Methane Concentration Research Articles

Discovery of the first hydrothermal field along the 500-km-long Knipovich Ridge offshore Svalbard (the Jøtul field)

Oceanic spreading centers north of Iceland are characterized by ultraslow spreading rates, and related hydrothermal activity has been detected in the water column and at the seafloor along nearly all ridge segments. An exception is the 500-km-long Knipovich Ridge, from where, until now, no hydrothermal vents were known. Here we report the investigation of the first hydrothermal vent field of the Knipovich Ridge, which was discovered in July 2022 during expedition MSM109. The newly discovered hydrothermal field, named Jøtul hydrothermal field, is associated with the eastern bounding fault of the rift valley rather than with an axial volcanic ridge. Guided by physico-chemical anomalies in the water column, ROV investigations on the seafloor showed a wide variety of fluid escape sites, inactive and active mounds with abundant hydrothermal precipitates, and chemosynthetic organisms. Fluids with temperatures between 8 and 316 °C as well as precipitates were sampled at four vent sites. High methane, carbon dioxide, and ammonium concentrations, as well as high 87Sr/86Sr isotope ratios of the vent fluids indicate strong interaction between magma and sediments from the Svalbard continental margin. Such interactions are important for carbon mobilization at the seafloor and the carbon cycle in the ocean.

Unraveling the dynamics of atmospheric methane: the impact of anthropogenic and natural emissions

Abstract The reduction in methane concentration is crucial for achieving the goals of the Paris Agreement. However, its annual growth rate is unstable, and understanding the reasons for changes in methane growth is essential for climate policy-making. Currently, there is considerable uncertainty regarding its attribution. Here, we utilize multi-source data and optimal fingerprinting methods to detect the contributions of several key drivers to the methane trend and interannual variability. We find that the methane growth trend is primarily influenced by anthropogenic emissions, while interannual variability is predominantly determined by wetland and biomass burning emissions. This result underscores the central role of anthropogenic emissions in methane dynamics, providing confidence in the effectiveness of human efforts to control methane atmospheric concentrations through emission reductions. It also helps alleviate concerns about the recent surge in atmospheric methane concentration, as it may be a short-term peak caused by increased wetland emissions rather than a trend change.

Upflow Anaerobic Sludge Blanket (UASB) reactors for Bio-methane production from Limed Tannery Fleshings: Lab and pilot scale reactors

The Upflow Anaerobic Sludge Blanket reactor is a viable high-rate anaerobic digestion design for the treatment of different wastewater with low to high solubility. This can also be used for the treatment of solid wastes with less HRT. In this study, the performance evaluation of a lab-scale UASB reactor was carried out for different hydraulic retention times of 24, 21, 18, 15 and 12h for obtaining the best HRT for tannery fleshings. The gas production varied between 3.7 – 4.5L with a methane content of 64.31 – 67.72%. It was observed that the maximum gas production was at 18h HRT and this optimized condition was applied to the pilot-scale UASB reactor. The performance evaluation of the pilot-scale UASB reactor was carried out with an HRT of 18h. The gas production of 450 ± 50L, the maximum specific gas production of 0.274 m3/kg of VS destroyed and 0.239 m3/kg of TS destroyed was obtained and the maximum biogas productivity of 0.495L was observed at 18h HRT with the highest methane content of 67.86%. The payback period of the pilot scale reactor is 3.2 years.

Experimental Study on Ultra-Low Concentration Methane Regenerative Thermal Oxidation

As a major coal country, China faces the issue of significant gas emissions during the coal mining process. This study aims to improve the utilization efficiency of mine gas, reduce greenhouse gas emissions, and promote the low-carbon and green transformation of the coal industry. A 10 kW gas regenerative thermal oxidizer (RTO) experimental system was constructed. The effects of initial methane concentration, low-temperature flue gas proportion, and operating load on combustion temperature, methane oxidation rate, high-temperature flue gas energy, and system thermal efficiency were studied. The results show that when the combustion temperature is below 600 °C, the CH4 combustion reaction cannot proceed effectively, and the system temperature continuously decreases and cannot be maintained stably. The experiment determines the stable operating methane concentration range of the RTO. In this experimental system, the lower limit of the initial methane concentration is 0.28%, corresponding to an 86% methane oxidation rate. As the initial methane concentration decreases, the combustion temperature also decreases, and the methane oxidation rate follows suit. The higher the low-temperature flue gas proportion, the higher the combustion temperature, and the system’s thermal efficiency and output heat decrease with the increase in the low-temperature flue gas proportion. This experiment explores multiple factors affecting regenerative thermal oxidation, providing a basis for ensuring the safe and stable operation of the system and its optimization. Improving the thermal insulation and heat exchange performance of the storage body can expand the lower limit of the initial methane concentration, thereby increasing the stability and thermal efficiency of the system.

