Adipic Acid Flowability Improvement via Low-Temperature Additive
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Solution Overview
Problem
Adipic acid tends to form hard lumps at high temperatures and humidity, leading to reduced flowability and costly, time-consuming processes to break them up, especially during storage and shipping, and existing anticaking agents added at high temperatures can cause fouling and hazardous reactions when recycled.
Innovation Solution
Adding a flowability improving agent like dodecanedioic acid (DDDA) at a relatively low temperature of 20 to 35°C to adipic acid to prevent lumps from becoming hard, ensuring they remain friable and improve flowability without causing process incidents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If adipic acid is stored at high temperature and humidity, then storage capacity is improved, but lumps form and flowability deteriorates
Solution Approach 1:
The patent applies preliminary action by adding the flowability improving agent (dodecanedioic acid) to the adipic acid before storage, specifically during the drying stage at 95-100°C. This pre-treatment prevents lump formation and maintains flowability during subsequent high-temperature storage, eliminating the need for post-storage breaking operations.
Solution Approach 2:
The patent uses dodecanedioic acid as an intermediary substance that mediates between the adipic acid and the harsh storage conditions (high temperature and humidity). This intermediary agent prevents direct harmful interaction between adipic acid and environmental conditions, maintaining flowability without requiring extreme storage control.
2Ease of operation
If existing anticaking agents are added at high temperature, then flowability is improved, but process fouling and hazardous reactions occur when recycled
Solution Approach 1:
The patent fundamentally changes the temperature parameter for adding the flowability improving agent, specifying addition at 95-100°C during drying rather than at higher temperatures. This parameter change prevents the recycled agent from causing fouling and hazardous reactions while still achieving the desired flowability improvement.
Solution Approach 2:
The patent employs dodecanedioic acid as a disposable flowability improving agent that is added in small amounts (25-200 ppm) and does not need to be recovered or recycled. This approach eliminates the problems associated with recycling anticaking agents, as the agent remains in the product stream without causing fouling or hazardous reactions.
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
The method effectively prevents adipic acid lumps from hardening, allowing for easy discharge and shipment without manual intervention, enhancing flowability and reducing the risk of process fouling and hazardous reactions.
Implementation Method 1
adding to the adipic acid a flowability improving agent... which improves flowability of adipic acid
Implementation Method 2
improves flowability... allowing for easy discharge and shipment without manual intervention
Implementation Method 3
The slurry is then refined by centrifuging and drying the solids in a dryer, such as a rotary drier or a fluid bed dryer, at 95-100° C.
Implementation Method 4
The slurry is then refined by centrifuging and drying the solids
Data Source
AI summary
A method of improving flowability of adipic acid includes adding to the adipic acid at a relatively low temperature a flowability improving agent, such as an acyclic saturated monobasic acid containing 10 to 22 carbon atoms or an acyclic saturated dibasic acid containing 10 to 14 carbon atoms.