47results about "Methane capture" patented technology

The invention belongs to the technical field of gas separation, and particularly relates to application of a tetramethylammonium-modified EMT zeolite molecular sieve in CH4 / N2 adsorption separation. According to the invention, tetramethylammonium ions (TMA < + >) are introduced into the zeolite molecular sieve EMT, so that the EMT which has no performance originally shows efficient CH4 / N2 separation performance. Due to the introduction of TMA, the SBET value of the EMT molecular sieve is obviously reduced compared with that of the original EMT molecular sieve, but the adsorption capacity of methane is increased. Due to the introduction of TMA, the interaction affinity of CH4 and a zeolite framework is enhanced. Under the conditions that the K is 298 K, the pressure is 1 bar and the pressure is 10 bar, the EMT-TMA shows relatively high CH4 / N2 selectivity of 5.43 and 7.48.

The invention provides an inorganic membrane for extracting helium as well as a preparation method and application of the inorganic membrane. The inorganic membrane comprises a molecular sieve membrane and a protective coating, the molecular sieve membrane comprises a carrier and a molecular sieve layer, the protective coating is located on the surface of the side, away from the carrier, of the molecular sieve layer, and the protective coating comprises beta-cyclodextrin and / or polydimethylsiloxane. The inorganic membrane for helium extraction comprises the molecular sieve membrane and the protective coating, the protective coating comprises beta-cyclodextrin and / or polydimethylsiloxane, and due to the existence of the protective coating, the separation selectivity of the inorganic membrane on helium in mixed gas containing helium and methane can be high.

Disclosed is a greenhouse gas reduction device combining EGR and iCER for a ship, including: an exhaust gas receiver 110 temporarily storing exhaust gas discharged from each cylinder of a ship engine 10 and removing pulsation; a supercharger 120 compressing and supplying combustion air by means of exhaust gas supplied from the exhaust gas receiver 110; a washing section 130 spraying washing water to exhaust gas supplied through the supercharger 120, washing and removing SO X and soot, and circulating coolant to cool exhaust gas; a CO2 absorbing section 140 spraying absorbing liquid to exhaust gas passing through the washing section 130 to absorb and remove CO2; a combustion air receiver 150 temporarily storing combustion air compressed by the supercharger 120, removing pulsation, and supplying air to each cylinder of the ship engine 10; and an exhaust gas circulation section 160 supplying exhaust gas passing through the CO2 absorbing section 140 to the supercharger 120 so as to be mixed with outside air; by combining EGR with iCER, it is possible to reduce NO X generation by means of EGR, while absorbing CO2 and SO X x and converting them into substances that do not affect the environment, prevent corrosion of the engine, improve combustion quality, improve engine efficiency by means of iCER, and reduce methane escape.

An air conditioning and filtering system 10 is provided that includes a pre-treatment system 12 for initially filtering air drawn from an external environment, a pressurizing means 50 for pressurizing the air filtered by the pre-treatment system 12 to a positive pressure, and at least one circulation means 106. Each circulation means 106 draws air from the external environment through the pre-treatment system 12 and the pressurizing means 50, and air from at least one enclosed area 1, to combine into an air flow. The air flow is then directed to at least one set of a filtering means 94 and an air conditioning means 96 before being conveyed to at least one of the at least one enclosed area 1.

The invention discloses a method for high-selectivity separation of low-concentration coal bed gas by a hydrate method using tri-n-butylphosphine oxide as a thermodynamic accelerant. The method comprises the following steps: carrying out hydrate generation and separation on low-concentration coal bed gas in a 5 wt% tri-n-butyl phosphine oxide solution under the conditions of 277.15 K and 4 MPa, and increasing the methane concentration from 30.07 mol% to 88.17 mol% after purification; the separation performance is improved by further adding 0.5 wt% of a kinetic accelerator (preferably cocamidopropyl dimethylamine), and experimental results show that the methane concentration after single-stage separation can be improved from 30.07 mol% to 92.84 mol%, the separation factor reaches 40.93, and the system is in slurry dispersion and has no wall climbing phenomenon. The method is safe to operate, the accelerant can be recycled, and the method is suitable for efficient purification and resource utilization of methane in mixed gas such as low-concentration coal bed gas, biogas and coke-oven gas.