Living emission abolish filters (LEAFs) for methane mitigation: design and operation.

Abstract As one of the most potent greenhouse gases, methane is a critical target for the near-term mitigation of global warming. Efficient, scalable, easy-to-implement, and robust mitigation technologies are urgently needed to assist in reaching methane abolishment. The goal of this research was to test the applicability of active, extremophilic methanotrophic cells as a baseline concept for engineered systems aiming at methane capturing. The system, named Living Emission Abolish Filters (LEAFs), represents an array of immobilized biomaterials capable of capturing methane directly from vent streams. The biomaterials were made using cells of Methylotuvimicrobium alcaliphilum 20ZR, a robust halophilic methanotrophic bacterium with the ability to consume methane gas at low concentrations. Several critical parameters were tested, including (i) the composition of the matrix and optimal immobilization to increase catalyst load, (ii) the stability of methanotrophic cells, and (iii) the toxicity of trace gases (i.e., CO). We found that hydrogels coated with 2.3 mg cell dry weight/cm3 methanotrophic cells represent the best-performing biomaterials. The methane reduction potential of LEAFs fluctuated from 20% to 95% and depended on the methane concentration in the gas stream and the stream flow rates. The potential for commercial-scale deployment and emissions reductions was also evaluated. Total greenhouse gas emissions (combined using the global warming potential GWP100) from an example using a ventilation air methane source over a one-year period was shown to be reduced in two LEAF scenarios by 51% and 75%. Over longer time horizons, more significant reductions are possible as consistent methane consumption can be sustained. The study highlights the overall potential of the liquid-free bio-based composite methane mitigation system. Further improvements essential for system assembly and implementations should include (a) optimization of the cell immobilization protocols to improve cell load and the shelf-life of the system and (b) implementation of matrix moldings for cell immobilization to achieve optimal gas flow and increase the cell-gas interface.

Enhancing biomethane quality via the activation of natural zeolite from Lombok Island

<p>This study presents the results of the biogas purification test using the fixed-bed column method. As an adsorbent, natural zeolite from the Lombok island Indonesia was used. Zeolite is used for the purpose of purifying biogas produced from the anaerobic digestion (AD) process. To enhance the adsorption capacity, the zeolite underwent activation using distinct strong base and acid solutions—potassium hydroxide (KOH) and hydrochloric acid (HCl)—with concentrations of 10%, 15%, and 20%, individually. The experiment was carried out until the adsorbent reached saturation, at which point the methane (CH4) concentration began to decline. It was revealed that the typical Lombok zeolite showed good performance in increasing the concentration of CH4 in biogas. Furthermore, zeolites work better when activated with strong base solutions and at high concentrations. This is indicated by the achievement of higher CH4 concentrations and a longer saturation time. The results from analyzing zeolite features and pore characteristics indicate that acidic and base compounds yield distinct outcomes in terms of the surface structure of zeolite pores.</p>

Thermodynamic analysis of anaerobic digestion of Eichornia crassipes (Water Hyacinth) biomass from the Volta River basin of Ghana using fruit waste sludge as inoculum

