Hydrogen Production Thermal Integration for High CO2 Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hydrogen production methods, particularly autothermal reforming, face challenges in achieving high CO2 capture rates while minimizing indirect emissions, as increasing CO2 capture through additional hydrogen production and oxygen intake leads to higher Scope 2 and Scope 3 emissions, counterproductively increasing carbon footprint and operational costs.
Innovation Solution
An efficient thermal integration process in hydrogen production that eliminates the need for a fired heater, achieving >99% CO2 capture rate using a single CO2 removal unit, where syngas is preheated downstream of the shift reactor, and purge gases are recycled instead of being fired, utilizing a CO2 capture unit with physical or chemical absorption, and membrane separation to minimize hydrocarbon feedstock and emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If additional hydrogen is produced and fired in the fired heater to increase CO2 capture rate, then direct CO2 emissions are reduced, but Scope 3 emissions from increased hydrocarbon feedstock consumption increase
Solution Approach 1:
The invention extracts and removes the fired heater from the hydrogen production system, eliminating the need to burn additional hydrogen for heating. This allows CO2 capture to be improved without the counterproductive increase in hydrocarbon feedstock consumption that would be required to produce additional hydrogen for firing.
Solution Approach 2:
The invention introduces a heat exchanger as an intermediary to transfer heat from the hot syngas stream to the feedstock and water streams, replacing the function previously performed by the fired heater. This eliminates direct combustion while maintaining the necessary thermal energy for the reforming process.
2Object-generated harmful factors
If more oxygen is intake to reform more hydrocarbon feedstock for increased CO2 capture, then CO2 capture rate increases, but Scope 2 emissions from higher power consumption increase
Solution Approach 1:
The invention enables continuous heat recovery from the syngas stream throughout the process, maintaining thermal energy availability without requiring additional oxygen intake for reforming. This eliminates the need to increase power consumption for air separation while achieving improved CO2 capture.
Solution Approach 2:
The heat exchanger acts as an intermediary that transfers thermal energy from the syngas outlet stream to the feedstock and water inlet streams, eliminating the need for additional oxygen-intensive reforming processes to generate the required heat, thereby reducing Scope 2 emissions.
3Temperature
If fired heater is used for heating feedstock and generating steam, then process temperature requirements are met, but direct CO2 emissions increase
Solution Approach 1:
The invention implements a feedback loop where the hot syngas outlet stream (containing thermal energy) is used to preheat the feedstock and water inlet streams through a heat exchanger. This internal heat feedback eliminates the need for external fired heating, maintaining process temperatures without CO2 emissions.
Solution Approach 2:
The heat exchanger serves as an intermediary device that transfers thermal energy from the syngas stream to the feedstock and water streams, replacing the fired heater's heating function while eliminating direct CO2 emissions from combustion.
4Object-generated harmful factors
If thermal integration is improved to eliminate fired heater, then CO2 capture rate increases to >99%, but system complexity increases
Solution Approach 1:
The heat exchanger performs multiple functions simultaneously: it preheats the feedstock stream, preheats the water stream for steam generation, and enables thermal integration throughout the process. This multi-functionality achieves >99% CO2 capture without requiring multiple separate heating systems, thereby limiting the increase in system complexity.
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 achieves a direct CO2 capture rate of ≥99% without increasing indirect emissions, reducing operational and capital costs, and results in a more compact, energy-efficient hydrogen production unit with minimal emissions and capital investment.
Implementation Method 1
utilizing a CO2 capture unit with physical or chemical absorption
Implementation Method 2
utilizing a CO2 capture unit with physical or chemical absorption
Implementation Method 3
utilizing a CO2 capture unit with physical or chemical absorption, and membrane separation
Implementation Method 4
syngas is preheated downstream of the shift reactor
Implementation Method 5
an efficient thermal integration process
Data Source
AI summary
Process and method to generate hydrogen with high CO2 capture rate. The invention entails production of hydrogen in an efficient and innovative way without any continuous carbon emissions within the hydrogen production unit by use of only one CO2 removal unit. The proposed novel solution allows achieving a direct CO2 capture rate of >99% by the autothermal reforming based hydrogen generation process with one CO2 removal unit with an efficient thermal integration and without any fired heater.