scholarly journals Utilization of Refuse Derived Fuel for Energy Recovery Processes: Prediction of Environmental Emissions and Thermal Behaviour in Combustion Processes

Author(s):  
Deepak Kumar Singhal ◽  
Divya Gupta ◽  
Anurag Garg

Abstract In the present study, the environmental emissions from co-combustion of refuse derived fuel (RDF) in cement plants and coal-fired power plants are predicted using mass and energy flow modeling. Mumbai was considered as study area and RDF characteristics were assessed using MSW composition in Mumbai. The modeling results suggested that with increase in RDF share in fuel mixture, significant reduction in environmental parameters such as winter smog, global warming and acidification potentials could be achieved, though the electricity and heat generation were reduced. This problem can be overcome by improving the quality of RDF. Moreover, thermal gravimetric analysis (TGA) of individual RDF components (compostable organic matter, paper, wood and plastic) was carried out in oxidative environment to understand their thermal stability. Average activation energies for plastic, wood and compostable organics (98.6–183 kJ/mol) were comparable to those reported for coal. The results suggest that coal and RDF co-combustion should not affect the combustion profile. Moreover, high plastic content in RDF can assist in control of combustion process and also can enhance its calorific value.

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.


2012 ◽  
Vol 512-515 ◽  
pp. 1106-1112
Author(s):  
Da Wei Hu ◽  
Yan Min Wang ◽  
Ai Zhi Yu

Coal as the world's most widely used fossil fuels, during the combustion process large amounts of greenhouse gas emission, which has a huge impact on global climate warming. However, coal is a nonrenewable resource, and the energy conservation is imperative. This paper, through analyzed the essential of coal combustion, and the feasibility and means for coal saving by using chemical intervention combustion. After tested the practical effects of chemical intervention coal combustion catalyst, which provided by Guangzhou Fenfang Environmental Protection Technology Co., Ltd. The results shown, the as received basis net calorific value at constant volume of the selected coal sample improved 8% which was tested by an oxygen bomb calorimeter, almost 1/6 sulfur was fixed in the cinder and the practical application coal saving effects in new dry rotary kilns and thermal power plants were more than 6%. Therefore, the chemical intervention combustion method has important significance in research and practical for coal saving and reducing emissions of pollutants.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1779
Author(s):  
Rafał Ślefarski ◽  
Joanna Jójka ◽  
Paweł Czyżewski ◽  
Michał Gołębiewski ◽  
Radosław Jankowski ◽  
...  

There has been a gradual increase in the field of parts recovery from cars that are withdrawn from use. However, the disposal of automotive shredder residue (ASR) still remains a significant problem. ASR is refuse derived fuel (RDF), which contains mainly plastics, fiber sponges, and rubbers in different proportions, and therefore a thermal treatment of selected waste samples is applied. The presented research includes thermogravimetry (TG) analysis and differential thermogravimetric (DTG) analysis, as well as a proximate and an ultimate analysis of the ASR samples. The obtained results were processed and used as an input for modelling. The numerical calculations focused on the identification of the ASR’s average composition, the raw pyrolysis process product, its dry pyrolytic gas composition, and the combustible properties of the pyrolytic gases. The TGA analysis with three heating rate levels covered the temperature range from ambient to 800 °C. The thermal decomposition of the studied samples was in three stages confirmed with three peaks observed at the temperatures 280, 470, and 670 °C. The amount of solid residue grew with the heating rates and was in the range of 27–32 wt%. The numerical calculation of the pyrolysis process showed that only 0.46 kg of dry gas were formed from 1 kg of ASR. The gas yield increased with the rising temperature, and, at the same time, its calorific value decreased from 19.22 down to 14.16 MJ/m3. This is due to the decomposition of C6+ hydrocarbons and the promotion of CO formation. The thermodynamic parameters of the combustion process for a pyrolytic gas air mixture, such as the adiabatic flame temperature and laminar flame speed, were higher than for methane and were, respectively, 2073 °C and 1.02 m/s.


2020 ◽  
Vol 7 (4) ◽  
pp. 766-777
Author(s):  
Subhajit Aich ◽  
Dibyajyoti Behera ◽  
Barun Kumar Nandi ◽  
Sumantra Bhattacharya

AbstractThis work presents the analysis of combustion characteristics of high ash Indian coal (28%–40%) collected from different mines of Singaurali coalfield, India. All the coal samples were characterized by proximate and gross calorific value analysis. Combustion performance of the coals were characterised using thermo-gravimetric analysis to identify the burning profile of individual coals. Various combustion kinetic parameters such as ignition temperature, peak temperature and burnout temperature, ignition index and burnout index, combustion performance index plus rate and intensity index of combustion process, activation energy were determined to analyse the combustion behaviour of coal. Further all these combustion properties were compared with the volatile matter, ash, fixed carbon and fuel ratio of each coal. Theoretical analysis shows that with increase in ash content, combustion performance initially increases and later descends. Further, coal with (25 ± 1.75)% volatile matter, 20%–35% ash and fuel ratio 1.4–1.5 were found to be optimum for coal combustion.


