CH4 Pyrolysis Research Articles

MCM-41 from rice husk silica as a support for Ni catalyst in the emission-free production of H2 by CH4 cracking.

Selecting a sustainable source of silica from biomass waste was the research challenge that was put forth in this investigation. Herein, the MCM-41 support has been synthesized using a renewable rice husk and explored as a support for Ni-Cu catalyst in the production of zero-emission H2 through CH4 pyrolysis. The role of Cu promoter was investigated by doping different amounts of Cu loading to 30wt%Ni/R-MCM-41catalyst, which improved the catalytic performance in terms of CH4 conversion and stability. An optimum Cu loading of 3wt% addition to 30wt%Ni/R-MCM-41 catalyst demonstrated the best catalytic performance compared to all the catalysts in terms of hydrogen yield (15,218mol H2/mol Ni) and carbon formation rate. The Ni-Cu alloy formation was confirmed by X-ray diffraction, H2-temperature programmed reduction, and pulse chemisorption studies, as demonstrated by decreased H2 uptake (from 41 to 33μmol/gcat) and enhanced N2O (from 89.2 to 138.3μmol/g) uptakes, which results in a significant improvement in the availability of the surface metal species (both Cu and Ni), which in turn contributed to increase the CH4 cracking performance and stabilization of Ni species. Additionally, doping Cu results in better carbon nanotube production, as shown by the lowest ID/IG ratio from the Raman spectroscopic analysis.

Investigating the formation of soot in CH4 pyrolysis reactor: A numerical, experimental, and characterization study

Methane pyrolysis is a promising method for eco-friendly hydrogen production, but soot formation and carbon interaction pose challenges for scaling up. Therefore, understanding the dynamics of soot formation and carbon deposition is crucial. This study delves into the intricacies of soot formation in methane pyrolysis under industrially relevant conditions, namely operations at atmospheric pressure, employing a H2:CH4 ratio of 2 and exploring a range of hot zone temperatures (1473 K, 1573 K, 1673 K, and 1773 K) with a 5 s residence time. Utilizing a detailed gas-phase kinetic model with direct carbon deposition reactions, the research adopts the method of moments coupled with a one-dimensional plug flow reactor model to simulate soot formation. The model is validated by characterizing soot particles that were produced in a pyrolysis reactor by means of transmission electron microscopy, Dynamic light scattering (DLS), and Raman spectroscopy. Results show that lower temperatures lead to nucleation-dominated growth, whereas higher temperatures significantly restrain particle growth due to carbon deposition. DLS data indicate a complex balance between particle growth and deposition processes. These findings provide insights into operational parameters that can enhance reactor performance and sustainability in hydrogen production processes by mitigating soot and carbon deposition.

Catalytic and non-catalytic reactions of methane pyrolysis for hydrogen production in screening and electromagnetic levitation reactors using computational fluid dynamics

Molten metal (MM)-based methane (CH4) pyrolysis is a promising technology for clean hydrogen production with a minimal carbon footprint. Electromagnetic levitation (EMLR) and screening reactors (SR) were used to investigate the intrinsic catalytic reaction kinetics of MM-based CH4 pyrolysis. Heterogeneous catalytic reactions in the SR and EMLR occurred on the surfaces of the MM crucible and droplet, respectively. However, a homogenous non-catalytic reaction may occur just above the surface because the CH4 gas is preheated by the high-temperature MM. This study presents three-dimensional (3D) computational fluid dynamics (CFD) model coupled with chemical reactions to assess the extent to which non-catalytic reactions intervene in CH4 pyrolysis in both the SR and EMLR, which is difficult to measure experimentally. The CFD model validated against experimental data revealed that the non-catalytic reaction accounted for 4.0 % of CH4 pyrolysis in the CH4-Ni0.27Bi0.73 SR at 1045 °C, whereas it represented 0.02 % in the CH4-Sn EMLR at 1021 °C. This result highlights that the EMLR is suitable for studying the intrinsic catalytic reaction kinetics of MM-based CH4 pyrolysis because the non-catalytic reaction occurs to a lesser extent.

