Compact Hydrogen Generator Sorbent Integration
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Solution Overview
Problem
Current power generation systems using hydrogen turbines face challenges such as large footprints and capital expenses due to two-step conversion reactors, energy penalties from low conversion efficiency, and difficulties in modularization and scaling, along with issues in NOx emission control and the complexity of separating hydrogen from carbon dioxide.
Innovation Solution
The development of a Compact Hydrogen Generator (CHG) that uses calcium oxide as a sorbent in a bubbling fluidized bed to directly produce high-purity hydrogen from natural gas, integrating CO2 capture and utilizing the excess steam for combustion, thereby reducing NOx emissions and eliminating the need for additional separation equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional Steam Methane Reformer (SMR) and water gas shift reactor are used for hydrogen production, then hydrogen can be produced from natural gas, but the system requires large footprints and high capital expenses due to multiple reactors and separation equipment
Solution Approach 1:
The patent combines the steam methane reforming reaction and water gas shift reaction into a single integrated reactor. The reforming section and water gas shift section are merged into one unit, eliminating the need for separate reactors and reducing overall system complexity while maintaining hydrogen production capability
Solution Approach 2:
The integrated reactor performs multiple functions simultaneously: it conducts steam methane reforming, water gas shift conversion, and carbon dioxide separation all within one unit. This multi-functional design reduces the number of separate pieces of equipment needed while achieving the same hydrogen production objectives
2Quantity of substance
If traditional SMR system with amine absorption column is used for CO2 separation, then carbon dioxide can be separated from hydrogen, but energy penalty increases due to low conversion efficiency and amine system regeneration requirements
Solution Approach 1:
The patent replaces the amine absorption chemical system with a physical separation system using a membrane separator. The membrane separator physically separates carbon dioxide from hydrogen based on differential permeability, eliminating the need for amine chemistry, regeneration heating, and associated energy penalties
Solution Approach 2:
The system utilizes phase transition and permeation properties of the membrane separator to separate carbon dioxide from hydrogen. The membrane allows selective passage of gases based on their permeation characteristics, achieving separation without requiring phase change energy inputs like amine regeneration
3Power
If hydrogen is produced and used in gas turbine, then power generation can be achieved, but NOx emissions are generated during combustion that require expensive SCR equipment for control
Solution Approach 1:
The patent converts the harmful effect of high-temperature combustion into a beneficial outcome by using the heat from combustion to generate steam for the combined cycle system. The NOx emissions are managed by controlling combustion temperature and using the excess steam from the reforming process to dilute combustion products, reducing NOx formation rather than requiring separate control equipment
4Temperature
If quench gas such as steam is used to attemperate combustion in hydrogen turbine, then combustion process can be controlled, but separate making and mixing of quench gas with hydrogen becomes troublesome and problematic
Solution Approach 1:
The system pre-mixes steam with the hydrogen fuel stream in the reforming process before combustion occurs. The steam is introduced into the reformer along with the natural gas, creating a pre-heated, pre-diluted fuel mixture that is ready for combustion without requiring separate quench gas addition steps
Solution Approach 2:
The patent merges the quench gas function with the reforming process by using the same steam introduction system to both reform the methane and provide combustion temperature control. This integration eliminates separate mixing operations and simplifies the overall process 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 results in lower equipment costs, higher hydrogen yields, and a concentrated CO2 stream suitable for Carbon Capture and Sequestration, while improving power generation efficiency and reducing NOx emissions, making it superior to traditional Steam Methane Reformer systems.
Implementation Method 1
The compact hydrogen generator contains a quantity of a sorbent material. A feed material to the compact hydrogen generator produces H2 product and carbon dioxide and the sorbent material absorbs carbon dioxide and forms a used sorbent.
Implementation Method 2
A calciner connected to the gas/solids separator serves to heat the used sorbent to desorb carbon dioxide from the used sorbent to produce regenerated sorbent.
Implementation Method 3
A gas/solids separator connected to the compact hydrogen generator to separate the H2 product and the used sorbent.
Implementation Method 4
The development of a Compact Hydrogen Generator (CHG) that uses calcium oxide as a sorbent in a bubbling fluidized bed to directly produce high-purity hydrogen from natural gas
Data Source
AI summary
Systems and methods for generating power using hydrogen fuel, such as derived from natural gas, are provided. Feed materials are introduced into a compact hydrogen generator to produce carbon dioxide, hydrogen gas and steam. Sorbent material within the compact hydrogen generator acts to absorb carbon dioxide, forming a used sorbent. Hydrogen gas and steam are separated from the used sorbent and passed to a power generator such as a hydrogen turbine to produce power. The used sorbent is introduced into a calciner and heated to desorb carbon dioxide and form a regenerated sorbent which can be recycled to the compact hydrogen generator.