Acetic Acid Carbonylation Process Temperature Control
Solution Overview
Problem
Current processes for producing acetic acid by methanol carbonylation do not effectively utilize temperature increases across secondary reactors to enhance yield and separation efficiency.
Innovation Solution
A process involving a first reaction zone where methanol and carbon monoxide are carbonylated with a catalyst, followed by a secondary reactor where the temperature of the liquid reaction composition is elevated, allowing further carbonylation and improved separation in a flash zone, resulting in a higher acetic acid yield and reduced catalyst promoter passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the temperature of the liquid reaction composition is increased in the secondary reactor, then the acetic acid yield is improved and separation efficiency is enhanced, but the energy consumption increases
Solution Approach 1:
The patent applies parameter changes by increasing the temperature of the liquid reaction composition in the secondary reactor from the first reaction zone temperature to a higher temperature range. This temperature parameter change enables further carbonylation reaction to proceed, thereby increasing acetic acid yield and improving separation efficiency in the flash zone while managing energy consumption through optimized temperature control
Solution Approach 2:
The patent implements continuity of useful action by maintaining the liquid reaction composition flow from the first reaction zone through the secondary reactor to the flash zone, ensuring continuous carbonylation reaction and product formation. The continuous temperature increase and reaction progression maximize acetic acid production while minimizing energy waste through uninterrupted process operation
2Manufacturing precision
If the temperature increase across the secondary reactor is implemented, then the separation efficiency in the flash zone is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the reaction process into distinct zones: a first reaction zone for initial carbonylation, a secondary reactor for further reaction with temperature increase, and a flash zone for separation. This segmentation allows each zone to be optimized for its specific function, improving overall separation efficiency while maintaining manageable device complexity through modular design
Solution Approach 2:
The patent implements local quality by applying different temperature conditions to different parts of the system. The secondary reactor operates at a higher temperature than the first reaction zone, creating localized thermal conditions that enhance separation efficiency in the flash zone. This localized temperature control allows precise optimization of separation performance without requiring complex system-wide temperature management
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 increases acetic acid yield, reduces the volume and flow rate of the liquid fraction, and allows operation at lower temperatures in the first reaction zone, minimizing carbon monoxide loss and energy requirements.
Implementation Method 1
at least a portion of the dissolved and/or entrained carbon monoxide is consumed
Implementation Method 2
passing at least a portion of the liquid reaction composition from the second reaction zone into a flash separation zone to form: a vapour fraction, which comprises acetic acid
Data Source
AI summary
Process for the production of acetic acid by (a) introducing methanol, methyl acetate, dimethyl ether and/or methyl iodide and carbon monoxide into a first reaction zone containing a liquid reaction composition comprising a carbonylation catalyst, optionally a carbonylation catalyst promoter, methyl iodide, methyl acetate, acetic acid and water, (b) withdrawing at least a portion of the liquid reaction composition together with dissolved and/or entrained carbon monoxide and other gases from the first reaction zone, (c) passing at least a portion of the withdrawn liquid reaction composition to a second reaction zone, wherein at least a portion of the dissolved and/or entrained carbon monoxide is consumed, (d) passing at least a portion of the liquid reaction composition from the second reaction zone into a flash separation zone to form a vapor fraction, which comprises acetic acid, methyl iodide, methyl acetate and low pressure off-gas, comprising carbon monoxide; and a liquid fraction, which comprises carbonylation catalyst and optional carbonylation catalyst promoter, and (e) passing the vapor fraction from the flash separation zone to one or more distillation zones to recover acetic acid product. The temperature of the liquid reaction composition withdrawn from the first reaction zone is in the range of 170 to 195° C.; and the temperature of the liquid reaction composition passed from the second reaction zone to the flash separation zone is at least 8° C. greater than the temperature of the liquid reaction composition withdrawn from the first reaction zone.