Oxalate Production via Segmented Gas-Phase CO Coupling

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Solution Overview

Problem

Traditional methods for producing oxalates through esterification reactions result in high production costs, energy consumption, and environmental pollution, while oxidative carbonylation processes face challenges with equipment erosion and catalyst deactivation due to high pressure and temperature fluctuations.

Innovation Solution

A process involving the coupling of CO with nitrites in the presence of palladium-containing catalysts, utilizing multiple reaction zones with gas-liquid separation to optimize temperature profiles and reduce secondary reactions, enhancing selectivity and single-pass conversion of oxalates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If liquid phase oxidative carbonylation is used to synthesize oxalate, then the reaction can proceed under higher pressure to improve conversion, but the equipment suffers from erosion and catalysts become entrained

Engineering Contradiction:
ImproveconversionVSAvoidequipment erosion
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the physical state parameter of the reaction system from liquid phase to gas phase. This fundamental parameter change allows the reaction to proceed without the equipment erosion and catalyst entrainment problems associated with liquid phase processes, while still achieving high conversion through optimized gas phase reaction conditions and catalyst design

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a fixed bed catalyst structure where the catalyst is immobilized on a support material. This allows the catalyst to remain in the reactor (avoiding entrainment) while maintaining activity. The catalyst can be replaced as a unit when deactivated, rather than requiring complex recovery systems

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Ease of manufacture

If traditional esterification reaction is used to prepare oxalate, then the process is simple, but it results in high production cost, large energy consumption, and serious pollution

Engineering Contradiction:
Improveprocess simplicityVSAvoidenergy consumption
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent changes the chemical reaction pathway from esterification (requiring high temperature and acid catalysts) to oxidative carbonylation (proceeding under milder conditions with metal catalysts). This parameter change in reaction mechanism reduces energy consumption and eliminates the need for harsh conditions while maintaining process simplicity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs molecular oxygen as the oxidant in the oxidative carbonylation reaction. This strong oxidant enables the reaction to proceed efficiently under milder conditions compared to traditional esterification, reducing energy consumption and avoiding the formation of harmful byproducts that would require additional energy for treatment

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

3Reliability

If gas phase catalytic synthesis is used, then the process operates at lower pressure and temperature, but the single-pass conversion needs to be improved

Engineering Contradiction:
Improveoperating conditions stabilityVSAvoidsingle-pass conversion
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs a segmented fixed bed catalyst structure with multiple layers or zones. This segmentation allows different regions of the catalyst bed to perform different functions (e.g., activation, main reaction, selectivity enhancement), thereby improving overall conversion efficiency while maintaining stable operating conditions through the distributed catalyst architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite catalyst materials combining metal particles (e.g., palladium, platinum) supported on oxide materials (e.g., alumina, silica). This composite structure provides both the catalytic activity needed for high conversion and the structural stability required for reliable operation under mild conditions. The synergistic effects in the composite material enhance both productivity and reliability

Inventive Principle:
Principle #40Composite materials

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 process achieves high selectivity and conversion of oxalates with reduced catalyst deactivation and energy consumption, offering a more efficient and environmentally friendly method for producing oxalates.

Implementation Method 1

contact them with a first palladium-containing catalyst, to form a first reaction effluent containing unreacted nitrite, CO and oxalate product

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

passing the first reaction effluent into a gas-liquid separator to conduct gas-liquid separation, to obtain a liquid product stream and a gas mixture stream

Methodology Applied
Scientific EffectGas-liquid separation: Density Gradient

Data Source

PatentUS8269036B2Processes for producing an oxalate by coupling of CO
Publication Date: 2012.09.18 SHANGHAI RES INST OF PETROCHEMICAL TECH SINOPEC

AI summary

Provided are processes for producing an oxalate by coupling of CO in the presence of a nitrite, wherein two or more reaction zones in series are used, and at least a portion of the oxalate as reaction product is separated between the reaction zones, and/or the nitrite is fed stagewise. The processes described herein can effectively enhance the selectivity to the oxalate and the single-pass conversion of the feedstock.