In order to gain understanding on the utilization of biogas fuel derived from water hyacinth (WH) biomass and render it appealing as a sustainable gaseous fuel, the study reports on its various thermophysical, combustion and thermodynamic parameters. The parameters include, specific enthalpy, internal energy, low heating value, Wobbe number index, changes in Enthalpy, Entropy and Gibbs free energy. The experimental procedure was performed at temperature range of 29±3 °C for 61 days in a BlueSens laboratory-scale anaerobic digestion equipment. It comprised of three fermenter bottles designated as F1, F2 and F3. F1 served as the control and the rest served as the test fermenter bottles. The digestion of water hyacinth and fruit waste sludge (WH+FWS) recorded the highest biogas volumes of 19,798.79 ml in fermenter F2 and 19,168.55 ml in fermenter F3 with methane contents of 53.46 % and 51.85 %, respectively. In comparison, the biogas produced exclusively from the water hyacinth (WH) biomass yielded 12,014.49 ml in F2 and 11,384.25 ml in F3, with methane contents of 46.41 % and 43.31 %, respectively. The best biogas fuel was produced from the digestion of (WH+FWS) in fermenter F2 with an internal energy and enthalpy values of 258.6 KJ/kg. K and 344.9 KJ/kg. K, respectively. A low heating value and Wobbe number of 17.51 MJ/m³ and 17.78 MJ/m³ were determined respectively. The biogas production was simulated using the Gompertz modified kinetic equation in MATLAB and an average specific rate (Kexp) of 371.49 ml/gVS.day was obtained. The rate constant (Kexp) was applied in the linearized form of the Erying-Polanyi equation to determine the changes in Enthalpy Entropy, and Gibbs free energy as -2510.66 J, -304.78 J and 94,219 J, respectively which indicated that, the anaerobic digestion process in this study was only thermodynamically feasible at low temperatures.

Dimethyl Ether Biogas Reactivity-Controlled Compression Ignition for Sustainable Power Generation with Low Nitrogen Oxide Emissions

<div>Biogas (60% methane–40% CO<sub>2</sub> approximately) can be used in the reactivity-controlled compression ignition (RCCI) mode along with a high-reactivity fuel (HRF). In this work dimethyl ether (DME) that can also be produced from renewable sources was used as the HRF as a move toward sustainable power generation. The two-cylinder turbocharged diesel engine modified to work in the DME–biogas RCCI (DMB-RCCI) mode was studied under different proportions of methane (45–95%) in biogas since the quality of this fuel can vary depending on the feedstock and production method. Only a narrow range of biogas to DME ratios could be tolerated in this mode at each output without misfire or knock. Detailed experiments were conducted at brake mean effective pressures (BMEPs) of 3 and 5 bar at a speed of 1500 rpm and comparisons were made with the diesel–biogas dual-fuel and diesel–biogas RCCI modes under similar methane flow rates while the proportion of CO<sub>2</sub> was varied. The DMB-RCCI mode exhibited superior brake thermal efficiency (25.3% as against 22% and 31.5% as against 29% at the BMEPs of 3 and 5 bar) as compared to the other modes and was not sensitive to the concentration of methane. The NOx and soot emissions were also negligible and the lowest CH<sub>4</sub> emission levels were also attained. The cyclic fluctuations in IMEP were lower than 5% in this mode. Thus, DME can be used along with biogas to enhance its reactivity for sustainable power generation in the RCCI mode.</div>

A Life Cycle Assessment of Methane Slip in Biogas Upgrading Based on Permeable Membrane Technology with Variable Methane Concentration in Raw Biogas

While energy-related sectors remain significant contributors to greenhouse gas (GHG) emissions, biogas production from waste through anaerobic digestion (AD) helps to increase renewable energy production. The biogas production players focus efforts on optimising the AD process to maximise the methane content in biogas, improving known technologies for biogas production and applying newly invented ones: H2 addition technology, high-pressure anaerobic digestion technology, bioelectrochemical technology, the addition of additives, and others. Though increased methane concentration in biogas gives benefits, biogas upgrading still needs to reach a much higher methane concentration to replace natural gas. There are many biogas upgrading technologies, but almost any has methane slip. This research conducted a life cycle assessment (LCA) on membrane-based biogas upgrading technology, evaluating biomethane production from biogas with variable methane concentrations. The results showed that the increase in methane concentration in the biogas slightly increases the specific electricity consumption for biogas treatment, but heightens methane slip with off-gas in the biogas upgrading unit. However, the LCA analysis showed a positive environmental impact for treating biogas with increasing methane concentrations. This way, the LCA analysis gave a broader comprehension of the environmental impact of biogas upgrading technology on GHG emissions and offered valuable insights into the environmental implications of biomethane production.

