Fluidized Bed Combustion Device with Catalytic Reforming Tubes
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Solution Overview
Problem
Current energy production plants using fossil fuels emit significant CO2 and underutilize resources, particularly during low electricity production, and existing methods for producing hydrogen-rich fuels are inefficient, relying on additional fuels for heating.
Innovation Solution
A combustion device with a circulating fluidized bed and catalytic tubes that reform natural gas or naphtha using recycled CO2 and water vapor to produce hydrogen-rich syngas with minimal water vapor and no additional fuel, utilizing a metal oxide catalyst in a thermochemical cycle for efficient hydrogen production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If reforming of natural gas is carried out in bundles of catalyst tubes partially immersed in a dense fluidized bed using additional fuel for heating, then hydrogen-rich syngas can be produced, but fuel consumption increases and production cost rises
Solution Approach 1:
The patent combines the combustion chamber and reforming chamber into a single integrated device where the fluidized bed serves dual purposes: combustion of carbonaceous material to generate heat, and simultaneous reforming of natural gas to produce hydrogen-rich syngas. This eliminates the need for separate heating fuel by using the carbonaceous material itself as the heat source.
Solution Approach 2:
The fluidized bed is designed to perform multiple functions simultaneously: it acts as a combustion zone for carbonaceous material, a heating medium for catalyst tubes, and a reactor for reforming natural gas. The catalyst tubes are partially immersed in the fluidized bed, allowing them to benefit from the hot particles while maintaining structural integrity.
2Object-generated harmful factors
If combustion of solid fuels is performed in air to produce electricity, then nitrogen-free fumes can be achieved by using oxygen from recycled CO2, but the device is underutilized during low production periods
Solution Approach 1:
The device is designed to operate in multiple modes: during high production periods it generates electricity through combustion, while during low production periods it continues to operate as a reforming unit producing hydrogen-rich syngas. This multi-functionality ensures continuous utilization of the infrastructure regardless of electricity demand fluctuations.
Solution Approach 2:
The device can dynamically switch between different operational modes (combustion for electricity generation vs. reforming for syngas production) based on production requirements. The fluidized bed and catalyst tubes can be adjusted to optimize for either electrical power output or chemical fuel output as needed.
3Manufacturing precision
If catalytic tubes are placed in dense fluidized bed for reforming, then homogeneous heating and promoted reforming reaction are achieved, but device complexity increases
Solution Approach 1:
The patent merges the heating function and reforming function into a single integrated structure where catalyst tubes are directly immersed in the fluidized bed. The hot particles in the bed provide uniform external heating to the tubes while the reforming reaction occurs inside the tubes, eliminating the need for separate heating systems.
Solution Approach 2:
The fluidized bed particles act as an intermediary heat transfer medium between the combustion zone and the catalyst tubes. The particles circulate through the system, absorbing heat from combustion and delivering it uniformly to the catalyst tubes, thereby achieving homogeneous heating without direct flame contact.
4Quantity of substance
If water vapor is used in reforming reactions, then hydrogen production is enhanced, but water vapor consumption increases
Solution Approach 1:
The patent implements a feedback system where water vapor produced during combustion and reforming reactions is recirculated back into the reforming chamber. This closed-loop approach allows the same water vapor to participate in multiple reforming cycles, enhancing hydrogen production while minimizing net water vapor consumption from external sources.
Solution Approach 2:
The system uses its own internally generated water vapor from combustion and reforming reactions to sustain the reforming process, rather than requiring continuous external water vapor supply. The water vapor produced by the reactions themselves is fed back into the catalyst tubes to maintain the reforming reaction.
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
The device effectively produces both electricity and hydrogen-rich syngas with reduced water vapor consumption and no additional fuel, optimizing CO/H2 mixture and minimizing fuel usage, while being adaptable to varying production loads.
Implementation Method 1
a combustion chamber (1) for combusting a carbonaceous material in a circulating fluidized bed
Implementation Method 2
The gas undergoes reforming which transforms it into synthesis gas containing hydrogen
Implementation Method 3
the part arranged in the bed of the heat recovery means consists of catalytic tubes through which a gas mixture passes
Implementation Method 4
The fact of arranging the catalytic tubes in the dense fluidized bed constituted by the ashes resulting from the combustion makes it possible to heat the catalyst in a homogeneous manner
Implementation Method 5
a water gas reaction stage which further increases the hydrogen content. This step is characterized by the following reaction: CO + H2O -> CO2 + H2
Data Source
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AI summary
The invention relates to a combustion device which produces fumes containing CO2 and steam and which consists of: a circulating fluidised bed reaction chamber (1, 2), a separator (10, 20), and heat recuperator means comprising one part which is disposed in a dense fluidised bed (12, 12a, 22). The inventive device is characterised in that the part of the heat recuperator means that is disposed in the bed comprises catalyst tubes (120, 120a, 220) through which a gas mixture flows. The aforementioned gas mixture comprises natural gas and/or naphtha or refinery gas or two or more of said gases. The gas is reformed and transformed into synthesis gas containing hydrogen. Since the catalyst tubes are disposed in the dense fluidised bed formed by the ash from the combustion, the catalyst can be heated uniformly and the natural gas mixture reforming reaction can be promoted.