Hydrogen Purification Using Shared Dryer Regeneration
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Solution Overview
Problem
Existing hydrogen purification systems for hydrogen produced by water electrolysis suffer from high manufacturing costs and energy waste due to the use of multiple electric heating rods and coolers, which do not effectively utilize residual heat from high-temperature regeneration tail gas.
Innovation Solution
A system with a deoxygenation module, drying module, and regeneration cycle module, including parallel-connected dryers and a gas-gas heat exchanger, allows for sequential flow of hydrogen streams for purification and regeneration, utilizing residual heat for energy efficiency and reducing the number of heating and cooling components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple electric heating rods and coolers are used for regeneration of desiccant in each drying tower, then the drying towers can independently perform regeneration, but the manufacturing cost increases and energy is wasted due to inability to utilize residual heat
Solution Approach 1:
The patent merges the heating and cooling functions into a shared regeneration cycle module that serves multiple drying towers. The hot regeneration tail gas from one tower is used to preheat the inlet gas of another tower through a heat exchanger, combining waste heat recovery with the regeneration process. This eliminates the need for independent electric heating rods and coolers in each tower, reducing manufacturing cost while improving energy efficiency.
Solution Approach 2:
The patent converts the harmful waste heat in regeneration tail gas into a useful resource by using it to preheat the inlet gas for desiccant regeneration in other drying towers. The heat exchanger captures the residual heat that would otherwise be discarded and redirects it to serve the regeneration process, transforming energy waste into energy recovery.
2Ease of operation
If each drying tower is equipped with independent electric heating rods and coolers, then regeneration can be performed independently, but the manufacturing cost becomes high
Solution Approach 1:
The patent creates a universal regeneration cycle module that can serve multiple drying towers simultaneously. The heat exchanger and cycle module perform multiple functions: heating inlet gas, cooling outlet gas, and enabling inter-tower heat recovery. This multi-functional design reduces the total number of components while maintaining operational flexibility, as the system can still independently regulate each tower's regeneration process through control valves.
Solution Approach 2:
The patent combines the heating and cooling functions that were previously distributed across multiple independent components into a single shared regeneration cycle module. By merging these functions and adding inter-tower heat exchange, the system reduces component count and manufacturing cost while preserving the ability to independently control each drying tower's regeneration through the heat exchanger network.
3Loss of energy
If a shared regeneration cycle module with heat exchanger is used among multiple dryers, then manufacturing cost and energy consumption are reduced, but the system complexity increases
Solution Approach 1:
The patent introduces a heat exchanger as an intermediary device that mediates heat transfer between the regeneration tail gas of one drying tower and the inlet gas of another tower. This intermediary component enables efficient heat recovery without requiring direct physical connection or complex integration between towers, simplifying the overall system architecture while achieving energy savings.
Solution Approach 2:
The system incorporates control valves that regulate the flow of gas between drying towers based on temperature and pressure conditions. This feedback mechanism automatically adjusts the heat exchange process to maintain optimal regeneration conditions, managing system complexity through automated control rather than manual intervention.
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 low manufacturing costs and reduced energy consumption by sharing a regeneration cycle module among multiple dryers, fully utilizing residual heat, and minimizing the need for additional heaters and coolers.
Implementation Method 1
a first gas-gas heat exchanger having a first gas channel and a second gas channel... allow a portion of the purified hydrogen stream to sequentially flow through the first gas channel of the first gas-gas heat exchanger... to exchange heat with the inlet gas
Implementation Method 2
regenerate a spent molecular sieve desiccant in the second dryer... to obtain high-temperature regeneration tail gas
Data Source
AI summary
Disclosed are a system and method for purifying hydrogen, and a system for producing hydrogen by water electrolysis. The system for purifying hydrogen includes three dryers, and the three dryers share one regeneration cycle module. This significantly reduces a quantity of regeneration cycle modules, and therefore, manufacturing cost of the system is relatively low. In addition, a first gas-gas heat exchanger (4) is arranged in a regeneration cycle system, so that heat exchange can be performed between low-temperature regeneration hydrogen before regeneration and high-temperature regeneration tail gas after regeneration. In this way, residual heat of the high-temperature regeneration tail gas can be fully utilized, and power consumption of a subsequent heater and regeneration cooler can be significantly reduced. Therefore, energy consumption of the system is relatively low.