Premixed Methane Flames Research Articles

Regional polarity in the laminar premixed flame considering the combined effect of positive and negative charge

The study of flame charge is helpful in analyzing the combustion regime, which is significant for optimizing energy conversion in the combustion. In this article, a method to calculate the charge density considering polarity (CDCP) for flame is presented. The charge in the flame local area is obtained by combining the effect of charged particles with positive and negative polarity. The CDCP in different zones of the premixed methane flame with three equivalence ratios of 0.9, 1.0, and 1.3 is measured in the Langmuir probe measurement experiment. The experiment result found that the regional polarity is shown in the premixed flame. Subsequently, the premixed methane flame was simulated using Fluent, and then the simulation distribution of CDCP in the premixed methane flame was obtained. The CDCP and polarity across the reactant, preheat, reaction, and product zones of the premixed flame are analyzed based on the experiment and simulation results. The CDCP of the reaction zone is greater than 0 C/m3 and reaches a peak, showing obvious positive polarity. The CDCP of the reactant zone is less than 0 C/m3, showing negative polarity. The CDCP changes rapidly from less than 0 C/m3 to greater than 0 C/m3 with the approach of the reactant zone to the preheating and reaction zones. The CDCP in the product zone gradually decreases with the increase of the distance from the reaction zone and finally less than and close to 0 C/m3, showing weak negative polarity. Finally, the cause of regional polarity formation is discussed based on the net production rate of charged particles and the velocity distribution of the flow field in the simulation results. The distribution of positive ions and electrons in the premixed flame is different due to the effect of the flow field and the different diffusion properties of charged particles. Thus, the regional polarity is exhibited in the premixed flame.

The effects of acoustic disturbances and mechanical vibration on laminar premixed flames: A comparative study

The energy conversion between the combustion process and acoustic waves is very complex in high-performance propulsion systems, which may trigger large-amplitude combustion instabilities, potentially leading to severe vibration or structural damage. Both acoustic disturbances and mechanical vibration are found to be able to cause the combustion instability, but their differences on the influence of laminar premixed flames are still unknown. In this paper, a premixed methane flame burner was disturbed by either a loudspeaker or an electromagnetic vibration exciter, and the effects of their forcing frequencies and amplitudes on the dynamic responses of the premixed methane flame were evaluated. Specifically, the unsteady heat release rate was measured by a photomultiplier tube, and the flame dynamic behaviors were captured by a high-speed camera with image intensifier. Furthermore, the acoustic disturbances upstream of the flame was measured by the two-microphone method, and the structure vibration was measured by an accelerometer. Then, the flame transfer functions were obtained at various equivalence ratios and mean flow velocities. The results demonstrated that the premixed flame exhibited obvious band-pass filtering characteristics when subjected to external forcing, whether through a loudspeaker or an electromagnetic vibration exciter. In addition, increasing either acoustic or structure excitation amplitude to a large extent can make the flame respond in a nonlinear manner. However, when the flame was subjected to mechanical vibration, the peak frequency corresponding to the maximum gain of the flame transfer function had minimal sensitivity to variations in equivalence ratios and mean flow velocities. In contrast, the acoustic disturbances were more likely to induce the nonlinear flame responses and flame front wrinkling.

Development of Equivalence Ratio Measurement Model of Premixed Methane Flames Using Hyperspectral Imaging of C2* and CH* Chemiluminescence and Random Forest Algorithm

ABSTRACT The C2*/CH* model is often used to measure the equivalence ratio of combustion. But only the band of C2*(0,0) at 516.5 nm of the C2* swan band system was employed as the input of the C2*/CH* model for equivalence ratio measurement. The relations of other components of the C2 swan band system with flame equivalence ratios and their impact on this equivalence ratio measurement are unreported. In this study, the visible emission spectrum of premixed methane flame, ranging from 425 to 700 nm, was measured/obtained by a hyperspectral imaging system under equivalence ratios from 0.72 to 1.52. The influence of the C2* swan bands on the C2*/CH* model was analyzed, and the intrinsic characteristics of the C2* swan bands were found. After that, a more sensitive soft measurement model for equivalence ratio measurement based on the ratio of C2*(0,0)/C2*(2,0) was proposed. The monotonicity and stability of the proposed model were discussed. At last, the proposed model was further validated by the random forest (RF) algorithm.