Influence of faults on late-stage migration of methane-rich gas in a major unconventional hydrocarbon accumulation: Montney Formation, western Canada

Faults are thought to act as barriers or conduits for intraformational hydrocarbon migration within unconventional low-permeability hydrocarbon accumulations. However, well-documented studies substantiating this phenomenon at the regional-scale are scarce. Here, we use an extensive molecular and isotopic dataset for produced-gas samples (n = 562) from the Montney unconventional hydrocarbon accumulation of northeast British Columbia to show that regional-scale secondary migration of methane-rich gas was significantly influenced by the distribution and orientation of faults. Cross-plots using iC4/nC4, δ13C ethane and δ13C propane exhibit single coherent distributions, suggesting that the C2+ components of most of these gases share interrelated histories of generation, maturation and primary migration. Conversely, cross-plots using gas dryness and δ13C methane against other selected gas parameters demonstrate geographic differentiation, with samples from the southeastern part of the study area generally exhibiting elevated molecular concentration and isotopic enrichment of methane compared to the samples from the northwestern part of the study area. The compositional and isotopic enrichment of methane in the southeastern samples signify significant late-stage secondary migration of highly mature methane-rich gas from deeper zones to shallower zones, and mixing with in-situ hydrocarbon fluids of lower thermal maturity. Previous structural mapping documents the presence of numerous subsurface thrust-faults related to the Cordilleran orogeny in the northwestern area, while these features are entirely absent in the southeastern area. Consequently, we conclude that thrust-faults, with accompanying clay-rich gouges, formed effective en-echelon barriers to the late-stage secondary migration of methane-rich gas in the northwestern area and prevented substantial mixing of hydrocarbon fluids.

A comparative assessment of biomethane potential of fresh fecal matter and fecal sludge and its correlation with malodor.

Comprehensive and proper management of fecal sludge (FS) is an ongoing concern in many nations.Decentralizedfecal sludge treatment plants (FSTPs) are effective in this regard; however, many have experienced strong public opposition based partly on suspicion of malodor. Fecal sludge and freshly generated fecal matter (FM) samples from various FSTPs were collected, characterized, and investigated for biomethane potential. The homogenized samples were anaerobically digested for 28days. Digestion successfully reduced total suspended solids, biochemical oxygen demand, and threshold odor number values of 97,350-97,420mg/l, 43,230-43,260mg/l, and 130-150 for FM, to 49,500-49,650mg/l, 23,760-23,850mg/l, and 3338, respectively, for FS samples. The comprehensive gas yield from Bhongir, Boduppal, and Shadnagar FS samples was 40, 55, and 31ml, respectively. In contrast, cumulative gas generation from the FM was 26,361ml. Digestion of FS samples also reduced concentrations of volatile solids and coliforms by 66-72% and 99%, respectively. Characterization of gas samples revealed methane and carbon dioxide concentrations as 56% and 22% for FM, and 0.4% and 61% for FS samples, respectively. Hydrogen sulfide and ammonia gas were absent in FS samples, dispelling common societal misconceptions of FSTPs being associated with malodor.

Fabrication of diamond film under low methane concentration by hot filament chemical vapor deposition with magnetic field assistance

This study focused on improving diamond film growth through hot filament chemical vapor deposition (HFCVD) with an innovative method, magnetic field assistance. The effects on diamond films were thoroughly investigated using a combination of experiments and simulations. The results of scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD) all showed significant improvements in nucleation rates, film thickness, and grain size, particularly for grains with (111) orientation, when exposed to a 400 mT magnetic field during HFCVD compared to non-magnetic conditions. Magnetic field application in HFCVD was found to promote the formation of larger diamond grains and increase the film growth rate by nearly 45 %. Concurrent Finite Element Method simulations confirmed that the magnetic field improved reactive gas flow and temperature distribution across the substrate, which was consistent with experimental results. These findings suggest that magnetic field assistance in HFCVD may mitigate the limitations of bias assistance, such as the antenna effect, overheating, and stress imbalance. This approach is especially useful for substrates with complex geometries, such as the sharp edges of cutting tools, as it promotes even film growth.

Exploring the bounds of methane catalysis in the context of atmospheric methane removal

