scholarly journals A comprehensive model of NOx and SO2 emissions from advanced coal combustion in a complex geometry CLC equipment

2021 ◽  
Vol 323 ◽  
pp. 00019
Author(s):  
Jaroslaw Krzywanski ◽  
Tomasz Czakiert ◽  
Anna Zylka ◽  
Kamil Idziak ◽  
Karol Sztekler ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Coal Combustion ◽  
Complex Geometry ◽  
Solid Fuels ◽  
Comprehensive Model ◽  
So2 Emissions ◽  
Fuel Reactor

The paper describes experiences in the modeling of complex geometry CLC equipment. The facility consists of two reactors: the air reactor and the fuel reactor. The fuzzy logic (FL) methods are used in the study for the prediction of NOx and SO2 from the solid fuels combustion in CLC equipment. Maximum errors between measured and predicted results are lower than 10 %.

scholarly journals Modern cyclone burners for the increase of operational flexibility of pulverized-fuel boilers

Mechanik ◽  
2017 ◽  
Vol 90 (2) ◽  
pp. 137-139
Author(s):  
Robert Zarzycki ◽  
Rafał Kobyłecki ◽  
Zbigniew Bis
Keyword(s):  
Power Generation ◽  
Coal Combustion ◽  
Solid Fuels ◽  
Operational Flexibility ◽  
Generation System ◽  
Thermal Output ◽  
Pulverized Fuel ◽  
Power Generation System ◽  
Burner Design ◽  
By Products

In this paper, the concept, as well as a model pilot cyclone burner are presented and discussed in order to provide a solution for both combustion and gasification of solid fuels (e.g. pulverized coal). The burner design allows to operate it as a separate structure or a part of an existing pulverized-fuel boiler. In the latter case, the cyclone burner increases the flexibility and dynamics of the power generation system, as well as boiler thermal output. The burner also provides the conditions for the reduction of boiler technological minimum without the necessity to ignite boiler startup burners, and also enables the realization of treatment and processing (e.g. the vitrification) of coal combustion by-products. The proposed solution can also become an interesting technological option aimed at the retrofitting and modernization of old 200 MW PC-based power generation facilities within the Framework Program “Power 200+. Revitalization and restoration of power on the basis of 200 MW power units”.

scholarly journals Variations of China's emission estimates: response to uncertainties in energy statistics

2017 ◽  
Vol 17 (2) ◽  
pp. 1227-1239 ◽  
Author(s):  
Chaopeng Hong ◽  
Qiang Zhang ◽  
Kebin He ◽  
Dabo Guan ◽  
Meng Li ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Coal Combustion ◽  
Emission Inventory ◽  
Mean Value ◽  
Data Sets ◽  
So2 Emissions ◽  
The Mean ◽  
Global Emissions ◽  
Official Data ◽  
Maximum Discrepancy

Abstract. The accuracy of China's energy statistics is of great concern because it contributes greatly to the uncertainties in estimates of global emissions. This study attempts to improve the understanding of uncertainties in China's energy statistics and evaluate their impacts on China's emissions during the period of 1990–2013. We employed the Multi-resolution Emission Inventory for China (MEIC) model to calculate China's emissions based on different official data sets of energy statistics using the same emission factors. We found that the apparent uncertainties (maximum discrepancy) in China's energy consumption increased from 2004 to 2012, reaching a maximum of 646 Mtce (million tons of coal equivalent) in 2011 and that coal dominated these uncertainties. The discrepancies between the national and provincial energy statistics were reduced after the three economic censuses conducted during this period, and converging uncertainties were found in 2013. The emissions calculated from the provincial energy statistics are generally higher than those calculated from the national energy statistics, and the apparent uncertainty ratio (the ratio of the maximum discrepancy to the mean value) owing to energy uncertainties in 2012 took values of 30.0, 16.4, 7.7, 9.2 and 15.6 %, for SO2, NOx, VOC, PM2.5 and CO2 emissions, respectively. SO2 emissions are most sensitive to energy uncertainties because of the high contributions from industrial coal combustion. The calculated emission trends are also greatly affected by energy uncertainties – from 1996 to 2012, CO2 and NOx emissions, respectively, increased by 191 and 197 % according to the provincial energy statistics but by only 145 and 139 % as determined from the original national energy statistics. The energy-induced emission uncertainties for some species such as SO2 and NOx are comparable to total uncertainties of emissions as estimated by previous studies, indicating variations in energy consumption could be an important source of China's emission uncertainties.

