Resin Catalyst Process for Alkyl Nitrite Selectivity

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Solution Overview

Problem

The existing processes for producing C1-C4 alkyl nitrite in the CO coupling method suffer from low selectivity and significant side reactions, particularly the formation of nitric acid, leading to increased energy consumption and apparatus erosion.

Innovation Solution

A process involving a resin catalyst and/or a porous filler layer in a rotating high-gravity reactor, where nitrogen oxide, oxygen, and C1-C4 alkanol are reacted under controlled conditions, including specific temperature, pressure, and molar ratios, to enhance selectivity and inhibit side reactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the gaseous phase method is used for CO coupling to produce oxalate, then the production cost and energy consumption are reduced compared to liquid phase method, but side reactions occur leading to formation of nitric acid which increases energy consumption and erodes apparatus

Engineering Contradiction:
Improveenergy consumptionVSAvoidnitric acid formation
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent changes the reaction parameters by introducing a resin catalyst and controlling the molar ratio of reactants (NO:O2:ROH = 1:(0.5-2): (1-10)) to suppress nitric acid formation while maintaining high energy efficiency. The resin catalyst modifies the reaction pathway to favor alkyl nitrite production over nitric acid formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The resin catalyst acts as an intermediary substance that facilitates the desired reaction between CO and ROH to form alkyl nitrite while preventing the side reaction that produces nitric acid. The catalyst selectively promotes the formation of the desired product and inhibits harmful byproducts.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If conventional CO coupling process is used, then the process is simple, but selectivity of alkyl nitrite is low and side reactions are significant

Engineering Contradiction:
Improveselectivity of alkyl nitriteVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent improves selectivity by changing key process parameters: introducing a resin catalyst, controlling temperature (0-150°C), pressure (-0.09-1.5 MPa), and molar ratios of reactants. These parameter changes enable high selectivity (>99%) while maintaining reasonable process complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The resin catalyst provides local catalytic activity with specific selectivity for alkyl nitrite formation. The catalyst creates localized active sites that favor the desired reaction pathway, improving product selectivity without requiring complex process modifications throughout the entire system.

Inventive Principle:
Principle #3Local quality

3Productivity

If high pressure conditions are used in liquid phase CO coupling, then the reaction efficiency is improved, but apparatus corrosion increases and catalyst loses during reaction

Engineering Contradiction:
Improvereaction efficiencyVSAvoidapparatus corrosion resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the pressure parameter range (-0.09-1.5 MPa) and introduces a resin catalyst that enables efficient reactions at lower pressures compared to conventional liquid phase methods. This reduces apparatus corrosion while maintaining high reaction efficiency and catalyst stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the liquid phase mechanical system with a gaseous phase system using a resin catalyst. This substitution eliminates the corrosion problems associated with liquid phase reactions while maintaining reaction efficiency through catalytic action and controlled gas-phase chemistry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 achieves selectivity of C1-C4 alkyl nitrite greater than 99% by improving gas-liquid mass transfer and reducing the formation of side products like nitric acid, thereby increasing the efficiency and reducing raw material consumption.

Implementation Method 1

loading a resin catalyst layer and/or a porous filler layer into a reactor

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

improving gas-liquid mass transfer

Methodology Applied
Scientific EffectGas-liquid mass transfer: Diffusion

Implementation Method 3

rotating high-gravity reactor

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

reacting under the conditions including a reaction temperature of from 0 to 150° C., a reaction pressure of from −0.09 to 1.5 MPa

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS8722918B2Process for producing Cl-C4 alkyl nitrite
Publication Date: 2014.05.13 CHINA PETROLEUM & CHEMICAL CORP

AI summary

The present invention relates to a process for producing C1-C4 alkyl nitrite, comprising loading a resin catalyst layer and/or a porous filler layer into a reactor, passing nitrogen oxide, oxygen and C1-C4 alkanol as raw materials through the resin catalyst layer and/or porous filler layer in a counter current, parallel current or cross current manner, reacting under the conditions including a reaction temperature of from 0 to 150° C., a reaction pressure of from −0.09 to 1.5 MPa, a molar ratio of C1-C4 alkanol/nitrogen oxide of 1-100:1, a molar ratio of nitrogen oxide/oxygen of 4-50:1, to obtain an effluent containing C1-C4 alkyl nitrite, wherein said nitrogen oxide is NO, or a mixed gas containing NO and one or more selected from N2O3 and NO2.