Coal In Coal-fired Power Plants Research Articles

Numerical and Experimental Investigation of the Decoupling Combustion Characteristics of a Burner with Flame Stabilizer

In order to integrate renewable electricity into the power grid, it is crucial for coal-fired power plant boilers to operate stably across a wide load range. Achieving steady combustion with low nitrogen oxide (NOx) emissions poses a significant challenge for boilers burning low-volatile coal in coal-fired power plants. This study focuses on developing a decoupling combustion technology for low-volatile coal-fired boilers operating at low loads. A three-dimensional numerical simulation is employed to analyze and optimize the geometrical parameters of a burner applied in a real 300 MW pulverized coal fired boiler. Detailed analysis of the burner’s decoupling combustion characteristics, including stable combustion ability and NOx reduction principles, is conducted. The results indicate that this burner showed three stages of coal/air separation, and the flame holder facilitates the stepwise spontaneous ignition and combustion of low-volatile coal. By extending the time between coal pyrolysis and carbon combustion, the burner enhances decoupling combustion and achieves low nitrogen oxide emissions. Based on optimization, a flat partition plate without inclination demonstrates excellent performance in terms of velocity vector field distribution, coal air flow rich/lean separation, combustion, and nitrogen oxide generation. Compared with the initial structural design, the average nitrogen oxide concentration at the outlet is reduced by 59%.

Study on Mixed Match Method of Factory-incoming Coal in Coal-fired Power Plants from the Perspective of Carbon Emission

In order to better guide the mixed match of furnace-incoming coal in coal-fired power plants from the perspective of carbon emission, according to national carbon emission accounting guidelines for power generation facilities, regardless of the impact of coal storage on coal quality, we have built a coal quality information database for carbon emissions of factory-incoming coal through analyzing the factory-incoming coal source and industrial analysis data on coal quality in a coal-fired power plant as well as using the element carbon content information estimated by soft measurement of element carbon content verified through the test. Based on this, we have constructed the theoretical method to guide the mixed match of furnace-incoming coal, and obtain the optimized mixed match results through the mixed match analysis.

Influence of collaborative disposal of sewage sludge in the fly ash partitioning and PM10 emission from a subcritical coal-fired boiler

Co-combustion of sewage sludge and coal in coal-fired power plants may be a reasonable alternative for intractable sewage sludge. The co-combustion experiments were conducted on a 600 MW subcritical coal-fired boiler to discuss the fly ash partitioning and PM10 emission characteristics. The sewage sludge was sent to the boiler through coal pulverizer with blending ratios of 5 and 10 wt% based on the coal mass. The results showed that the particle size distributions (PSDs) of PM10 present the typical two-peak distribution. The mass yields of PM1 dramatically decreased by 57.83 % and 61.67 % for the 5 % and 10 % blending ratios, respectively, compared with single coal combustion, corresponding to the increase in PM1-10 emissions. The reduced PM1 appears to be transferred toward PM1-10 during co-combustion. The Fe Al-silicate and the Fe-Ca-Si-Al species were formed by the co-combustion of sludge and coal, which were derived from the active Fe-rich fine particles in sludge and mainly mullite and Ca-Si-Al found in coal ash. These transformations can be intensified by the high temperature, intense turbulent flow fields and the consequent frequent contact and collision of minerals in the large capacity boiler to form molten aluminosilicates. Therefore, the condensable Ca and S vapor from coal combustion and fine Si and Al adhere to the surface of molten Fe Al-silicate to form PM1+, which is the main reason for PM1 reduction during co-combustion. In addition, Fe-rich and Ca-rich flocculants in sludge contribute to PM1-10 largely, while some of the fine Al-Si particles are partitioned from PM1 to PM1-10 as captured by the molten aluminosilicates, both contributing to the increased PM1-10 emission after co-combustion.

