Adsorbent Regeneration via Selective Purging
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Solution Overview
Problem
Existing processes for removing acidic gases like carbon dioxide and hydrogen sulphide from adsorbents used in water gas shift processes often result in these gases being present in the same product stream, making reuse or purification difficult.
Innovation Solution
A process involving two purging steps with specific gas compositions to selectively remove hydrogen sulphide and carbon dioxide from adsorbents, where the first purging gas contains hydrogen sulphide at a partial pressure higher than in the feed gas and the second purging gas contains carbon dioxide at a lower partial pressure, allowing for distinct mass-transfer zones and enhanced removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single purging step is used to remove acidic gases from adsorbent, then the process is simple, but the acidic gases (CO2 and H2S) end up in the same effluent stream making separate processing difficult
Solution Approach 1:
The single purging step is segmented into two sequential purging steps: first purging with a gas containing H2S at partial pressure ≥ feed gas to remove H2S selectively, then second purging with a gas containing CO2 at lower partial pressure to remove CO2 selectively. This segmentation creates separate effluent streams for H2S and CO2, enabling independent processing of each acidic gas.
2Object-generated harmful factors
If selective removal of H2S and CO2 is achieved through multiple purging steps, then separate processing of acidic gases is enabled, but the process complexity increases
Solution Approach 1:
The process utilizes parameter changes in gas composition and partial pressure to achieve selective removal. The first purging gas is configured with H2S at partial pressure ≥ that in feed gas, while the second purging gas contains CO2 at lower partial pressure. These parameter variations create distinct mass-transfer zones within the adsorbent bed, allowing selective desorption of different acidic gases without requiring complex additional equipment.
3Productivity
If conventional purging methods are used, then the adsorbent is regenerated, but the acidic gases cannot be separately utilized or purified
Solution Approach 1:
The process extracts H2S and CO2 from the adsorbent into separate effluent streams through the two-step purging method. The first purging step extracts H2S into a separate stream, and the second purging step extracts CO2 into another separate stream. This extraction enables downstream separate processing, purification, or utilization of each acidic gas component, transforming a mixed harmful effluent into separable valuable resources.
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 process achieves a high degree of removal of acidic components, enabling separate processing and utilization, with improved efficiency by creating distinct mass-transfer zones for H2S and CO2, particularly benefiting hydrogen-containing gas production.
Implementation Method 1
an adsorbent which has adsorbed the gaseous components as a result from contacting the adsorbent with a feed gas containing these acidic gaseous species
Implementation Method 2
The carbon dioxide and hydrogen sulphide are subsequently simultaneously removed from the adsorbent
Data Source
AI summary
Two or more acidic gaseous species such as hydrogen sulphide and carbon dioxide from an adsorbent can be selectively removed from a feed gas by contacting the feed gas with an adsorbent for these acidic species, followed by: a. subjecting the adsorbent to a first purging gas, said first purging gas not containing said first acidic gaseous species and containing said second acidic gaseous species at a partial pressure which is at least the partial pressure of said second gaseous species in said feed gas; b. subsequently subjecting the adsorbent to a second purging gas, said second purging gas not containing said first gaseous species and, containing this second gaseous species at a partial pressure which is lower than the partial pressure of said second gaseous species in said feed gas.