Coal Combustion Efficiency Research Articles

Effects of activated fuel and staged secondary air distributions on purification, combustion and NOx emission characteristics of pulverized coal with purification-combustion technology

Under the strategic objectives of carbon peaking and carbon neutrality, clean and efficient coal combustion was important in China. As a novel combustion technology, purification-combustion technology had good research prospects, and high-temperature reduction unit (HTRU) played a crucial role in fuel activation, subsequent combustion and NOx emissions based on the design of this technology. Despite previous research had proved the pivotal role of fuel and combustion air distributions in combustor in influencing the entire thermochemical process, there was the lack of research on their effects in HTRU employing purification-combustion technology. To realize deep NOx emission reduction, this study focused on influences of activated fuel and staged secondary air distributions in HTRU on purification, combustion and NOx emission characteristics in a 30 kW purification-combustion test rig. With the exception of carbon microcrystalline structure, the majority of reductive char properties exhibited superior performance when activated fuel was introduced tangentially, as opposed to axially. Nevertheless, the relationship of carbon microcrystalline structure was regulated by staged secondary air ratio (c12). Properly increasing c12 improved reductive char properties. Additionally, axial introduction of activated fuel more consistently yielded ultra-low levels of NOx emissions; however, this often occurred at the expense of combustion efficiency (η). Properly increasing c12 reduced NOx emissions while increasing η; nevertheless, the benefits derived from c12 were limited. By adjusting introduction direction and c12 (axial, 0.33), minimum NOx emissions decreased to 39.10 mg/m3 (@6 % O2) while maintaining high η of 99.39 %.

Catalytic influence of iron oxide (Fe2O3) on coal pyrolysis and char combustion at various temperatures

The conversion of coal into cleaner energy forms is essential for achieving sustainable development. This study investigates the role of Fe2O3 as a catalyst in enhancing the efficiency of coal pyrolysis and char combustion. A fixed-bed tube furnace (TF) was selected for pyrolysis, and a Thermogravimetric Analyzer coupled with Fourier Transform Infrared Spectroscopy (TG-FTIR) was used for combustion analysis. The produced syngas and tar were characterized using Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC/MS). Our results show higher volatile release volume (VRV) from coal with catalyst compared with without catalyst and the rise with temperature within the 600–1000 ℃ range. Although hydrogen production decreased with the addition of the catalyst, at 1000 ℃, the catalyst's impact was negligible. The catalyst notably facilitated the breakdown of heavy aromatic rings in tar, eliminating triple-bond aromatic structures. In contrast, tar from raw coal exhibited a 20% yield of such structures. Scanning Electron Microscopy (SEM) revealed a cubic structure of Fe2O3 in char, with an increased surface area compared to raw coal char (338.75 m2/g vs. 313.51 m2/g). TG-FTIR analysis indicated a lower activation energy for catalysts with char combustion. Overall, Fe2O3 improves tar structure, increases char surface area, and lowers activation energy.

Investigating the potential of a waste-derived additive for enhancing coal combustion efficiency and environmental sustainability in a circular economy

This study examines the impact of a waste-derived additive from alumina and shale oil production on the performance of coal combustion. The effects of individual additive components were investigated under oxidant-limited and oxidizing conditions using the isothermal flow reactor (IFR) equipped with gas analysers. The raw materials, as well as fly chars/ashes derived from the IFR, were characterized using standard physicochemical analysis, oxide analysis, oxygen functional group determination, the ash fusion test, thermogravimetry, scanning electron microscopy and energy dispersive X-ray spectroscopy. Results from experiments conducted under oxidant-limited conditions demonstrated that the analysed additive, at a 1% share, increased hydrogen content in char by over 3.5 times (from 600 ppm to 2160 ppm) and enhanced methane conversion by nearly 20%. Under oxidizing conditions, the additive reduced unburned carbon loss by approximately 50%, emissions of NOx from 400-460 ppm to 340–390 ppm and SO2 from 1410-1475 ppm to 1325–1410 ppm. The study emphasized the influence of moisture on thermochemical processes, confirming that a certain amount of water vapour accelerates the conversion of H2, SO2, and NOX. The analysis supported the commercial utilization of the additive from economic, environmental, and operational standpoints.

