Co-firing Conditions Research Articles

Utilization of Palm Frond Waste as Fuel for Co-Firing Coal and Biomass in a Tangentially Pulverized Coal Boiler Using Computational Fluid Dynamic Analysis

Renewable energy sources are becoming increasingly crucial in the global energy industry and are acknowledged as a significant substitute for fossil fuels. Oil palm fronds are a type of biomass fuel that can be utilized as a substitute for fossil fuels in the combustion process of boilers. Co-firing (HT-FRD) is a beneficial technology for reducing exhaust gas emissions generated by coal-burning power stations. By utilizing computational fluid dynamics (CFD), this study has modeled and evaluated co-firing palm frond residue (HT-FRD) with hydrothermal treatment into a 315 MWe boiler. In the simulation, six different HT-FRD co-firing ratios, 0%, 5%, 15%, 25%, 35%, and 50%, were used to demonstrate the differences in combustion characteristics and emissions in the combustion chamber. The data indicate that HT-FRD co-firing can enhance temperature distribution, velocity, and unburned particles. All in all, co-firing conditions with 5–15% HT-FRD ratios appear to have the most favorable combustion temperature, velocity, and exhaust gas characteristics.

Study on the Combustion Characteristics of a Gas Turbine Combustors under Hydrogen Co-firing Conditions

Study on the Combustion Characteristics of a Gas Turbine Combustors under Hydrogen Co-firing Conditions

Experimental study on the effects of co-firing mode and air staging on the ultra-low load combustion assisted by water electrolysis gas (HHO) in a pulverized coal furnace

Developing zero-carbon fuel (H2/NH3) co-firing technology with pulverized coal can improve the low-load flame instability and pollutant emissions of boilers during peak shaving. In this study, we propose to assist the low-load combustion of coal powder furnaces with the safer water electrolysis gas (HHO). To further optimize the combustion strategy, a one-dimensional furnace combustion system coupled with an HHO gas generation and transportation system was used to investigate the effects of injection methods and air staging on the flue gas emission and auxiliary combustion characteristics of the lignite load reduction process and ultra-low load. The results indicate that reducing the coal combustion load achieves carbon reduction and reduces actual CO2 emissions. The excess air coefficient increases, resulting in higher NOX and lower CO emissions. Air staging can control NOX and CO emissions during load shedding, with a 40.49 % reduction in NOX at 30 % load. Under ultra-low load, HHO-assisted combustion increases the oxygen concentration in the furnace, increasing NOX emissions, while SO2 decreases and then increases. However, the effect of HHO gas premixed mode (PM) on NOX generation is weaker than that of staged mode (SM). As the flow rate of HHO increases, HHO-SM promotes the conversion of CO to CO2 and reduces CO emissions, while CO emissions under PM remain at ∼10 ppm. Both HHO injection methods exhibit assisted combustion effects for ultra-low load operation. Due to the different effects of the two on the recirculation zone inside the combustion, the auxiliary combustion effect of PM is superior than that of SM. At 1800L/h HHO, the decrease in combustion instability coefficient (βT) of PM is 57.14 %, higher than that of SM. Air staging is beneficial for stable combustion under ultra-low load, but it can affect the auxiliary combustion of HHO gas. Under ultra-low load HHO co-firing conditions, 11%-OFA can also control NOX and CO emissions.

Review on Mercury Control during Co-Firing Coal and Biomass under O2/CO2 Atmosphere

Combining biomass co-firing with oxy-fuel combustion is a promising Bioenergy with Carbon Capture and Storage (BECCS) technology. It has the potential to achieve a large-scale reduction in carbon emissions from traditional power plants, making it a powerful tool for addressing global climate change. However, mercury in the fuel can be released into the flue gas during combustion, posing a significant threat to the environment and human health. More importantly, mercury can also cause the fracture of metal equipment via amalgamation, which is a major risk for the system. Therefore, compared to conventional coal-fired power plants, the requirements for the mercury concentration in BECCS systems are much stricter. This article reviews the latest progress in mercury control under oxy-fuel biomass co-firing conditions, clarifies the impact of biomass co-firing on mercury species transformation, reveals the influence mechanisms of various flue gas components on elemental mercury oxidation under oxy-fuel combustion conditions, evaluates the advantages and disadvantages of various mercury removal methods, and finally provides an outlook for mercury control in BECCS systems. Research shows that after biomass co-firing, the concentrations of chlorine and alkali metals in the flue gas increase, which is beneficial for homogeneous and heterogeneous mercury oxidation. The changes in the particulate matter content could affect the transformation of gaseous mercury to particulate mercury. The high concentrations of CO2 and H2O in oxy-fuel flue gas inhibit mercury oxidation, while the effects of NOx and SO2 are dual-sided. Higher concentrations of fly ash in oxy-fuel flue gas are conducive to the removal of Hg0. Additionally, under oxy-fuel conditions, CO2 and metal ions such as Fe2+ can inhibit the re-emission of mercury in WFGD systems. The development of efficient adsorbents and catalysts is the key to achieving deep mercury removal. Fully utilizing the advantages of chlorine, alkali metals, and CO2 in oxy-fuel biomass co-firing flue gas will be the future focus of deep mercury removal from BECCS systems.

