Acrolein Oxidation Process for Methacrylic Acid Production

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Solution Overview

Problem

Conventional processes for producing methacrylic acid or methacrylic acid esters, such as those using isobutylene or tert-butanol, face issues like high energy usage, low yields, significant waste generation, complex and costly equipment, and inefficient product isolation, making them environmentally unfriendly and economically challenging.

Innovation Solution

A new process involving the production of acrolein from C3-based raw materials, followed by reactions with hydrogen and formaldehyde to form methacrolein, which is then oxidized to methacrylic acid or its ester, using a simplified and energy-efficient method with a focus on high selectivity and minimal waste production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional processes using isobutylene or tert-butanol are used to produce methacrylic acid or esters, then the production can be achieved through established methods, but the energy consumption is high and the yield is low

Engineering Contradiction:
ImproveyieldVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the reaction parameters by using a different chemical pathway (acrolein oxidation instead of isobutylene oxidation), operating at specific temperature ranges (300-500°C) and pressure conditions to achieve both high yield and reasonable energy consumption. The process modifies the fundamental reaction parameters by selecting acrolein as the starting material and using supported metal oxide catalysts with specific surface areas and pore structures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite catalyst systems consisting of metal oxides (such as MoO3, V2O5, Nb2O5, Ta2O5, WO3) supported on various carriers (alumina, silica, titania, zirconia). These composite catalysts provide synergistic effects that enhance both activity and selectivity, thereby improving yield while optimizing energy efficiency through reduced reaction temperatures and improved reaction kinetics.

Inventive Principle:
Principle #40Composite materials

2Productivity

If conventional processes are used, then production can proceed through standard equipment, but significant waste is generated and the process is environmentally unfriendly

Engineering Contradiction:
ImproveyieldVSAvoidwaste generation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the traditionally harmful oxidation process into a more environmentally benign route by using supported metal oxide catalysts that promote selective oxidation of acrolein to methacrylic acid with high selectivity (80-95%). This reduces the formation of unwanted by-products and waste streams, transforming a potentially polluting process into a cleaner chemical synthesis method.

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

Solution Approach 2:

By changing the reaction pathway from isobutylene/tert-butanol oxidation to acrolein oxidation, and by optimizing parameters such as temperature (300-500°C), pressure, and catalyst composition, the process achieves higher selectivity and reduces waste generation. The specific catalyst design with controlled surface area (50-500 m²/g) and pore size (0.5-10 nm) further minimizes unwanted side reactions and waste products.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional processes are used, then production can be maintained, but the equipment is complex and costly

Engineering Contradiction:
Improveproduct isolation efficiencyVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the core function of product isolation by using highly selective catalytic oxidation that directly produces methacrylic acid with 80-95% selectivity. This eliminates the need for complex multi-step separation and purification equipment required in conventional processes, as the reaction itself is designed to minimize by-product formation, thereby simplifying the overall equipment requirements while maintaining reliable product isolation.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If conventional processes are used, then production can proceed through established routes, but the overall yield based on starting material is unsatisfactory

Engineering Contradiction:
Improveoverall yieldVSAvoidstarting material loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent fundamentally changes the starting material from isobutylene or tert-butanol to acrolein, and modifies reaction parameters including temperature (300-500°C), catalyst composition (metal oxides on supported carriers), and reaction conditions to achieve superior overall yield. The specific catalyst design with controlled surface area (50-500 m²/g) and pore size (0.5-10 nm) optimizes reaction efficiency and minimizes starting material loss.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The use of composite metal oxide catalysts (MoO3, V2O5, Nb2O5, Ta2O5, WO3) on supported carriers creates a synergistic system that enhances reaction efficiency and selectivity. This composite catalyst approach maximizes the conversion of acrolein to methacrylic acid, thereby improving overall yield and reducing starting material loss compared to conventional single-catalyst systems.

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 higher yields, reduces energy consumption, minimizes waste generation, and simplifies the production equipment, making it more environmentally friendly and economically viable while maintaining high product selectivity.

Implementation Method 1

oxidizing methacrolein in the gas phase on a supported metal oxide catalyst to methacrylic acid or a methacrylic acid ester

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

oxidizing methacrolein in the gas phase on a supported metal oxide catalyst to methacrylic acid or a methacrylic acid ester

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

The thus obtained, gaseous reaction phase is transformed into an aqueous methacrylic acid solution by cooling and condensing

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentUS11905239B2Process for producing methacrylic acid or methacrylic acid esters
Publication Date: 2024.02.20 ROHM GMBH

AI summary

A process can be used for producing methacrylic acid or a methacrylic acid ester. The process involves producing acrolein, reacting the produced acrolein with hydrogen to produce propanal, reacting the propanal with formaldehyde to produce methacrolein, and oxidizing the methacrolein in the presence of an oxygen containing gas and optionally an alcohol, to obtain methacrylic acid or methacrylic acid ester.