The tragedy that struck RR Venkatapuram here on Thursday could have been of a greater magnitude, experts said.
A storage tank at the plant behaved like a pressure cooker of sorts due to a variance in temperature, and had the safety valves not functioned at the right time allowing the gas to leak, the tank would have eventually exploded due to the high pressure killing many more people, it is learnt.
Experts said that the plant was closed for over 40 due to the lockdown, causing a variation in temperature between the bottom and upper parts of the storage tank. This variation in temperature led to self-polymerisation inside the tank, due to which vapours were formed.
The 2,400 MT tank contained 1,800 MT of styrene monomer, indicating that some portion of the tank was empty which gave enough room for the formation of vapour. As the quantity of vapour began to increase, the tank started to behave like a pressure cooker used in kitchens. When the pressure rose beyond control, the safety valves opened, allowing the vapour to find its way into the atmosphere, said an expert, who is leading a team in the containment operation.
“Had the vapour not escaped through the safety valves, there might have been the possibility where the tank would have exploded and that could have been disastrous,” he said.
The sytrene monomer vapour leak from the tank in the early hours of Thursday ended up killing 12 persons. Over 300 were admitted to various hospitals and over 2,000 families living in the vicinity of the plant have been evacuated to safer zones.
Situation under control
Now, things are under control and the solidifying process is on by adding para-tertiary butyl catechol (PTBC), which was flown into the city on a special cargo flight from Gujarat.
Most of the liquid has solidified and thus the formation of vapour has been contained, said NDRF 10th Battalion Commandant Zahid Khan.
According to R. Karikal Valaven, Special Chief Secretary of Industries & Commerce, who is on the five-member committee constituted by the State Government to probe the incident, the temperature which shot over 140° C has also been brought down considerably. “The boiling point of styrene monomer is 145° C, and at one point it reached that temperature. Now, inside the tank, it has dropped to around 95° C while outside, it is around 75° C. In the next 24 hours, we expect the temperature to drop to below 30° C, which is the ideal storing temperature for styrene monomer,” Mr. Valaven told The Hindu .
Keeping the progress in mind, we hope that things would come back to normal within the next 48 hours, he said.