Stable and highly efficient HMDS terminated m-Cresol inhibitor for inhibiting coal spontaneous combustion

A stable and highly efficient 1, 1, 3, 3, 3-hexamethyldisilazane (HMDS) terminated m-Cresol inhibitor was synthesized based on the protection-deprotection strategy. The inhibitory effect of HMDS terminated m-Cresol inhibitor on spontaneous combustion of lignite was explored through temperature-programmed oxidation tests, in-situ infrared analysis and thermogravimetric analysis. Results show that, the oxidation of active phenolic hydroxyl groups in the m-Cresol inhibitor can be hindered by the protection of HMDS. After encountering coal, the HMDS terminated inhibitor can be gradually deprotected to regenerate the m-Cresol inhibitor that contains massive active phenolic hydroxyl groups, thus improving the chemical inhibition efficiency of coal spontaneous combustion. For the coal sample inhibited with HMDS terminated m-Cresol inhibitor, the initial contents of the active functional groups are lower and more stable during heating, and the inhibition rate reaches 70% at 130 °C. Moreover, the crossing-point temperature rises by 32.4 °C–181.2 °C. The activation energy increases by 11 kJ/mol and 18 kJ/mol at below and above 130 °C respectively. The peak temperature at maximum weight loss rate rises by 65 °C–431.2 °C, and the corresponding residual carbon rate increased by 31.3%–61.6%. The inhibition mechanism of the HMDS terminated m-Cresol inhibitor on coal spontaneous combustion was deduced.

Clean Preparation of Formed Coke from Semi-coke by the Carbonated Consolidation Process.

In order to address the low thermal efficiency of low-rank coal combustion and the accompanying serious environmental issues, formed coke was prepared using a carbonization consolidation method with low-rank coal semi-coke. The test for briquetting and carbonation consolidation conditions revealed that the optimal parameters were a briquetting pressure of 93.63 MPa, moisture content of 16%, Ca(OH)2 binder amount of 10%, and a CO2 concentration of 30% at 20 °C. Under these conditions and a carbonation consolidation time of 60 min, high-quality formed coke was produced, exhibiting a compressive strength of 1256.2 N/a, redrying strength of 286.2 N/a, and a dropping strength of 10.6 number/a. The combustion characteristics of the prepared formed coke were investigated, revealing that ignition temperatures (345.39 °C), burnout temperatures (495.57 °C), and peak of the maximum weight loss rate temperatures (437.93 °C) are slightly higher than those of bituminous coal. The low calorific value of the briquette was 20.4 MJ/kg. During the combustion process, the emission concentrations of SO2, NOX, and solid particles from the formed coke were significantly lower than those of bituminous coal, indicating that it is a cleaner energy source. Moreover, adding Ca(OH)2 effectively reduced SO2 emissions and achieved sulfur fixation and emission reduction.

Study of the Structure and Catalytic Activity of B-Site Doping Perovskite for an Inferior Anthracite Coal Combustion

