Biomass Gasification Furnace with Nested Tubes
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Solution Overview
Problem
Existing biomass gasification furnaces face inefficiencies due to separate pyrolysis and gasification portions, requiring large facilities and excessive oxygen, which reduces fuel gas quality by converting CO and H2 to CO2 and H2O, leading to lower heat capacity and quality.
Innovation Solution
A compact biomass gasification furnace design featuring an outer and inner tube structure with external heating, where biomass is supplied from above and combustion air is introduced inside the inner tube, allowing for efficient gasification and discharge of fuel gas through the space between the tubes, optimizing heat transfer and reducing oxygen usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate pyrolysis and gasification portions are constructed as independent apparatuses, then the pyrolysis and gasification functions are clearly separated, but the facility size becomes large and the device complexity increases
Solution Approach 1:
The patent combines the pyrolysis portion and gasification portion into a single integrated reactor vessel. The pyrolysis occurs in the upper portion where biomass is heated by radiant heat from the lower gasification zone, while the gasification occurs in the lower portion where combustion air is supplied. This merging eliminates the need for separate independent apparatuses while maintaining distinct functional zones through vertical stratification and controlled air supply.
Solution Approach 2:
The patent implements a nested structure where the inner tube is positioned inside the outer tube, creating concentric functional zones. The combustion air supply portion is located inside the inner tube, while the biomass processing occurs in the space between the inner and outer tubes. This nested arrangement allows multiple functions to be contained within a compact vertical structure, reducing overall facility footprint.
2Productivity
If heat is supplied externally to the gasification portion, then the fuel gas production efficiency is improved, but the facility size must be made even larger
Solution Approach 1:
The gasification portion generates its own heat through the combustion of biomass and produced gases. Combustion air is supplied to the lower gasification zone where biomass undergoes partial oxidation, releasing heat that directly drives the gasification reactions. This self-heating mechanism eliminates the need for external heat supply equipment while maintaining high fuel gas production efficiency.
Solution Approach 2:
The patent uses the produced fuel gas itself as an intermediary to transfer heat within the system. The hot fuel gas generated in the lower gasification zone rises through the upper pyrolysis zone, providing radiant heat for biomass decomposition. This internal heat circulation mechanism achieves efficient heat utilization without requiring external heat supply infrastructure.
3Object-generated harmful factors
If a large amount of oxygen is supplied to decompose tar components, then the tar decomposition is promoted, but the carbon monoxide and hydrogen react with excess oxygen to produce carbon dioxide and water, reducing fuel gas quality and heat capacity
Solution Approach 1:
The patent applies different oxygen concentrations to different zones within the reactor. The lower gasification portion receives sufficient combustion air for controlled partial oxidation and tar decomposition, while the upper pyrolysis portion operates with limited oxygen to preserve CO and H2. This localized oxygen distribution allows effective tar removal in the gasification zone without excessive oxidation in the fuel gas collection zone.
Solution Approach 2:
The reactor is segmented into distinct functional zones with controlled air supply. The combustion air supply portion is positioned to deliver oxygen specifically to the gasification zone where tar decomposition is needed, rather than uniformly throughout the entire reactor. This segmentation ensures oxygen is available where needed for tar breakdown while preventing excess oxygen from reaching and oxidizing the valuable CO and H2 in the fuel gas.
4Productivity
If the inner tube lower end is positioned higher than the outer tube lower end, then the accumulation portion is properly formed for fuel gas production, but the structural complexity increases
Solution Approach 1:
The patent resolves the structural complexity issue by utilizing the vertical dimension rather than horizontal expansion. The inner tube is positioned higher than the outer tube lower end, creating a vertical accumulation zone where biomass accumulates from the outer tube bottom to a level above the inner tube bottom. This vertical arrangement achieves proper fuel gas production conditions without requiring complex horizontal structural modifications.
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 design efficiently produces high-quality fuel gas with a compact structure, maintaining high CO and H2 concentrations while minimizing oxygen consumption and facility size, enhancing fuel gas production efficiency and quality.
Implementation Method 1
a reactor that heats the outer tube from outside
Implementation Method 2
a reactor that heats the outer tube from outside
Implementation Method 3
a combustion air supply portion that supplies combustion air
Implementation Method 4
the carbon monoxide and hydrogen can sometimes react with excess oxygen (O2) to produce carbon dioxide (CO2) and water (H2O)
Implementation Method 5
The pyrolysis portion indirectly heats and pyrolyzes the raw material biomass, producing char and pyrolysis gas containing tar components
Implementation Method 6
the fuel gas that has been produced is discharged through a space between the inner tube and the outer tube
Implementation Method 7
the fuel gas that has been produced is discharged through a space between the inner tube and the outer tube
Data Source
Figure 1
AI summary
[Problem] To provide a biomass gasification furnace that can efficiently produce high-quality fuel gas, and that can be realized with a compact structure. [Solution] A biomass gasification furnace 1 provided with an outer tube 10, an inner tube 20 provided inside the outer tube 10 so that a lower end 20b thereof is located higher than a lower end 10b of the outer tube 10, and a reactor 30 that heats the outer tube 10 from outside, wherein a combustion air supply portion 40 that supplies combustion air A is provided inside the inner tube 20 so as to be spaced from the lower end 20b of the inner tube 20, a biomass raw material F is supplied from above to the inside of the inner tube 20 so as to form an accumulation portion 100 in which the biomass raw material F has accumulated from the lower end 10b of the outer tube 10 to a location higher than the combustion air supply portion 40 inside the inner tube 20, a fuel gas G is produced in the accumulation portion 100, and the fuel gas G that has been produced is discharged through a space S between the inner tube 20 and the outer tube 10.