Revisit the PAH and soot formation in high-temperature pyrolysis of methane

As the major component of natural gas, most basic and stable hydrocarbon molecule, methane (CH4) is an important source in industrial processing. The polycyclic aromatic hydrocarbons (PAHs) and the soot produced in the utilization of CH4 also attract particular attention. In this work, CH4 pyrolysis was studied with gas chromatographs (GCs) and a gas chromatography-mass (GC-MS) spectrometry within the temperature range of 1073–1623 K at atmospheric pressure. Mole fraction profiles of 11 species, including CH4, C2H2, C2H4, C2H6, aC3H4, pC3H4, C3H6, C4H6, C6H6, C10H8 (naphthalene) and C12H8 (acenaphthylene) were quantified. C10H8 and C12H8 were detected during the pyrolysis of CH4. A detailed kinetic model involving 300 species and 1840 reactions was proposed with reasonable prediction against the measured data. During pyrolysis, CH4 is mainly consumed by the H-abstraction reactions. 2CH3=C2H5+H and C9H7+C3H3=A2R5+H2 are the two major reactions controlling CH4 consumption according to sensitivity analysis. In addition, the soot generated in the reactor was analyzed by Raman spectroscopy and Scanning Electron Microscope (SEM), showing the morphology and structural characteristics of the soot. The detailed formation and consumption pathways of PAHs such as naphthalene and acenaphthylene were analyzed. This work will enrich the understanding of CH4 pyrolysis and promote experimental and theoretical studies on the formation of PAHs and soot.

On the lower explosion limit of ventilation air methane under high temperatures

Regenerative thermal oxidation of Ventilation-Air-Methane is a technology for clean utilization of energy. Increasing methane concentration can enhance utilization efficiency, but pose a risk of explosion. To ensure the safe and effective utilization of VAM, critical concentration of oxidation to explosion is determined through experiments and simulations. Results indicate that GRTO model established by our group exhibits the highest prediction accuracy of 99.57%. The model was selected to study critical mechanisms of oxidation to explosion, thereby providing theoretical guidance for VAM utilization. The oxidation process can be divided into three stages: CH4 pyrolysis, rapidly generation/consumption of ·CH3/·HCO, and CO oxidation. With temperature rises from 600 °C to 800 °C and then to 1000 °C, the explosion limit of methane decreases mainly by speeding up ·H + O2⇔·O+·OH, and the ignition timing at critical limit shifts from the stage of ·CH3O generation/consumption to ·CH3 generation/consumption, and ultimately to ·OH formation/accumulation.

Distributed electrified heating for efficient hydrogen production

This study introduces a distributed electrified heating approach that is able to innovate chemical engineering involving endothermic reactions. It enables rapid and uniform heating of gaseous reactants, facilitating efficient conversion and high product selectivity at specific equilibrium. Demonstrated in catalyst-free CH4 pyrolysis, this approach achieves stable production of H2 (530 g h−1 L reactor−1) and carbon nanotube/fibers through 100% conversion of high-throughput CH4 at 1150 °C, surpassing the results obtained from many complex metal catalysts and high-temperature technologies. Additionally, in catalytic CH4 dry reforming, the distributed electrified heating using metallic monolith with unmodified Ni/MgO catalyst washcoat showcased excellent CH4 and CO2 conversion rates, and syngas production capacity. This innovative heating approach eliminates the need for elongated reactor tubes and external furnaces, promising an energy-concentrated and ultra-compact reactor design significantly smaller than traditional industrial systems, marking a significant advance towards more sustainable and efficient chemical engineering society.

Zero-emission hydrogen production by CH4 pyrolysis over Ni/Ferrierite catalyst: Examination of the deactivated catalysts for electrical conductivity and H2 storage properties

An economic route for the generation of hydrogen and utilization of carbon nanofibers (CNFs) was achieved by CH4 cracking over 20 wt%Ni/FER catalyst. The deactivated catalyst demonstrated electrical conductivity and hydrogen storage properties. TEM images displayed open mouths of CNFs and XRF data showed nearly 70% of nickel was recovered from the deactivated catalyst. Impedance studies of the CNFs exhibit prominence as battery electrodes due to their significant conductivity in the presence of nickel. While the hydrogen storage capacity was around 0.151 mmol (gcat)−1 of H2 on the obtained CNFs, it was increased to 0.361 mmol (gcat)−1 upon Ni recovery from the CNFs. A seven-fold increase in the H2 storage of ∼0.862 mmol (gcat)−1 was obtained upon Li doping, exhibiting its distinct property as a hydrogen storage material. The fresh, reduced, used, and deactivated catalysts were characterized by BET-SA, H2-TPR, XRD, Raman spectroscopy, TEM, and H2 pulse chemisorption and Ni/FER was established as an economically viable catalyst for high rates of H2 and CNF production.

