PSA Inert Gas Slippage in ATR Hydrogen Production Loops
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In autothermal reforming (ATR) based hydrogen production processes, the recirculation of inert gases leads to a buildup, reducing the flow rate of hydrocarbon feedstock and increasing carbon emissions, necessitating higher energy consumption and operational costs due to the need for additional hydrogen combustion in fired heaters.
Innovation Solution
A modified pressure swing adsorption (PSA) process allows slippage of inert gases into the hydrogen product stream, reducing their concentration in the residual gas stream, enabling more residual gas to be recycled to the ATR step and minimizing the need for combustion in fired heaters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If residual gas is recirculated to the synthesis gas generation section, then hydrogen production efficiency is improved, but inert gas components build up in the recirculation loop over time, limiting the flow rate of hydrocarbon feedstock
Solution Approach 1:
The patent extracts a portion of the residual gas stream from the recirculation loop and directs it to the fired heater for combustion. This removal mechanism prevents inert gas buildup while maintaining the beneficial recirculation of combustible components, resolving the contradiction between productivity and inert gas accumulation
Solution Approach 2:
The patent discards inert gas components by combusting them in the fired heater while recovering the energy content. The residual gas stream is partially burned to provide process heat, simultaneously removing inert gases from the system and utilizing the combustible components for energy generation
2Quantity of substance
If residual gas stream is sent to the fired heater for combustion, then inert gas components are removed from the recirculation loop, but carbon dioxide emissions increase as carbon containing compounds end up as carbon dioxide in the flue gas
Solution Approach 1:
The patent converts the harmful effect of carbon dioxide emissions into a beneficial outcome by using the combustible components of the residual gas as fuel in the fired heater. The carbon containing compounds that would otherwise be wasted are transformed into a useful energy source, and the resulting carbon dioxide is utilized for carbon dioxide capture processes
3Manufacturing precision
If hydrogen purification step is installed downstream of the carbon capture unit to minimize carbon containing impurities, then hydrogen purity is improved, but a residual gas stream is produced containing hydrogen, unconverted hydrocarbon, carbon monoxide and inert gases
Solution Approach 1:
The patent recovers valuable components from the residual gas stream by recirculating it to the synthesis gas generation section. Instead of discarding the residual gas, the system utilizes the hydrogen, unconverted hydrocarbons, and carbon monoxide for further hydrogen production, while selectively removing inert gases through partial combustion
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 reduces inert gas concentration in the residual gas stream, allowing more efficient hydrogen production with lower energy consumption and operational costs by recycling a larger portion of residual gas to the ATR step, thus optimizing the hydrogen production process.
Implementation Method 1
the purification step comprises a pressure swing adsorption (PSA) step, by which the hydrogen product stream is obtained
Implementation Method 2
slippage of a portion of the inert gas component along with the hydrogen product stream is enabled
Implementation Method 3
Converting the hydrocarbon-containing feedstock stream to a first synthesis gas stream by means of an autothermal reforming (ATR) step
Implementation Method 4
the first synthesis gas stream comprises hydrogen, carbon monoxide, carbon dioxide and an inert gas component
Implementation Method 5
Converting the hydrocarbon-containing feedstock stream to a first synthesis gas stream by means of an autothermal reforming (ATR) step
Implementation Method 6
Converting the first synthesis gas stream to a second synthesis gas stream by means of a water-gas shift step, wherein the second synthesis gas stream is depleted in carbon monoxide and enriched in hydrogen and carbon dioxide
Data Source
Figure 1
AI summary
A process to produce hydrogen, in which a hydrocarbon-containing feedstock stream is converted to a hydrogen and carbon dioxide rich synthesis gas stream by means of autothermal reforming and water-gas shift. The shifted synthesis gas stream is subjected to a purification step, in which a hydrogen product stream, a carbon dioxide product stream, and a residual gas stream are obtained. The residual gas stream comprises a carbon containing gas component and an inert gas component. The purification step comprises a pressure swing adsorption (PSA) step, by which the hydrogen product stream is obtained, and wherein in the PSA step, slippage of an inert gas component along with the hydrogen product stream is enabled, so that the hydrogen product stream contains a measurable concentration of said inert gas component, and wherein at least a portion of the residual gas stream is supplied to the ATR step.