunyuan Ma
Keyword(s):  
Coal Combustion ◽  
Room Temperature ◽  
Combustion Process ◽  
Three Dimensional ◽  
Cooling Effect ◽  
Combustion Mechanism ◽  
Three Dimensional Model ◽  
Combustion Technology ◽  
Top Gas Recycling ◽  
Effect Of Oxygen

The cooling effect of room-temperature oxygen in oxygen blast furnaces with top gas recycling (TGR-OBF) delays the coal combustion process. To further explore the oxygen–coal combustion mechanism and intensify coal combustion in TGR-OBF, the effect of oxygen temperature on coal combustion was investigated using computational fluid dynamics (CFD). A three-dimensional model was developed to simulate the lance–blowpipe–tuyere–raceway of TGR-OBF. The effect of oxygen temperature at the same oxygen velocity and mass flow on coal combustion was investigated. Results showed the cooling effect of room-temperature oxygen was weakened, and the coal burnout was greatly increased with the increase in oxygen temperature. In particular, the coal burnout increased from 21.64% to 81.98% at the same oxygen velocity when the oxygen temperature increased from 300 to 500 K. The results provide useful reference for the development of TGR-OBF and coal combustion technology.

Effects of mustard husk, wheat straw and flaxseed residue blending on combustion behavior of high ash coal and petroleum coke blends

2022 ◽  
pp. 1-22
Author(s):  
Pritam Kumar ◽  
Barun Kumar Nandi
Keyword(s):  
Wheat Straw ◽  
Thermodynamic Parameters ◽  
Petroleum Coke ◽  
Coal Combustion ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Combustion Behavior ◽  
Combustion Properties ◽  
The Impact

Abstract This present work reports the combustion studies of coal, petroleum coke (PC) and biomass blends to assess the effects of the mustard husk (MH), wheat straw (WS) and flaxseed residue (FR) blending towards improvement of coal combustion characteristics. Ignition temperature (TS), maximum temperature (TP), burnout temperature (TC), activation energy (AE) and thermodynamic parameters (ΔH, ΔG and ΔS) were analyzed to evaluate the impact of biomass and PC blending on coal combustion. Experimental results indicate that coal and PC have inferior combustion characteristics compared to MH, WS and FR. With the increase in WS content in blends from 10 to 30%, TS reduced from 371 to 258OC, TP decreased from 487 to 481OC, inferring substantial enhancements in combustion properties. Kinetic analysis inferred that blended fuel combustion could be explained mostly using reaction models, followed by diffusion-controlled and contracting sphere models. Overall, with the increase in FR mass in blends from 10 to 30%, AE decreased from 108.97 kJ/mol to 70.15 kJ/mol signifying ease of combustion. Analysis of synergistic effects infers that higher biomass addition improves coal and PC blends' combustion behavior through catalytic effects of alkali mineral matters present in biomass. Calculation of thermodynamic parameters signified that combustion of coal and PC is challenging than biomasses, however, blending of biomass makes the combustion process easier.

Experimental Study on Oxygen-Enriched Combustion Characteristics of Pure Cotton

2013 ◽  
Vol 724-725 ◽  
pp. 253-256
Author(s):  
Hai Yu Meng ◽  
Shu Zhong Wang ◽  
Lin Chen ◽  
Jun Zhao ◽  
Zhi Qiang Wu
Keyword(s):  
Oxygen Concentration ◽  
Compensation Effect ◽  
Combustion Process ◽  
Energy Resource ◽  
Combustion Characteristics ◽  
Experimental Results ◽  
Exponential Factor ◽  
Combustion Phase ◽  
Carbon Combustion ◽  
Two Phases

This paper describes the oxygen-enriched combustion characteristics of pure cotton from municipal solid waste applying the non-isothermal thermogravimetric analysis, the apparent activation energy and the pre-exponential factor of oxygen-enriched combustion were obtained by kinetic analysis. Experimental results show that the pure cotton combustion process consists of two phases, which are volatile release and combustion phase and fixed carbon combustion phase. It has been found that combustion performance of pure cotton is improved when oxygen concentration increases to certain value and compensation effect exists in pure cotton combustion with the variation of oxygen concentration. The experimental results can provide direction for disposal of pure cotton as an energy resource.

EFFECT OF METALLIC FUEL NATURE ON COMBUSTION CHARACTERISTICS OF AMMONIUM PERCHLORATE / BINDER / METAL COMPOSITE SOLID PROPELLANTS

2020 ◽  
Author(s):  
V. A. Poryazov ◽  
◽  
O. G. Glotov ◽  
V. A. Arkhipov ◽  
G. S. Surodin ◽  
...  
Keyword(s):  
Ammonium Perchlorate ◽  
Combustion Process ◽  
Experimental Information ◽  
Combustion Characteristics ◽  
Transformer Oil ◽  
Metal Composite ◽  
Butadiene Rubber ◽  
Solid Propellants ◽  
Metallic Fuel ◽  
Composite Solid Propellants

The goal of this research is to obtain experimental information about combustion characteristics of the composite propellant containing various metallic fuels. The propellant formulations contained two fractions of ammonium perchlorate (64.6%), inert binder (19.7%) - butadiene rubber SKD plastized with transformer oil, and metal fuel (15.7% of aluminum ASD-4, ASD-6, Alex; boron; aluminum diboride; aluminum dodecaboride; some mixtures of above listed ingredients). Experimental information will be used further as a background to develop the physical and mathematical model of combustion process.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li
Keyword(s):  
Combustion Chamber ◽  
Combustion Temperature ◽  
Combustion Efficiency ◽  
Middle Part ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Excess Air ◽  
Element Simulation ◽  
Excess Air Coefficient ◽  
Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

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