Ignition characteristics of single coal particles under ammonia co-firing conditions

To meet the goal of an international carbon-neutral framework, the promotion of clean coal utilization occupies a vital position in reducing greenhouse gas emissions. Ammonia co-firing is considered as a potential strategy for future power generation to reduce fossil energy consumptions, soot, CO2 emissions, and hydrocarbon pollutants. In the present work, the ignition characteristics of single coal particles under ammonia (NH3) co-firing conditions were investigated. Particles were injected with NH3 or N2 into a hot flue gas environment at 1550 K generated by a CH4-fired Hencken burner. Temporally resolved images of CH* chemiluminescence and char thermal radiation were captured. Combining the signal profiles, ignition modes and characteristic times of single burning particles were studied with different coal types, carrying atmospheres, and O2 contents. When the carrier gas was replaced by NH3 atmosphere, the ignition delay time of all coal particles was greatly shortened, and the time interval from ignition to peak, as well as the combustible component burnout time, were both lengthened due to the promoted devolatilization and combustion reaction rates of coal particles caused by the NH3 flame. Concerning the ignition mode in the NH3-blended cases, the homogeneous ignition behaviors of the lignite particles were further enhanced, while the bituminous particles transitioned to the homogeneous-heterogeneous united ignition mode. As the O2 content in the flue gas increased, the ignition of all coal particles was advanced monotonously, and the chemiluminescence became more intense in both N2 and NH3 atmospheres.

Industrial scale testing on the combustion and NOx emission characteristics of ammonia cofiring in a 40 MWth coal-fired boiler

This paper reports the first industrial scale testing on ammonia (NH3) cofiring in a 40 MWth coal-fired boiler under high ammonia cofiring ratio (ENH3, percent of thermal input) ranging from 0 % to 25 %. A full-scale cofiring swirl burner is designed to inject NH3 gas with pulverized coal through the primary air pipe of the burner. The effects of ammonia cofiring ratio and key boiler operating parameters on boiler NOx emission and fuel burnout are examined. The results show that the boiler can establish stable ignition and combustion under all ammonia cofiring conditions in this study. The burnout of coal under ammonia cofiring conditions are better than those of coal combustion cases. Overfire air (SOFA) has significant influences on boiler NOx emission and burnout of coal and NH3. It is found that there exists optimal SOFA ratio in the range of 15–20 % within which both boiler NOx emission and NH3 slip can be well controlled. Under 20 % SOFA ratio, boiler NOx emission tends to increase and then decrease with the increase of ENH3 reaching the peak value under ENH3 = 5 %. As a result, the NOx emission can be reduced to the level lower than that of coal combustion case under ENH3 > 20 %. Boiler excess O2 also shows significant influences on boiler NOx emission and NH3 slip. With the decrease of boiler O2, boiler NOx emission decreases significantly while NH3 slip increases rapidly. It is found that there exists optimal boiler O2 in the range of 3.0–3.7 % within which both boiler NOx emission and NH3 slip can be kept at relatively low levels. Injection of NH3 from the side wall of furnace is also tested in this study. The NOx emission shows similar trends with the change of ENH3 in the range of 0–20 %. However, above this range the NOx emission tends to increase with further increase of ENH3. The results of this paper demonstrate the technical feasibility of NH3 cofiring in large-scale coal-fired boilers under high cofiring ratios and provide important guidance to the operation of boilers.