Numerical study on the temperature dependence of soot formation in acetylene pyrolysis blended with methane, formaldehyde, methanol, and dimethyl ether

Abstract This paper addresses the combined effects of varying C/H and C/O ratios as well as of the molecular structure of the fuels selected on the normalized soot volume fraction f V. For the simulations, an already existing and validated reaction mechanism for the pyrolysis of C2H2 in argon, Aghsaee et al. (Combust. Flame 2014, 161, 2263–2269), was used in the current work. It was extended with PAH reactions from coronene (C24H12) up to ovalene (C32H14), whereas general principles for the rapid build-up of large PAHs were presented. Soot formation was modeled according to Appel et al. (Combust. Flame 2000, 121, 122–136) by applying the method of moments. A validation of the extended reaction model was carried out for shock-wave-induced O2/C2H2 mixtures from literature. In the following, the influence of blends of methane (CH4), formaldehyde (CH2O), methanol (CH3OH), and dimethyl ether (CH3)2O on soot formation during C2H2 pyrolysis diluted in Ar was studied. Special emphasis was laid on the inception chemistry of soot formation. The role of intermediates, such as the propargyl radical (C3H3), leading towards benzene and polyaromatic hydrocarbon (PAH) formation and their interplay with hydrogen molecules (H2) to H atoms (H) ratio was examined. All blends increased the ratio of the concentrations of H2 and H leading thus to reduced soot inception and soot formation. However, soot suppressing effects were overrun by supporting ones when the additives provided suitable molecular groups, such as methyl radicals (CH3), in sufficient high concentrations for early aromatic ring formation. Thus, a prominent synergistic effect on soot formation was found for the CH4/C2H2 mixture only. Besides, species able to mirror characteristics of the soot formation process, such as the peak value of the normalized soot volume fraction, are presented. The findings of this work indicate the synergistic effect of H2/H and C/O ratios as well as of methyl radicals on the PAHs’ production of appropriate size able to initiate soot inception process in an aliphatic fuel.

Molten salts coupled Ni/Al2O3 for hydrogen from CH4 pyrolysis at mild temperature in bubble-cap reactor

Methane pyrolysis is a promising sustainable technology for CO2-free hydrogen production. However, the development of stable methods for methane pyrolysis to produce hydrogen at lower temperatures has presented significant challenges. This study presents a reaction system that combines molten carbonate with Ni/Al2O3 catalyst and investigates methane pyrolysis using this system in a bubble-cap reactor. Remarkably, this system exhibited a low activation energy of 145.8 kJ per mole, enabling the achievement of a methane conversion of 92.5 % at 580 °C by employing a double-layer bubble cap tray configuration. Furthermore, the system showcases sustained activity for a duration of up to 72 h.

Experiment and simulation of non-catalytic thermal decomposition of CH4 for CO2-free hydrogen production in a vertical tube

To address climate change issues, there has been growing interest in low-carbon H2 production technologies with the potential for zero-CO2 emissions. Non-oxidative CH4 pyrolysis is a promising method for producing H2 and solid carbon without generating CO2 emissions. This study presents experimental and numerical studies on non-catalytic CH4 pyrolysis using a vertical tube reactor (28 mm in diameter and 1800 mm in height). A three-dimensional (3D) Eulerian computational fluid dynamics (CFD) model coupled with chemical reaction and heat transfer was developed and validated against the experimentally determined axial temperature profiles and methane conversion (XCH4). The hydrodynamics, reaction kinetics, and heat transfer characteristics were investigated using the validated CFD model. The highest XCH4 of 99% was achieved at 1200 °C with a gas flow rate of 0.5 LPM. Heat transfer combined with natural and forced convection was confirmed by the CFD simulation of the tubular reactor. The heat transfer coefficient in the reaction zone ranged from 43 to 46 W/m2/°C. The CFD simulation served as a viable tool for examining the influence of the hydrodynamics, heat transfer, and reaction kinetics on the performance of the reactor with a given geometry and under specified operating conditions in non-catalytic CH4 pyrolysis.

Hydrodynamics of CH4-Sn molten-metal bubble columns under electromagnetic field using computational fluid dynamics

The use of molten metal bubble column reactors (MMBCRs) for CO2-free H2 production via non-oxidative CH4 pyrolysis has gained attention due to little catalyst deactivation and simple downstream processing. Maintaining a small size of bubbles is crucial to enhance CH4 decomposition rates in MMBCRs. In this study, the effect of electromagnetic field on the hydrodynamics of MMBCRs was investigated using volume-of-fluid computational fluid dynamics (VOF-CFD) coupled with a large-eddy simulation (LES) model for turbulence and a magnetohydrodynamic (MHD) model for the electromagnetic field. Hydrodynamic parameters such as the gas holdup (αG), mean bubble size (d32), and gas–liquid interfacial area (as) were obtained from the validated VOF-CFD model in the bench-scale CH4-Sn system at 900 °C. A horizontal electromagnetic field with alternating current (AC) at an electromagnetic field strength of 1.0 T promoted bubble breakup and increased as from 8.6 to 18.2 m2/m3 compared to the MMBCR without electromagnetic field.

