Lessons and Measures from the Accident of the Resin Tower in Hydrogen Peroxide Plant

It was started that hydrogen peroxide (60 wt %) was flowed to the resin tower from November 1, 2015 after the maintenance of the equipment. Just after the start, leakage of hydrogen peroxide occurred from the drain valve located between the resin tower and the hydrogen peroxide tank, and the feed flow was stopped.

Replacement with water in the resin tower was not carried out, after the flowing of hydrogen peroxide was stopped. Thereby, hydrogen peroxide remained in the resin tower. Further, the leakage resulted that the liquid level in the tower decreased, and the resin at the top of the tower was exposed.

Decomposition of hydrogen peroxide was occurred and continued in the tower. Decomposition heat was accumulated at exposed resin, and this heat storage resulted in abnormal decomposition.

Finally, explosion and fire occurred at the resin tower on November 3, 2015.

2. Damage situation

• Human damage: None

• Facilities damage: the resin tower and peripheral equipment (in plant only)

• Environmental damage: None

3. Causes of accident

• Direct cause

By exposing to a vapor-phase, resin immersed in hydrogen peroxide accumulated heat.

• Root cause

Lack of recognition of danger suggested above.

4. Countermeasures

• Hardware measures

a) Setting up level meter for liquid level management of the resin tower

b) Adding thermometer in the resin tower for measuring temperature

c) Adding the emergency sequence; hydrogen peroxide is replaced with water automatically if the temperature inside the resin tower is high.

• Software measures

a) Reviewing of SOP at emergency stop and appending Know-Why to SOP

b) Education of potential hazards of hydrogen peroxide and prohibition things on operation

c) Repetitive education of this accident and past accidents

d) Promotion of deployment this experience and measures to other departments and plants

Keywords: hydrogen peroxide, heat storage, abnormal decomposition