Batch reaction process safety equipment

The American Institute of Chemical Engineers (AICliE) wishes to thank the Center for Chemical Process Safety (CCPS) and those involved in its operation, including its many sponsors whose funding and technical support made this project possible. Particular thanks are due to the members of the Batch Reaction Subcommittee for their enthusiasm, tireless effort and technical contributions. Members of the subcommittee played a major role in the writing of this book by suggesting examples, by offering failure scenarios for the major equipment covered in the book and by suggesting possible solutions to the various Con-cerns/Issues mentioned in the tables. 

The fine chemicals business is characterized by a small volume of products manufactured. Therefore, batch production predominates and small-scale reactors are used. The need to implement fine chemistry processes into existing multiproduct plants often forces the choice of batch reactors. However, safety considerations may lead to the choice of continuous processing in spite of the small scale of operation. The inventory of hazardous materials must be kept low and this is achieved only in smaller continuous reactors. Thermal mnaways are less probable in continuous equipment as proven by statistics of accidents in the chemical industries. For short reaction times, continuous or semicontinuous operation is preferred. 

Safety is another reason for con.structing dedicated in.stallations, sometimes for a continuous process. The inventory of dangerous materials in continuous equipment is usually much smaller than that in batch equipment, which results in a safer process. Danger of explosions leads to performing reactions in isolated bunkers, the cost of which is comparable to that of the... 

Safety. Because of the relatively small size of continuous-process equipment, there is less material in process at any time than at certain times in a comparable batch process. For example, at the completion of a batch-process nitration and during its normal separation of the product from spent nitrating acid, the entire batch of an often hazardous compound will be present in the equipment. In the continuous process, only as much material need be present in hazardous conditions as needed to gain sufficient reaction or process time. In the case of high explosives made by nitration, such as nitroglycerine, this inherent safety factor of a continuous process is very attractive. 

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