Fischer-Tropsch Inert Removal via Carbon Molecular Sieve Membranes
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Solution Overview
Problem
The Fischer-Tropsch process is limited by the accumulation of inert gases like nitrogen and argon in the reactor, which reduces the efficiency of recycling Fischer-Tropsch off-gas, leading to incomplete conversion of carbon atoms to desired C5+ hydrocarbons.
Innovation Solution
A system utilizing carbon molecular sieve membranes with high selectivity for carbon dioxide and nitrogen separation is integrated into the process, allowing for effective removal of inerts from the off-gas, enabling higher recycle rates and increased conversion of carbon atoms to paraffinic compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Fischer-Tropsch off-gas is recycled to the syngas manufacturing or Fischer-Tropsch reactor, then the conversion of carbon atoms to desired C5+ hydrocarbons is improved, but the accumulation of inert gases (nitrogen and argon) in the reactor increases, reducing process efficiency
Solution Approach 1:
The patent extracts and removes inert gases (nitrogen and argon) from the recycled Fischer-Tropsch off-gas stream using a gas separation unit positioned between the reactor and syngas manufacturing unit. This extraction prevents the accumulation of inerts in the reactor while maintaining high recycle rates, thereby resolving the contradiction between improving carbon conversion and preventing inert gas buildup.
2Productivity
If a gas separation unit is introduced to remove inerts from off-gas, then the recycle rate of off-gas can be increased, but the device complexity of the system increases
Solution Approach 1:
The gas separation unit is integrated into the existing syngas manufacturing unit, allowing it to perform dual functions: removing inerts from the off-gas stream and preparing clean syngas for the Fischer-Tropsch reactor. This multi-functional integration minimizes additional device complexity while enabling increased off-gas recycle rates.
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
The system achieves significant recovery of carbon dioxide and reduction of inerts in the retentate gas, allowing for increased recycling and improved conversion of carbon atoms to desired hydrocarbons, thereby enhancing the overall efficiency of the Fischer-Tropsch process.
Implementation Method 1
A system utilizing carbon molecular sieve membranes with high selectivity for carbon dioxide and nitrogen separation is integrated into the process
Data Source
AI summary
The Fischer-Tropsch process can be used for the conversion of hydrocarbonaceous feed stocks into normally liquid and/or solid hydrocarbons (i.e. measured at 0° C., 1 bar). The feed stock (e.g. natural gas, associated gas, coal-bed methane, residual oil fractions, biomass and/or coal) is converted in a first step into a mixture of hydrogen and carbon monoxide. This mixture is often referred to as synthesis gas or syngas. The present invention relates to process for preparing a paraffin product from a carbonaceous feedstock and a system for preparing a paraffin product from a carbonaceous feedstock.