Emission characteristics of coal gasification fine slag direct combustion and co-firing with coal

Coal gasification is an effective way to use coal cleanly and efficiently, and coal gasification fine slag is a by-product of coal gasification with high carbon content, large specific surface area, developed pore structure and large output during production. At present, combustion has become an effective way to dispose of coal gasification fine slag on a large scale, and the coal gasification fine slag after combustion treatment can be further used for construction raw materials. In this paper, the emission characteristics of gas-phase pollutants and particulate matter under different combustion temperatures (900 °C, 1100 °C, 1300 °C) and combustion atmosphere (5%, 10%, 21% O2 concentration) are studied with the drop tube furnace experimental system. By co-firing different proportions of coal gasification fine slag (10%, 20%, 30%) and raw coal, the pollutants formation law under co-firing conditions is studied. Scanning electron microscopy-energy spectroscopy (SEM-EDS) is used to characterize the apparent morphology and elemental composition of particulate samples. The measurement results of gas-phase pollutants show that the increase of furnace temperature and O2 concentration can effectively promote combustion and improve burnout characteristics, but the emission of gas-phase pollutants increases. A certain proportion (10%–30%) of coal gasification fine slag is added to the raw coal, which reduces the total emission of gas-phase pollutants (NOx and SOx). Studies on the characteristics of particulate matter formation show that co-firing with coal gasification fine slag in raw coal can effectively reduce submicron particle emission, and the lower fine particle emission is also detected at lower furnace temperature and oxygen concentration. The element analysis of particulate matter formation shows that the Fe, Si and S elements content of submicron particle generated by YL (the coal gasification fine slag generated by water slurry furnace in of Shaanxi Extended China Coal Yulin Energy Chemical Co., Ltd) sample increases significantly with the increase of furnace temperature and O2 concentration, which is the main influencing factor for the increase of submicron particle. With the increase of the mixing ratio of YL sample, the content of major elements such as Fe, K and Mg of submicron particle decreases significantly, which is an important reason why the amount of the submicron particle decreases.

Behavior of nitrogen oxides in a lab-scale coal ammonia co-firing system

The objective of this study was to determine the ideal coal–ammonia (NH3) co-firing conditions to achieve carbon neutrality and suppress NOx formation. This paper describes the characteristics of NOx formation in NH3–coal co-firing experiments. NH3 co-firing experiments were performed under intensive and air-staged combustion conditions using a 5 kW fluidized bed reactor. Air-staged combustion and divided fuel-injection were effective in suppressing NOx formation during NH3 co-firing combustion. The minimum and maximum NO concentration observed during intensive and air-staged combustion was 70 ppm and 700 ppm, respectively. In addition, some NH3 slips were observed under an NH3 co-firing ratio of 20% or more; however, the reduction effect of NO was observed. The NO concentration increased to approximately 500 ppm under pure NH3 combustion. The simultaneous injection of fuel and oxygen under fuel-rich conditions generated NO and N2O. It increased rapidly under incomplete combustion conditions and increased in proportion to the concentrations of HCN and CO. NH3 co-firing was accompanied by the suppression of NO formation and reduction of N2O and CO2 if injected in consideration of the temperature and oxygen concentration.

Comparison between pilot and lab scale testing of aluminide coated and uncoated ferritic steels under oxy-fuel and coal/thistle co-firing conditions

The present study compares the biomass corrosion behavior of two diffusion aluminide coating obtained by slurry application, which were deposited on two low-chromium content steels, ferritic-martensitic P92 (8.7 wt% Cr) and ferritic T22 (2 wt% Cr). Their performance degradation was conducted under an oxy-fuel combustion environment for both coated and uncoated materials both under laboratory conditions and in a pilot plant burning thistle for 500 h. Exposures were carried out in the laboratory at two different temperatures, 600 °C and 650 °C, under a model atmosphere consisting of 60 % CO2, 30 % H2O, 8 % O2, bal.% N2 (in vol%), 500 vppm HCl and 2 vppm SO2. The pilot plant used a mixed fuel of 60 wt% coal and 40 wt% thistle that was burnt and the samples were exposed to a temperature range of 600–620 °C. After testing, the results revealed that the aluminide-coated materials exhibited a very high resistance under both extreme scenarios, with a variable protective character related to their Al content. On the contrary, uncoated material exhibited severe degradation, in particular T22. Microstructural and morphological studies showed up similar corrosion patterns and products on coated and uncoated materials for both testing environments.

