Dividing Wall Column Alkylation Effluent Separation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional alkylation processes face challenges in improving efficiency, reducing energy and utility requirements, minimizing CO2 and NOx emissions, enhancing plant safety, and optimizing product value.

Innovation Solution

The implementation of a dividing wall column (DWC) in the alkylation system, which receives feed comprising olefin and make-up iso-butane, separates the alkylate reactor effluent into product streams including iso-butane, n-butane, and alkylate, thereby enhancing fractionation efficiency and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional three-product or four-product columns are used for separation, then product separation is achieved, but energy consumption and utility requirements increase

Engineering Contradiction:

Improveenergy consumptionVSAvoidproduct separation efficiency

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The patent combines multiple separation functions (propane removal, iso-butane/n-butane separation, and alkylate purification) into a single integrated dividing wall column. This merging of conventional separate columns into one DWC reduces the number of reboilers and condensers needed, thereby lowering energy consumption and utility requirements while maintaining effective product separation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The dividing wall column is designed to perform multiple separation tasks simultaneously: it acts as a depropanizer, a splitter for iso-butane and n-butane, and a purifier for alkylate product. This multi-functionality allows a single column to replace what would traditionally require multiple separate columns, reducing overall energy demand while achieving the same separation precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of manufacture

If conventional column schemes are used, then product separation is achieved, but capital requirements and equipment footprint increase

Engineering Contradiction:

Improvecapital requirementsVSAvoidproduct separation efficiency

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

By merging multiple conventional columns into a single dividing wall column structure, the patent reduces the total number of vessels, supports, foundations, and associated equipment needed. This consolidation directly lowers capital requirements and reduces the equipment footprint while maintaining the separation efficiency achieved by conventional multi-column schemes.

Inventive Principle:

Principle #5Merging (Combining)

3Object-generated harmful factors

If conventional distillation trains are used, then product separation is achieved, but CO2 and NOx emissions increase

Engineering Contradiction:

ImproveCO2 and NOx emissionsVSAvoidproduct separation efficiency

Core Design Contradiction:

Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The integration of multiple separation functions into one dividing wall column reduces the number of heating units (reboilers) required, thereby lowering fuel consumption and associated CO2 and NOx emissions. The single column design achieves the same separation precision as conventional multi-column trains but with a smaller environmental footprint.

Inventive Principle:

Principle #5Merging (Combining)

4Loss of substance

If conventional separation processes are used, then product recovery is achieved, but iso-butane loss increases

Engineering Contradiction:

Improveiso-butane lossVSAvoidproduct separation efficiency

Core Design Contradiction:

Loss of substanceVSManufacturing precision

Solution Approach 1:

The dividing wall column design incorporates optimized internal configurations and operating parameters that enhance the recovery of iso-butane in the distillate stream. By carefully controlling the dividing wall position, tray configurations, and reflux ratios, the system maximizes iso-butane recovery while maintaining effective separation of n-butane and alkylate products, thereby reducing valuable material loss.

Inventive Principle:

Principle #23Feedback

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 use of a DWC in the alkylation system improves fractionation efficiency, reduces utility and energy requirements, decreases CO2 and NOx emissions, enhances plant safety, and minimizes iso-butane loss, resulting in lower capital and equipment footprint requirements while improving product value.

Implementation Method 1

the DWC separates the alkylate reactor effluent into product streams including, but not necessarily limited to an iso-butane product stream, a n-butane product stream, and an alkylate product stream

Methodology Applied

Scientific EffectFractional distillation: Distillation

Data Source

PatentUS12312289B2Dividing wall column in alkylation process for reactor recycle and product separation

Publication Date: 2025.05.27 KELLOGG BROWN & ROOT INC

AI summary

A dividing wall column is used in an alkylation process flow scheme to fractionate an alkylate reactor effluent to produce an iso-butane-rich stream as a recycle feed for the alkylation reactor while also separating iso-butane, normal butane and alkylate as separate product streams depending on the reactor effluent composition. In an optional embodiment, the scheme may contain propane.