A system for removing methane oxidation catalyst (MOC) poisons from an exhaust gas includes a methane abatement unit capable of receiving an exhaust gas containing methane (CH4) and MOC poisons. The methane abatement unit includes a guard bed capable of removing MOC poisons from the exhaust gas and generating an intermediate exhaust gas containing CH4 and free of MOC poisons. The guard bed includes an MOC poison capture component having a first transition metal oxide, an aluminum oxide (Al2O3) support material, and a dolomite-derived support material. The methane abatement unit also includes an MOC bed fluidly coupled to and positioned downstream of the guard bed. The MOC bed includes MOC and is capable of removing CH4 from the intermediate exhaust gas to generate a treated exhaust gas having less than about 200 parts per million by volume (ppmv) of CH4.

The invention belongs to the technical field of separation membrane preparation, and provides a method for preparing a polyimide gas separation membrane through in-situ fluorination, and the method comprises the steps of preparation of polyamide acid, imidization of polyamide acid, in-situ fluorination of polyimide and preparation of the polyimide gas separation membrane, the air pressure is 1-6 bar, and the fluorinated gas is introduced for 0-30 min. According to the invention, nitrogen and fluorine are introduced after imidization of polyamide acid, and the temperature, air pressure and introduction time of the reaction kettle are controlled, so that the fluorination degree of polyimide is more effectively improved compared with the traditional way of introducing a fluorinated group by synthesizing polyimide with a fluorine-containing monomer; compared with the mode of purely introducing the fluorinated gas into the reaction kettle, the mode of introducing the fluorinated gas into the solution from the bottom of the reaction kettle has the advantages that the fluorination efficiency is higher, the fluorination degree is deeper, the overall operation is simple and feasible, the cost is favorably reduced, and the method is suitable for large-scale popularization.

The invention belongs to the technical field of gas separation and purification, and particularly relates to a preparation method of a coal carbolic oil-based adsorption material and a coal carbolic oil-based carbon adsorption material. The preparation method comprises the following steps: extracting phenolic substances in coal carbolic oil serving as a raw material by using a KOH solution, then adding aldehyde substances to polymerize, and then carbonizing a polymer at high temperature to prepare the porous adsorption material. According to the method, phenolic substances can be obtained without acid liquid replacement, generation of waste acid and waste salt is reduced, meanwhile, KOH can serve as a basic catalyst to catalyze polymerization of the phenolic substances and aldehyde substances and can also serve as a pore forming agent, and therefore the porous adsorption material generated after high-temperature carbonization is moderate in pore and concentrated in pore distribution. According to the method disclosed by the invention, carbolic oil extraction, polymer synthesis and high-temperature carbonization are coupled into a whole, so that the use of an alkaline agent is effectively reduced, and the prepared adsorption material is high in methane selectivity and large in adsorption capacity.

A biogas collection and purification system that includes a plurality of sources of biogas and a network of conduits configured to convey the biogas from the sources to a central processing facility for processing the biogas into methane. The central processing facility removes impurities to convert biogas to biomethane and may include an H2S removal stage; an activated carbon scrubber; a gas drier; and a carbon dioxide removal stage. The facility also has a biomethane gas compressor configured to deliver the biomethane for use in power plants, for CNG production. Ancillaries to the system include fuel cells for direct electricity generation from biogas / biomethane.

Method for the aftertreatment of the exhaust gas of an internal combustion engine (1) burning a gaseous fuel, namely a gas engine or a dual-fuel engine which can be operated in a gas fuel operating mode, wherein the exhaust gas is passed over a CH4 oxidation catalyst (7) and over an SCR reduction catalyst (8), which are designed as separate catalysts, wherein the CH4 oxidation catalyst (7) for CH4 oxidation and thus as an active compound comprises at least one pyrochlore, wherein the at least one pyrochlore is selected from the following group: Sm2Zr2O7, Sm2Mo2O7, La2Ti2O7, La2Co x Sn 2-x O 7-δ , La2Co x Zr 2-x O 7-δ , Mn2Co x Zr 2-x O 7-δ , Pr2Ru2O7, ZrTiGd2O7, Pr2Co2O7 and Pr2Co x Zr 2-x O 7-δ , where 0 ≤ δ ≤ 2 and where 0 ≤ x ≤ 1, wherein NH3 or an NH3 precursor substance is introduced into the exhaust gas upstream of the CH4 oxidation catalyst (7) as a reducing agent for the SCR reduction catalyst (8).