The unique structure and physical properties of perovskite-type catalysts make them highly promising for catalyzing efficient coal combustion. Mesoporous perovskite LaNixFe1−xO3 (x = 0.2, 0.4, 0.6, 0.8) coal combustion catalysts were synthesized using the sol–gel method. The effects of the doping amount of B-site doped nickel on both the crystal structure and catalytic performance were investigated. X-ray diffraction, scanning electron microscopy, and nitrogen adsorption–desorption tests were used to characterize the catalyst samples. Thermogravimetric analysis (TG) and activation energy (Ea) calculations were used to assess the catalyst’s activity for the catalytic combustion of anthracite coal (JF coal, originating from Shanxi, China). Results revealed that nickel doping created lattice distortion and Ni-Fe alloy interactions. The difference in nickel doping significantly affects the morphology and catalytic activity of perovskite. The addition of LaNi0.6Fe0.4O3 (NI6) with a mass fraction of 5% resulted in the highest average burning rate value (va = 4.52%/min) of JF coal among all synthesized catalysts. The Ea of JF coal catalytic combustion, calculated using the Coats–Redfern method and the Doyle method, showed a good agreement with the TG curves. The LaNixFe1-xO3 series catalysts were found to significantly decrease the Ea of JF coal combustion, with a maximum reduction of 42% compared to the case without any catalyst added. Among the synthesized catalysts, NI6 exhibited a favorable catalytic combustion performance and is thus a promising candidate for the clean and efficient utilization of coal resources.

Kömür Yakıcılarında Yanma Verimi Tahmini için Gömülü Platformda Çalışabilen Evrişimsel Sinir Ağının Parametre Analizi

Accurately and effectively calculating combustion efficiency in coal burners is crucial for industrial boiler manufacturers. Two main approaches can be used to calculate boiler efficiency: 1) Analyzing the gas emitted from the flue; 2) Visualizing the combustion chamber in the boiler. Flue gas analyzers, which are not user-friendly, come with high costs. Additionally, the physical distance between the flue and the combustion chamber causes the measurement to be delayed. Methods based on visualizing the combustion chamber do not have these disadvantages. This study proposes a system based on visualizing the combustion chamber and has two contributions to the literature: 1) for the first time, the modern Convolutional Neural Networks (CNN) approach is used to estimate combustion efficiency; 2) the CNN architecture with optimal parameters can work on an embedded platform. When classical classification techniques and a CPU-supported processor card are used, efficiency can be calculated from one flame image in 1.7 seconds, while this number increases to approximately 20 frames per second (34 times faster) when the proposed CNN architecture and GPU-supported processor card are used. The results obtained demonstrate the superiority of the proposed CNN architecture and hardware over classical approaches in estimating coal boiler combustion efficiency.

Laser-induced breakdown spectroscopy combined with principal component analysis-based support vector machine for rapid classification of coal from different mining areas

Coal is one of our most important energy sources. Because of differences in coal-forming year and coal seam quality, the elemental compositions of coal vary among different mining areas, directly affecting coal combustion efficiency and pollution emission. To improve the accuracy of coal classification, laser-induced breakdown spectroscopy (LIBS) combined with a support vector machine (SVM) algorithm model based on principal component analysis (PCA) is proposed to identify and classify coal from 10 different regions. The samples were first penetrated using LIBS, and spectral data were collected. The spectral data were then normalized to improve their signal-to-noise ratio. Finally, the PCA-SVM model is established, the model parameters are evaluated using the grid search method, and the spectral feature classification performance is determined via cross-validation. The results show that the classification accuracy of the PCA-SVM model can reach 98.52%. To verify the performance of this classification model, it was compared with those of five other common classification models and proved that PCA-SVM has great potential for coal quality identification and classification, thus providing a new data analysis and processing solution for coal quality identification and classification in industrial applications.