Measuring methane destruction efficiency in gas flares with dual comb spectroscopy

Gas flaring is used as an alternative to venting when waste gases cannot be captured from industrial processes such as oil and natural gas production, chemical processing, and waste management. In the oil and natural gas production sector alone, an estimated 3.5 % of total global natural gas production is flared. Survey studies have shown that the methane destruction efficiency (DE) of flares is lower than expected due to real-world conditions (weather and equipment malfunction) and estimate that improving flare efficiency is a 0.5 Tg/yr methane emissions reduction opportunity. Continuous monitoring of flare DE would provide the opportunity for feedback to lower emissions; however, there are currently no technologies used at scale that can provide such a measurement. Here we present a method for measuring the operational methane DE from flares by monitoring methane levels in flares using dual-frequency comb spectroscopy. This method leverages the temperature-dependent absorption fingerprint of methane to differentiate heated and ambient methane. We assess the capabilities of this technique through a set of laboratory-based experiments utilizing a partially premixed methane flame. We estimate the limit of detection (LOD) and sensitivity of the measurements for directly monitoring a flame, and monitoring a flame from a distance of 1 km in the presence of ambient methane. For our configuration, a targeted monitoring scenario (direct flame measurement) results in the ability to distinguish methane DE up to 99.9 %; whereas in the presence of a 1 km background methane signal, the approach is able to quantify methane DE to 97.5 %. These performance metrics could be improved through an updated high-temperature spectral absorption database for methane, however the current estimated performance could already substantially impact flare emissions by closing the gap between the flare design specifications and what research studies estimate from actual in-field performance.

Optical Study on the Effects of Methane Equivalence Ratio and Diesel Injection Mass on Diesel-Ignited Methane Combustion Process

Pilot diesel ignition is an effective approach for achieving efficient and clean combustion of natural gas. In this study, a rapid compression and expansion machine (RCEM) was constructed for examining diesel-ignited premixed methane combustion. The effects of the methane equivalence ratio and pilot diesel mass on the combustion process of diesel-ignited premixed methane gas were investigated. The results show that the combustion process can be divided into two stages: diesel dominance and premixed methane combustion. An increase in the methane equivalence ratio inhibits diesel combustion, leading to delayed CA10 and OH radical generation. However, it enhances premixed methane flame propagation and improves the heat release rate, resulting in a shorter combustion duration. An increase in the pilot diesel mass contributes to a larger flame area and higher OH generation intensity in the ignition region; however, too large a diesel mass inhibits methane flame propagation towards the diesel nozzle due to an extended injection duration. In conclusion, a larger pilot diesel mass can achieve better overall combustion performance, but excessive amounts may be counterproductive.

Effects of local temperature on carbon nanotubes growth in premixed flame

The growth of carbon nanotubes (CNT) in flame requires imperative conditions that are difficult to achieve in a highly heterogeneous environment. Therefore, the analysis of the properties of the reaction zone within the flame is critical for the optimal growth of CNT. In the present study, a comprehensive analysis of the CNT synthesis using premixed methane flame is conducted regarding the morphology and crystallinity of the grown products. The premixed burner configuration created a flame that is stabilized across axisymmetric stagnation flow through sintered metal, making the flame one-dimensional. As a result, a relatively uniform temperature distribution is achieved across radial directions but 17% temperature different in vertical distances, causing a difference in the characteristic pattern of the growth products. A 44% of CNT diameter variation was observed between high and low height-above-burner (HAB). Additionally, 66% variation ID/IG ratio was observed on the same HAB range. The relationship between temperature distribution, morphology, and HAB created a simpler control parameter that can be further optimized for better yield.

