The Use and Storage of Methyl Isocyanate (MIC) at Bayer CropScience (2012) / Chapter Skim
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5 MIC and Pesticide Production at the Institute Plant: Alternatives Assessment
5 MIC and Pesticide Production at the Institute Plant: Alternatives Assessment
Pages 83-112
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From page 83... ...
First, when the committee began its work, there was an assumption that Bayer CropScience would be restarting production of MIC and the carbamate pesticides. Were that to be done, then a "[r]
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From page 84... ...
However, a key motivation for this NRC study is to evaluate whether Bayer could have identified a superior process for manufacturing pesticides at the Institute facility that would have reduced risks to the surrounding communities. Any potential changes proposed by Bayer CropScience were compared to the processes in place in 2008, referred to here as the "existing process," for the chemistry and production methods in place at that time.
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From page 85... ...
In addition, none of the processes had been run at a scale similar to the existing MIC process at Institute. Note that all process flow diagrams below were provided by Bayer CropScience to the committee.
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From page 86... ...
at very high temperatures to generate gaseous MIC and water. To prevent the MIC from reacting with the water, it is almost immediately fed into a process to produce methomyl and oxamyl carbamate pesticides.
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From page 87... ...
In contrast to the DuPont process, but similar to the UCC process, the cyanate process is a batch process and requires some capacity for storing MIC. The yield of MIC was reported in a patent awarded in 1980 as on the order of 80-85 percent relative to added potassium cyanate (Giesselmann et al., 1980)
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From page 88... ...
Hydrolysis Solvent Recycle Solvent drying Organic stripping Sodium Cyanate Process Residue via Dimethyl Sulfate (DMS) Waste water FIGURE 5.5 Process flow diagram for production of methyl isocyanate via dimethyl sulfate and sodium cyanate (cyanate process)
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From page 89... ...
and Dimethylurea (DMU) FIGURE 5.7 Process flow diagram for production of MIC via diphenylcarbonate and dimethylurea (Bayer diphenylcarbonate process)
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From page 90... ...
The company then engaged with Enichem to evaluate the feasibility of adopting and licensing this process from Enichem in Institute, West Virginia. Carbamate Pesticide Production MIC was produced at the Institute facility to act as a reactant in the synthesis of carbamate pesticides.
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From page 91... ...
Alternative processes that lead to lower quality and reduced effectiveness in the resulting pesticides, also relate to the overall benefits of the pesticide under consideration. Consideration of the various nonprocess alternatives are discussed briefly in Chapter 6 when ways to quantify the benefits and costs from different production processes are described.
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From page 92... ...
The most recent processes used by Bayer, DuPont, and Enichem to produce carbamate pesticides (described earlier)
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From page 93... ...
The MIC-based aldicarb production process used a batch reactor, with an extended cook-out period that generated a complete reaction (see Figure 5.13)
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From page 94... ...
Other Carbamates Other carbamate pesticides (utilizing MIC) were also in production at Institute in 2008, but were not analyzed by the Committee for reasons described below.
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From page 95... ...
. FIGURE 5.13 Basic process flow diagram for production of aldicarb.
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From page 96... ...
Given the decision by Bayer to discontinue production of both MIC and N-monomethyl carbamate pesticides at the Institute plant, such a detailed review became unnecessary. ALTERNATIVE ARRANGEMENTS OF PROCESSES A key concern with the overall design of the production processes at the Institute plant was the need for storage of considerable amounts of MIC.
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From page 97... ...
In 1993, Rhône-Poulenc's Institute Modification Project allowed the MIC production unit to operate at reduced rates, permitting a better match between MIC and carbamate production rates without increasing MIC storage. Most recently, in August 2009, Bayer announced plans to reduce the amount of MIC storage from 200,000 pounds to 40,000 pounds, as part of a $25 million investment project that also strengthened the layers of pro tection around the MIC production and storage units, and eliminated aboveground storage of MIC (Bayer CropScience, 2009)
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From page 98... ...
Finally, as mentioned previously, the cyanate process generates significant quantities of hazardous waste that would need to be controlled and disposed of appropriately. The diphenylcarbonate process for MIC production was used by Bayer in Germany until 2002.
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From page 99... ...
Any firm approaching a redesign must consider the position of the product in the market and its expected life-cycle. At this point, carbamate pesticides are relatively mature products, with a limited remaining market life, and hence a less desirable focus for new investment.
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From page 100... ...
Regulatory Considerations A company's decisions about production processes are also strongly influ enced by constraints imposed by other entities. For example, manufacturing carbamate pesticides for sale in the United States requires that the pesticide be approved by EPA.
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From page 101... ...
Community perceptions of risk stem from a diverse set of factors ranging from the psychological to social processes of framing, to cultural expectations, and these factors play themselves out within a context of a particu lar facility and the risks associated with that facility, the relationship between the facility and the surrounding community, and corresponding processes of com munication, control, and conflict or collaboration.
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From page 102... ...
This contributed to a complete shutdown of MIC production, even though Bayer had been producing MIC there for many years, had recently spent $25 million installing additional safety features, had reduced MIC storage levels by 80 percent, and was planning to phase out MIC production altogether within a few years. Thus, good commu nity relations are crucial to a facility's gaining local acceptance of their decisions.
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From page 103... ...
provides a standard textbook discussion of various terms used in this section, including profit-maximization, capital costs, expected value, and externalities. In terms of the technical considerations mentioned earlier, decision making involves a com parison of the revenues generated by a production process with the costs of that production.
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From page 104... ...
that constrain firms' decisions about utilizing hazardous production processes with high levels of external risks. The presence of regulators imposing penalties for violations of safety regulations can provide an incentive to firms to reduce the risks associated with their production processes.
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From page 105... ...
Regulatory decisions under BCA can depend heavily on the calculations of the risk of low-probability events, such as the probability of a large accident at a chemical plant, or the probability of a given person dying of lung cancer after being exposed to air pollutants. A key difference between these two examples lies in the frequency of their observations.
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From page 106... ...
It is unclear whether onsite production of DMU was considered as part of the analysis. When Bayer explained how this information was used in its decision making about the best MIC production process, major advantages were seen for the incumbent process.
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From page 107... ...
) Low Medium License fee No Yes Yes No Yes Adaption of infrastructure No Yes Yes Yes Yes R&D required No Yes Yes Yes Yes Registration required No Yes Yes Yes Yes Other factors Catalyst exchange Batch process External intermediate every 2 weeks (dimethylurea)
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From page 108... ...
Bayer eventually decided to continue the existing MIC production process, but with an 80 percent reduction in the maximum MIC storage levels (from 200,000 pounds to 40,000 pounds) , and other safety enhancements, including the elimination of aboveground MIC storage and the closure of the methomyl facility.
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From page 109... ...
The 2008 methomyl accident and EPA regulatory decisions led Bayer to not restart the methomyl and carbofuran production lines, and the court injunction and other delays in restarting production eventually led Bayer to close down MIC production at Institute. The decisions at the Institute plant also demonstrate the importance of vari
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From page 110... ...
On the cost side, there are investment costs for installing new production equipment and the uncertainty and learning costs associated with beginning a new process. In addition to these cost factors, a key factor in recent decisions at the Institute plant about their carbamate pesticide production process was the requirement for EPA registration of pesticides.
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From page 111... ...
Presentation at the First Meeting on Inherently Safer Chemical Processes. February 9.
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