Cleaning of Thar coal by froth flotation and water washing

The demand for a constant supply of energy is increasing day by day. To meet these increasing demands the natural resources must be utilized smartly. Coal can be a promising fuel due to its large reserves available in Pakistan. About 175 billion tons of coal reserves are found in Thar region of Sindh province. The major issue is the pre-processing cleaning of coal after it is mined out. A number of methods have been adopted to clean coal.
 Presently, cleaning of Thar coal was carried out using froth flotation and water washing techniques. Three different particle sizes (-60#, -100# and -150#) were employed to study the effect of froth flotation on ash and sulfur reduction. Experiments were carried out in laboratory flotation cell and beakers under different set of conditions (i.e., flotation with and without collector and frother and by simple water washing). Kerosene oil was used as a collector and pine oil as a frother. Characterization of raw and treated Thar coal samples was carried out by ASTM standards. The results exhibited an inverse relationship of particle size towards efficiency of the cleaning process; thus, the optimal combustible recovery was attained at -150# particle size. Furthermore, FTIR results disclosed the presence of aromatic and aliphatic structure in treated coal samples. Thermo-gravimetric analysis was also made to determine the weight loss in raw and treated samples and observed increased combustion efficiency and reactivity of Coal.

The use of numerical simulation to determine the coal combustion efficiency in the A-USC boiler

In this paper, numerical simulation of coal combustion in the invert furnace of a boiler for a 500 MW power unit designed to operate on advanced ultra-supercritical steam parameters (A-USC) is performed. The use of A-USC technology makes it possible to reduce fuel costs for electricity production compared to steam turbine units of previous generations. Also it influences to reduce the level of emissions of harmful substances into the atmosphere. Modeling of the invert furnace at the nominal boiler load was carried out for the developed direct-flow burners and nozzles arrangement of burning coal. After numerical simulation the results were obtained and made it possible to analyze the furnace aerodynamics and the temperature distribution inside the furnace volume. The calculation of the indicators of efficiency and environmental friendliness was carried out and their values appeared smaller than regulatory permissions, which allows us to recommend the developed burners arrangement scheme for its use in invert furnaces. The furnace operation simulation at reduced loads of 70% and 50% was carried out and the results showed the reliability of the developed combustion scheme.

Combustion effectivity of high ash coal in adiabatic calorimeter

A series of coal-mineral matter mixtures was investigated by bomb combustion calorimetry (IKA C4000, Germany) to elucidate boundary for ash content in coal at which combustion proceeds with lowered efficiency. For the experiments, a high rank bituminous coal was mixed with particles of mine stone, both being milled to size below 0.2 mm. Before the usage, the sample of stone was heated at 900°C for 2 hours in air to stabilize mineral matter composition. Mixtures 5, 10, 15, 20, 25, 30, 40, and 50% of coal were used, with sample weights both of 1 g and/or 2 grams being applied. The efficiency of the combustion process at the bomb test was assessed of the measured calorific value and that of “theoretically” calculated. The “theoretical” calorific value of the mixture was determined from the actual content of the coal proving known specific calorific value (36.6 MJ/kg). Based on the measurements, mineral matter content of about 50% was found as limiting for fully efficient combustion of coal in the bomb calorimeter. At content of 90% of mineral matter, the efficiency of combustion is about 70 % (sample weight 1 g) and/or 50 % (sample weight 2 g). Afterwards, the combustion efficiency steeply decreases to zero.

Coal Identification Based on Reflection Spectroscopy and Deep Learning: Paving the Way for Efficient Coal Combustion and Pyrolysis.

Coal plays an indispensable role in the world’s energy structure. Coal converts chemical energy into energy such as electricity, heat, and internal energy through combustion. To realize the energy conversion of coal more efficiently, coal needs to be identified during the stages of mining, combustion, and pyrolysis. On this basis, different categories of coal are used according to industrial needs, or different pyrolysis processes are selected according to the category of coal. This paper proposes an approach combining deep learning with reflection spectroscopy for rapid coal identification in mining, combustion, and pyrolysis scenarios. First, spectral data of different coal samples were collected in the field and these spectral data were preprocessed. Then, an identification model combining a multiscale convolutional neural network (CNN) and an extreme learning machine (ELM), named RS_PSOTELM, is proposed. The effective features in the spectral data are extracted by the CNN, and the feature classification is realized utilizing the ELM. To enhance the identification performance of the model, we utilize a particle swarm optimization algorithm to optimize the parameters of the ELM. Experimental results show that RS_PSOTELM achieves 98.3% accuracy on the coal identification task and is able to identify coal quickly and accurately, providing a low-cost, efficient, and reliable approach for coal identification during the mining and application phases, as well as paving the way for efficient combustion and pyrolysis of coal.