Effect of hydrogen addition on the consumption speed of lean premixed laminar methane flames exposed to combined strain and heat loss

This study presents a numerical analysis of the impact of hydrogen addition on the consumption speed of premixed lean methane-air laminar flames exposed to combined strain and heat loss. Equivalence ratios of 0.9, 0.7, and 0.5 with fuel mixture composition ranging from pure methane to pure hydrogen are considered to cover a wide range of conditions in the lean region. The 1-D asymmetric counter-flow premixed laminar flame (aCFPF) with heat loss on the product side is considered as a flamelet configuration that represents an elementary unit of a turbulent flame and the consumption speed is used to characterise the effect of strain and heat loss. Due to the ambiguity in the definition of the consumption speed of multi-component mixtures, two definitions are compared. The first definition is based on a weighted combination of the consumption rate of the fuel species and the second one is based in the global heat release rate. The definition of the consumption speed based on the heat release results in lower values of the stretched flame speed and even an opposite response to strain rate for some methane-hydrogen-air mixtures compared to the definition based on the fuel consumption. Strain rate leads to an increase of the flame speed for the lean methane-hydrogen mixtures, reaching a maximum value after which the flame speed decreases with strain rate. Heat loss decreases the stretched flame speed and leads to a sooner extinction of the flamelet due to combined strain and heat loss. Hydrogen addition and equivalence ratio significantly impact the maximum consumption speed and the flame response to combined strain rate and heat loss. The effect of hydrogen on the thermo-diffusive properties of the mixture, characterised by the Zeldovich number and the effective Lewis number, are also analyzed and related to the effect on the consumption speed. Two definitions of the Lewis number of the multi-component fuel mixture are evaluated against the results from the aCFPF.

Premixed combustion and emission characteristics of methane diluted with ammonia under F-class gas turbine relevant operating condition

Ammonia has been used on a small scale in other industrial equipment, such as gas turbines, as a carbon-free fuel. However, ammonia fuel suffers disadvantages such as high ignition temperature, low flame velocity and high NOx emissions. Doping with ammonia using a more reactive fuel, such as methane, can solve the above problems. Therefore, under the relevant operating conditions of the gas turbine (T = 723 K, p = 16.5 atm), the effect of ammonia content on the combustion and emission characteristics of laminar premixed methane flames was numerically investigated. This research uses the PREMIX code from ANSYS CHEMKIN-PRO 2020 and Okafor chemical kinetic mechanisms and provides a reference for our subsequent analysis of gas turbine operating conditions. Firstly, the emission data of major pollutants under different ammonia content (XNH3 = 0–1.0) and equivalent ratio (Φ = .6–1.4) were calculated. Then, the laminar premixed flame structure is analyzed under the lean fuel conditions associated with gas turbines (Φ = .6, .8). Finally, the effect of ammonia addition on the chemical reaction path of NO and CO emission was studied. The results show that ammonia/methane mixture fuel is more suitable for combustion at .6 < Φ < .8 under high temperature and pressure. High ammonia content (XNH3 > .6) and low equivalent ratio can reduce NO and CO emissions. The molar fractions of H, O, and OH radicals and flame temperature decreased with the increase in ammonia content. In addition, high temperature and high pressure conditions and ammonia content greatly influence the reaction path of NO and CO production. The increase in pressure resulted in a change in the primary reaction that produced NO. In conclusion, this study guides reducing the emission of NO and CO from lean side of gas turbine plants.