A biogas collection and purification system that includes a plurality of sources of biogas and a network of conduits configured to convey the biogas from the sources to a central processing facility for processing the biogas into methane. The central processing facility removes impurities to convert biogas to biomethane and may include an H2S removal stage; an activated carbon scrubber; a gas drier; and a carbon dioxide removal stage. The facility also has a biomethane gas compressor configured to deliver the biomethane for use in power plants, for CNG production. Ancillaries to the system include fuel cells for direct electricity generation from biogas / biomethane.

The invention discloses a helium purification method based on multistage membrane separation, and belongs to the field of gas purification, and the helium purification method comprises the following steps: S1, raw material gas pretreatment: carrying out primary treatment on helium-containing raw material gas to remove large solid particle impurities, water and oil stains in the helium-containing raw material gas; s2, primary membrane separation, to be more specific, pressurizing the pretreated raw material gas, and feeding the pressurized raw material gas to a primary membrane separation component which adopts a helium selective separation membrane to obtain helium-rich primary permeable gas and helium-poor primary tail gas mainly containing nitrogen and methane; and S3, secondary membrane separation: pressurizing the permeated gas obtained by the primary membrane separation again, and feeding the pressurized permeated gas to a secondary membrane assembly, wherein the secondary membrane assembly adopts a fluorine-containing polymer membrane. According to the helium purification method based on multistage membrane separation, efficient purification of helium is achieved, the helium purity and separation efficiency are remarkably improved, meanwhile, different raw material gas working conditions are adapted by means of flexible stage adjustment and diversified pretreatment assemblies, and high reliability and economical efficiency are achieved.

The invention relates to the technical field of methane catalytic oxidation, in particular to a methane-poor gas catalyst and a preparation method and application thereof.The preparation method comprises the steps that S1, nickel salt, ferric salt, chromium salt and water are mixed, and a mixed solution is obtained; s2, mixing the mixed solution, a precipitant and water, stirring, co-precipitating, aging and drying to obtain an aged product; and S3, calcining the aged product in a mixed atmosphere to obtain the methane-poor gas catalyst. The methane-poor gas catalyst obtained by the preparation method disclosed by the invention can realize 50% of methane conversion rate at 250 DEG C and 90% of conversion rate at 410 DEG C under the condition of not containing noble metal, and has excellent low-temperature catalytic activity. For the methane-poor gas with the volume concentration smaller than 1%, the activity is high in the low-temperature section (150-550 DEG C), the methane removal rate is high, and almost all the gas is converted into CO2 with the relatively low greenhouse effect after the reaction.

The invention provides a high-stability water-resistant methane catalytic oxidation catalyst as well as a preparation method and application thereof, and relates to the technical field of industrial waste gas treatment. The catalyst comprises 0.5 wt.%-2 wt.% of an active component, 5 wt.%-10 wt.% of an auxiliary agent (based on oxide), and the balance of a carrier material, the active component is Pd or a combination of Pd and Pt; the carrier material is formed by compounding silicate modified MOx-CeO2 crystal grains and Al2O3 crystal grains. According to the invention, the composite carrier of the silicate-modified MOx-CeO2 crystal grains and the Al2O3 crystal grains with a specific phase structure is combined with the synergistic effect of the noble metal active component and the auxiliary agent, so that the catalytic activity, the water resistance and the high-temperature stability are comprehensively improved, and the catalyst has a good application prospect.

The invention discloses a method and device for analyzing the sensitivity of methane gas adsorbed by coal to temperature and pressure, and the device comprises a pressure stabilizing system of a press for applying axial pressure to an adsorption container and keeping the pressure stable, and a precision heating furnace for heating the adsorption container arranged in the precision heating furnace; the gas adsorption earthenware is a cylindrical metal container and is used for loading a coal sample, high-temperature-resistant sealing gaskets are arranged at two ends of the gas adsorption earthenware, and the gas adsorption earthenware is connected to a gas source and a metering system through pipelines; the gas storage tank and the gas metering device are used for storing methane gas and accurately metering the gas volume change in the experiment process; the vacuum system is used for vacuumizing the adsorption tank and the pipeline before an experiment; and the data acquisition system is used for synchronously acquiring and recording temperature, pressure and gas volume data in the adsorption pottery in real time. According to the method, optimization of a coalbed methane exploitation scheme can be guided, when the depressurization desorption effect is poor, the adsorption capacity can be reduced by 30% or above by adopting heat injection (such as 200 DEG C), and the exploitation efficiency is improved.