Emission Characteristics of Gaseous and Particulate Mercury from a Subcritical Power Plant Co-Firing Coal and Sludge

Field tests were carried out in a subcritical coal-fired power plant co-firing coal and sludge to analyze the emission characteristics of gaseous and particulate mercury. EPA30B method was applied to determine the mercury speciation in different positions of the flue gas, including the inlet and outlet of the selective catalytic reduction DeNOX system (SCR) and electrostatic precipitator (ESP); PM10 (with aerodynamic diameter ≤10 μm) was collected using a cyclone and a Dekati low-pressure impactor (DLPI). Before accessing the SCR, Hg in flue gas from both single coal combustion and co-firing mainly existed as Hg0; the higher content of Hg in sludge than coal led to the much higher Hg0 concentration for co-firing. The total Hg concentration at not only the SCR inlet and outlet but also the ESP inlet did not change obviously. However, Hgp concentration at the ESP inlet increased significantly, accompanied by a decrease in Hg0. The transformation of Hg0 to Hgp appeared to be more distinct for co-firing. The higher HCl concentration of co-firing derived from the much higher Cl content of sludge than coal, and together with the higher ash content of sludge containing more minerals capable of adsorbing Hg0, may lead to the greater transformation from Hg0 to Hg2+ and Hgp when co-firing. After the ESP disposal, nearly all Hgp was removed along with PM10, and most Hg0 was also removed. The removal efficiency of mercury after the ESP was 92.12% under coal firing and 92.83% under co-firing conditions, respectively. The slightly higher mercury removal efficiency under co-firing should be attributed to the complete removal of the higher concentration of Hgp.

Co-firing of coal and biomass under pressurized oxy-fuel combustion mode in a 10 kWth fluidized bed: Nitrogen and sulfur pollutants

Co-firing coal and biomass under pressurized oxy-fuel combustion (POFC) mode in fluidized beds is a novel and promising technology to capture CO2 at a low cost and with eco-friendly waste disposal. However, large knowledge gaps exist in combustion characteristics and pollutant generation owing to the tremendous lack of practices. Following our successful testing of co-firing coal and biomass under POFC mode in a10 kWth pressurized fluidized bed (PFB) [Chem. Eng. J. 2022, 431,133457], this study conducted a special and in-depth investigation of nitrogen and sulfur pollutants. Based on a comprehensive analysis of flue gas and solid residues, the effects of key operating parameters, such as combustion pressure (P), biomass blending ratio (Mb), and combustion temperature (T), on the emissions of gaseous and solid pollutants, transformation and distribution of nitrogen and sulfur, sulfur self-retention (SSR) process, and ash properties and potentials of deposition and agglomeration, were investigated. The results show that increase in P and Mb significantly reduces NOx, N2O, SO2, and CO emissions and improves the SSR efficiency. Notably, the pressurized and co-firing conditions have a synergistic effect on SO2 emission reduction. The T dependence of these products under POFC mode is clearly less than that under atmospheric oxy-fuel combustion mode. Within the typical operating temperature range of an oxy-fuel PFB, SSR occurs through the direct sulfation route. The ash and bed material have an overall low potential for slagging, fouling, and agglomeration, with no indication of ash-related problems during testing. This work will be helpful for the development of oxy-fuel co-firing in PFBs for CO2 capture.

Effects of the staging position and air−LPG mixing ratio on the combustion and emission characteristics of coal and gas co-firing

Experiments were performed to study the effect of the staging air−liquefied petroleum gas (LPG) mixing ratio and staging position on the exhaust gas emissions and carbon burnout of LPG and coal under co-firing conditions. An air−LPG mixture was supplied at three ratios (10%, 20%, and 30%) to four staging positions: upstream, midstream, downstream, and below the primary combustion zone. The results showed that the combustion was unstable when the staging position was downstream of the primary combustion zone, and the highest carbon monoxide (CO) emission with standard deviation (1500 and 730 ppm, respectively) were observed at a mixing ratio of 30%. Meanwhile, supplying the air−LPG mixture at a mixing ratio of 30% and upstream of the primary combustion zone resulted in the lowest nitric oxide (NO) emission of about 134 ppm. At a mixing ratio of 10%, the mixture was instantaneously burned out at the staging position on the inner wall of the furnace, which had a negative effect on the burnout performance. The air−LPG mixing ratios of 20% and 30% staged upstream of the primary combustion zone had a synergistic effect on the reduction of CO and NO emissions and the burnout performance.

