C4 Hydrocarbon Recovery in Isomerization Effluent Stabilization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current processes for recovering C4 hydrocarbons from isomerization effluents are inefficient due to the presence of chlorides, which require additional processing steps and equipment, limiting the effective recovery and recycling of these hydrocarbons.

Innovation Solution

A process involving multiple stabilization zones and chilling steps to separate and recycle C4 hydrocarbons, where the C4 liquid stream from one isomerization zone is passed to a second stabilization zone, allowing for the separation of iC4 and nC4 streams without the need for additional equipment to remove HCl, thereby increasing recovery efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the LPG draw is used to remove light ends and chlorides, then the chlorides are removed from the stream, but the C4 hydrocarbons are lost and cannot be directly recycled

Engineering Contradiction:

Improvechloride removalVSAvoidC4 hydrocarbon loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent extracts only the necessary components (light ends C2- and chlorides) from the effluent stream through the LPG draw, while retaining the C4 hydrocarbons in the liquid draw for subsequent recovery and recycling. This selective extraction allows chloride removal without sacrificing C4 hydrocarbons.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent discards the C2- light ends and chlorides through the LPG draw while recovering the C4 hydrocarbons in the liquid draw. The recovered C4 hydrocarbons are then recycled back to the isomerization unit, transforming what would have been waste into a valuable recovered stream.

Inventive Principle:

Principle #34Discarding and recovering

2Ease of manufacture

If a stripping zone is used to remove light ends and chlorides, then the stream can be cleaned for further processing, but additional equipment and processing steps are required

Engineering Contradiction:

Improveprocess simplicityVSAvoidequipment requirements

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent makes the stabilization zone serve multiple functions: it stabilizes the effluent, separates the C4 liquid draw containing C4 hydrocarbons, and enables their recovery and recycling. This multi-functionality eliminates the need for separate stripping zones and reduces overall equipment complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the stabilization and C4 recovery functions into a single integrated process within the stabilization zone. By merging these operations, the patent eliminates redundant equipment and simplifies the overall process flow.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If the C4 liquid stream is passed directly to the saturated gas plant, then the processing flow is simplified, but the C4 hydrocarbons cannot be effectively recovered and recycled

Engineering Contradiction:

ImproveC4 recovery efficiencyVSAvoidprocess operation

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent performs preliminary separation of the C4 liquid stream from the effluent in the stabilization zone before sending any streams to the saturated gas plant. This preliminary action isolates the C4 hydrocarbons for recycling while allowing the gas plant to process only the necessary gas stream.

Inventive Principle:

Principle #10Preliminary action

4Loss of substance

If additional processing units are added to remove HCl from the C4 stream, then the C4 stream can be recycled, but capital and operating expenses increase

Engineering Contradiction:

ImproveC4 hydrocarbon recoveryVSAvoidprocessing units

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent converts the presence of HCl, which would normally require additional removal equipment, into a benefit by designing a process where the C4 liquid draw is separated in a way that minimizes HCl contamination. The stabilization zone operation allows C4 recovery without requiring additional HCl removal units.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 process enhances C4 hydrocarbon recovery by up to 85% without requiring additional processing units, reducing capital and operating expenses, and allows for more efficient recycling of C4 hydrocarbons without the need for an LPG stripper section.

Implementation Method 1

stabilizing and separating a first effluent stream in a first stabilization zone into an overhead stream, a C4- liquid stream, and a bottoms stream

Methodology Applied

Scientific EffectCondensation: Condensation

Implementation Method 2

separating the second effluent stream and the at least a portion of the C4- liquid stream into a C4 stream and a C3- stream

Methodology Applied

Scientific EffectPhase separation:

Implementation Method 3

cooling the vapor stream from the receiver in the chilling zone

Methodology Applied

Scientific EffectCooling: Cooling

Data Source

PatentUS9567271B2Process for the recovery of paraffins from an isomerization effluent

Publication Date: 2017.02.14 UOP LLC

AI summary

A process for the recovery of C4 hydrocarbons from a C5/C6 isomerization zone. A portion of the effluent stream from the C5/C6 isomerization zone comprising C4 hydrocarbons is combined in a stabilizer section with an effluent from a C4 isomerization zone. In order to increase the C4 hydrocarbons in the effluent stream from the C5/C6 isomerization zone, a chilling zone may be used.