HMB-CFD study of oxygen-enriched pulverised coal combustion in an ironmaking blast furnace

Pulverised coal injection (PCI) into blast furnace (BF) is a dominant technology for partial coke replacement and lowering production cost, and high oxygen enrichment is a recent promising technology for further increasing coal combustion and thus increasing pulverised coal rate (PCR) and lowering emissions. In this paper, a heat and mass balance (HMB) model and a three-dimensional computational fluid dynamics (CFD) model of pulverised coal flow and combustion in the lower part of the BF are combined to investigate the effect of oxygen enrichment on coal combustion in terms of operational feasibility and coal combustion efficiency, where the injection schemes such as blast volume, oxygen enrichment, PCR are designed using the HMB model; and the local detailed coal combustion is studied using the CFD model, including the effect of oxygen enrichment and PCR on in-furnace phenomena including gas-solid flow, temperature field and particularly, coal burnout. The CFD simulations reveal that the combustion efficiency is the result of the combined effects of oxygen enrichment and PCR. The high oxygen enrichment in the blast enhances gaseous combustion and coal combustion. The high PCR needs more time and distance for preheating and devolatilisation, which was detrimental to coal combustion near tuyere; on the other hand, more particles in combustion release more heat which is beneficial to the continued combustion of unburned particles. As a result of the combined effects, the inflection points could be found in some key phenomena, including gas temperature, particle temperature, O2 mass fraction, etc. This HMB-CFD study implies that it is highly necessary to consider both feasible operation windows and the detailed impacts of the oxygen enrichment on coal combustion under industrial BF conditions; and thus should be used in future PCI investigations.

Effectiveness analysis of Maikuben brown coal combustion in the heating boiler “Kamkor-300”

This research presents the results of studying the efficiency of Maikuben brown coal combustion in low-power heating boilers using the case of the Kamkor-300 boiler. Improving the combustion efficiency of low-grade fuels is directly related to fuel economy and the decrease of toxic emissions into the atmosphere. The research results show the possibility of adjusting the boiler according to the “fuel-air” ratio in the furnace volume, without violation of its general heat exchange structure and changing the heat-transfer operation in the device. In the research the adjustment of the operation of a long-burning boiler with an upper air supply in order to increase the time of combustion gases dwell in the boiler furnace volume drum is proposed. It is also possible to reduce the excess air coefficient to 0.55 and to operate the boiler under conditions of oxygen deficiency. Under such conditions, in the presented boiler, additional synthesis gases are released during the combustion of low-grade coals, in particular of coal rank “B”, to obtain an additional thermal effect. The resulting thermal effect leads to an increase of the boiler efficiency and its operational and economic indicators.

Coal combustion emissions and ash formation characteristics during oxy-fuel combustion in a 100 kWth pressurized circulating fluidized bed

Pressurised circulating fluidized bed oxy-fuel combustion (PCFB-OFC) is a promising technology for CO2 capture because of its high carbon capture efficiency and net efficiency. However, there is a lack of comprehensive experimental studies on PCFB thermal state experimental devices due to the complexity of their design, construction, and operation. In this study, a 100 kWth PCFB-OFC experimental device was developed, and a series of coal combustion experiments were conducted under 0.1 to 0.6 MPa at an average oxygen concentration of 30% with a fixed peroxygen coefficient β (1.1–1.3). The effect of combustion pressure was investigated to determine the influence of pressure on coal combustion efficiency, furnace temperature distribution, gaseous pollutant emissions, and fly ash chemical composition. The experimental results showed that the increase in pressure increased the particle concentration in the dilute phase zone and increased the temperature at the top of the furnace, with a more uniform temperature distribution. The carbon content in the fly ash and the CO emissions in the flue gas were gradually reduced, and the combustion efficiency increased to 97.3%. The emissions of NO and N2O gradually decreased with the increase in load, and the NO emissions reduced by approximately 70% at 0.6 MPa. The emission of SO2 showed a downward trend as the pressure increases. Affected by the increase in pressure, the self-desulfurization capability of fly ash was improved. In addition, lower K2O and Na2O contents may reduce the deposition of fly ash in the furnace.