Characteristics of low-rank and medium-rank Indonesian coal using the TG-DSC method

Low-rank and medium-rank coal are dominant coal resources in Indonesia. Considering the decisive role of coal in coal-fired power plants, it is crucial to examine the combustion characteristics before burning coal in the boiler. This paper presents the effect of moisture content, heating value, and volatile matter on ignition temperature and burn out of five samples of low-rank coal and five samples of medium-rank coal using TG-DSC analysis which was carried out using LINSEIS High-Pressure STA at atmospheric pressure with an air rate of 25 ml/min and heating rate of 10 °C/min. The investigation results show that low-rank coal with the higher volatile matter has tremendous reactivity and is more flammable, and favours of burning through itself than medium-rank coal. Medium-rank coal has better combustion with short residence time because it has a lower burnout temperature (Tbo) value than low-rank coal. However, medium-rank coal burns more instantly because it has a lower temperature interval than low-rank coal. Medium-rank coal, which has fixed carbon and higher heating value, but lower moisture content, has a higher Rmax value than low-rank coal. In conjunction with these properties, it is crucial to examine the implementation in boilers.

Simulation of Dispersion Potential and Fatality Percentage of SO2 and CO2 Flue Gas from Combustion of Coal in West Lombok Power Plant using Gaussian Model

Combustion of coal in coal-fired power plants produces air pollution such as SO 2 , NO x , CO 2, and Particulates. The Jeranjang power plant in West Lombok Regency uses 300,000 tons/year of coal to generate 75 MW of electricity. It can be a large potential for environmental pollution. This research aims to simulate the potential of SO 2 and CO 2 exhaust gas dispersion to the environment and the fatality percentage caused by burning the Jeranjang coal power plant using the Gauss Model. The research was conducted by a literature study and direct observation of PLTU Jeranjang. After that, in this research, the SO 2 and CO 2 concentration were calculated. At the end of the study, estimating the potential dispersion and fatality percentage by SO 2 and CO 2 gas was also calculated around the Jeranjang power plant. The results are SO 2 dispersion with a dispersion mass of 0.145 kg/sec from a distance of 2,000 to 46,000 m increased from 1x10 -45 to 1.9x10 -5 ppm and decreased to 0 ppm. The fatality percentage generated is 0%. The CO 2 dispersion potential into the environment without a mass of 12.378 kg/sec increases at a distance of 2,000 to 58,000 m, from a concentration of 2.7x10 -65 to 0.00184 ppm. The CO 2 concentration decreases to 0 ppm. The fatality percentage generated is 0%. The calculation of settlement dispersion around the PLTU Jeranjang can be safe from SO 2 and CO 2 dispersion, and the fatality percentage generated is 0%.

Aluminum extraction technologies from high aluminum fly ash

Abstract Coal fly ash (CFA), an industrial by-product of high-temperature combustion of coal in coal-fired power plants, is one of the most complex and largest amounts of industrial solid wastes generated in China. It is widely recognized that CFA should be considered as a potential alumina resource to substitute bauxite. In this review, the features of high-alumina fly ash and aluminum recovery technologies are first described. Later, the merits and drawbacks of alumina extraction technologies in recovering more valuable materials are compared in terms of extraction mechanisms and equipment requirements. It is shown that “predesilicating-sodium carbonate (Na2CO3) activation-acid leaching” is currently a promising method in achieving multimetal synergistic extraction. Finally, the hydrochloric acid and sulfuric acid combination process is proposed as a sustainable development of the predesilicating-Na2CO3 activation-acid leaching process. The findings of this review provide theoretical guidance for novel developments and applications of aluminum extraction technologies.

Recent Trends in Fly Ash Utilization in Polymer Composites

Fly ash (FA) is one of the residues created during the combustion of coal in coal-fired power plants. Fine particles rise with flue gases and are collected with filter bags or electrostatic precipitators. FA is a waste by-product material that must be disposed of or recycled. 131 million tons of FA is produced annually by 460 coal-fired power plants in the U.S. alone. Experts have predicted possible human health effects, like permanent respiratory disorder on inhalation of metals present in FA, especially by persons living in the vicinity of disposal sites [1]. Dumping of FA in to the environment causes pollution of air, land and water. FA is a waste ceramic that contains some heavy metal compounds and these could lead to a number of diseases, such as lung cancer, anemia, dermatitis and skin cancer. Since FA contains particulate matter (PM) these can penetrate into different organs of the human system depending upon the size of PM [2].