Mitigating CO2 emission in pulverized coal-fired power plant via co-firing ammonia: A simulation study of flue gas streams and exergy efficiency

Coal-fired power plants are one of the major sources of CO2 emission, and the novel application of directly co-firing the carbon-free fuel ammonia into the coal-fired power plants is emerging as a promising method of CO2 emission reduction. In this study, simulations of the boiler system of a 600 MWe coal-fired power plant unit were performed in both coal-fired condition and ammonia-coal co-firing conditions, and the impacts of ammonia co-firing on the emission and thermal properties of flue gas, exergy loss, and exergy efficiency were analyzed. Two co-firing scenarios (identical adiabatic flame temperature scenario and identical excess air coefficient scenario) were compared, both assuming that the total heating value of the fuel into the furnace kept unchanged with different ammonia co-firing ratios (5%, 10%, 15%, 20% on heating value basis). The results showed that CO2 emission was effectively reduced by 24.08 t/h for every 5% increase in the ammonia co-firing ratio. The amount of total flue gas was also reduced while both the content and the emission rate of H2O were increased with ammonia co-firing. Consequently, the specific heat capacity of flue gas increased and further changed its temperature distribution profile. Compared with the coal-fired base case, the exergy loss in the furnace under the ammonia co-firing conditions increased continuously as the ammonia co-firing ratio increased, suggesting that the irreversible loss of the ammonia combustion process was greater than that of coal. By contrast, the exergy loss of heat exchangers and fans decreased in ammonia co-firing conditions. Finally, the exergy efficiency of the boiler system was only slightly reduced (53.82% vs. 53.27%–53.22%) in ammonia co-firing conditions, showing that co-firing ammonia in coal-fired power plant would not significantly deteriorate the thermal economy.

Fundamental Study on Ammonia Low-NOx Combustion Using Two-Stage Combustion by Parallel Air Jets

Ammonia, which has advantages over hydrogen in terms of storage and transportation, is increasingly expected to become a carbon-free fuel. However, the reduction of fuel NOx emitted from ammonia combustion is an unavoidable challenge. There is the report that two-stage combustion with parallel independent jets could achieve Low-NOx combustion under ammonia/methane co-firing conditions. In order to further improve NOx reduction, we experimentally evaluated the effects of secondary air nozzle parameters, such as nozzle diameter and nozzle locations, on combustion characteristics in two-stage combustion of ammonia/natural gas co-firing using parallel independent jets. As a result of the experiments under various secondary air nozzle conditions, it was found that under the conditions where NOx was significantly reduced, the peak temperature in the furnace was observed at 300–500 mm in the axial direction from the burner, and then the temperature decreased toward the downstream of the furnace. We assumed that this temperature distribution reflected the mixing conditions of the fuel and secondary air and estimated the combustion conditions in the furnace. It was confirmed that the two-stage combustion was effective in reducing NOx by forming a fuel rich region near the downstream of the burner, and the lean combustion of the unburned portion of the first stage combustion with secondary air. We confirmed that the low NOx effects could be achieved by two-stage combustion using independent jets from the same wall under appropriate combustion and air nozzle conditions.

A comprehensive analysis of recombination and resistive losses in silicon solar cells induced by co-firing process

In this paper, we critically assess and present characterization methods to observe the impact of co-firing conditions initially on global parameters and subsequently, on local parameters of solar cells. Two different schemes, namely Scheme-A and Scheme-B, where the former is a closed and static system and the latter is an open and dynamic system are used to achieve two different co-firing conditions. Solar cells co-fired with these schemes are used in this study for investigating both global as well as the local performance parameters, majorly responsible for the losses in solar cells. In order to investigate the lateral variations of the diode parameters contributing to the loss mechanisms, combination of spatially resolved measurements have been carried out including light beam-induced current, photoluminescence and dark lock-in thermography. The proposed set of characterizations and methodology qualitatively compare the local two diode model parameters of each pixel in the spatially resolved images of a solar cell, responsible for the losses in all three performance parameters; open circuit voltage, short circuit current density and fill factor. The analysis reveals that even optimum firing conditions in two different schemes affect the surfaces in different ways where recombination and resistive losses become major contributors towards the power losses, primarily reverse saturation current density for first diode J01 and series resistance Rs. The characterization methods suggested are expected to become more significant during co-firing of advanced solar cell structures like passivated emitter and rear contact (PERC) solar cells where surface modifications are done to improve the solar cell output parameters.

