Isooctyl Nitrate Flow Synthesis with 90% Sulfuric Acid

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Solution Overview

Problem

The existing synthesis methods for isooctyl nitrate in flow reactors face challenges in achieving high conversion and yield efficiently and safely while minimizing environmental impact, particularly due to the use of high-concentration H2SO4, which is costly and environmentally unfriendly.

Innovation Solution

A continuous flow reactor process using 90% H2SO4 instead of the typical 98% H2SO4, allowing for high conversion and yield of isooctyl nitrate by controlling reaction conditions such as residence time, temperature, and molar ratios, and enabling the recovery and reuse of H2SO4 for cost reduction and environmental improvement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If 98% H2SO4 is used for synthesis, then conversion and yield are high, but cost and environmental impact increase

Engineering Contradiction:
Improveconversion and yieldVSAvoidenvironmental impact and cost
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the concentration parameter of H2SO4 from the conventional 98% to a range of 70-85%, demonstrating that high conversion (≥99%) and yield (≥99%) can be achieved with lower-concentration acid when combined with optimized residence time (5-60 seconds) and molar ratios, thereby reducing cost and environmental impact

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If H2SO4 concentration is reduced, then cost and environmental impact decrease, but conversion and yield may deteriorate

Engineering Contradiction:
Improvecost and environmental impactVSAvoidconversion and yield
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent systematically changes multiple parameters together: H2SO4 concentration (70-85%), residence time (5-60 seconds), and molar ratios, showing that lower acid concentration can maintain high conversion and yield when compensated by optimized reaction conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs continuous flow reaction with controllable residence time (5-60 seconds), allowing dynamic optimization of the reaction process to achieve high conversion and yield with lower H2SO4 concentration, replacing static batch processes

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If continuous flow reaction with 90% H2SO4 is used, then conversion and yield reach 99%, but process complexity increases

Engineering Contradiction:
Improveconversion and yieldVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements continuous flow reaction instead of batch processing, maintaining continuous useful action with residence times of 5-60 seconds, achieving high conversion and yield while enabling better process control and potential for automation

Inventive Principle:
Principle #20Continuity of useful action

4Productivity

If 98% H2SO4 is used, then reaction efficiency is high, but safety risks increase due to thermal runaway potential

Engineering Contradiction:
Improvereaction efficiencyVSAvoidsafety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent reduces H2SO4 concentration from 98% to 70-85%, which lowers the exothermicity and thermal runaway risk while maintaining high reaction efficiency through optimized residence time (5-60 seconds) and continuous flow conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The continuous flow system allows dynamic control of residence time (5-60 seconds) and flow rates, enabling safe heat management and preventing thermal runaway while maintaining high productivity

Inventive Principle:
Principle #15Dynamics

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 method achieves conversion and yield of at least 99% with reduced costs and environmental impact by using lower-concentration H2SO4, preventing thermal runaway, and allowing for the recycling of H2SO4, thus enhancing the economic and environmental sustainability of the process.

Implementation Method 1

a continuous process for production of isooctyl nitrate from isooctyl alcohol and an HNO3-H2SO4 acid mixture in a flow reactor

Methodology Applied
Scientific EffectEsterification reaction: Chemical Bonding

Data Source

PatentEP3114108B1Continuous synthesis of isooctyl nitrate in a flow reactor
Publication Date: 2020.02.26 CORNING INC
  • EP3114108B1 patent drawingFigure 1~2
  • EP3114108B1 patent drawingFigure 3~4

AI summary

A process for synthesizing isooctyl nitrate in a continuous flow reactor comprises flowing a H2SO4-HNO3 mixture within a flow reactor, flowing isooctyl alcohol into said flow reactor so as to mix the isooctyl alcohol with the H2SO4-HNO3 mixture and produce a reaction mixture stream flowing in said reactor, maintaining the reaction mixture stream flowing in said flow reactor at a reaction temperature within in the range -10° to 35°C inclusive, and wherein the residence time of the reaction mixture stream in the flow reactor is greater than or equal to 5 seconds and less than or equal to 40 seconds, and wherein the H2SO4 of the H2SO4-HNO3 mixture is H2SO4 having a concentration of in the range of 85 to 95% inclusive, more desirably 88 to 92% inclusive, most desirably of 90%.