How sustainable and profitable are large-scale hydrogen production plants from CH4 and H2S?

The large-scale production of hydrogen through mature technologies such as steam methane reforming (SMR) has set a benchmark for emerging hydrogen production processes to gauge their economic viability for the hydrogen economy. In this work, we use detailed process modeling to perform a techno-economic and environmental assessments on the potential of alternative emerging hydrogen production processes based on H2S utilization including H2S-methane reforming (H2SMR), and H2S pyrolysis (H2SPyrol) compared to steam methane reforming (SMR), SMR with CO2 capture, storage, and utilization (CCUS), and CH4 pyrolysis (CH4Pyrol). Technically, the energy intensity of these processes in terms of electrical and thermal energy consumption was ranked as CH4Pyrol < SMR < SMR + CCUS < H2SMR < H2SPyrol. However, lower CH4 feedstock and absence of direct CO2 emissions were seen for H2SMR for the same target hydrogen production. Economically, both H2S-based hydrogen production technologies were competitive with levelized cost of hydrogen (LCOH) of $-1.000 and $3.537 per kg for H2SMR and H2SPyrol, respectively, compared to LCOH of $2.400, $2.410, and $1.930 per kg for SMR, SMR + CCUS, and CH4Pyrol, respectively, with consideration for by-product sales, and sensitivity analysis to their market prices and effect of carbon taxes. Environmentally, H2SMR and H2SPyrol revealed their lower contribution to global warming, with the absence of direct CO2 emissions, qualifying as low carbon hydrogen production processes. Although direct CO2 emissions are missing from CH4Pyrol, its qualification as low carbon hydrogen producer hinges on the level of decarbonization for the electricity grid. Conversely, the water footprint of H2S-based hydrogen production process remains to be the largest due to the indirect consumption of cooling water required for product recovery, although not necessarily impacting water stress, due to the lower quality of water required for cooling. In summary, transitioning from SMR wo/w CCUS to H2SMR or CH4Pyrol seems to be potentially attractive for competing with current processes for H2 production within the existing policies for decarbonization.

Carbon/iron co-product from clean hydrogen production as a tri-functional adsorbent and catalyst for efficient wastewater treatment

Clean hydrogen production via methane pyrolysis (CH4 → 2H2 + C) generates large quantities of solid carbon. Realizing their applications is a critical gap to enable its broader adoption. Here, we show that carbon nano onions encapsulated with iron cores (Fe@CNO) produced in CH4 pyrolysis using low-cost Fe ore catalysts can serve as a tri-functional adsorbent and catalyst for organic contaminant degradation. Fe@CNO has a high adsorption capacity and fast pseudo-second-order adsorption kinetics for antibiotics in wastewater. Surface oxidized Fe@CNO presents a high catalytic activity for in situ hydrogen peroxide production. Fe@CNO is also an efficient heterogeneous Fenton catalyst to degrade adsorbed antibiotics. Further, the Fe core is magnetic, enabling easy separation from solvents as reusable adsorbents and catalysts. We demonstrate that the adsorption and electro-Fenton process applies to various organic pollutants in different water matrices. This opens a new strategy for utilizing co-products from H2 production for sustainable environmental applications.

Reactive molecular dynamics simulation and chemical kinetic modeling of ammonia/methane co-combustion

