ATR-based hydrogen process and plant
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Solution Overview
Problem
Current hydrogen production methods are inefficient in terms of hydrocarbon feed and fuel consumption, leading to high energy costs and capital expenditures, particularly in plants based on steam methane reformers.
Innovation Solution
A hydrogen production process utilizing an autothermal reformer, high temperature shift section, CO2 removal, and hydrogen purification, with off-gas recycling to reduce steam consumption and eliminate the need for steam methane reformers, employing a promoted zinc-aluminum oxide catalyst to operate at lower steam-to-carbon ratios and incorporating off-gas recycling to enhance hydrogen recovery and reduce equipment size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If steam methane reformers are used for hydrogen production, then hydrogen can be produced, but hydrocarbon feed consumption and energy costs increase
Solution Approach 1:
The invention changes the operating parameters by using an autothermal reformer that operates at lower steam-to-carbon ratios compared to conventional steam methane reformers. This parameter change reduces hydrocarbon feed consumption and energy costs while maintaining hydrogen production efficiency
Solution Approach 2:
The off-gas recycling system allows the process to serve itself by recovering hydrogen from off-gas and feeding it back into the reformer, reducing the need for additional hydrocarbon feed and external hydrogen sources, thereby lowering energy costs
2Quantity of substance
If conventional steam methane reformers are used, then hydrogen production is achieved, but capital expenditures increase
Solution Approach 1:
By changing to an autothermal reforming process with lower steam-to-carbon ratios, the invention reduces equipment size requirements and capital expenditures while maintaining hydrogen production capacity
Solution Approach 2:
The off-gas recycling system increases hydrogen recovery efficiency, allowing for smaller equipment sizes and reduced capital expenditures by maximizing the utilization of hydrogen produced within the system
3Productivity
If off-gas is recycled to the reformer, then hydrogen recovery is enhanced, but process complexity increases
Solution Approach 1:
The invention merges the off-gas recycling stream with the main reformer feed stream, combining multiple functions into a single integrated process flow that enhances hydrogen recovery without proportionally increasing process complexity
Solution Approach 2:
The off-gas recycling system implements a feedback mechanism where hydrogen-rich off-gas is recovered and fed back into the reformer, creating a self-reinforcing cycle that enhances hydrogen recovery while maintaining manageable process complexity through automated control
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 significantly reduces hydrocarbon feed consumption, energy usage, and capital expenditures while maintaining energy efficiency, allowing for smaller equipment sizes and lower CO2 emissions by operating at lower steam-to-carbon ratios and recycling off-gas streams within the process.
Implementation Method 1
the hydrocarbon feed is subjected to reforming in an autothermal reformer (ATR) for generating a synthesis gas
Implementation Method 2
subjecting the synthesis gas to shift conversion step in a shift section including one or more shift steps for enriching the synthesis gas in hydrogen
Implementation Method 3
treating the shifted gas in a hydrogen purification unit, such as a pressure swing adsorption (PSA) unit
Data Source
AI summary
A plant and process for producing a hydrogen rich gas are provided, said process comprising the steps of: reforming a hydrocarbon feed in a reforming step thereby obtaining a synthesis gas comprising CH4, CO, CO2, H2 and H2O; shifting said synthesis gas in a shift configuration including a high temperature shift step; removal of CO2 upstream hydrogen purification unit, such as a pressure swing adsorption unit (PSA), and recycling off-gas from hydrogen purification unit and mix it with natural gas upstream prereformer feed preheater, prereformer, reformer feed preheater or ATR or shift as feed for the process.