Methane, a potent greenhouse gas, is a significant contributor to global warming, with future increases in its abundance potentially leading to an increase of more than 1∘C by 2050 beyond other greenhouse gases if left unaddressed. To remain within the crucial target of limiting global warming to 1.5 ∘C, it is imperative to evaluate the potential of methane removal techniques. This study presents a scoping analysis of different catalytic technologies (thermal, photochemical and electrochemical) and materials to evaluate potential limitations and energy requirements. An analysis of mass transport and reaction rates is conducted for atmospheric methane conversion system configurations. For the vast majority of catalytic technologies, the reaction rates limit the conversion which motivates future efforts for catalyst development. An analysis of energy requirements for atmospheric methane conversion shows minimum energy configurations for various catalytic technologies within classic tube or parallel plate architectures that have analogs to ventilation and industrial fins. Methane concentrations ranging from 2 ppm (ambient) to 1000 ppm (sources, such as wetlands, fossil-fuel extraction sites, landfills etc) are examined. The study finds that electrocatalysis offers the most energy efficient approach (∼0.2 GJ tonne−1 CO2e) for new installations in turbulent ducts, with a total energy intensity < 1 GJ tonne−1 CO2e. Photocatalytic methane removal catalysts are moderately more energy intensive (∼2 GJ tonne−1 CO2e), but could derive much of their energy input from ‘free’ solar energy sources. Thermal systems are shown to be excessively energy intensive ( > 100 GJ tonne−1), while combining photovoltaics with electrochemical catalysts (∼1 GJ tonne−1 CO2e) have comparable energy intensity to photocatalytic methane removal catalysts.

A novel additive for enhancing biomass energy production from agro-industrial wastes: synthesis of hydrophobic nanoporous silica aerogel and its effect on methane production

AbstractAnaerobic digestion (AD) is one of the most preferred processes for the treatment of organic waste. However, additional processes such as co-digestion, pretreatment, and additive addition continue to be explored to remove the limits on the applicability of AD. This study investigated the effects of hydrophobic nanoporous silica aerogel (NpSA) synthesized from waste rice husks on the anaerobic co-digestion (AnCD) of the mixture consisting of sewage sludge and fruit processing industry wastes. All bioreactors containing NpSA-free, 0.1 g, 0.2 g, 0.5 g, and 1 g NpSA (0.03–0.3 gNpSA/gVSadded) were operated in a mesophilic-batch process. Biogas and methane yields increased from 346 mL/gVS (NpSA-free) to 387 mL/gVS and from 231 mL/gVS (NpSA-free) to 288 mL/gVS, respectively, with 0.1 g NpSA addition. NpSA additive increased biogas production in all bioreactors compared to the blank. However, biogas production rate and methane content increased faster at lower doses of NpSA. Maximum soluble chemical oxygen demand (sCOD), protein, carbohydrate, and volatile solid (VS) reductions were between 45–71%, 35–54%, 44–65%, and 34–91% for NpSA added mixtures, respectively. The hydrophobic NpSA additive was effective in improving the AnCD performance and biogas/methane production. Experimental results fit the kinetic models frequently preferred in such AD processes. In addition, the possible energy and financial potential of the produced methane were also discussed, and it was determined that the direct sale of methane gas produced by the addition of NpSA in the global market could provide 1.4 $/Lmixture more financial gain than the mixture NpSA-free. Graphical Abstract

Enhanced atmospheric oxidation toward carbon neutrality reduces methane’s climate forcing

The hydroxyl radical (OH), as the central atmospheric oxidant, controls the removal rates of methane, a powerful greenhouse gas. It is being suggested that OH levels would decrease with reductions of nitrogen oxides and ozone levels by climate polices, but this remains unsettled. Here, we show that driven by the carbon neutrality pledge, the global-mean OH concentration, derived from multiple chemistry-climate model simulations, is projected to be significantly increasing with a trend of 0.071‒0.16% per year during 2015–2100. The leading cause of this OH enhancement is dramatic decreases in carbon monoxide and methane concentrations, which together reduce OH sinks. The OH increase shortens methane’s lifetime by 0.19‒1.1 years across models and subsequently diminishes methane’s radiative forcing. If following a largely unmitigated scenario, the global OH exhibits a significant decrease that would exacerbate methane’s radiative forcing. Thus, we highlight that targeted emission abatement strategies for sustained oxidation capacity can benefit climate change mitigation in the Anthropocene.

Numerical Simulation of Urban Natural Gas Leakage Dispersion: Evaluating the Impact of Wind Conditions and Urban Configurations

This study investigates the dispersion of natural gas leakages in urban environments under varying wind conditions (Beaufort levels 1, 2, and 6) and street layouts, with a focus on the implications for mobile leak detection at a height of 0.3 m above ground. Through numerical simulations, we analyze how urban canyons influence wind field and methane (CH4) concentration distributions, highlighting the impact of wind speed and urban geometry on gas dispersion. The key findings indicate that urban structures significantly affect gas dispersion patterns, with higher wind speeds facilitating better dispersion and reducing the risk of high-concentration gas buildups. The study underscores the need to consider both meteorological conditions and urban design in enhancing gas leak detection and safety measures in cities. The results contribute to improving emergency response strategies and urban planning for mitigating the risks associated with gas leaks.

