Concentric Fluidized Bed Reactor for Activated Carbon
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Solution Overview
Problem
Existing methods for producing activated carbon from carbon bio-precursors face inefficiencies in temperature control and energetic efficiency, particularly in vertical heating furnaces and complex fluidized bed reactor arrangements, which complicate the activation process and gas contact, limiting the use of bio-charcoal with varying particle sizes and shapes.
Innovation Solution
A concentric arrangement of two fluidized bed reactors, functioning as a circulating fluidized bed reactor, allows for stable temperature control and efficient energetic use by recirculating particles of varying sizes, using superheated steam and reusing synthesis gases for activation, enabling the production of high-quality activated carbon with tailored properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a vertical heating furnace is used where carbon material falls gravitationally through the heating chamber, then the structure is simple, but the temperature control is inefficient and the contact of carbon precursor with activation gas is not ideal
Solution Approach 1:
The patent replaces gravitational fall with pneumatic fluidization, using gas flow to suspend and circulate carbon particles through the heating chamber. This allows controlled particle movement and enhanced contact with activation gas while maintaining temperature control efficiency.
Solution Approach 2:
The patent introduces dynamic particle circulation through fluidized bed technology, where carbon particles are continuously moved and mixed by gas flow. This dynamic behavior improves heat and mass transfer efficiency compared to static gravitational fall.
2Temperature
If a complex reactor with multiple spiral elements is used to control carbon particle movement, then the temperature control improves, but the device complexity increases and the exhaust of spent gases becomes complicated
Solution Approach 1:
The patent uses gas flow dynamics to control particle movement instead of mechanical spiral elements. The fluidized bed system naturally circulates particles through gas flow patterns, eliminating the need for complex mechanical structures while maintaining temperature control.
Solution Approach 2:
The patent replaces mechanical spiral elements with pneumatic systems. Gas flow patterns create the circulation effect that would otherwise require mechanical components, simplifying the reactor structure while maintaining particle control.
3Productivity
If two independent fluidized bed reactors are arranged vertically for regeneration, then the activation efficiency improves, but the device complexity increases and the arrangement is not suitable for simultaneous activation and regeneration
Solution Approach 1:
The patent places one fluidized bed reactor inside another concentrically, creating a nested arrangement. This allows simultaneous operation of both reactors in a compact configuration, enabling both activation and regeneration processes to occur at the same time without requiring separate vertical arrangements.
Solution Approach 2:
The concentric fluidized bed reactor system can perform multiple functions: the inner reactor can be used for activation while the outer reactor performs regeneration, or both can be used for activation simultaneously. This multi-functionality allows the system to handle both activation and regeneration processes with a single integrated design.
4Productivity
If water steam is used to fluidize the bed and activate bigger vegetable carbon particles, then the activation of larger particles improves, but the smaller particles are transported prior being fully activated
Solution Approach 1:
The patent uses controlled gas flow rates to dynamically adjust particle movement. By regulating the fluidizing gas flow, the system can prevent excessive transport of small particles while maintaining adequate activation of larger particles, achieving balanced processing across different particle sizes.
Solution Approach 2:
The patent adjusts operating parameters including gas flow rate, temperature, and steam concentration to optimize the balance between particle activation and transport. By changing these parameters, the system can ensure complete activation of small particles while effectively processing larger particles.
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 configuration ensures higher temperature stability and energetic efficiency, enabling the simultaneous activation of carbon particles with a wide range of sizes and shapes, producing high-surface-area activated carbon with excellent adsorption capabilities while minimizing environmental impact.
Implementation Method 1
two fluidized bed reactors concentrically arranged for the production of activated carbon
Implementation Method 2
The combustion gases that leaves the outer fluidized bed are sent to the heat exchanger to take advantage of this hot stream to overheat the steam
Implementation Method 3
The activation process originates gases that are fed into the burners, thus replacing the auxiliary gas used to start the process
Data Source
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AI summary
The present invention relates to an equipment to produce activated carbon from carbon bio-precursors by physical activation containing an external fluidized bed reactor (2); an internal fluidized bed reactor (1); one silo for the vegetable carbon (R1); one silo for the activated carbon (R2); at least 3 cyclones (C1, C2 and C3); at least one pressure valve (V1); at least one rotary valve for the activated carbon discharge (V2); at least one rotary valve for feeding the vegetable carbon (V3); at least one screw feeder (T); at least one blower (B) wherein the internal fluidized bed reactor (1) is concentrically inserted into the external fluidized bed reactor (2) and the clean gas outlet of the activated carbon discharge cyclone (C1) is connected to .the line (G2) for collecting the discharge.