Effect of helium dilution on the dynamic stability of lean premixed methane flame in a model gas turbine combustor

Today, where clean, renewable and high efficiency energy production gains importance, methane gas draws attention due to its low carbon content. In this study, flame instability and temperature of methane gas were tested in a premixed model gas turbine combustor at different helium dilution conditions. The burner power was kept constant as 3 kW and the equivalence ratio as 0.7. In addition, a swirl generator with a swirl number of 1 is placed at the burner outlet. The dynamic pressure values of the flame were recorded under external acoustic enforcements at different frequencies applied to the flame and thermo-acoustic combustion instability was interpreted. Methane flame diluted with Helium at 10, 20, 30, 40 and 45 volumetric ratios showed the following results. If helium dilutions of up to 20% did not significantly affect flame instability, instability increased at 30% He. After this critical value, when 45% He dilution was tested, the lowest instability value was determined. In addition, the burner exit temperature of the flame decreased at all helium dilution ratios.

Analysis of Lewis number effects on dynamic response of laminar premixed flames

The dynamic response of premixed flames with different fuel Lewis numbers is crucial to understand for the design of safe combustion chambers with wide operating range. Due to preferential diffusion effects associated with fuel Lewis number for lean mixtures, a premixed flame responds differently to flame stretch. These responses could manifest in the flame’s response to small perturbations. In order to investigate this effect, in this study, lean premixed hydrogen, methane and propane flames at the same adiabatic unstretched flame speed are studied using numerical simulations. Steady unperturbed flames show significant differences in flame stand-off distances, flame height, flame stabilization limits, burner temperature and recirculation zone length. Flames are perturbed using a step function excitation and noticeable changes in the gain and phase of the flame transfer function are found even when the flame burning velocity and the inlet flow speed are kept the same. Maximum gain of the response is found to increase with the mixture Lewis number and is shown to be directly dependent on the flame tip burning strong or weak. Phase difference at low frequencies is found to depend on the average of the time scales of the recirculation vortex which in turn depends on the flame burning stronger or weaker under the influence of positive stretch at the flame base, axial convective wave and perturbation travelling along the flame front. Time for the flame to settle to a new position after the step excitation is found to correlate well with the sum of time scales of vortex, flame tangential speed and flame tip speed. Overall, it is found that hydrogen flame responds the fastest to the perturbations and exhibits smaller increase in gain compared to methane and propane.

An empirical formula to predict the overall irreversibility of counter-flow premixed flames of methane and its mixtures

An empirical formula to predict the overall irreversibility of counter-flow premixed flames of methane and its mixtures

Numerical Prediction and Suppression of Thermoacoustic Longitudinal Mode in Annular Combustor

Many industrial applications, such as gas turbines or aeroengines, are subject to thermoacoustic instability, especially in the lean combustion regime. In this paper, the linearized Navier–Stokes equations (LNSEs) framework is applied to predict the acoustic liner damping effects with real geometry and different bias flow velocities. The results show that the LNSEs can capture the tilt angle effect of the orifice or grazing and bias flow coupling phenomenon. The forced large-eddy simulation results of premixed methane flame present the same trend in gain and phase of the flame transfer function with the equation. Then, the flame response model is coupled into the Helmholtz and LNSE solvers. The mean flow from Reynolds-averaged Navier–Stokes calculation is used in the LNSEs, and no assumption of liner geometry is made. The linear stability analysis reveals that the velocity fluctuation in the combustion is also damped when a stable acoustic mode is achieved with the acoustic liner. The flame dynamic, the hydrodynamic, and the acoustic phenomena can all be considered when using the LNSEs. This indicates that the LNSEs may allow us to consider a more complex mechanism that can affect the thermoacoustic inability in the combustor system and help us to design better dampers to control.

