Methane Conversion to Alkylated Aromatics via Dehydrocyclization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for converting methane to aromatic hydrocarbons face challenges such as limited commercial potential due to the production of benzene and naphthalene, which have limited market value and environmental concerns, along with issues like high energy consumption, hazardous reactions, and the need for expensive co-feeds and hydrogen utilization, especially in natural gas fields with high carbon dioxide content.
Innovation Solution
A process involving dehydrocyclization of methane to aromatic hydrocarbons followed by alkylation with an alkylating agent to produce alkylated aromatic hydrocarbons, which includes recovering aromatic hydrocarbons, reacting hydrogen with an oxygen-containing species to reduce hydrogen content, and recycling hydrocarbons, utilizing a dehydrocyclization catalyst under non-oxidizing conditions with additives like H2, CO, and CO2 to enhance catalyst activity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If methane is converted to benzene and naphthalene via dehydroaromatization, then aromatic hydrocarbons are produced, but the market value is limited and environmental concerns arise
Solution Approach 1:
The patent changes the chemical parameters of the product by introducing alkyl groups onto the aromatic ring structure through alkylation reactions. This transforms benzene and naphthalene into higher-value alkylated aromatics (such as toluene, ethylbenzene, and alkyl naphthalenes) that have broader commercial applications and reduced environmental impact, thereby resolving the contradiction between production capability and market value.
2Productivity
If synthesis gas generation is used to convert methane to liquid hydrocarbons, then conversion is achieved, but capital and energy consumption increase
Solution Approach 1:
The patent extracts and eliminates the synthesis gas generation step from the conventional two-step process. By using a single-step dehydroaromatization reaction with a specialized catalyst system, the process directly converts methane to aromatic hydrocarbons without requiring intermediate synthesis gas production, thereby reducing both capital investment and energy consumption while maintaining productivity.
3Productivity
If oxidative coupling of methane to olefins is used, then conversion to liquid hydrocarbons is achieved, but hazardous reactions and high energy consumption occur
Solution Approach 1:
The patent employs an inert atmosphere by conducting the dehydroaromatization reaction in the absence of oxygen and other oxidizing agents. This eliminates the hazardous oxidative coupling step while maintaining the conversion of methane to liquid hydrocarbons through a safer, non-oxidative catalytic process, thereby resolving the contradiction between productivity and safety.
4Adaptability or versatility
If natural gas with high carbon dioxide content is used, then feedstock availability is improved, but process efficiency decreases due to hydrogen utilization issues
Solution Approach 1:
The patent converts the harmful effect of carbon dioxide (which typically poisons catalysts and reduces efficiency) into a beneficial component by utilizing it as a hydrogen acceptor in the dehydroaromatization reaction. The CO2 reacts with hydrogen to form water and additional hydrocarbons, thereby improving process efficiency and product yield while maintaining the ability to process high-CO2 natural gas feedstocks.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process effectively converts methane to higher value alkylated aromatic hydrocarbons like toluene and xylenes, reducing environmental concerns and energy costs by utilizing natural gas feedstocks efficiently, even in fields with high carbon dioxide levels, and improving the selectivity and economic viability of methane conversion.
Implementation Method 1
contacting a feed containing methane with a dehydrocyclization catalyst under conditions effective to convert said methane to aromatic hydrocarbons
Implementation Method 2
contacting at least a portion of said aromatic hydrocarbon from said first effluent stream with an alkylating agent under conditions effective to alkylate said aromatic hydrocarbon
Implementation Method 3
reacting at least part of the hydrogen from said first effluent stream with an oxygen-containing species to produce a second effluent stream having a reduced hydrogen content
Data Source
AI summary
In a process for converting methane to alkylated aromatic hydrocarbons, a feed containing methane is contacted with a dehydrocyclization catalyst under conditions effective to convert said methane to aromatic hydrocarbons and produce a first effluent stream comprising aromatic hydrocarbons and hydrogen. At least a portion of said aromatic hydrocarbon from said first effluent stream is then contacted with an alkylating agent under conditions effective to alkylate said aromatic hydrocarbon and produce an alkylated aromatic hydrocarbon having more alkyl side chains than said aromatic hydrocarbon prior to the alkylating.