Split Shell Fractionation Column HPNA Stripping

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Solution Overview

Problem

The existing hydroprocessing technologies face challenges in efficiently removing heavy polynuclear aromatics (HPNA) from hydroprocessed products, leading to catalyst deactivation and high stripping steam requirements, which increase the size of the fractionation column and overhead condenser system.

Innovation Solution

The proposed solution involves using the vapor from the HPNA stripping section as the stripping vapor for the bottom stripping zone of the product fractionation column, rather than relying on separate steam inputs, thereby reducing the total stripping steam requirement and improving separation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If separate steam inputs are used for HPNA stripping section and bottom stripping zone, then stripping effectiveness is maintained, but total stripping steam requirement increases

Engineering Contradiction:

Improvetotal stripping steam requirementVSAvoidstripping effectiveness

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent combines two separate steam input systems into a single integrated stripping vapor feed system. The stripping vapor generated in the HPNA stripping section is merged with the bottom stripping zone function, eliminating redundant steam inputs while maintaining stripping effectiveness through unified vapor-liquid contact in the split shell configuration

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The stripping vapor feed serves multiple functions simultaneously: it strips lighter materials from HPNA compounds in the first compartment and also provides stripping vapor for the bottom stripping zone in the second compartment. This multi-functional approach replaces what previously required separate steam inputs for each zone

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If substantial stripping steam is used to strip lighter materials from HPNA's, then separation efficiency is improved, but column size and overhead condenser system size increase

Engineering Contradiction:

Improveseparation efficiencyVSAvoidcolumn size

Core Design Contradiction:

Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The patent merges the stripping functions into a single integrated system where the same stripping vapor feed serves both the HPNA stripping section and the bottom stripping zone. This consolidation reduces the total vapor requirement while maintaining separation efficiency through optimized vapor-liquid contact in the split shell fractionation column

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the parameter of stripping vapor quantity by utilizing the vapor generated in the HPNA stripping section for dual purposes. This parameter optimization reduces the total steam requirement while maintaining the necessary separation efficiency through the split shell configuration that enhances vapor-liquid contact efficiency

Inventive Principle:

Principle #35Parameter changes

3Productivity

If split shell fractionation column is used to concentrate HPNA's, then HPNA removal efficiency is improved, but stripping steam requirement increases

Engineering Contradiction:

ImproveHPNA removal efficiencyVSAvoidstripping steam requirement

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system uses the vapor generated during HPNA stripping to serve the bottom stripping zone as well. The vapor produced in the first compartment self-services the second compartment's stripping needs, reducing external steam requirements while maintaining HPNA removal efficiency through the integrated split shell design

Inventive Principle:

Principle #25Self-service

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 significantly reduces the total stripping steam requirement, minimizes column diameter and overhead condenser system size, and enhances separation efficiency, while maintaining or improving product quality, as demonstrated by simulation data comparing the proposed method to existing technologies.

Implementation Method 1

A stripping vapor feed is provided to a second compartment to strip lighter materials from HPNA's in a liquid stream

Methodology Applied

Scientific EffectVapor-liquid mass transfer: Diffusion

Implementation Method 2

A passage directs stripping vapor from the second compartment to the first compartment

Methodology Applied

Scientific EffectVapor flow: Convection

Data Source

PatentUS8852404B2Apparatus for removing heavy polynuclear aromatic compounds from a hydroprocessed stream

Publication Date: 2014.10.07 UOP LLC

AI summary

An improved apparatus strips HPNA's from hydroprocessed streams in a fractionation column having a split shell configuration. Only one vapor stripping feed is required to the split shell of the fractionation column. The resulting reduction in steam requirement provides a superior fractionation in the column.