Possibilities of Utilising Biomass Collected from Road Verges to Produce Biogas and Biodiesel

Grass collected as part of roadside maintenance is conventionally subjected to composting, which has the disadvantage of generating significant CO2 emissions. Thus, it is crucial to find an alternative method for the utilisation of grass waste. The aim of this study was to determine the specific biogas yield (SBY) from the anaerobic mono-digestion of grass from road verges and to assess the content of Fatty Acid Methyl Esters (FAMEs) in grass in relation to the time of cutting and the preservation method of the studied material. The biochemical biogas potential (BBP) test and the FAMEs content were performed on fresh and ensiled grass collected in spring, summer, and autumn. The highest biogas production was obtained from fresh grass cut in spring (715.05 ± 26.43 NL kgVS−1), while the minimum SBY was observed for fresh grass cut in summer (540.19 ± 24.32 NL kgVS−1). The methane (CH4) content in the biogas ranged between 55.0 ± 2.0% and 60.0 ± 1.0%. The contents of ammonia (NH3) and hydrogen sulphide (H2S) in biogas remained below the threshold values for these inhibitors. The highest level of total FAMEs was determined in fresh grass cut in autumn (98.08 ± 19.25 mg gDM−1), while the lowest level was detected in fresh grass cut in spring (56.37 ± 7.03 mg gDM−1). C16:0 and C18:0, which are ideal for biofuel production, were present in the largest amount (66.87 ± 15.56 mg gDM−1) in fresh grass cut in autumn. The ensiling process significantly impacted the content of total FAMEs in spring grass, leading to a reduction in total saturated fatty acids (SFAs) and an increase in total unsaturated fatty acids (USFAs). We conclude that grass biomass collected during the maintenance of road verges is a valuable feedstock for the production of both liquid and gaseous biofuels; however, generating energy from biogas appears to be more efficient than producing biodiesel.

An Analysis of the Methane Explosion in the Area of the Return Shaft Bottom at Mine

Methane explosions are one of the greatest hazards in the coal mining industry and have caused many accidents. On 27 July 2016 at approximately 11:01 a.m., an explosion of methane occurred at the bottom of Zygmunt return shaft at the depth of 411 metres. The explosion resulted in one casualty. The article presents the results of, and the conclusions from, an in-depth analysis of the changes in the parameters of mine air, especially methane concentration, air flow and the operation of mine fans, recorded by sensors installed in the workings and in Zygmunt ventilation shaft around the time of the accident. The analysis was based on signals recorded by the monitoring system, related to the evolution of methane and fire hazards prior to and after the accident occurred. An attempt was made to identify the cause and the circumstances of the methane explosion at the bottom of the return shaft.

Methane Emission Measurements Along Underground Galleries of Coal Mine

The article shows the results of research on methane concentration changes along mine galleries. The experiment was conducted in a longwall area mined using a U-type system, and the results were obtained in situ. The main goal was to measure methane concentration by function of gallery length and dividing segments of methane data into segments, which ultimately enabled separate analysis of these methane data. The analysis led to the diagnosis of methane hazard through the detection of exceedance of the assumed tolerance area.

Surface plasmon resonance methane sensor based on the D-type photonic quasi-crystal fiber with double-layer films

A high-sensitivity photonic quasi-crystal fiber surface plasmon resonance (PQF-SPR) methane sensor is designed and analyzed. The six-fold Penrose PQF has a D-type structure with two grooves on which TiO2 and Au films are deposited, and methane-sensitive film containing cryptophane-E is coated on the surface of the D-type structure. The characteristics of the sensor are analyzed by the finite element method and the influence of different coating materials (Au-TiO2, Au-MgF2, Au-ITO) on the sensitivity and FOM of the sensor is analyzed and compared. The results show that the PCF-SPR sensor with the dual Au-TiO2 film has better sensing properties. The maximum wavelength sensitivity and average wavelength sensitivity reach 40 nm/% and 34.74 nm/% in the methane concentration range of 0–3.5 % respectively. These properties are significantly better than those of similar sensors reported recently, and the sensor thus has large potential in the development of high-sensitivity and miniaturized methane sensors.