Rate-Ratio Asymptotic Analysis of Strained Premixed Laminar Methane Flame Under Nonadiabatic Conditions

ABSTRACT Motivated by the pioneering activation-energy asymptotic analysis of strained laminar premixed flames in counterflow by Libby and his coworkers, a rate-ratio asymptotic analysis is carried out to elucidate the structure and predict the critical conditions of extinction of strained premixed methane flames. Steady, axisymmetric, laminar flow of two counterflowing streams: a reactive mixture stream and a product stream toward a stagnation plane is considered. The temperature of the reactive mixture stream is and it is made up of methane (CH4), oxygen (O2) and nitrogen (N2), while the temperature of the product stream is , and it is made up of O2, carbon dioxide, water vapor and N2. The asymptotic flame structure is presumed to be made up of a thin reaction zone where all chemical reactions take place. On one side of the reaction-zone is an inert, preheat zone containing the reactants and on the other side a post-flame zone made up of products. Analysis of the preheat zone gives matching conditions that is required to analyze the structure of the reaction zone. A four-step, reduced mechanism is used to describe the chemical reactions. The reaction zone is presumed to be made up of an inner layer, where CH4 is consumed. The hydrogen (H2) and carbon monoxide that are formed in this layer are consumed in an oxidation layer that is made up of two layers: an H2-oxidation layer and a CO-oxidation layer. The results of the analysis are used to predict the flame location, , flame temperature, , and the speed of the convective flow, , in the reaction zone as a function of the strain-rate, . Classical C-shaped curves were obtained when , and are plotted as a function of and they were used to predict extinction. A key finding of this work is that is proportional to , where is the crossover temperature predicted by the rate-ratio asymptotic analysis. Whether abrupt extinction will take place or not was found to depend on the value of relative to , which is different from the predictions of activation-energy asymptotic analysis where must be compared with the value of the adiabatic temperature. Similar to the analysis of Libby and his coworkers, the rate-ratio asymptotic analysis predicts the existence of “negative flame speeds,” where the convective flow and the diffusive flow of reactants in the reaction zone, are in opposite directions. The predictions of the rate-ratio asymptotic analysis were found to agree with the results of computations with detailed chemistry and previous experimental data.

Hydrogen as a fuel additive in laminar premixed methane flames: Impact on the nucleation and growth of soot particles

This work reports new experimental data regarding the impact of H2 on slightly sooting methane flames (Φ–1.91) characterized by the formation of soot particles undergoing growth processes. This study has been carried out in three atmospheric sooting premixed methane flames with added H2 (2% of the total flowrate) or substituted (10% molar comparing to CH4 fuel).The mole fraction profiles of selected aliphatic and aromatic compounds (C1-C16) have been measured by Gas Chromatography and Jet-Cooled Laser-Induced Fluorescence. Concerning the soot particles, we have implemented for the first time an analytical methodology based on in-situ measurements by Laser-induced Incandescence and Cavity Ring-Down Spectroscopy coupled with ex-situ measurements by Scanning Mobility Particle Sizing (SMPS). This original approach allows to determine the soot volume fraction profiles and corresponding evolution of the particle number density and particles size density function without requiring accurate knowledge of the dilution ratio during SMSP measurements.The reported data highlight that the introduction of H2 strongly influences the formation of aromatic species and soot depending on the operating conditions (H2 addition or substitution). The impact of H2 was evaluated on the nucleation step and the soot growth processes. In that context, we notably show that the H2 substitution inhibits while the H2 addition favors the formation of nascent soot particles, and furthermore the H2 addition generates substantial modifications in the dynamic of the soot growth processes. This work also supports the idea that the onset of the particle nucleation might be controlled by specific concentration thresholds of aromatic precursors.

Imaging-based harmonic frequency analysis of a bluff-body premixed flame under acoustic excitations

The dynamic responses of a bluff-body premixed methane flame under acoustic excitations were studied using high speed color and schlieren imaging techniques. Two excitation frequencies at different amplitudes were tested and analyzed (50 Hz-105, 110, 115 dB and 200 Hz-120, 125, 130 dB). The fast Fourier transform (FFT) analysis reveals the dominant excitation frequency, as well as several harmonic frequencies as nonlinear responses. The dynamic mode decomposition (DMD) analysis was conducted using the time-resolved color and schlieren images to extract the spatial pattern at the dominant and multiplication harmonic frequencies. The results indicate that under these frequencies, the energy distribution has exhibited axisymmetric patterns to the nozzle axis, with positive and negative energy bands appearing alternatively. The spatial distribution has shown great variances under different excitation frequencies and amplitudes. An energy band sub-dividing phenomenon at multiplication frequencies was observed from the DMD results of both color and schlieren images.