Effect of Blast Furnace Sludge on SO2 Emissions from Coal Combustion

2016 ◽  
Vol 30 (4) ◽  
pp. 3320-3330 ◽  
Author(s):  
Zhifang Gao ◽  
Zhaojin Wu ◽  
Mingdong Zheng
Keyword(s):  
Blast Furnace ◽  
Coal Combustion ◽  
So2 Emissions ◽  
Blast Furnace Sludge

scholarly journals Biobriquettes-an Alternative Fuel for Sustainable Development

1970 ◽  
Vol 10 ◽  
pp. 121-127 ◽  
Author(s):  
Ramesh Man Singh ◽  
Hee Joon Kim ◽  
Mitsushi Kamide ◽  
Toran Sharma
Keyword(s):  
Mechanical Properties ◽  
Coal Combustion ◽  
Alternative Fuel ◽  
Biomass Combustion ◽  
Waste Biomass ◽  
So2 Emissions ◽  
Fuel Wood ◽  
Combustion Properties ◽  
Composite Fuel ◽  
And Storage

Raw coal is still burnt as fuel in many developing countries. These also have a lot of waste biomass, which finds limited use or used inefficiently. Besides pollution from coal and biomass combustion, they always face problems during transportation and storage because they are susceptible to moisture. Biobriquettes are composite fuel prepared from a mixture of biomass and coal in a roller press briquetting machine. They consist of different proportions of biomass (up to 30%) and coal or lignite (up to 70%). Introduction of lime based desulfurizing agents (DSA) such as CaCO3 and Ca (OH)2 into the briquettes can reduce the SO2 emissions by 80-90%, thus minimizing the pollution coming from coal combustion. Some fuel and combustion properties of these briquettes were studied. The briquette fuels have better physico-mechanical properties and combustion properties in comparison to coal/lignite. The ignition temperatures of biobriquettes are lower than coal or lignite, whereas the calorific values are greater than biomass. Hence, the biobriquettes can be used as an alternative fuel to fuel wood, coal and lignite in the kilns, boilers, combustors and for cooking as well.Key words: Coal; Biomass; Biobriquettes; Desulfurizing agents; Ignition temperatureDOI: 10.3126/njst.v10i0.2944 Nepal Journal of Science and Technology Vol. 10, 2009 Page: 121-127

Numerical Simulations of Biomass Co-Firing in a Fluidized Bed Combustor

2004 ◽  
Author(s):  
R. Sreenivasa ◽  
K. Aung
Keyword(s):  
Fluidized Bed ◽  
Coal Combustion ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Solid Fuels ◽  
System Efficiency ◽  
Fuel Flexibility ◽  
Attractive Option ◽  
High System ◽  
Fluidized Bed Combustor

Fluidized bed technology is an established technology for energy generation due to low operating temperatures, high system efficiency, fuel flexibility, and easier control of pollutants such as NOx and SO. Co-firing of biomass is an attractive option for power generation as it increases use of renewable and waste materials, thereby replacing the conventional coal. This paper investigated biomass co-firing in a fluidized bed using two models. The first model is based on the recent study on the high-volatile solid fuels in a fluidized bed. The first model considered the fluidized bed combustor as three distinct zones: bed zone, splashing zone, and freeboard zone, and took into account material balances in each zone. In addition, sub-models for estimating the pollutants such as NOx and SO were also included in the model. The second model was based on the coal combustion in a fluidized bed. The second model only considered bed and freeboard zones in a fluidized bed. The model for pollutant emissions was also included in the second model. The predictions of both models included char loading in the bed, combustion efficiency, and pollutant emissions. Predictions of both models were compared with the available experimental data to validate the models. The results of the study suggest that current coal models may be appropriate to apply for biomass co-firing in fluidized coal combustors as long as the biomass co-firing is limited to not more than 30% of the total fuel.

