Rotary Pressure Filter Segmentation for Aromatic Acid Filtration

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Solution Overview

Problem

Current separation processes for aromatic carboxylic acid reaction effluents using rotary pressure filter apparatuses are inefficient, leading to complications in treating and recovering components of the filtrate, particularly due to the inclusion of un-settled solid aromatic carboxylic acid in the initial filtration stage with large pore filters, which allows particulates through and complicates further processing.

Innovation Solution

Implementing a rotary pressure filter with at least two filter zones to separate a first feed filtrate rich in solids and a second feed filtrate low in solids, where the first feed filtrate is recycled to the reactor zone and the second feed filtrate is directed to a catalyst recovery zone, allowing for effective recovery of oxidation catalyst and improved processing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single filter zone with large pore filters is used in the rotary pressure filter, then flow rates are enhanced and rinsing is simplified, but solids (particulates) pass through the filter and complicate further processing

Engineering Contradiction:
Improveflow rateVSAvoidfiltrate purity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The feed zone is divided into at least two separate filter zones: a first filter zone with large pore filters that allows high flow rates, and a second filter zone with smaller pore filters that captures solids. This segmentation resolves the contradiction by allowing each zone to optimize for its specific function - the first zone prioritizes productivity while the second zone ensures filtrate purity.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If multiple-stage separation techniques are used to achieve high purity solid products, then product purity is improved, but capital expenditures and equipment investment increase substantially

Engineering Contradiction:
Improveproduct purityVSAvoidequipment investment
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple filtration stages are merged into a single rotary pressure filter apparatus by incorporating multiple filter zones within one device. The first filter zone with large pores and the second filter zone with smaller pores work sequentially in the same equipment, achieving multi-stage separation purity benefits while avoiding the need for multiple separate filtration devices, thereby reducing capital expenditures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotary pressure filter apparatus is designed to perform multiple functions within a single device: it conducts both coarse filtration (first filter zone) and fine filtration (second filter zone), combines solid-liquid separation with filtrate classification, and integrates washing and drying functions. This multi-functionality achieves high product purity without requiring separate specialized equipment for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If a single filtrate stream is produced from filtration, then equipment complexity is reduced, but effective recovery and recycling of catalyst and solvent becomes difficult

Engineering Contradiction:
Improvefiltration system simplicityVSAvoidcatalyst recovery efficiency
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The filtration system segments the single filtrate stream into two separate streams based on the filter zones: a first filtrate from the large pore filter zone and a second filtrate from the small pore filter zone. This segmentation allows the system to maintain relative equipment simplicity while enabling differentiated handling and recovery of catalyst and solvent in each stream, improving substance recovery efficiency.

Inventive Principle:
Principle #1Segmentation

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 enables efficient recycling and recovery of catalysts, reduces the amount of solids in the filtrate, and allows for the use of large pore filters, enhancing flow rates and simplifying rinsing while maintaining high purity of the aromatic carboxylic acid product.

Implementation Method 1

filtering the solid/liquid mixture in a feed zone of a rotary filter (e.g., a rotary pressure filter), the feed zone having at least two filter zones to form a first feed filtrate comprising monocarboxylic acid solvent and solids, and a second feed filtrate separate from the first feed filtrate

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

oxidizing in a reactor zone a feedstock comprising a substituted aromatic hydrocarbon in the presence of an oxidation catalyst and monocarboxylic acid solvent under reaction conditions suitable to form crude aromatic carboxylic acid

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

oxidizing in a reactor zone a feedstock comprising a substituted aromatic hydrocarbon in the presence of an oxidation catalyst

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 4

recovering oxidation catalyst from the second feed filtrate in a catalyst recovery zone

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP4051658B1Solid-liquid separation processes
Publication Date: 2024.09.04 INEOS US CHEMICALS CO
  • EP4051658B1 patent drawingFigure 1
  • EP4051658B1 patent drawingFigure 2
  • EP4051658B1 patent drawingFigure 3

AI summary

The present disclosure relates generally to solid/liquid separation processes. One aspect of the disclosure is a process including filtering a solid/liquid mixture comprising a solid crude aromatic carboxylic acid, a monocarboxylic acid solvent, and minor amounts of an oxidation catalyst in a feed zone of a rotary filter (e.g., a rotary pressure filter), the feed zone having at least two filter zones to form a first feed filtrate comprising monocarboxylic acid solvent and solids; and a second feed filtrate separate from the first feed filtrate, the second feed filtrate comprising monocarboxylic acid solvent and solids, the second feed filtrate being lower in solids than the first feed filtrate; and transferring at least a portion of the first feed filtrate to the reactor zone as recycle.