Method for preparing aromatic hydrocarbons by methane-plasma-activated oxygen-free aromatization

Abstract

The invention relates to a method for preparing aromatic hydrocarbons by methane-plasma-activated oxygen-free aromatization. The method comprises a multistage-series plasma activation reactor, an aromatization reactor, a palladium hydrogen permeation membrane separator, a condensation cooler, a heat recovery device and a gas-liquid separator. Unconverted methane in the reaction system is recycled; hydrogen permeated by the palladium hydrogen permeation membrane separator is recovered through a hydrogen vacuum pump; the unpermeated ethane, acetylene, propane, butane and aromatic hydrocarbons pass through the condenser and gas-liquid separator to recover the liquid aromatic hydrocarbons; and uncondensed ethane, acetylene, propane, butane and methane are merged and return to the reaction system. The method can recover the coproduct hydrogen; the plasma is adopted to activate and induce the reaction, thereby enhancing the methane conversion rate and promoting the generation of small-molecular paraffin hydrocarbons in the reaction system; and the paraffin hydrocarbons can be recycled as a methane reaction aid and a free radical chain initiator, thereby greatly enhancing the methane aromatization selectivity and yield, reducing the carbon deposit and lowering the production cost of aromatic hydrocarbons.

Description

technical field [0001] The invention relates to a multi-stage serial plasma catalytic activation method for preparing aromatic hydrocarbons in a methane oxygen-free aromatization reactor system, which belongs to the technical field of chemical industry. Background technique [0002] With the consumption of non-renewable petroleum resources and the continuous improvement of biomethane (biogas) and natural gas development capabilities in the future, biogas and natural gas have attracted great interest as renewable energy and petrochemical raw materials in recent years. Due to the main components of biogas and natural gas It is methane, and its industrial utilization is to produce synthesis gas. In an oxidizing atmosphere, use O 2 、H 2 O or CO 2 As an oxidant, methane is easy to generate syngas at high temperature and thermodynamics, so the production of syngas avoids the challenges of methane conversion in terms of kinetics and selectivity, but it needs to bear high construc...

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Problems solved by technology

[0008] In order to overcome the high-temperature dehydrogenation of methane to acetylene existing in the existing aromatics synthesis technology, the temperature is as high as 700-1100 ° C, the coking and carbonization consumes a lot of energy, and the preparation of synthesis gas from methane, and the preparation of gasoline aromatics by the F-T method has large equipment investment costs and routes. Long shortcoming; The present invention aims to provide a kind of methane low-temperature plasma catalytic activation induction, anaerobic aromatization reaction, gas-liquid separation preparation method for aromatics, a large amount of ethane, propane and butane induced by plasma catalytic activation, generated Small molecular alkanes such as alkanes can be used as co-reactants for methane conversion in the aromatization reactor, providing methyl radical initiators for methane dehydrogenation, thereby greatly reducing the temperature and reaction difficulty of methane aromatization

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