Biomass Pyrolysis Chemical Looping Hydrogen Generation
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Solution Overview
Problem
Current hydrogen generation from biomass pyrolysis/gasification involves a complex and energy-intensive process, leading to high operational costs and complexity, which hinders efficient production of high-purity hydrogen.
Innovation Solution
A device and method incorporating a biomass pyrolysis unit, a chemical looping hydrogen generation unit, and a waste heat recovery unit, where biomass is pyrolyzed to produce pyrolysis gas, which is then used in chemical looping combustion with packed bed reactors undergoing different reaction stages to generate high-purity hydrogen, simplifying the process and enabling low-cost CO2 capture and thermal energy supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional biomass pyrolysis/gasification process is used to generate high-purity hydrogen, then hydrogen can be produced through catalytic cracking and steam reforming, but the process becomes overly long and complex with increased operational complexity and energy consumption
Solution Approach 1:
The invention extracts and eliminates the complex intermediate steps (catalytic cracking, steam reforming, purification, decarburization) from the conventional process. Instead, it directly gasifies biomass in a fluidized bed reactor and captures CO2 through chemical looping combustion, keeping only the essential functions of hydrogen production and CO2 separation.
Solution Approach 2:
The invention merges the hydrogen production process with CO2 capture in a single integrated system. The chemical looping combustion technology combines fuel gasification and CO2 separation functions in one reactor, eliminating the need for separate purification and decarburization units.
2Manufacturing precision
If conventional biomass pyrolysis/gasification process is used to generate high-purity hydrogen, then hydrogen can be produced through multiple processing steps, but energy consumption increases substantially
Solution Approach 1:
The invention converts the CO2 that would normally be a waste product requiring energy-intensive removal into a valuable byproduct that is directly captured and concentrated during the gasification process itself. The chemical looping combustion naturally produces high-concentration CO2 in the flue gas, eliminating the need for energy-consuming CO2 separation processes.
Solution Approach 2:
The invention changes the operating parameters and reaction conditions to achieve direct CO2 capture during gasification. By controlling the chemical looping combustion process and oxygen carrier materials, the system achieves both hydrogen production and CO2 separation under optimized conditions, reducing the need for additional energy input.
3Productivity
If conventional biomass pyrolysis/gasification process is used to generate high-purity hydrogen, then hydrogen production is achievable, but the process requires numerous processing steps leading to increased operational complexity
Solution Approach 1:
The invention segments the complex conventional process into two main functional modules: (1) biomass gasification in a fluidized bed reactor, and (2) CO2 capture through chemical looping combustion. This segmentation simplifies the overall process structure while maintaining hydrogen production capability and CO2 separation efficiency.
Solution Approach 2:
The chemical looping combustion reactor serves multiple functions simultaneously: it acts as a gasifier for biomass conversion, a reactor for chemical reactions, and a CO2 capture device. This multi-functionality reduces the number of separate units needed and simplifies operational procedures.
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 hydrogen generation costs, simplifies the process flow, and achieves high-purity hydrogen production with efficient CO2 capture and energy recovery, making the process more environmentally friendly and sustainable.
Implementation Method 1
biomass is pyrolyzed to produce pyrolysis gas
Implementation Method 2
chemical looping combustion of the pyrolysis gas
Implementation Method 3
waste heat recovery unit
Data Source
AI summary
The present invention discloses a device and method for generating high-purity hydrogen by biomass pyrolysis-chemical looping combustion. The device comprises a biomass pyrolysis unit, a chemical looping hydrogen generation unit and a waste heat recovery unit; the biomass pyrolysis unit comprises a vertical bin, a screw feeder, a rotary kiln pyrolysis reactor and a high temperature filter; the chemical looping hydrogen generation unit comprises a path switching system of intake gas end, at least one packed bed reactor and a path switching system of tail gas end, wherein the packed bed reactor is composed of three parallel packed bed reactors I, II and III, which are continuously subjected to fuel reduction-steam oxidation-air combustion stages (steam purging stage) successively; the waste heat recovery unit comprises a waste heat boiler, a cooler and a gas-liquid separator. According to the present invention, a process flow of generating hydrogen from biomass is short, high-purity hydrogen can be obtained by simple condensation and water removal of a hydrogen-containing product that is generated after entrance of a pyrolysis gas into the chemical looping hydrogen generation unit, no complex gas purification device is employed, and the costs for hydrogen generation are low.