Hydrocracking Stripping Gas Sponge Absorber
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Solution Overview
Problem
Current hydrocracking recovery processes are inefficient in recovering petrochemical feedstock from hydrocracked distillate stocks, relying heavily on external utilities for heating and requiring complex column configurations, which increases energy consumption and operational costs.
Innovation Solution
The proposed process incorporates a cold stripping column and a hot stripping column with integrated reboilers, eliminating the need for separate deethanizer and naphtha splitter columns by using a prefractionator in the product fractionation column to produce three product streams, and employs a sponge absorber to recover LPG hydrocarbons without the use of steam, thereby reducing energy requirements and capital expenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If steam stripping is used to separate volatile materials from heavier hydrocarbon materials, then separation efficiency is improved, but energy consumption increases due to external utility requirements
Solution Approach 1:
The stripping column uses a reboiler to generate steam in situ from the process stream itself, eliminating the need for external steam utilities. The heavy hydrocarbon stream is heated in the reboiler to vaporize light components, which then rise and strip volatile materials from the liquid phase, allowing the system to serve its own separation needs without external energy input.
Solution Approach 2:
The process changes the thermal parameters by using controlled heating in the reboiler to achieve selective vaporization. By adjusting the reboiler temperature and residence time, the system optimizes the vaporization of light hydrocarbons while maintaining liquid phase heavier components, achieving efficient separation with minimized energy input.
2Measurement precision
If multiple fractionation columns are used to separate hydrocarbon streams, then product separation precision is improved, but device complexity increases
Solution Approach 1:
The stripping column is designed to perform multiple functions simultaneously: it strips volatile materials from the hydrocarbon stream, fractionates the vaporized components, and separates products in a single integrated unit. This consolidation eliminates the need for separate deethanizer and naphtha splitter columns, reducing device complexity while maintaining separation precision through the unified design.
Solution Approach 2:
The single stripping column is designed as a multi-functional unit that performs stripping, fractionation, and product separation operations that would traditionally require multiple specialized columns. The column handles diverse separation tasks through its integrated reboiler, fractionation section, and product withdrawal mechanisms, achieving universal functionality within one device.
3Power
If external utilities are used to provide heater duty for vaporization, then vaporization efficiency is improved, but capital expenses increase
Solution Approach 1:
The system uses its own heavy hydrocarbon feed stream as the heating medium in the reboiler, eliminating the need for external utility systems such as steam boilers or fired heaters. The process stream itself provides the thermal energy required for vaporization, reducing capital expenses for external utility infrastructure while maintaining effective vaporization through internal heat integration.
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 enhances energy efficiency by minimizing steam usage, reducing heater duty, and eliminating the need for additional columns, resulting in capital and operational savings while effectively recovering valuable hydrocarbon products.
Implementation Method 1
a vaporized stripping overhead stream has LPG hydrocarbons absorbed from it with an absorbent stream comprising the stripped stream
Data Source
AI summary
A process and apparatus for hydrocracking a hydrocarbon stream strips a liquid hydrocracked stream in a reboiled stripping column to provide a stripping overhead stream and a stripped stream and a vaporized stripping overhead stream has LPG hydrocarbons absorbed from it with an absorbent stream comprising the stripped stream. No equipment is needed to remove water from the absorbent stream due to the lack of steam added during stripping with a reboil column.