This invention discloses a Ni(ina)₂ particulate material for methane adsorption and separation, and its molding and granulation method, belonging to the field of adsorption material preparation technology. The method involves bonding Ni(ina)₂ with a binder, polyvinylpyrrolidone (PVP), followed by drying to prepare MOF particles with controllable size. Simultaneously, doping the MOFs with a small amount of composite reinforcing agents (graphite and PVP) significantly improves the compressive strength of the material, meeting the strength requirements of industrial adsorption tower packing. The reinforced PVP molding method of this invention has simple operating steps, good guiding significance in practical industrial applications, and significant industrial value. It is applicable not only to Ni(ina)₂ but also to the molding and granulation of other organometallic materials.

The invention relates to a sulfydryl modified SEBS and a preparation method of a separation membrane of the sulfydryl modified SEBS and application of the separation membrane in CH4 / N2 gas separation, and belongs to the technical field of gas separation membranes, and the preparation method specifically comprises the following steps: performing vacuum drying on SEBS, and crushing for later use; dissolving the dried SEBS in anhydrous toluene, stirring until the SEBS is completely dissolved to form a transparent homogeneous solution, and introducing nitrogen for bubbling; adding a sulfhydryl compound and a catalyst into the SEBS solution, and placing a reaction system under an ultraviolet light source for irradiation reaction; the preparation method comprises the following steps: slowly pouring a reaction solution into excessive absolute ethyl alcohol, stirring to form flocculent precipitate, filtering and washing the precipitate, and drying the precipitate in a vacuum drying oven to obtain the sulfydryl modified SEBS block polymer. Non-polar long-chain alkyl is introduced into an SEBS molecular chain through a Michael addition reaction, the chemical structure and pore characteristics of the material are regulated and controlled, and the sulfydryl modified SEBS block polymer is obtained. The gas separation membrane with high CH4 permeability and selectivity is prepared, and the problem that a traditional SEBS membrane is insufficient in CH4 / N2 separation performance is solved.

The utility model is applied to the technical field of gas monitoring, and discloses a cowshed methane monitoring device which comprises two sliding rails, guide grooves are formed in the surfaces of the opposite sides of the two sliding rails, a displacement frame is arranged on the opposite sides of the two sliding rails, a lifting mechanism is arranged at the lower end of a mounting base, and the lifting mechanism is connected with the guide grooves. Methane gas detection in a larger range is realized in a manner of driving the gas sensor to lift and cooperating with the displacement frame to move on the sliding rail. According to the cowshed methane monitoring device, a double-end motor is arranged to drive a displacement wheel to move in a guide groove of a sliding rail, the displacement wheel is matched with movement of a displacement frame, a gas sensor can achieve large-range displacement in the horizontal direction of a cowshed, the limitation of traditional fixed point monitoring is broken through, meanwhile, a lifting motor in a lifting mechanism drives a center gear to rotate, and the methane monitoring efficiency is improved. Through meshing with the side gear, the take-up wheel is synchronously driven to take up and pay off the connecting wire, precise lifting of the suspension disc and the gas sensor is achieved, and the monitoring height can be flexibly adjusted.

The invention relates to a preparation method of a polybenzimidazole gas separation membrane and application of the polybenzimidazole gas separation membrane in extraction of helium from natural gas, and belongs to the technical field of gas separation membranes, and the preparation method specifically comprises the following steps: synthesizing a polybenzimidazole copolymer, purifying the polybenzimidazole copolymer, adding the passivated polybenzimidazole copolymer and N, N-dimethylformamide into a dissolving kettle, and stirring to obtain the polybenzimidazole gas separation membrane. Heating, stirring and dissolving to prepare a membrane casting solution; the prepared membrane casting solution is subjected to heat preservation and standing, vacuumizing and defoaming are conducted, the membrane casting solution is injected into a spinning nozzle through a gear pump at the speed of 30-200 mL / h, and the hollow fiber membrane is prepared through a phase inversion method. Helium with a smaller molecular diameter preferentially penetrates through membrane holes, and methane with a larger molecular diameter is intercepted, so that efficient separation of helium and methane is realized.