Quantification of the size, 3D location and velocity of burning iron particles in premixed methane flames using high-speed digital in-line holography

Due to its low emission and high energy density, iron powder has been proposed as a promising recyclable metal fuel for a future low-carbon society. The comprehensive understanding of combustion behavior of iron particles is crucial for studying fundamental mechanisms, developing suitable combustion technologies, and designing efficient iron powder combustor. In this work, iron particles are combusted in a modified Bunsen burner with a stable metal powder supplying system. As a versatile three-dimensional (3D) imaging technique, high-speed digital in-line holography (DIH) is employed to reconstruct the 3D particle field and simultaneously quantify the size, 3D location and velocity of burning iron particles. The statistical results of three cases with oxygen volume fraction varying from 24% to 40% are obtained and compared at different heights above the burner. Along the height, some typical features of the burning iron particles were observed. The violent combustion of iron particles accelerates the ejection of the particles radially outward from the central region of the flame, resulting in non-uniform spatial distribution of the particles and reducing the particle number density in the measurement volume. Such trend is enhanced with increased oxygen concentration. Besides, the observed particle size enlarged as the height increases, which validates the swelling phenomenon of iron particle oxidation. The results demonstrate that DIH is a powerful tool for in-situ, quantitative characterization of particle dynamics in flames.

Effects of jet diameter and spacing in a micromixer-like burner for clean oxy-fuel combustion in gas turbines

The effects of jet diameter and spacing on flame structure and stability are examined in an oxy-methane micromixer-like burner for potential implementation in zero-emission gas turbines. Three burner headend geometries (HE1, HE2, and HE3) are compared at fixed flame-base velocity of 5.2 m/s and over ranges of equivalence ratio and oxygen fraction (O2 vol% in the O2/CO2 oxidizer). HE1 has 61 jets of 3.175-mm diameter, arranged on a hexagonal matrix with a uniform jet spacing of 5.5 mm. HE2 has 37 jets of 3.970-mm diameter (25% increase), also arranged hexagonally with a spacing of 5.5 mm. HE2 has fewer jets to maintain almost the same combustor power. HE3 is similar to HE2, but with a jet spacing of 7.0 mm (27% increase). The three blowout limits were found to be only ∼45 K apart, despite the considerable differences in jet diameter and spacing, which demonstrates the remarkable geometry flexibility of micromixers. HE1 outperformed HE2 and HE3. Increasing the jet diameter adversely affects flame stability, because the burner deviates from the stable lean-direct-injection concept. Increasing jet spacing is also unfavorable. The adiabatic flame temperature is the primary parameter controlling the structure and stability of premixed methane flames for different burner geometries.

CO emissions and temperature analysis from an experimental and numerical study of partially premixed methane flames impinging onto a cooking pot

The increase of thermal efficiency compatible with low carbon monoxide (CO) emissions is a challenging and permanent target in the design of any burning technology such as domestic gas cooking burners. The main goal of this work is to provide a deeper insight into the CO formation and its relationship with the flame structure when natural gas (NG) is burnt in these devices. Given their geometrical complexity, a simpler configuration is employed to carry out new experimental tests assuming similar operating conditions. Then, numerical modeling is validated and subsequently used to deeply analyze the flame-wall interaction phenomena. The simplified burner consists of an axisymmetric, partially premixed methane flame impinging perpendicularly onto the bottom wall of a water pot. The influence of burner-to-pot distance, flame thermal power, primary aeration and inside-pot water temperature on CO emissions and thermal efficiency is evaluated. A decrease in CO emissions is observed as primary aeration or wall temperature increases. Nevertheless, non-monotonic trends appear for changes in burner-to-pot distance or flame thermal power. The trends are numerically well captured selecting the detailed GRI-Mech 3.0 chemistry mechanism. The analysis of the computational results reveals that CO emissions and thermal efficiency are strongly related to the relative boundary position of the inner premixed flame cone and the wall. The growth of the distinct zones of the flame where CO chemically reacts with primary and secondary air is constrained by the presence of the pot wall. This fact drives the final CO concentration, and incidentally the thermal efficiency, leading to a factual criterion for the design of NG burners.

