Spouting Bed Pyrolysis Reactor for Low-Coking Hydrogen Production
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Solution Overview
Problem
Existing hydrocarbon reaction processes face challenges in preventing solid carbon deposition on reactor surfaces and efficiently producing solid carbon and hydrogen products without coking, particularly at high temperatures.
Innovation Solution
A pyrolysis reactor system utilizing a tapered spouting bed reactor (TSBR) with a separate solid heating vessel, incorporating non-mechanical valves and external cyclones, enables the circulation of heated particulates to maintain a temperature gradient and separate solid carbon from hydrogen, using a combination of spouting fluid beds and riser reactors to control carbon deposition on particulates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature heating is applied to hydrocarbon reaction processes, then reaction efficiency and productivity are improved, but solid carbon deposition on heat transfer surfaces occurs
Solution Approach 1:
The patent introduces a fluidized bed of inert particulate material (sand, alumina, silica, or activated carbon) as an intermediary medium between the heat transfer surfaces and the hydrocarbon feed. This particulate bed absorbs the heat from external heating sources and transfers it to the hydrocarbons through fluidization, preventing direct contact between hot surfaces and hydrocarbons that would cause carbon deposition. The particulates circulate continuously, maintaining uniform temperature distribution while eliminating coking on reactor walls.
2Device complexity
If conventional fixed-bed reactors are used for hydrocarbon pyrolysis, then equipment simplicity is maintained, but carbon deposition on internal structures prevents continuous operation
Solution Approach 1:
The patent transforms the static fixed-bed reactor into a dynamic fluidized bed system where inert particulates are continuously circulated between the reactor and an external heater. This dynamic circulation allows the bed material to be constantly renewed and prevents carbon buildup on reactor surfaces. The system includes circulation pumps, fluidization gas injectors, and temperature sensors that actively maintain optimal operating conditions, enabling continuous operation without shutdown for cleaning.
Solution Approach 2:
The reactor system is divided into separate functional zones: a reaction zone where hydrocarbons contact the hot particulate bed, an external heating zone where particulates are reheated, and a separation zone where product gases are separated from unreacted particulates. This segmentation allows each zone to be optimized independently and facilitates continuous operation by isolating the reaction process from the heating and separation processes.
3Quantity of substance
If solid carbon products are produced on reactor surfaces, then carbon production is achieved, but the carbon adheres to internal structures causing maintenance issues
Solution Approach 1:
The inert particulate material serves as a mobile carrier that transports solid carbon products away from the reactor walls. Instead of carbon depositing directly on fixed internal structures, it forms on the circulating particulates that can be continuously removed and regenerated. This eliminates the need for periodic shutdowns to clean carbon deposits from reactor surfaces, as the particulate bed is continuously circulated and replaced.
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 system effectively produces solid carbon and hydrogen while minimizing coking on reactor walls, allowing for high-temperature operation with low-cost materials and efficient heat integration, reducing carbon deposition on internal surfaces.
Implementation Method 1
Processes and methods for producing hydrogen and carbon from hydrocarbons
Implementation Method 2
heating the portion of the particulates from the pyrolysis reactor to produce heated particulates
Implementation Method 3
external cyclones
Data Source
AI summary
A system includes a pyrolysis reactor containing a bed of particulates, a solids heating section, and a separator in fluid communication with the pyrolysis reactor through the product gas outlet. The pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed, a product gas outlet above the bed, a particulate outlet above the feed gas inlet, a particulate inlet near the top of the bed, and a solids product outlet in a lower portion of the pyrolysis reactor. The solids heating section is configured to accept a portion of the particulates from the pyrolysis reactor through the particulate outlet, heat the portion of the particulates to form heated particulates, and return the heated particulates to the pyrolysis reactor through the particulate inlet, and the separator is configured to separate any particulates in a product gas produced, and return the particulates to the pyrolysis reactor.