Under the vision of “low carbonization”, ammonia (NH3), as a carbon-free hydrogen-rich fuel, blended with reactive additives, is an effective means to achieve low carbon emissions and reduce the consumption of traditional fossil fuels. In this work, the combustion behaviors of NH3 and CH4, the distribution of main products and the formation and reduction characteristics of NO at different temperatures, CH4 mixing ratios, and O2 equivalence ratios are explored by means of reactive molecular dynamics simulation to reveal the microscopic mechanism of NH3/CH4 co-combustion. The calculated results show that CH4 takes the lead in producing H radicals which react with O2 to generate OH radicals to promote the oxidation of NH3, and it is found that the co-combustion process of NH3/CH4 in the radical chain transfer stage is similar to the respective pyrolysis and oxidation reactions of CH4 and NH3. Accordingly, an optimized kinetic mechanism of NH3/CH4 co-combustion is constructed based on the mechanisms proposed by Glarborg et al. and Okafor et al. by incorporating the NH3 pyrolysis sub-mechanisms related to NH2, HNO, and N2H2 and the skeletal mechanism of CH4 oxidation. The optimized mechanisms of NH3/CH4 co-combustion are found to improve the prediction of the ignition delay time (IDT) and laminar burning velocity (LBV) of NH3/CH4 mixture under wide ranges of conditions compared to the original mechanisms of Glarborg et al. and Okafor et al. To decrease the computational cost of three-dimensional combustion numerical simulations, the skeletal mechanism models are established by simplification of the optimized mechanisms of NH3/CH4 co-combustion using direct relation graph method with error propagation and sensitivity analysis, which can provide nearly the same estimates of IDTs and LBVs as the optimized mechanisms mentioned above.

On the Practical Applicability of Rambutan‐like SiOC Anode with Enhanced Reaction Kinetics for Lithium‐Ion Storage

AbstractSilicon oxycarbide (SiOC) possesses great potential in lithium‐ion batteries owing to its tunable chemical component, high reversible capacity, and small volume expansion. However, its commercial application is restricted due to its poor electrical conductivity. Herein, rambutan‐like vertical graphene coated hollow porous SiOC (Hp‐SiOC@VG) spherical particles with an average diameter of 302 nm are fabricated via a hydrothermal treatment combined CH4 pyrolysis strategy for the first time. As‐prepared Hp‐SiOC@VG exhibits a large reversible capacity of 729 mAh g−1 at 0.1 A g−1, remarkable cycling stability of 98% capacity retention rate after 600 cycles at 1.0 A g−1 and high rate capability of 289 mAh g−1 at 5.0 A g−1 owing to the unique structure of the particles and the electrical conductivity of the vertical graphene. Density functional theory calculations reveal that the higher contents of SiO3C and SiO2C2 structural units in the SiOC are beneficial to enhance the Li+ storage capacity. Additionally, the full‐cell assembled with Hp‐SiOC@VG and LiFePO4 delivers up to 74% capacity retention rate after 100 cycles at 0.2 A g−1. This work reports a new way for the facile preparation of template‐free hollow porous materials and expands the application prospects of SiOC‐based anode for lithium‐ion batteries.

One-dimensional kinetic model with heat transfer and axial dispersion of molten-metal bubble column reactors for hydrogen production via methane pyrolysis

A one-dimensional (1D) molten-metal-based bubble-column reactor (MMBCR) model coupled with heat transfer and axial dispersion was developed for non-oxidative CH4 pyrolysis to produce low-carbon H2. The MMBCR model included mass, momentum, and energy balances, accounting for catalytic and non-catalytic reaction kinetics, and hydrodynamic parameters such as the gas holdup (αG), gas velocity (uG), bubble size (db), and specific interfacial surface area of bubbles (as). The 1D MMBCR model was compared with other 1D reactor models and bench-scale experimental data for CH4 conversion (XM). The MMBCR model agreed well with the experimental data. When heat transfer and axial dispersion were considered for an industrial-scale MMBCR to produce 10,000 Nm3/h, the reactor length increased to 2.4 times higher than that estimated by the model without axial dispersion to meet 80% XM. The MMBCR model has the potential to design industrial-scale MMBCRs and optimize operating conditions.

Catalytic CH4 pyrolysis promoted by the interface of a molten metal–salt hybrid system

Hydrogen is an important chemical feedstock and energy carrier. A promising idea for a bridging technology for net-zero carbon emission is the catalytic pyrolysis of natural gas into hydrogen and solid carbon. However, the activation of methane and recovery of the produced carbon with high purity are the main hurdles for process commercialization. In the present study, molten metal–salt layered reaction beds for methane pyrolysis were investigated to determine the effect of the interface and the optimal ratio of metal and salt. These layered catalyst beds had several advantages over pure molten metal or molten salt catalyst beds. First, the length of the molten metal layer could be minimized to a level where the methane bubbles only touch the metal–salt interface, enhancing the economic feasibility of the process. Second, the metal–salt interface could delay bubble rising in proportion to the interfacial tension. Third, the molten salt layer could wash out the residual metal traces from the produced carbon, improving the carbon purity. This study would provide hints for building economically viable catalytic pyrolysis of methane based on molten metal-salt layered reaction bed.

