Studies on the runaway reaction of ABS polymerization process

Area of Science:

• Polymer Chemistry
• Chemical Engineering
• Process Safety

Background:

• Taiwan leads global acrylonitrile-butadiene-styrene (ABS) copolymer production.
• Ensuring safety in ABS emulsion polymerization requires preventing exothermic reactions and managing emergency relief hazards.
• Industrial processes require robust safety controls for both normal and abnormal operating conditions.

Purpose of the Study:

• To identify the worst-case scenario in ABS emulsion polymerization.
• To evaluate emergency relief system design using thermokinetic data.
• To compare vent sizing calculations with existing industrial practices.

Main Methods:

• Utilized the VSP2 (Vent Sizing Package 2) apparatus to simulate industrial process conditions.
• Investigated abnormal scenarios including cooling failure, initiator/monomer overcharge, solvent absence, and external fire.
• Applied thermokinetic analysis and DIERS (Design Institute for Emergency Relief Systems) methodology for vent sizing.

Main Results:

• External fire scenario leads to a higher self-heat rate in butadiene emulsion polymerization.
• Cooling failure combined with a bulk reactant system was identified as the most credible worst-case scenario for ABS emulsion polymerization.
• Vent sizing was evaluated based on VSP thermokinetics and DIERS methodology.

Conclusions:

• The study provides critical insights into worst-case scenarios for ABS emulsion polymerization safety.
• Accurate vent sizing is essential for effective emergency relief system design in ABS production.
• The findings support the optimization of safety protocols in the chemical industry.