Swirl Feed Reactor Nozzle for Flashback-Safe Hydrocarbon Pyrolysis
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Solution Overview
Problem
Conventional methods for converting lower molecular weight carbon-containing molecules to higher molecular weights face challenges such as flashback risks in single-stage processes and large heat losses in two-stage processes, leading to inefficiencies and increased costs.
Innovation Solution
A pyrolysis reactor design featuring a converging-diverging burner nozzle and disk-like inlets for tangential injection of hydrocarbon and oxidizer gases, enabling nearly simultaneous mixing, combustion, and pyrolysis with a compact flame, utilizing annular highly swirled jets under specific fluid-dynamics to achieve high temperatures for pyrolysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single-stage partial oxidation method is used, then acetylene production is simplified, but flashback risks increase and burner complexity increases
Solution Approach 1:
The reactor is divided into distinct functional zones: a combustion zone for oxidizing hydrocarbons to generate heat, and a separate pyrolysis zone for converting hydrocarbons to acetylene. This segmentation allows each zone to operate under optimized conditions independently, eliminating flashback risks while maintaining simplicity.
Solution Approach 2:
Hot combustion gases serve as an intermediary heat transfer medium, transferring thermal energy from the combustion zone to the pyrolysis zone through convection and conduction. This intermediary mechanism enables efficient heat transfer without direct contact between fuel and oxidizer, eliminating flashback risks.
2Productivity
If two-stage process with quenching zone is used, then pyrolysis efficiency is improved, but heat losses increase
Solution Approach 1:
The combustion zone and pyrolysis zone are merged into a single integrated reactor vessel, allowing hot combustion gases to directly heat the hydrocarbon feed in the pyrolysis zone. This merging eliminates the need for separate quenching zones and reduces heat losses by minimizing thermal energy transfer to external cooling systems.
3Temperature
If multiple burners are used in single-stage process, then heat distribution is improved, but reliability decreases and cost increases
Solution Approach 1:
The complex multi-burner system is extracted and replaced with a single combustion zone that utilizes the natural convection and turbulence of the reacting gas mixture to achieve uniform heat distribution. This extraction simplifies the system, improving reliability while maintaining effective heat distribution through the combustion of hydrocarbon feed.
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 reactor design provides a safe, efficient, and cost-effective process for converting light alkanes to pyrolysis products with high yield and minimal heat loss, eliminating flashback risks and reducing reactor complexity.
Implementation Method 1
A burner assembly of the reactor has a burner conduit with a circumferential wall that surrounds a central longitudinal axis and extends from opposite upstream and downstream ends of the burner conduit
Implementation Method 2
The feed assembly has a downstream feed assembly wall that extends circumferentially around and joins the upstream end of the burner assembly inlet
Implementation Method 3
A pyrolysis reactor for the pyrolysis of hydrocarbon gases has a pyrolysis reactor vessel having a reactor wall that defines a pyrolysis reaction chamber
Data Source
AI summary
A reactor (12) and method for the conversion of hydrocarbons utilizes a reactor (12) having a unique feed assembly (56) that creates an inwardly spiraling fluid flow pattern of the feed gases to form a swirling gas mixture that passes through a conduit (46) with a constricted neck portion or nozzle (52). At least a portion of the swirling gas mixture forms a thin, annular mixed gas flow layer immediately adjacent to the conduit (46). A portion of the swirling gas mixture is combusted as the swirling gas mixture passes through the conduit (46) for conversion of hydrocarbons.