FCC Renewable Oil Feed Cooling to Prevent Coking and Clogging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for co-processing hydrocarbon and pyrolysis oil streams in fluid catalytic cracking (FCC) units face issues such as clogging and fouling due to the immiscibility and high oxygen content of pyrolysis oils, leading to excessive deposit formation and equipment plugging.
Innovation Solution
The method involves separately introducing a renewable oil stream and an FCC hydrocarbon stream into the FCC reaction zone, maintaining the renewable oil stream at a temperature below 100°C using a cooling stream of light hydrocarbons, and optimizing the mixing ratio to minimize deposit formation and clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pyrolysis oil stream is co-processed with hydrocarbon stream in FCC unit, then renewable content is increased and petroleum-based hydrocarbon content is decreased, but feed line clogging and equipment fouling occur due to high oxygen content and immiscibility
Solution Approach 1:
The patent divides the feed stream into separate hydrocarbon stream and pyrolysis oil stream, introducing them into the reaction zone through separate feed lines. This segmentation prevents the pyrolysis oil from clogging the feed lines while still allowing it to be processed in the FCC unit, thus resolving the contradiction between incorporating renewable content and avoiding feed line clogging.
Solution Approach 2:
The patent uses a carrier gas as an intermediary substance to transport the pyrolysis oil stream into the reaction zone. The carrier gas facilitates the introduction of pyrolysis oil without direct contact between the pyrolysis oil and the feed line walls, preventing clogging while enabling the pyrolysis oil to be processed alongside hydrocarbon streams.
2Reliability
If pyrolysis oil is deoxygenated before FCC processing, then feed line clogging is reduced, but additional unit operations and capital costs are required
Solution Approach 1:
The patent extracts the problematic oxygen content issue from the pyrolysis oil stream by introducing it separately into the reaction zone where the high temperature and catalyst automatically facilitate cracking and conversion. This eliminates the need for prior deoxygenation unit operations while still preventing feed line clogging through separate introduction.
Solution Approach 2:
The patent performs preliminary separation of the pyrolysis oil stream from the hydrocarbon stream before introduction into the reaction zone. This preliminary action prevents clogging in the feed lines while the actual cracking and conversion occur inside the reaction zone, eliminating the need for complex deoxygenation equipment.
3Productivity
If renewable oil stream is introduced at high temperature, then cracking reaction is enhanced, but polymerization and deposit formation increase
Solution Approach 1:
The patent applies different temperature conditions to different parts of the process: the feed lines and reaction zone inlet maintain lower temperatures to prevent polymerization and deposit formation, while the reaction zone itself provides the high temperature needed for cracking. This local quality differentiation resolves the contradiction between enhancing cracking reaction and preventing harmful deposits.
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 approach reduces deposit formation in feed lines and the reaction zone, enhancing the efficiency and reliability of the FCC process while producing valuable products like ethylene and propylene.
Implementation Method 1
actively cooling and maintaining the renewable feed stream and the outlet of the renewable feed line at a temperature less than or equal to 100° C. substantially up to introduction of the renewable feed stream into the FCC reaction zone with a cooling stream
Implementation Method 2
catalytically cracking the mixture of the FCC feed stream, the renewable feed stream, and the light hydrocarbon in the cooling stream in the presence of a particulate cracking catalyst in the reaction zone
Implementation Method 3
Fluid catalytic cracking (FCC) is a well-known process for the conversion of relatively high boiling point hydrocarbons to lower boiling point hydrocarbons
Data Source
AI summary
Methods and apparatus for upgrading renewable oils stream are described. The method involves using a cooling stream surrounding the tip of the renewable feed line to prevent polymerization/coking. The cooling stream, which comprises gases or liquids that can be converted to valuable products such as olefins, flows into the FCC reaction zone where it mixes with the FCC feed stream and the renewable oil. The renewable oil can be atomized with an atomizing gas.