Coal and biomass combustion with CO2 capture by CLOU process using a magnetic Fe-Mn-supported CuO oxygen carrier

The Chemical Looping with Oxygen Uncoupling (CLOU) process is a derivative technology of the Chemical Looping Combustion (CLC) process for the combustion of both renewable and non-renewable solid fuels. The present work studies the combustion and CO2 capture efficiency of burning coal or biomass using a single Cu-based oxygen carrier with magnetic properties as an oxygen carrier. The combustion of two different coals and three different biomasses was performed in a 1.5 kWth CLOU continuously operated unit for 36 h. The magnetic properties of the oxygen carrier were also studied after combustion and its separation from the ashes. Complete combustion of the fuel to CO2 and H2O was achieved in all cases. For both coals, CO2 capture efficiency increased with fuel reactor temperature, with both reaching values of 97% at 900 °C. The same increase was obtained with the biomasses. The highest CO2 capture efficiency for a biomass was obtained with pine sawdust, which achieved a value of 93%, followed by almond shell (86%) and olive stone (80%) at 900 °C. Oxygen carrier reactivity remained constant after use in the continuous unit with one small increase in the attrition jet index (AJI) value. The used particles were found to still be as magnetic as the fresh particles, and the fines were also highly magnetic. Values higher than 99% were achieved with separation from the fines reached. It was therefore proven that the elutriated oxygen carrier from the plant was still magnetic and could be easily separated from the elutriated ash.

Mathematical modeling of the thermochemical processes of sequestration of SOx when burning the particles of the coal and wood mixture

The article presents the results of mathematical modeling of the initial stage of the combustion of wood and coal particles in conditions corresponding to the combustion chambers of boiler units of thermal power plants. A hypothesis is formulated that describes the sequestration of anthropogenic sulfur oxides (SOx) under the conditions of combustion of mixed fuels based on coal and wood as a result of the interaction of water vapors (formed during the evaporation of interporeal and adsorbed biomass moisture) with SOx with the formation of sulfuric (H2SO4) acid vapors. When these vapors of sulfuric acid H2SO4 interact with iron oxides of the mineral part of the coal. To test the formulated hypothesis, a new mathematical model has been developed for the processes of co-ignition and combustion of wood and coal particles under high-temperature heating conditions. The mathematical model of the ignition process developed by the authors differs from the known ones (published in leading international scientific periodicals on the combustion of solid fuels) by a detailed description of a complex of gas-phase and heterogeneous thermochemical reactions occurring both in the boundary layer of fuel particles and in their porous structure. The mathematical model of the combustion process of wood-coal fuel particles developed by the authors is currently the most detailed in describing the thermophysical, thermochemical and aeromechanical processes occurring both in the fuel particles and in their small vicinity. Multistage kinetic schemes for the oxidation of the main volatile components (methane ‒ CH4, carbon monoxide ‒ CO, hydrogen ‒ H2), as well as the formation of sulfur oxides by means of oxidation of hydrogen sulphide (H2S), released as a result of pyrolysis of the organic part of coal, have been adopted. Based on the results of numerical modeling, the possibility of intensifying the processes of sequestration of sulfur oxides by moistening the wood component of the fuel mixture has been established. It is shown that water vapor can act as an agent adsorbing anthropogenic sulfur oxides, transforming the latter into sulfuric acid vapor, respectively. In turn, the vapors H2SO4 and HNO- 3 can be relatively easily captured by means of condensation. It has been established that for effective SOx capture during co-combustion of coal and biomass, the moisture content of the latter must be at least 5% by weight. The research provides grounds for the conclusion about the possibility of environmentally efficient combustion of coal in the composition of wood-coal fuel composites.

