PSA Adsorbent Bed Segmentation for Hydrogen Purification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional PSA methods for hydrogen gas purification face challenges in efficiently removing CO, CO2, N2, and Ar impurities, leading to large equipment sizes and high purification costs, with existing adsorbents having insufficient CO adsorption capacity and incomplete regeneration of CO2, resulting in residual CO2 re-adsorption and decreased CO adsorption capacity over time.
Innovation Solution
A PSA apparatus with a layered adsorbent bed structure including a CO adsorbent layer, a carbonaceous adsorbent layer, and a zeolite layer, where the purge gas passes through in the opposite direction during regeneration, preventing CO2 re-adsorption and utilizing released gases as purge components, thereby reducing equipment size and increasing hydrogen recovery rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional hydrogen PSA method is used to purify hydrogen gas by removing CO, CO2, N2, and Ar impurities, then hydrogen purity can be achieved, but equipment size becomes large and purification cost increases
Solution Approach 1:
The adsorbent bed is divided into multiple functional layers: a CO-removing adsorbent layer (upper), a CO2-removing adsorbent layer (middle), and an N2/Ar-removing adsorbent layer (lower). This segmentation allows each layer to target specific impurities, improving purification efficiency while reducing the overall equipment size compared to conventional single-layer or multi-bed systems.
Solution Approach 2:
The patent inverts the conventional regeneration flow direction. Instead of purging from the bottom up, the purge gas is introduced from the upper end and flows downward through the adsorbent layers. This reverse flow prevents CO2 released from the middle layer from being re-adsorbed by the upper CO-removing layer, maintaining CO removal capacity while improving regeneration efficiency and reducing equipment size.
2Duration of action of stationary object
If conventional adsorbent regeneration is performed, then adsorbent can be reused, but CO2 is incompletely regenerated and re-adsorbed, decreasing CO adsorption capacity over time
Solution Approach 1:
The patent inverts the conventional regeneration flow direction. Instead of purging from the bottom up, the purge gas is introduced from the upper end and flows downward through the adsorbent layers. This reverse flow prevents CO2 released from the middle layer from being re-adsorbed by the upper CO-removing layer, maintaining CO removal capacity while improving regeneration efficiency.
Solution Approach 2:
The patent extracts and removes CO2 from the system during the regeneration phase by introducing purge gas that flows through the adsorbent layers, carrying away CO2 before it can be re-adsorbed. This extraction mechanism ensures complete CO2 removal and prevents capacity degradation in the CO-removing adsorbent layer.
3Object-affected harmful factors
If larger amounts of adsorbent are used to improve CO removal capacity, then CO concentration can be reduced to required levels, but equipment size and cost increase
Solution Approach 1:
The adsorbent bed is divided into multiple functional layers: a CO-removing adsorbent layer (upper), a CO2-removing adsorbent layer (middle), and an N2/Ar-removing adsorbent layer (lower). This segmentation allows each layer to target specific impurities with optimized adsorbent quantities, improving purification efficiency while reducing the overall equipment size compared to conventional single-layer or multi-bed systems.
Solution Approach 2:
The patent uses composite adsorbent materials with different functionalities arranged in layers: Cu-based adsorbents for CO removal, carbonaceous adsorbents for CO2 removal, and zeolite for N2/Ar removal. This composite approach allows each material to be optimized for its specific function, achieving high purification performance with smaller overall equipment volume.
Data Source
AI summary
A PSA apparatus for high-purity hydrogen gas production is provided which can recover high purity hydrogen gas at a high recovery rate from a reformed gas (hydrogen-containing gas) produced by a reforming process, for example an autothermal reforming process, and containing, as impurity components, at least CO, CO2, N2 and/or Ar, and can contribute to reducing the equipment size, hence reducing the equipment cost. The PSA apparatus for high-purity hydrogen gas B production by removing CO, CO2 and N2 by adsorption from a hydrogen containing gas A, comprises an adsorption tower 1; and an adsorbent bed 2 in the adsorption tower, wherein, on the occasion of regeneration of the adsorbent bed 2, a purge gas C is passed through in the direction opposite to the direction of passage of the hydrogen-containing gas A.