Mixed Refrigerant Composition for Cryogenic Hydrogen Separation
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Solution Overview
Problem
Conventional cryogenic separation systems for propylene recovery from light hydrocarbons are inefficient and require multiple refrigeration packages, leading to high operational costs and emissions.
Innovation Solution
A single refrigeration package using a mixed refrigerant composition comprising inert gas, methane, C2 hydrocarbons, C3 hydrocarbons, and C5 hydrocarbons to efficiently separate hydrogen from light hydrocarbons across a wide temperature range, integrating hydrogen, C2−, and C3+ hydrocarbon separation into a single system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cryogenic separation systems are used to separate hydrogen from light hydrocarbons, then separation is achieved, but multiple refrigeration packages are required leading to high capital and operational expenses
Solution Approach 1:
The patent combines multiple refrigeration packages into a single integrated refrigeration system that uses a mixed refrigerant composition. This merging approach reduces the number of separate refrigeration units needed while maintaining the ability to perform multiple separation functions (hydrogen removal, C2- fractionation, and C3+ separation) within one system, thereby reducing capital and operational expenses.
Solution Approach 2:
The single refrigeration package is designed to perform multiple functions simultaneously: it removes hydrogen from light hydrocarbons, fractionates C2- materials, and separates C3+ hydrocarbons. The mixed refrigerant composition is tailored to enable this multi-functional operation, making one refrigeration system as effective as multiple conventional separate systems.
2Manufacturing precision
If multiple refrigeration packages are used for fractionation, then C2- and C3+ separation is achieved, but operational costs and emissions increase
Solution Approach 1:
The patent merges the fractionation functions for C2- and C3+ separation into a single integrated process using one refrigeration package. This eliminates the need for multiple separate refrigeration systems, reducing energy consumption and operational costs while maintaining precise fractionation capabilities through the optimized mixed refrigerant composition.
Solution Approach 2:
The patent uses a mixed refrigerant composition with specific molecular weight distribution and compositional ranges to change the thermal and separation parameters of the system. This allows a single refrigeration package to achieve the fractionation effects that previously required multiple systems, improving energy efficiency and reducing operational costs.
3Reliability
If conventional separation systems are used, then hydrogen and hydrocarbon separation is achieved, but equipment count and capital expenses are high
Solution Approach 1:
The patent consolidates multiple separation functions (hydrogen removal, C2- fractionation, C3+ separation) into a single equipment train using one refrigeration package with mixed refrigerant. This merging reduces the total equipment count and capital expenses while maintaining high separation purity through the specialized refrigerant composition designed for multi-component separation.
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 solution significantly reduces capital and operational expenses, emissions, and equipment count, achieving high purity hydrogen and hydrocarbon recovery with improved propylene production efficiency.
Implementation Method 1
Cooling and separation of the dehydrogenation reactor effluent into a hydrocarbon-rich fraction and a hydrogen-rich vapor fraction
Implementation Method 2
separate hydrogen from light hydrocarbon liquid
Implementation Method 3
A single refrigeration package using a mixed refrigerant composition... to efficiently separate hydrogen from light hydrocarbons across a wide temperature range
Data Source
AI summary
A composition for a mixed refrigerant can be used to efficiently separate hydrogen from light hydrocarbons. The mixed refrigerant can comprise about 0 to about 7 mol % inert gas, about 11 to about 35 mol % methane, about 25 to about 40 mol % C2 hydrocarbon, about 20 to about 50 mol % C3 hydrocarbon and about 0 to about 15 mol % C5 hydrocarbon.