Sweep Membrane Separator for High-Pressure Hydrogen Production
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Solution Overview
Problem
Current fuel processing systems face challenges in efficiently supplying hydrogen at high pressure for hydrodesulfurization (HDS) and other applications, particularly when dealing with liquid hydrocarbon fuels that contain high sulfur levels, which are not directly compatible with fuel cells.
Innovation Solution
A sweep membrane separator is used to selectively permeate hydrogen from a mixed gas stream to a permeate side, where it is then compressed with a high-pressure sweep gas, such as steam, to achieve high-purity hydrogen at elevated pressures suitable for HDS systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a membrane separator is used to separate hydrogen from mixed gas stream, then hydrogen purity is improved, but hydrogen pressure remains low and requires additional compression equipment
Solution Approach 1:
The patent combines the membrane separation function with the compression function into a single integrated device. The sweep gas system not only removes hydrogen from the permeate side but also pressurizes it, merging separation and compression operations that would traditionally require separate equipment.
Solution Approach 2:
The sweep gas acts as an intermediary medium that transfers momentum and pressure to the hydrogen permeate stream. By introducing high-pressure sweep gas on the permeate side, hydrogen is swept across the membrane and pressurized simultaneously, using the sweep gas as a mediator to achieve both separation and pressure increase.
2Object-generated harmful factors
If conventional HDS systems are used with liquid hydrocarbon fuels, then sulfur removal is achieved, but the system requires complex condensation and pumping equipment to handle liquid fuel
Solution Approach 1:
The patent utilizes phase transition by vaporizing the liquid hydrocarbon fuel before it enters the reformer. This phase change from liquid to vapor simplifies the overall system by eliminating the need for complex condensation and pumping equipment that would be required to handle liquid fuel through the HDS process.
3Productivity
If high pressure is applied to the reformer to improve hydrogen production, then hydrogen yield increases, but the HDS system cannot operate independently at its optimal pressure
Solution Approach 1:
The patent segments the pressure control for the reformer and HDS system by introducing an intermediate membrane separation stage. This allows the reformer to operate at high pressure for maximum hydrogen yield while the membrane separator and sweep gas system create a pressure buffer, enabling the HDS system to operate at its own optimal pressure independently.
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 approach allows the HDS system to operate at higher pressures independently of the reformer, reduces the need for condensation and pumping, and enhances hydrogen production, enabling the processing of more difficult fuels like diesel and naval fuels, while minimizing carbon and sulfur carbonyl formation.
Implementation Method 1
a membrane that is selectively permeable to a selected gas, the membrane including a retentate side and a permeate side
Implementation Method 2
A sweep gas at high pressure enters the sweep membrane separator and sweeps the selected gas from the permeate side of the membrane
Data Source
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AI summary
A sweep membrane separator includes a membrane that is selectively permeable to a selected gas, the membrane including a retentate side and a permeate side. A mixed gas stream including the selected gas enters the sweep membrane separator and contacts the retentate side of the membrane. At least part of the selected gas separates from the mixed gas stream and passes through the membrane to the permeate side of the membrane. The mixed gas stream, minus the separated gas, exits the sweep membrane separator. A sweep gas at high pressure enters the sweep membrane separator and sweeps the selected gas from the permeate side of the membrane. A mixture of the sweep gas and the selected gas exits the sweep membrane separator at high pressure. The sweep membrane separator thereby separates the selected gas from the gas mixture and pressurizes the selected gas.