Beckmann Reaction Heat Recovery for Ammonium Sulfate Crystallization

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Solution Overview

Problem

Existing ε-caprolactam production processes face high energy consumption and carbon footprint due to the need for external steam in ammonium sulfate crystallization, and prior methods using impure solutions as coolants lead to fouling and increased costs.

Innovation Solution

Transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section using heat exchangers, reducing the need for external steam and cooling water, and utilizing a multiple-stage process to optimize heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If external steam is used for ammonium sulfate crystallization, then crystallization can be achieved, but energy consumption and carbon footprint increase significantly

Engineering Contradiction:

Improveenergy consumptionVSAvoidcrystallization process

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The invention converts the harmful waste heat from the Beckmann rearrangement reaction into a beneficial heat source for ammonium sulfate crystallization. The waste heat, which would otherwise be discarded, is now utilized to provide the necessary thermal energy for evaporative crystallization, thereby reducing external steam requirements and lowering energy consumption while maintaining manufacturing capability

Inventive Principle:

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

Solution Approach 2:

The invention merges the heat removal function from the Beckmann rearrangement reaction section with the heat supply function for the ammonium sulfate crystallization section. By integrating these two previously separate thermal processes through heat exchangers, the system achieves internal heat balance, reducing dependence on external energy sources and decreasing carbon footprint

Inventive Principle:

Principle #5Merging (Combining)

2Temperature

If impure solutions are used as coolants in heat exchangers, then cooling capacity is available, but fouling occurs leading to increased costs

Engineering Contradiction:

Improvecooling capacityVSAvoidfouling

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes the harmful impurities from the coolant stream before it enters the heat exchanger. By introducing a filtration system that captures particulate matter and other contaminants, the purified coolant maintains its cooling capacity while preventing fouling of the heat exchanger surfaces, thereby eliminating the associated maintenance costs and operational inefficiencies

Inventive Principle:

Principle #2Taking out (Extraction)

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 energy consumption, lowers production costs, and decreases the carbon footprint while maintaining efficient ε-caprolactam and crystalline ammonium sulfate production.

Implementation Method 1

Transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section using heat exchangers

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section, wherein the heat of reaction removed from the Beckmann rearrangement reaction section is at least partially or fully transferred to the ammonium sulfate crystallization section

Methodology Applied

Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 3

forming ammonium sulfate crystals by evaporative crystallization in the ammonium sulfate crystallization section

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS12486225B2Process and plant for the production of ε-Caprolactam and ammonium sulfate on industrial scale

Publication Date: 2025.12.02 CAP III

AI summary

The invention provides a process and a plant for the production of ε-caprolactam and crystalline ammonium sulfate in an industrial-scale plant, wherein the plant comprises a Beckmann rearrangement reaction section, an ammonium sulfate crystallization section, and one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section and wherein the process comprises the steps of:a) feeding(i) cyclohexanone oxime and(ii) oleum and/or sulfuric acidto the Beckmann rearrangement reaction sectionb) reacting components (i) and (ii) in the Beckmann rearrangement reaction section to form a reaction mixture comprising ε-caprolactam, whereby heat of reaction is generated;c) discharging the reaction mixture comprising ε-caprolactam from the Beckmann rearrangement reaction section;d) removing partially or fully the heat of reaction generated in the Beckmann rearrangement reaction section by one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section;e) feeding an aqueous liquid comprising ammonium sulfate to the ammonium sulfate crystallization section;f) introducing heat into the ammonium sulfate crystallization section comprising the aqueous ammonium-sulfate-comprising liquid by one or more heat exchangers configured to transfer heat into the ammonium sulfate crystallization section;g) forming ammonium sulfate crystals by evaporative crystallization in the ammonium sulfate crystallization section;characterized in thath) the heat of reaction removed from the Beckmann rearrangement reaction section in step d) is at least partially or fully transferred to the ammonium sulfate crystallization section in step f).