Facile synthesis of homogeneously dispersed carbon nanotubes on TC4 alloy powder by in-situ CVD and its growth behavior

We developed a simple method of in-situ synthesize carbon nanotubes (CNTs) on Ti–6Al–4V (TC4) alloy powder to fabricate CNTs/TC4 compound powders through plasma-enhanced chemical vapor deposition (PECVD). By this approach, CNTs on TC4 alloy powder exhibit better uniform dispersion and morphology compared with the traditional CVD methods. In order to reveal the growth behavior of CNTs during the PECVD process, XRD, SEM, TEM, and Raman spectroscopy were used to analyze the morphology and graphitization of CNTs at different synthesis conditions. The plasma is benefit to the pyrolysis of CH4, but overmuch plasma bombardment also reduces the yield and quality of CNTs. The number of CNTs can be significantly improved with appropriately increasing the temperature and time, but excessive temperature, time and carbon concentration can increase the number of impurities such as amorphous carbon. Significantly, the growth mechanism of CNTs synthesized in TC4 powders is following tip-growth mode in PECVD process. Additionally, the quantity and quality were satisfactory at 600 °C for 30 min with 50 W plasma power. This study about PECVD process lays a foundation for improving the comprehensive properties of CNTs/TC4 composites in the future.

Evaluation of process conditions for methane pyrolysis applying the triple thermal plasma system

Among various thermal plasma sources for CH4 pyrolysis, singular direct current (DC) thermal plasma has limited capacity, erosion, and efficiency. However, the triple thermal plasma system has been applied for nanomaterial synthesis and exhibited results overcoming these limitations. This study used the triple thermal plasma system to investigate the most suitable conditions for CH4 pyrolysis. CH4 conversion rate and selectivity of H2 and C2H2 were analyzed by varying the CH4 flow rate and quenching conditions at a fixed power supply of approximately 30 kW, and the specific energy requirement (SER) per 1 kg H2 was compared with that of previous works. The maximum conversion rate was 97% at 50 L/min of CH4, which is approximately 7% higher than earlier studies under conditions with similar process enthalpy. In addition, the conversion of CH4 to C2H2 and further to heavier hydrocarbons proceeded one order of magnitude faster than the reaction time expected by the gas-phase reaction. This result is attributed to the easy penetration of CH4 into the core region with the highest temperature and the strong interaction between the processing gas and graphite surface due to the arrangement of the torches in the triple plasma system. C2H2 selectivity was relatively high, while it was less affected by the increase in the quenching gas than generally expected. This finding was attributed to the naturally fast quenching rate without quenching gas due to the structure expanding from the first to the second graphite. While quenching can enhance selectivity by stabilizing the radicals as intermediates such as H2 or C2H2, it depressed the following reaction with dehydrogenation. Thus, the quenching conditions must be optimized. Finally, we demonstrated that the triple thermal plasma enhanced CH4 pyrolysis regarding H2 production efficiency.

The ro-vibrational ν2 mode spectrum of methane investigated by ultrabroadband coherent Raman spectroscopy.

We present the first experimental application of coherent Raman spectroscopy (CRS) on the ro-vibrational ν2 mode spectrum of methane (CH4). Ultrabroadband femtosecond/picosecond (fs/ps) CRS is performed in the molecular fingerprint region from 1100 to 2000cm-1, employing fs laser-induced filamentation as the supercontinuum generation mechanism to provide the ultrabroadband excitation pulses. We introduce a time-domain model of the CH4 ν2 CRS spectrum, including all five ro-vibrational branches allowed by the selection rules Δv = 1, ΔJ = 0, ±1, ±2; the model includes collisional linewidths, computed according to a modified exponential gap scaling law and validated experimentally. The use of ultrabroadband CRS for in situ monitoring of the CH4 chemistry is demonstrated in a laboratory CH4/air diffusion flame: CRS measurements in the fingerprint region, performed across the laminar flame front, allow the simultaneous detection of molecular oxygen (O2), carbon dioxide (CO2), and molecular hydrogen (H2), along with CH4. Fundamental physicochemical processes, such as H2 production via CH4 pyrolysis, are observed through the Raman spectra of these chemical species. In addition, we demonstrate ro-vibrational CH4 v2 CRS thermometry, and we validate it against CO2 CRS measurements. The present technique offers an interesting diagnostics approach to in situ measurement of CH4-rich environments, e.g., in plasma reactors for CH4 pyrolysis and H2 production.