The application belongs to the field of material and chemical process research, and particularly relates to a large-scale water-based preparation process of a zinc-based MOF material and application thereof, and comprises the following steps: configuring a mixed solution of a zinc salt and an anion regulator; configuring a solution of a first ligand 1,2,4-triazole and derivatives thereof; configuring a second ligand aqueous solution, adding an alkali, and configuring a mixed solution of the second ligand and the alkali; mixing the three solutions and adding them into a reactor, performing a reaction, filtering and separating after the reaction, washing with deionized water, and drying to obtain a zinc-based metal organic framework material. The application utilizes the synergistic effect of the anion regulator for regulating the crystal growth process and the alkali for promoting the deprotonation of the second ligand, so that the MOF crystal can be prepared within several minutes, the production efficiency is greatly improved, and an unprecedented space-time yield is achieved.

The application discloses a low-concentration gas enrichment and membrane repair self-circulation device, which comprises a kettle body, a guide channel and a turnover mechanism; the kettle body is internally divided into an enrichment area and a repair area; a membrane adsorption separation module is arranged in the enrichment area, and the membrane adsorption separation module comprises an adsorption membrane; a membrane self-repair module is arranged in the repair area, and the membrane self-repair module comprises a cleaning material; the guide channel is used for guiding the decomposition products of the cleaning material to enter the adsorption membrane in the enrichment area; a valve for controlling opening and closing is installed on the pipeline of the guide channel; a solar energy driving module is inlaid on the outer wall of the bottom of the kettle body and is used for providing heat energy for the cleaning material; and the turnover mechanism can drive the kettle body to overturn and stand upside down. The low-concentration gas is efficiently treated and the self-repair function of the membrane is realized by utilizing heat energy to drive the cleaning material to automatically clean the impurities on the surface of the membrane, so that the service life of the membrane is prolonged, the artificial maintenance cost is reduced, the service life of the membrane is prolonged, and the device is environment-friendly and safe.

The utility model relates to a coal mine ventilation air methane circulating into-mine concentration system which comprises an air inlet pipeline, an air outlet pipeline, a desorption pipeline, more than two adsorption devices and a regeneration fan, the air inlet pipeline is connected with the first air port of each adsorption device and is suitable for introducing to-be-treated ventilation air methane into the adsorption devices; adsorption purifying agents are arranged in the adsorption devices, the second air opening of each adsorption device is connected with an air outlet pipeline, and the other end of the air outlet pipeline is suitable for being connected with an air inlet of an air inlet shaft; the desorption pipeline is connected with the second air port of each adsorption device, the first air port of each adsorption device is connected with waste gas treatment equipment, and a first valve is arranged at the first air port of each adsorption device and located on the air inlet pipeline; a second valve is arranged at the second air port of each adsorption device and is positioned on the air outlet pipeline; a third valve is also arranged at the second air port and is positioned on the desorption pipeline.

The present application relates to melamine modified resin-based activated carbon and its preparation method and application, belong to pressure swing adsorption technical field.The technical problem solved by the present application is to provide a preparation method of melamine modified resin-based activated carbon.The method reacts resorcinol and formaldehyde solution to obtain resorcinol resin solution;Melamine and formaldehyde solution are reacted to obtain melamine resin solution;Then the resorcinol resin solution and the melamine resin solution are mixed uniformly, and the hydrothermal reaction is carried out to obtain melamine modified resorcinol resin;Then the melamine modified resorcinol resin is carbonized in a protective atmosphere to obtain melamine modified resin-based activated carbon.The melamine modified resin-based activated carbon of the present application has the advantages of simple preparation method, good adsorption performance, and can be applied in adsorption separation of methane-nitrogen, excellent CH4 adsorption capacity and separation performance, and the adsorption material can be recycled, low replacement cost and low energy consumption.

The present invention relates to a method for continuously obtaining carbon dioxide from a carbon-dioxide containing atmosphere, in which a fibrous carrier material charged with polyethylene imine is guided alternately through at least one adsorption zone and at least one desorption zone. In addition, the present invention relates to a device by which the method according to the invention can be carried out.