Experimental study of the influence of hydrogen as a fuel additive on the formation of soot precursors and particles in atmospheric laminar premixed flames of methane

We report here the experimental investigation of lightly sooting methane premixed flames with and without hydrogen. Two different approaches were considered to introduce hydrogen in the methane flame, either by keeping the total gas flow rate constant or not. Speciation data were obtained using a set of analytical tools including Gas Chromatography, Fourier-Transform Infrared Spectroscopy, Jet-Cooled Laser-Induced Fluorescence, Laser-induced Incandescence coupled with Cavity Ring-Down Spectroscopy.The results include mole fraction profiles of gaseous species (C0-C16) and soot volume fraction (fv) measured in all studied flames. These results demonstrate that the introduction of hydrogen to the flame insignificantly impacts the maximum mole fractions of small species (<C6) while it strongly influences the concentration of aromatics and fv. Interestingly, this influence is different, depending on how hydrogen was added to the reference methane flame. An excellent linear relationship between pyrene squared concentration [C16H10]2 and fv is demonstrated in all investigated flames. Moreover, hydrogen addition changes the slope of these data indicating a non-negligible impact of hydrogen on the rate of the soot nucleation process. These data and the observed linearity between fv and [C16H10]2 supports therefore the idea of a soot nucleation step initiated by a dimerization process implicating moderate-size polyaromatic hydrocarbons (PAHs) as pyrene. Finally, we note that PAH mole fractions at the beginning of soot formation highlight similar values regardless the flame conditions, which suggests that the inception of the soot formation might be dependent of a minimum concentration threshold of aromatic precursors required to initiate the soot nucleation process.

Experimental and modeling study of the high-temperature combustion chemistry of tetrahydrofurfuryl alcohol

Lignocellulosic tetrahydrofuranic (THF) biofuels have been identified as promising fuel candidates for spark-ignition (SI) engines. To support the potential use as transportation biofuels, fundamental studies of their combustion and emission behavior are highly important. In the present study, the high-temperature (HT) combustion chemistry of tetrahydrofurfuryl alcohol (THFA), a THF based biofuel, was investigated using a comprehensive experimental and numerical approach.Representative chemical species profiles in a stoichiometric premixed methane flame doped with ∼20% (molar) THFA at 5.3 kPa were measured using online gas chromatography. The flame temperature was obtained by NO laser-induced fluorescence (LIF) thermometry. More than 40 chemical products were identified and quantified. Many of them such as ethylene, formaldehyde, acrolein, allyl alcohol, 2,3-dihydrofuran, 3,4-dihydropyran, 4-pentenal, and tetrahydrofuran-2-carbaldehyde are fuel-specific decomposition products formed in rather high concentrations. In the numerical part, as a complement to kinetic modeling, high-level theoretical calculations were performed to identify plausible reaction pathways that lead to the observed products. Furthermore, the rate coefficients of important reactions and the thermochemical properties of the related species were calculated. A detailed kinetic model for high-temperature combustion of THFA was developed, which reasonably predicts the experimental data. Subsequent rate analysis showed that THFA is mainly consumed by H-abstraction reactions yielding several fuel radicals that in turn undergo either β-scission reactions or intramolecular radical addition that effectively leads to ring enlargement. The importance of specific reaction channels generally correlates with bond dissociation energies. Along THFA reaction routes, the derived species with cis configuration were found to be thermodynamically more stable than their corresponding trans configuration, which differs from usual observations for hydrocarbons.