Last year I took two senior design courses Ch E 401 and Ch E 464, both focus on the designing of plant producing styrene. One of the main concerns in designing a plant is the safety. We went through many technical analysis in order to make sure everything is under control, or at least under our prediction of situation. But who knows, nothing can be so sure now.
For instance, in the night of December 3rd, 1984, a lethal gas of methyl isocyanate MIC leaked from Union Carbide plant in Bhopal, India, causing 3,000 instant deaths to people who lived surrounding the plant. In addition to that, Amnesty International's report shows that a number of death due to the incident comes close to 15,000. That is the worst industrial accident ever occured in the history of chemical industry.
Methyl Isocyanate which carries the notorious and dangerous cyanide molecules can cause many health problems such as eye pain (eventually lead to blindness/cataracts), vomitting and breathing problems, abdominal pain, decreased lung function, chemical burn on skins and finallly, the reproduction problems. Safety requirements required MIC to be kept cool at the room temperature and far away from the water to avoid spontaneous exothermic reaction which later produces gaseous MIC.
In class, we were taught to take a few things to consider before choosing a strategic location to build a plant. First, the population nearby. Secondly is the water resource like river or lake for steam production in heat management and cooling management. Things like these are made priorities partly because of environmental and human live factors. Furthermore, the plant management is responsible to alert the local authority if an accident occurs in the plant may endanger the surrouding area so that the public can take precaution step.
But this didn't happen in Bhopal. Union Carbide, the owner of the plant, didn't address the locals of what to do in facing such incident. A simple instruction of staying indoor and seal the windows and doors with damp clothes may save thousand of lives on that unfateful night. Many were confuse and strayed in the streets without warning either from the plant management or the local authority.
Another imperative step need to be taken seriously by the plant management is to make sure all personnel in the plant are aware about the danger of the chemical used and produced in the plant. They also are responsible to safely handle these chemicals. Unfortunately, in Bhopal incident, the workers did not know the safety procedure in handling the chemical. The pipe which carried MIC reacted in reactors was washed with water. The water managed to get inside the pipe through cracks and caused MIC to react exothermically (producing heat at 200 degree Celsius) and later produced gas. Through the same pipe, the water managed to find its way to the storage tank and reacted with the rest of MIC to produce clouds of lethal gas. This gas were migrated to the near city by the wind.
Standard safety apparatus such as cooling system, vent scrubber, flare tower and water curtain were failed to operate during the accident. Cooling system responsibles to cool down the storage, possibly by flushing the outer wall of storage tank and consequently brings down the temperature to the standard room temperature. Vent scrubber is supposedly to neutralize the gas escaped through the 30 meter vent. Flare tower is supposedly to connect to the storage tank just in case to burn the excess gas. These are the failures squarely put on the Union Carbide engineers.
Hardware can err but the worst err is lied upon human. This blunder can be stopped if the engineers paid a little extra attention to the operation of plant, particularly on the safety aspect of it. I hope one day when I become an engineer involves in commissioning a plant, I will make sure I take these issues into considerations and become sincere in doing my job.
Who knows, my job may save thousand of live in case of lethal accident!
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