Research on tomography algorithm of furnace flame temperature field based on acoustic method in thermal power station

An improved Tikhonov regularization algorithm MCTR based on Markov radial basis function is proposed to obtain the feedback of closed-loop control for pulverized coal injection process in thermal power plant, so as to solve the ill posed problem in temperature field reconstruction in furnace. The algorithm constructs a new regularization matrix to replace the standard Tikhonov regularization element matrix, so as to achieve the correction effect of the new algorithm. MCTR algorithm determines the boundary singular value of small singular value defined in this paper by determining the proportion between the standard deviation component corresponding to small singular value and the sum of standard deviation components corresponding to all singular values after singular value decomposition of coefficient matrix. After determining the boundary, a new regularization matrix is constructed according to the eigenvector corresponding to small singular value. Compared with the MTR algorithm using the identity matrix as the regularization matrix, MCTR algorithm only selectively modifies the parameters corresponding to small singular values after determining the regularization parameters, which improves the stability of the parameter solution and the reconstruction accuracy of the temperature field, and is helpful to the automatic control of thermal power plants and the efficiency of coal combustion.

Hybrid inorganic-organic membranes in the service of clean coal technologies

Clean coal technologies (CCT) are all technological solutions that are designed to increase the efficiency of coal combustion, processing and extraction. They are therefore, all the technologies that will help to reduce its environmental nuisance during the production and use of coal and can be introduced at various stages of coal application. Earlier was stated that none of the energy sources (natural gas, crude oil and renewable energy sources), their native resources, the used technologies and the sources of imports are not able to eliminate hard coal from the energy mix of Poland in the near future. That is why the authors began research to create a new clean-coal technology based on the hybrid inorganic-organic membranes, which can be used for elimination of harmful substances generated during coal combustion, especially CO2. This work concerns the study of the inorganic-organic hybrid membranes based on few modified polymer matrices and various inorganic fillers. It was found that incorporation of zeolite 4A into the polymer matrix had significantly changed the gas transport parameters (D, P, S and α). In turn, the mechanical (Rm and E) parameters have increased with the filler content. The application allows the initial selection of ingredients from which the final membrane will be created. The designed technology does not require high financial expenditures, and it is also highly universal. It can be used both in households, heating plants and, above all, in power plants.

A novel clean combustion technology for solid fuels to efficiently reduce gaseous and particulate emissions

Approximately three billion people worldwide rely on solid fuels for cooking and heating with traditional stoves or open fires, resulting in severe air pollution which leads to approximately four million premature deaths every year. Here, we present a novel clean combustion technology (NCT) to overcome the inherent defects of existing technologies and reduce emissions from solid fuel combustion. We compared gaseous and particulate emissions from coal combustion between a prevailing traditional domestic stove and an NCT stove. The average reductions were 99% for particulate matter with dynamic diameter less than 2.5 μm (PM2.5), 99% for organic carbon (OC), 98% for elemental carbon (EC), 96% for carbon monoxide (CO), 93% for methane (CH4), 91% for volatile organic compounds (VOCs), 89% for ammonia (NH3), and 99% for carbonyl sulfur (COS). The average coal combustion efficiency was enhanced from 52.6% in the traditional stove to 92.6% in the NCT stove. The novel technology was also successfully applied to the construction of an industrial boiler with a similar or better reduction in air pollutants than the NCT stove. The emission factors of various pollutants from the NCT stoves and boilers fueled with bituminous coal are comparable to those from advanced coal-fired power plants. The wide application of the NCT worldwide, especially in developing countries, would be beneficial to individual health, local air quality, and global climate change.