The present application relates to a kind of equipment and process for purifying helium from helium-lean natural gas, equipment for purifying helium from helium-lean helium-lean natural gas includes pre-purification system, membrane separation system, desulfurization unit, hydrogen removal unit, low-temperature impurity removal unit.The present application is mainly used according to the present situation of resources to solve the helium purification in helium-lean, helium-lean natural gas, by pre-purification, remove all CO2, water, heavy hydrocarbon, part of organic sulfur and inorganic sulfur in raw gas, greatly reduce the fast gas component of membrane separator, it is conducive to the concentration of helium, adopt multistage membrane separator to carry out helium concentration, it is applicable to process helium-lean, helium-lean natural gas, and in the process, catalytic hydrogenation process+dry desulfurization is used to remove sulfide completely, which plays a very key role for helium purification;The present application solves the problems of decarburization, desulfurization, dehydrogenation, drying, trace impurities, especially neon removal in natural gas, thereby improving the purity of helium.

The application discloses a wearable methane breathing filtering device for a dairy cow, and belongs to the field of methane filtering devices. The device can detect methane gas generated by the dairy cow when burping or breathing. When the methane gas is excessive, the methane gas is transmitted to a reaction area for a reduction reaction to generate carbon dioxide and water, so that the methane gas is filtered and purified, the effect of reducing methane emission is achieved, and the product after the purified methane is discharged in the next absorption process of the methane gas, so that the value of the greenhouse effect caused by the methane emission is reduced. Meanwhile, the data of the methane gas is recorded every time the methane gas is detected, the data of the methane emitted by the dairy cow is recorded, and the feeding efficiency and the physical condition of the dairy cow are compared with the data, so that it is determined that the content of the methane generated by the dairy cow is increased due to a certain condition. Corresponding measures are taken in the later period, so that the health condition of the dairy cow is ensured.

The invention refers to a far infrared heater comprising a backing cover and a radiant front cover and at least one heating element thermally coupled to an inner surface of the radiant front cover to heat the radiant front cover so as to radiate far infrared radiation from a radiant heat emitting outer surface thereof. The radiant front cover comprises a first outer rib and a corresponding first inner rib located at a first distance inwards from each first outer rib, and the backing cover comprises a second outer rib and a corresponding second inner rib located along the long edge and at a second distance inwards from each second outer rib, the outer ribs and the inner ribs defining side sub-chambers and a main sub-chamber. The heater comprises sealing elements between the first and second inner ribs to seal the main sub-chamber from the side sub-chambers.

The present application belongs to the technical field of gas separation and purification, and particularly relates to a preparation method of a coal phenol oil-based adsorption material and a coal phenol oil-based carbon adsorption material. The present application uses coal phenol oil as raw material, extracts phenolic substances in the coal phenol oil by using KOH solution, then adds aldehyde substances for polymerization, and then prepares a porous adsorption material by high-temperature carbonization of the polymer. The present application does not need to use acid liquor to replace the phenolic substances, reduces the generation of waste acid and waste salt, and KOH can not only be used as an alkaline catalyst to catalyze the polymerization of the phenolic substances and the aldehyde substances, but also can be used as a pore-forming agent, so that the porous adsorption material generated after high-temperature carbonization has moderate pores and concentrated distribution. The present application couples phenol oil extraction, polymer synthesis and high-temperature carbonization into an integrated whole, effectively reduces the use of alkaline reagents, and the prepared adsorption material has strong selectivity to methane and large adsorption capacity.

Provided is a method for purifying carbon monoxide with which it is possible to obtain high-purity carbon monoxide. In a catalyst preparation step, water is removed from a platinum catalyst by heat treatment of a platinum catalyst in a heat treatment vessel. This heat treatment is carried out until the concentration of water contained in the inert gas discharged from the heat treatment vessel after being supplied to the heat treatment vessel and used in heat treatment is less 1000 vol ppm. In an oxygen molecule removal step, carbon-monoxide-containing gas is brought into contact with a platinum catalyst, an oxygen molecule is removed from the carbon-monoxide-containing gas, and gas having an oxygen molecule removed is obtained. In a carbon dioxide removal step, carbon dioxide is removed from gas having an oxygen molecule removed using a carbon dioxide adsorbent, and gas having carbon dioxide removed is obtained. In a pressure swing adsorption step, carbon monoxide is recovered from gas having carbon dioxide removed by a pressure swing adsorption method, and purified carbon monoxide having a purity of 99.95 vol% or higher is obtained.

Provided herein is a methane oxidation catalyst having a support comprising alumina doped with lanthanum and comprising platinum and palladium as active phases. The platinum and palladium are present in the catalyst at an amount effective for producing an exhaust stream from a natural gas vehicle having reduced levels of methane. The catalyst disclosed herein may exhibit improvements in sulfur and water resistance.