Methane Dehydroaromatization Integrated With LNG Cryogenic Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for converting methane to aromatic hydrocarbons are inefficient due to high energy consumption, capital-intensive synthesis gas production, and difficulties in separating hydrogen (H2) and methane (CH4), leading to suboptimal methane utilization and increased costs.
Innovation Solution
Integration of dehydroaromatization processes with natural gas liquefaction and regasification facilities, utilizing cryogenic separation and shared refrigeration and compression systems to enhance efficiency and reduce energy and capital requirements, while utilizing boil-off gas as a feedstream for dehydroaromatization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If synthesis gas production is used as an intermediate step for liquid hydrocarbon synthesis, then liquid hydrocarbons can be produced from light hydrocarbonaceous feedstock, but capital and energy costs increase significantly
Solution Approach 1:
The patent extracts and eliminates the synthesis gas production step from the conventional two-step process (methane to synthesis gas, then synthesis gas to liquid hydrocarbons). Instead, it directly converts methane to liquid hydrocarbons through catalytic reforming followed by Fischer-Tropsch synthesis in an integrated system, removing the capital-intensive and energy-consuming syngas intermediate production infrastructure while achieving the same end product
Solution Approach 2:
The patent merges the catalytic reforming and Fischer-Tropsch synthesis processes into an integrated system where the effluent from catalytic reforming is directly fed to the Fischer-Tropsch reactor. This combination eliminates the need for separate synthesis gas production facilities and reduces overall energy consumption by optimizing the transition between reaction stages
2Adaptability or versatility
If there is a large pressure differential between liquefaction effluent stream and preferred operating pressure for liquid hydrocarbon synthesis, then integration of natural gas liquefaction and liquid hydrocarbon synthesis is claimed, but efficiency is reduced
Solution Approach 1:
The patent employs dynamic pressure control systems with adjustable compressors and pressure regulation valves that can adapt to varying feedstock conditions and product demands. The system dynamically adjusts operating pressures at different stages of the process to optimize both the liquefaction effluent handling and the Fischer-Tropsch synthesis conditions, eliminating the efficiency loss from fixed pressure differential constraints
Solution Approach 2:
The patent changes the operating pressure parameters throughout the process by using multi-stage compression with intercooling and pressure regulation. The system transforms the pressure profile from the liquefaction stage to the synthesis stage through controlled compression and expansion processes, allowing efficient operation across different pressure requirements without sacrificing integration benefits
3Ease of operation
If dehydroaromatization is performed without recycle, then the process is simpler to operate, but methane utilization is suboptimal and separation of H2 and CH4 becomes difficult
Solution Approach 1:
The patent implements a feedback control system where the effluent stream is analyzed and unreacted methane is selectively separated and recycled back to the dehydroaromatization reactor. The system uses online monitoring of conversion rates and automatically adjusts the recycle ratio to optimize methane utilization while maintaining operational simplicity through automated control rather than complex manual procedures
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 integration significantly reduces capital and energy costs, improves methane conversion efficiency, and enables more effective separation of H2 and CH4, leading to higher aromatic hydrocarbon production and more efficient use of associated gas.
Implementation Method 1
passing a gaseous hydrocarbon stream comprising methane to one or more conversion zones and contacting the stream with a dehydroaromatization catalyst in the zones under dehydroaromatization conditions to convert the methane to an aromatic hydrocarbon and H2
Implementation Method 2
utilizing cryogenic separation and shared refrigeration and compression systems
Data Source
AI summary
The invention relates to the integration of a dehydroaromatization process with the processes for the utilization of associated gas; gases comprising methane and higher hydrocarbons, and/or liquefied natural gas (LNG) production or usage.