2018 ◽  
Vol 240 ◽  
pp. 05013
Author(s):  
Piotr Krawczyk ◽  
Krzysztof Badyda ◽  
Aleksandra Mikołajczak

Legal regulations on waste disposal require waste producers to limit landfilling and to find different ways of waste management, the preferred methods being recycling of material and energy potential. Currently, in Poland, the only consumers of refuse-derived fuels (RDF) are cement plants. However, their ability to utilize alternative fuel is far from the estimated potential. One solution would be to redirect the excess fuel to power and heat production facilities. Unfortunately, these sectors are facing a number of problems related to the thermal treatment of waste, mainly formal nature. Co-combustion of waste in power plants raises a lot of concern among their employees and local communities. Especially significant is the harmfulness of usage of fuel from waste for the people’s lives or health, or the environment. The article compares the environmental footprints of the combustion process of: waste - based fuel (RDF) and lignite. The analysis was performed for a standard pulverized coal fired boiler. Comparative assessment was made by analyzing the total environmental impact of all combustion products of the two fuels. Final results have shown, that the environmental footprint of waste-based fuels can be similar or even smaller than traditional coal-based fuels


Author(s):  
A. P. Shaikin ◽  
I. R. Galiev

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.


Author(s):  
O. M. Salamov ◽  
F. F. Aliyev

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.


2013 ◽  
Vol 856 ◽  
pp. 338-342 ◽  
Author(s):  
Chin Yee Sing ◽  
Mohd Shiraz Aris

Burning fossil fuel like coal in power plants released carbon dioxide that had been absorbed millions of years ago. Unfortunately, excessive carbon dioxide emission had led to global warming. Malaysia, as one of the major exporters of palm oil, has abundant oil palm mill residues that could be converted into value-added product like biomass fuel briquettes. Fuel briquette with palm kernel shell and palm mesocarp fibre as its main ingredients showed satisfactory fuel characteristics and mechanical properties as a pure biomass fuel briquette. The effects of adding some coal of higher calorific value to the satisfactory biomass fuel briquette were focused in this study. Various coal-biomass fuel blends were used, ranging from 0wt% coal to 50wt% coal. The fuel properties and mechanical properties of pure biomass briquette and briquettes with different amount of coal added were compared experimentally. From the fuel properties tests, it was found that as the coal content in the briquette was increased, the carbon content and calorific value increased. Mechanical property tests on the fuel briquettes showed a mixture of results, with some favored higher portion of coal in the briquette for better handling, transport and storage properties while some favored greater amount of biomass.


Author(s):  
O.V. Guskov ◽  
V.S. Zakharov ◽  
Minko

The development and research of high-speed aircrafts and their individual parts is an urgent scientific task. In the scientific literature there is information about the integral characteristics of aircrafts of this type, but there is no detailed consideration of such an important part as the transition channel between the air intake and the combustion chamber. The article considers several flow path configurations. The numerical simulation results of hydrogen combustion in the channels of variable cross section using a detailed kinetic mechanism are presented. Based on the analysis of the data obtained, the models of the transition channel and the combustion chamber showing the best characteristics were selected. The impulse and the fuel combustion efficiency are used as criteria for comparing the flow paths. The difference in the application of two calculation methods is described. The presented results and calculation methods can be used at the stage of computational research of the working processes in advanced power plants.


Author(s):  
Christopher Y. H. Chao ◽  
Philip C. W. Kwong ◽  
J. H. Wang

In many Asian countries Coal is frequently used a major fuel in power plants. Burning coal creates quite a lot of environmental problems when compared to other cleaner fuels such as natural gas. Experimental study of co-combustion of coal and biomass was conducted in a laboratory scale combustion facility to evaluate the combustion and pollutant emission performance under different operation parameters. Rice husk and bamboo were used as the biomass fuels in this study. This paper reported the influence of the biomass blending ratio in the fuel mixture and the excess air ratio on the combustion behavior. It was noted that the combustion temperature and the energy output from the co-firing process were reduced compared to coal combustion alone owing to the fact that biomass has lower heating value compared to coal. However, the high volatile matter (VM) content of biomass improved the combustion time scale so that the carbon monoxide (CO) emissions were reduced substantially. In addition, the fuel nitrogen and sulfur content in biomass were lower than that of coal and hence suppressed the formation of nitrogen oxides (NOx) and sulfur dioxide (SO2) during the cocombustion process. The increase of excess air ratio also affected most of the pollutant emissions. The pollutant emission per unit energy output at different excess air ratios and biomass blending ratios were studied in detail in this paper. Attention should be paid to the high potential of slagging and fouling in the boiler when co-firing coal with biomass.


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