Fractionator Startup Using Hydrocracked Product Preheating
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Solution Overview
Problem
The existing methods for preheating a fractionator to prevent solidification of hydrocracked wax fractions require dedicated heating oils, which are inefficiently used and often discarded or burned as fuel, rather than being integrated into the product stream.
Innovation Solution
A startup method for a fractionator that utilizes a mixture of hydrocracked and hydrotreated products to preheat the system, where the hydrocracked product is heated and liquefied, and the hydrotreated product is used to reflux and heat the fractionator, eliminating the need for a dedicated heating oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated heating oil is used to preheat the fractionator, then the hydrocracked product can be prevented from solidifying and blocking the system, but the heating oil is inefficiently used and often discarded or burned as fuel
Solution Approach 1:
The invention merges the preheating function with the product stream by combining the hydrocracked product with a hydrocarbon oil that is liquid at normal temperature and pressure. This combined stream serves both as preheating medium and as a usable product, eliminating the need for separate dedicated heating oil and preventing its waste.
Solution Approach 2:
The hydrocarbon oil used for preheating is selected to have the property of being liquid at normal temperature and pressure, enabling it to serve dual functions: as a preheating medium during startup and as a usable product in the final output. This multi-functionality resolves the contradiction by making the heating oil productive rather than wasteful.
2Ease of operation
If a dedicated heating oil is used to preheat the fractionator, then the system can be started up without blockage, but the heating oil becomes waste or fuel rather than product
Solution Approach 1:
The invention combines the hydrocracked product with a hydrocarbon oil that remains liquid at normal conditions, creating a mixed stream that fulfills both the preheating requirement for successful startup and the product output requirement, thereby eliminating substance loss.
Solution Approach 2:
The invention converts what would normally be waste (the hydrocarbon oil used for preheating) into a beneficial product by selecting an oil that is liquid at normal temperature and pressure, allowing it to be incorporated into the final product stream rather than being discarded or burned.
3Device complexity
If hydrocracked product containing uncracked wax is supplied to the fractionator at normal temperature, then the process is simple, but the product solidifies and blocks the fractionator and lines
Solution Approach 1:
The invention applies preliminary action by preheating the fractionator and associated lines with a hydrocarbon oil before supplying the hydrocracked product. This preliminary heating action prevents the wax-containing product from solidifying upon contact with cold surfaces, thereby preventing blockages while maintaining process simplicity.
Solution Approach 2:
The hydrocarbon oil serves as an intermediary substance that facilitates the successful introduction of the hydrocracked product by first conditioning the fractionator and lines to an appropriate temperature, preventing direct contact between the cold wax-containing product and cold equipment surfaces.
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 method allows for efficient preheating of the fractionator without using special heating oils, enabling the hydrocarbon oil to be used as a product rather than waste, thereby reducing costs and environmental impact.
Implementation Method 1
the hydrocracked product is heated and supplied to the fractionator
Implementation Method 2
The hydrocracked product containing the uncracked wax is usually a solid or semisolid that exhibits no fluidity at a normal temperature and normal pressure
Implementation Method 3
the hydrocracked product and hydrotreated product supplied to the second fractionator 20 are fractionally distilled
Data Source
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AI summary
A startup method for a fractionator that is supplied with, and fractionally distills, a hydrocracked product obtained in a wax fraction hydrocracking step by hydrocracking a wax fraction contained within a Fischer-Tropsch synthetic oil, the method including a preheating step of preheating the fractionator using a hydrocarbon oil that includes at least a portion of the hydrocracked product and is liquid at a normal temperature and normal pressure.