Monolithic catalyst for coal mine low-concentration ventilation air methane (VAM) combustion and preparation method thereof

Abstract

The invention provides a monolithic catalyst for coal mine low-concentration ventilation air methane (VAM) combustion and a preparation method thereof. The catalyst is composed of a honeycomb ceramic support with a coating and a noble metal active component Pd on the support, wherein the honeycomb ceramic coating is prepared from the following components in percentage by weight: 20-80% of activated Al2O3 and 20-80% of hexaaluminate; and a H2PdCl4 water solution which is the active Pd component impregnates and is supported on the surface of the honeycomb ceramic support coating, and the active Pd component accounts for 0.3-1 wt% of the catalyst. When the catalyst is filled in a catalytic reflux reactor in a self-made laboratory, the inspection on the catalytic combustion reaction using simulated VAM containing 1% of methane indicates that the methane conversion rate is up to more than 99% within the 1000-hour running period.

Description

technical field [0001] The invention relates to a low-temperature catalytic combustion catalyst and a preparation method thereof, in particular to a coal mine exhaust gas low-concentration methane combustion integral catalyst and a preparation method thereof. Background technique [0002] Coal mine ventilation gas (VAM) refers to the mine gas that is directly discharged to the atmosphere by the ventilation system in order to ensure safe production in coal mines. The methane concentration is usually below 1%, which is an important source of greenhouse gases emitted to the atmosphere. In the context of increasing global warming and increasing pressure to reduce greenhouse gas emissions, it is of great significance to develop industrial technologies that directly utilize coal mine exhaust gas. The concentration of methane in VAM is low, and methane is the most stable hydrocarbon. In the traditional combustion method, the adiabatic combustion temperature is about 1900 ° C. At th...

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Problems solved by technology

Chinese patent CN1013245B discloses a catalyst for purifying exhaust gas and its production method. This patent technology uses zirconia loaded with precious metals and other oxides to mix to make an aqueous slurry to wash and coat the honeycomb ceramic substrate, and then dry and roast to prepare The method of monolithic catalysts, the limitation of this method is that the highly active noble metal components are difficult to avoid being covered by other oxides and cannot be uniformly loaded on the surface of the carrier, which affects the catalytic performance of the noble metal components

Chinese patent CN0113374.X discloses a catalytic combustion monolithic catalyst for treating organic industrial waste gas and its preparation method. It uses honeycomb ceramics as the substrate and is coated with Al 2 o 3 、TiO 2 , CeO 2 , ZrO 2 For the mixed oxide coating, after drying and roasting, the noble metal Pt active component is supported on the carrier by impregnation method. This method can make the noble metal disperse evenly on the coating to a certain extent, but due to the 2 o 3 The force is weak, and it is easy to aggregate to form large grains and reduce the activity

The preparation process is relatively cumbersome, and the catalyst prepared at the same time is used to treat methane gas with a concentration of 2%, and does not involve catalytic combustion of VAM with a methane concentration below 1%.

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