Hydrotreating FCC Product to Saturate Olefins for Crude Flow
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Solution Overview
Problem
Transporting crude oil with high wax content poses challenges due to wax solidification and buildup in pipelines, which is costly and time-consuming to clear, and existing methods like FCC produce olefins and diolefins that cause fouling in refinery equipment.
Innovation Solution
A process involving hydrotreating a portion of the FCC product using hydrogen-rich streams to saturate olefins and diolefins, combined with blending with unprocessed crude to improve flow properties, reducing viscosity and pour point, and using dry gas purification to enhance hydrogen availability for hydrotreating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If FCC process is used to convert heavy hydrocarbons into lighter hydrocarbons, then flow properties are improved (lower viscosity and pour point), but olefins and diolefins are produced which cause fouling of heat exchangers and refinery equipment
Solution Approach 1:
The patent converts the harmful olefins and diolefins produced during FCC into beneficial saturated hydrocarbons through hydrotreating. The hydrogenation process saturates the olefinic bonds, eliminating the fouling problem while maintaining the improved flow properties achieved by cracking
Solution Approach 2:
The patent changes the chemical composition parameters of the cracked stream by adjusting hydrogen partial pressure, temperature, and catalyst properties in the hydrotreating process. This transforms the product from olefin-rich (harmful) to saturated (beneficial) while controlling viscosity and pour point improvements
2Object-generated harmful factors
If hydrotreating is performed to saturate olefins and diolefins, then fouling is prevented, but substantial amounts of hydrogen are consumed and elevated temperature and pressure are required
Solution Approach 1:
The patent makes the FCC unit self-sufficient by using its own dry gas product (containing hydrogen) as the hydrogen source for hydrotreating the cracked stream. This internal hydrogen recycling eliminates the need for external hydrogen supply and reduces overall hydrogen consumption
Solution Approach 2:
The dry gas from FCC serves multiple functions: it is used as fuel in the FCC regenerator and simultaneously as the hydrogen source for hydrotreating. This multi-functional use maximizes the utility of the hydrogen produced during cracking
3Quantity of substance
If wax content is high in crude oil, then viscosity increases and pour point rises, but clearing pipelines when clogged is very expensive and time-consuming
Solution Approach 1:
The patent changes the physical parameters of the crude oil by cracking heavy hydrocarbons into lighter components, thereby reducing viscosity and pour point. This transformation allows high-wax crudes to meet pipeline specifications without requiring expensive heating infrastructure or frequent clearing operations
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 process effectively lowers the concentration of problematic olefins and diolefins, improving the flow properties of crude oil, reducing viscosity and pour point, and preventing fouling, thus facilitating safer and more efficient pipeline transportation.
Implementation Method 1
Hydrotreating is a process in which hydrocarbon feeds are contacted with catalyst in the presence of added hydrogen to saturate olefins and diolefins
Implementation Method 2
FCC is a catalytic process for converting heavy hydrocarbons into lighter hydrocarbons by contacting the heavy hydrocarbons in a fluidized reaction zone with a catalyst
Implementation Method 3
High temperature regeneration burns coke from the spent catalyst
Data Source
AI summary
A process and apparatus for improving flow properties of crude may include processing a first crude stream, which may in turn include cracking the first crude stream with catalyst to form a cracked stream and spent catalyst, hydrotreating a portion of the cracked stream and then mixing the hydrotreated stream with an unprocessed second crude stream.