¶ … Interactions of Hazardous Materials
Chemistry of the process
MCMT, methylcyclopentadienyl manganese tricarbonyl, was manufactured in a three-step process by T2 Laboratories, Inc. The first step of the chemical reaction necessitated the use of heating to activate or initiate the reaction. All three of the steps that followed were heat producing (exothermic) and in turn required some form of cooling. The first step (known as metalation), involves molten metallic sodium being reacted together with methylcyclopentadiene (MCPD) using diglyme (diethylene glycol dimethyl ether) as a catalyst in order to produce two MCPD molecules; these then reacted with sodium. The T2 firm released the hydrogen gas by-product produced by this reaction into the atmosphere.
The second step, referred to as substitution, involved the addition of dry manganese chloride powder to the reactor by the T2 firm employees. The manganese chloride then reacts with sodium MCPD within the reactor, resulting in the formation of sodium chloride as a by-product and manganese dimethylcyclopentadiene.
The third and final step, referred to as carbonylation, involves the injection of Carbon monoxide gas (CO) at the rear end of the reactor by the T2 chemists. The gas is bubbled, under pressure, through manganese dimethylcyclopentadiene. This final step also involves each of the two methylcyclopentadiene molecules on the manganese complex being replaced by 3 carbon monoxide molecules, thus forming MCMT.
After the carbonylation phase, the process operator at T2 then distilled the mixture to eliminate diglyme and MCMT....
The remaining sodium chloride and methlycyclopentadiene were eliminated as solid wastes. Diglyme was however recovered, and later reused in the three step process (United States (U.S.) Chemical Safety and Hazard Investigation Board, 2009).
What the company and other organizations should have done to prevent the incident from occurring.
The T2 chemists failed to recognize the reaction runaway hazard linked to the MCMT that they were producing. Assuming that they had been aware of the reaction hazard, they could have incorporated additional safety mechanisms or measures. The cooling system utilized by the T2 firm was vulnerable to point failures, because of the absence of design redundancy. Thus a backup cooling mechanism could have stopped the disaster from occurring. The MCMT process relief system was not capable of relieving a runaway reaction pressure (U.S. Chemical Safety and Hazard Investigation Board, 2009).
The risks of an overheating reaction mixture were overlooked or underestimated by the T2 laboratory chemists. Adequate backup mechanisms were not put in place to offer additional quenching or cooling of the reaction mixture, and/or to relieve the pressure if overheating occurred. The most crucial aspect was the ability to foresee, expect, or at the very least, test for the likelihood of any unwanted exothermic reaction(s) occurring in the accessible temperature range of the experimental conditions utilized. It is sensible to make sure that a safety allowance, or margin of 100 oC or more, in the range of the set reaction temperature and the thermal runaway starting temperature should…