Thermo-fluid-mechanical numerical simulations of surface subsidence at the site of underground coal gasification

2021 ◽  
pp. qjegh2020-106
Author(s):  
Yury Derbin ◽  
James Walker ◽  
Liphapang Khaba
Keyword(s):  
Coal Combustion ◽  
Coal Gasification ◽  
Complex Geometry ◽  
Surface Subsidence ◽  
Three Dimensions ◽  
Successful Implementation ◽  
Underground Coal Gasification ◽  
Model Surface ◽  
Fluid Analysis ◽  
Upper Aquifer

This work deals with modelling surface subsidence that aims to help industrialize Underground Coal Gasification (UCG). UCG is a long-known, but poorly industrialized method of energy extraction from coal. Risks of surface subsidence and groundwater pollution are two main hurdles that are affecting the potential industrialization of UCG. The particular challenge is the existence of groundwater because of implications to both its pollution and its influence on surface subsidence. Additionally, the coal combustion and the complex geometry of the UCG reactors impacts surface subsidence. To meet these challenges, the thermal and fluid analyses should be included in the model and surface subsidence should be modelled in three dimensions to capture the collapsed shape of the UCG reactor. Based on nature of these challenges and an earlier successful implementation, the commercial software FLAC3D by Itasca with the intrinsic thermal and fluid models is chosen to model surface subsidence.This study discovers that the inclusion of fluid analysis improves the predictions of surface subsidence when compared with measurements at the highly watered Shatsk UCG site. In turn, thermal analysis mildly influences the modelled surface subsidence. The fluid analysis shows that the flow in the upper aquifer influences surface subsidence more greatly than the flow in the lower aquifers. High temperature causes an upward flow in the lower aquifer located above the UCG reactor, but does not change the flow pattern in the upper aquifer. The fluid analysis also reveals that if the UCG reactor is filled with water, the surface subsidence does not occur.

scholarly journals Variations of China's emission estimates response to uncertainties in energy statistics

2016 ◽  
Author(s):  
Chaopeng Hong ◽  
Qiang Zhang ◽  
Kebin He ◽  
Dabo Guan ◽  
Meng Li ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
Coal Combustion ◽  
Emission Inventory ◽  
Mean Value ◽  
Nox Emissions ◽  
So2 Emissions ◽  
The Mean ◽  
Global Emissions ◽  
Maximum Discrepancy

Abstract. The accuracy of China's energy statistics is of great concern because it contributes greatly to the uncertainties in estimates of global emissions. This study attempts to improve the understanding of uncertainties in China's energy statistics and evaluate their impacts on China's emissions during the period of 1990–2013. We employed the Multi-resolution Emission Inventory for China (MEIC) model to calculate China's emissions based on different official datasets of energy statistics using the same emission factors. We found that the apparent uncertainties (maximum discrepancy) in China's energy consumption increased from 2004 to 2012, reaching a maximum of 646 Mtce (million tons of coal equivalent) in 2011, and that coal dominated these uncertainties. The discrepancies between the national and provincial energy statistics were reduced after the three economic censuses conducted during this period, and converging uncertainties were found in 2013. The emissions calculated from the provincial energy statistics are generally higher than those calculated from the national energy statistics, and the apparent uncertainty ratio (the ratio of the maximum discrepancy to the mean value) owing to energy uncertainties in 2012 took values of 30.0 %, 16.4 %, 7.7 %, 9.2 % and 15.6 %, for SO2, NOx, VOC, PM2.5 and CO2 emissions, respectively. SO2 emissions are most sensitive to energy uncertainties because of the high contributions from industrial coal combustion. The calculated emission trends are also greatly affected by energy uncertainties – from 1996 to 2012, CO2 and NOx emissions, respectively, increased by 191 % and 197 % according to the provincial energy statistics but by only 145 % and 139 % as determined from the original national energy statistics. The energy-induced emission uncertainties for some species such as SO2 and NOx are comparable to total uncertainties of emissions as estimated by previous studies, indicating variations at energy consumption could be an important source of China's emission uncertainties.

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