Loop Reactor Temperature Control for Organopolysiloxane Production

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Solution Overview

Problem

The existing process for producing organopolysiloxanes faces challenges in reducing alcohol usage, minimizing unrecoverable HCl loss, and increasing production capacity without altering end product properties, as reducing alcohol content can lead to changes in the degree of alkoxylation and reactivity, affecting molecular weight and gelation.

Innovation Solution

A circulation reactor with a heating unit and phase separation unit is used to control reaction temperature accurately and recycle the alcohol phase, allowing for reduced alcohol usage without changing end product properties, enabling efficient HCl recovery and increased production capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the amount of alcohol is reduced to lower production costs, then alcohol consumption decreases, but the degree of alkoxylation changes leading to altered reactivity and end product properties

Engineering Contradiction:
Improvealcohol consumptionVSAvoidend product properties
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the reaction temperature (e.g., 20-60°C ranges with specific preferred values like 25-45°C) and pressure conditions in the circulation reactor to compensate for reduced alcohol content. This maintains the degree of alkoxylation and reactivity while using less alcohol, thus resolving the contradiction between reducing substance loss and maintaining manufacturing precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The circulation reactor implements a feedback mechanism where the reaction mixture is continuously circulated and the temperature is controlled based on feedback from temperature sensors. This ensures that even with reduced alcohol content, the reaction conditions are optimized to maintain consistent end product properties, addressing the contradiction between alcohol reduction and property consistency

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If HCl is not recovered but neutralized with caustic soda, then the process is simpler, but additional costs are incurred and environmental pollution increases

Engineering Contradiction:
Improveprocess simplicityVSAvoidenvironmental pollution
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful HCl byproduct into a beneficial resource by implementing an HCl recovery system where HCl gas is captured and reacted with methanol to form methyl chloride, which is then used to produce chlorosilanes. This closes the material cycle, eliminates environmental pollution, and reduces the need for caustic soda neutralization, thus converting a harmful factor into a benefit while maintaining process feasibility

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

3Device complexity

If the reaction temperature is not precisely controlled, then the process is simpler, but the degree of alkoxylation and reactivity become inconsistent affecting product properties

Engineering Contradiction:
Improvetemperature control systemVSAvoiddegree of alkoxylation
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent employs precise parameter control by implementing a temperature control system that maintains specific temperature ranges (e.g., 20-60°C with preferred ranges of 25-45°C) in the circulation reactor. This precise thermal parameter control ensures consistent degree of alkoxylation and reactivity, maintaining manufacturing precision while the circulation design keeps the overall device complexity manageable

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The circulation reactor implements dynamic temperature control where the reaction mixture is continuously circulated and temperature is adjusted based on real-time conditions. This dynamic approach allows the system to maintain precise degree of alkoxylation control without requiring overly complex static control systems, balancing device complexity with manufacturing precision

Inventive Principle:
Principle #15Dynamics

4Device complexity

If alcohol phase is not recycled but discharged with waste water, then the process is simpler, but production capacity and economic efficiency decrease

Engineering Contradiction:
Improvephase separation and recycling systemVSAvoidproduction capacity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements a phase separation unit that separates the alcohol phase from the reaction mixture, and the recovered alcohol is recycled back to the circulation reactor. This recovery system increases production capacity by allowing higher throughput of silane mixture while maintaining consistent reaction conditions, and the added complexity of phase separation is justified by the significant productivity improvement

Inventive Principle:
Principle #34Discarding and recovering

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 reduces alcohol consumption by 30-50% and enhances production capacity by 30-40% in the hydrolysis step, maintaining end product properties and facilitating HCl recycling, thus minimizing environmental impact and costs.

Implementation Method 1

the temperature of the reaction medium being controlled by a heating unit with a control device connected to the heating unit for controlling the temperature in the circuit, which allows the temperature in the reaction medium to be controlled with an accuracy of at least 5° C.

Methodology Applied
Scientific EffectTemperature control: Heating

Implementation Method 2

an additional phase separation unit being connected to the overflow, which separates the excess alcohol phase and returns it to the circulation reactor

Methodology Applied
Scientific EffectPhase separation: Liquid-Liquid Extraction

Implementation Method 3

a circulation reactor which is equipped with a heating unit and which allows the reaction temperature to preferably be 20-60°C

Methodology Applied
Scientific EffectCirculation: Convection

Implementation Method 4

a degassing vessel which is provided with a discharge line for the gaseous reaction product

Methodology Applied
Scientific EffectGas separation: Cyclone Separation

Data Source

PatentEP2491071B1Process for preparing organopolysiloxanes
Publication Date: 2014.07.16 WACKER CHEMIE AG
  • EP2491071B1 patent drawingFigure 1
  • EP2491071B1 patent drawingFigure 2

AI summary

The invention relates to a vertically disposed loop-type reactor for partially alkoxylizing chlorosilanes, having separate feed lines for alcohol-water mixture and silane mixture, a degasification vessel having a discharge line for the gaseous reaction product, and an overflow for the liquid reaction products, wherein the loop-type reactor comprises a heating system and a control device connected to the heating system for controlling the temperature in the loop, allowing the temperature in the reaction medium to be regulated with a precision of at least 5°C, wherein an additional phase separating unit is connected to the overflow and separates the excess alcohol phase and feeds same back into the loop-type reactor.