Hybrid Olefin Pyrolysis Heater With Electric Radiant Cracking
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Solution Overview
Problem
Conventional pyrolysis processes using fuel-fired heaters result in high CO2 emissions and require additional hydrocarbons for fuel, leading to inefficient energy use and excess steam production, while existing air preheat methods only marginally reduce fuel consumption.
Innovation Solution
A hybrid heater system utilizing a convection section for preheating and a radiant section with electrical heating elements and excess air injection, combined with a transfer line exchanger for rapid quenching, to optimize hydrocarbon cracking and minimize fuel consumption and CO2 emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fuel fired burners are used to supply heat for cracking, then the heat requirement is met, but CO2 emissions increase and additional hydrocarbons must be added to the fuel gas mix
Solution Approach 1:
The patent combines fuel fired burners with electrical heating elements in a hybrid heater system. The electrical heating elements provide a portion of the heat duty without producing CO2 emissions, while the fuel fired burners provide the remainder. This merging of two different heating methods allows the system to meet the heat requirement while reducing CO2 emissions compared to 100% fuel firing.
Solution Approach 2:
The patent changes the energy source parameter from exclusively fossil fuel to a hybrid of electrical energy and fossil fuel. By adjusting the proportion of electrical heating duty versus fuel fired duty, the system can optimize between operational cost, CO2 emissions, and heat supply efficiency.
2Object-generated harmful factors
If air preheat is used to reduce CO2 emissions, then some fuel consumption is reduced, but super high pressure steam production remains high and fuel consumption reduction is marginal
Solution Approach 1:
The patent replaces the mechanical/chemical system of fuel combustion with an electrical heating system for portion of the heat duty. Electrical heating elements directly convert electrical energy to thermal energy without combustion, eliminating CO2 emissions from that portion of heating while providing precise temperature control.
3Quantity of substance
If excess hydrogen is produced from ethane cracking, then hydrogenation requirements are met, but additional methane or hydrocarbons must be added to satisfy heat requirement
Solution Approach 1:
The patent utilizes the hydrogen produced from ethane cracking to satisfy the hydrogenation requirements for acetylene and MAPD conversion. The hybrid heater system then provides the additional heat duty needed through electrical heating elements, eliminating the need to add extra hydrocarbons to the fuel gas mix solely for heat supply.
4Object-generated harmful factors
If a hybrid heater with electrical heating elements is used, then CO2 emissions are reduced, but device complexity increases
Solution Approach 1:
The patent divides the heater into distinct segments: fuel fired burners for combustion heating and electrical heating elements for electric heating. Each segment can be independently controlled and optimized. The convection section and radiant section are also segmented with different heating methods applied to different zones, allowing flexible operation and maintenance.
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 reduces fuel consumption, eliminates or minimizes CO2 emissions, and decreases the need for hydrogen import by efficiently utilizing excess air and electrical heating, while maintaining high ethylene yield and flexibility for various hydrocarbon feeds.
Implementation Method 1
The radiant heating zone has one or more coils that are configured for cracking hydrocarbons in the cracking feed stream with fuel fired burners and electrical heating elements
Implementation Method 2
The convection heating zone contains a first preheat zone that is configured for preheating a hydrocarbon feed and recovering a preheated hydrocarbon stream
Implementation Method 3
The cracked hydrocarbon product is cooled in a transfer line exchanger to recover a cooled hydrocarbon product stream
Implementation Method 4
one or more coils of a radiant section with fuel fired burners and electrical heating elements
Data Source
AI summary
A process including preheating a hydrocarbon feed, feeding the preheated hydrocarbon stream to a second preheat zone for cracking, and feeding the cracking feed stream to one or more coils in a radiant section to recover a cracked hydrocarbon product. The process includes injecting excess air and cooling the cracked hydrocarbon product in a transfer line exchanger. The system includes a pyrolysis heater, a first and second preheat zone of the convection heating zone, and one or more coils in the radiant heating zone. The system includes one or more inlets for injecting an amount of excess air, one or more electrical heating elements in the radiant heating zone, and a feedline for directing the cracked hydrocarbon product to a transfer line exchanger.