A kind of method that is used for the direct selective oxidation of methane to prepare methanol, formaldehyde, CO

Abstract

The invention discloses a method for preparing methyl alcohol, formaldehyde and CO used for methane direct selective oxidation. The method comprises the following steps: preparing a BN powder materialcatalyst, after mixing boric acid with urea, dissolving and stirring with a water and methyl alcohol mixed solvent, carrying out thermostatic waterbath standing for crystallization, and roasting under an inert atmosphere to obtain a BN powder material; tabletting and forming a roasted sample, smashing and sieving to obtain a BN powder material catalyst; catalyst activation: introducing oxygen-containing gas into a continuous flow reactor filled with the BN powder material catalyst for heating, activating, introducing inert gas, adjusting to a reaction temperature, and switching into a reaction gas; and preparing methyl alcohol, formaldehyde and CO.

Description

technical field [0001] The invention relates to methane, in particular to a method for preparing methanol, formaldehyde and CO by direct selective oxidation of methane. Background technique [0002] With the continuous discovery of new reserves of natural gas resources, especially the exploitation of shale gas and combustible ice, the effective utilization of natural gas with methane as the main component has attracted more and more attention. Methane conversion is divided into direct conversion and indirect conversion. In the indirect conversion, it is first converted into synthesis gas or methyl halide, and then generates oxygenated compounds such as methanol and formic acid or hydrocarbons such as alkanes and olefins. The indirect conversion process has a long process flow, high energy consumption or serious equipment corrosion, and high equipment investment. In the direct conversion of methane, oxidative coupling to ethane or ethylene, dehydroaromatization, etc., all r...

AI Technical Summary

Problems solved by technology

Therefore, it is usually difficult to obtain the desired target product selectivity at a suitable methane conversion rate

For now, the yield of heterogeneous catalytic methane oxidation to methanol and formaldehyde, which has the most industrial application prospect, is generally less than 5%, and the catalyst is easily deactivated.

The process has so far been a batch reaction, limiting its further scale-up and even industrialization

However, in the Chinese patent CN 102285864 B, palladium noble metal and various organic solvents are used to catalyze and oxidize methane into methyl trifluoroacetate, and the methyl trifluoroacetate is hydrolyzed to produce methanol. The catalyst system and reaction process are complex and the reaction conditions Harsh (pressure 2 ~ 5MPa)

[0005] At present, the work of using BN as a catalyst to catalyze the dehydrogenation of alkanes above C2 to produce corresponding alkenes has been reported (Chinese patent CN 106140240 A; Chinese patent CN 106694017 A; Science 2016,354:1570; ChineseJ Catal.2017,38:389) , but the literature and patents for the direct catalytic oxidation of methane to prepare platform molecules such as methanol, formaldehyde, and CO have not been reported

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