Transient LES based CFD modeling of coal-biomass co-firing combustion

Transient simulation using Large-Eddy Simulation of multiphase coal/biomass gasification has been conducted to evaluate the design of an entrained flow reactor to produce syngas. This work considers fast and slow fuel devolatilization, volatile and oxygen transport, chemical reaction and heat release, soot formation, diffuse radiation in the combustion zone and radiation to surrounding objects. Reaction rates and radiation parameters are based upon a local equivalence ratio calibrated against experimental data. This work evaluates reactor design for various co-firing conditions with model verification performed by comparing predictions to measured values of an experiment published by the Advanced Combustion Engineering Research Center. Results confirm the importance of small particles in flame stabilization and overall combustion efficiency.

석탄-바이오매스 혼소에 따른 슈퍼히터 튜브 고온 부식 특성 연구

석탄-바이오매스 혼소에 따른 슈퍼히터 튜브 고온 부식 특성 연구

Co-firing of coal/biomass blends in a pilot plant facility: A comparative study between Opuntia ficus-indica and Pinus radiata

Chile has begun to promote the use of biomass to replace a fraction of the energy produced from coal. However, the power plants are located in the world driest desert, the Atacama Desert, and far from the forest resources. Fortunately, a cactaceous species named Opuntia ficus-indica, has proven to be able to grow under climate desert conditions. In this study the behavior of Opuntia ficus-indica under co-firing conditions with coal, is evaluated and compared to that of Pinus radiata, in terms of heat transfer, ash deposits formation and pollutant emissions in a 150 kW fluidized bed pilot plant. The results revealed a variation of the temperature profile inside the reactor, as well as a relationship between the efficacy factor and the base-acid ratio. The heat transfer coefficients in the dense bed evidenced a decrease in the heat transfers mechanisms attributed to a variation of the mean particle diameter and a greater presence of fuel particles. Under coal-Pine co-firing conditions, an increase in NO formation and a decrease of PM and SO2 concentrations was observed. While co-firing coal with Opuntia showed an increase in the particulate matter and a reduction of NO and SO2 concentrations.

Ash deposition behavior under coal and wood co-firing conditions in a 300 kW downfired furnace

Growth of ash deposits when wood was co-fired with coal was visually investigated in a 300 kW pilot-scale furnace. For comparison, combustion of pure coal was also conducted. A total of 10% and 20% wood were mixed with coal. The thickness and heat flux were obtained. The collected ash deposits and fly ash were characterized by a series of analysis methods to determine the physical and mineral properties. Their relationships were also revealed. Results showed that co-firing of coal with wood dramatically increased the ash deposition propensity. During the coal combustion, shedding of ash deposit occurred and the maximum deposit thickness was 15.33 mm. A deposit thickness of up to 27.02 mm was achieved for 10% wood, and the thickness increased to 34.20 mm for 20% wood. The variation in heat flux with deposit thickness substantially changed when wood was co-fired. A significant change was also observed in the mineral composition of ash deposit with the increase in wood ratio. The proportion of anorthite increased because that of lime in fly ash increased with wood ratio. In addition, the mean diameter of fly ash particles increased as wood ratio increased.

Analysis of industrial flame characteristics and constancy study using image processing technique

The study of characterizing and featuring different kinds of flames has become more important than ever in order to increase combustion efficiency and decrease particulate emissions, especially since the study of industrial flames requires more attention. In the present work, different kinds of combustion flames have been characterized by means of digital image processing (DIP) in a 500 kW PF pilot swirl burner. A natural gas flame and a set of pulverized fuel flames of coal and biomass have been comparatively analyzed under co-firing conditions. Through DIP, statistical and spectral features of the flame have been extracted and graphically represented as two-dimensional distributions covering the root flame area. Their study and comparison leads to different conclusions about the flame behavior and the effect of co-firing coal and biomass in pulverized fuel flames. Higher oscillation levels in co-firing flames versus coal flames and variations in radiation regimen were noticed when different biomasses are blended with coal and brought under attention.