Batch reaction process safety

Process chemistry issues and their effects on batch reaction systems safety are presented in Table 2, beginning on page 11. This table is meant to be illustrative but not comprehensive. 

Takeshi Haga and Michio Naito, "1981-Interim Report, by the Committee for Investigation of Safety of Batch Reaction Processes", Central Association for Labor Hazard Prevention (1982)... 

The Center for Chemical Process Safety (CCPS) has identified the need for a publication dealing with process safety issues unique to batch reaction systems. This book, Guidelines for Process Safety in Batch Reaction Systems, attempts to aid in the safe design, operation and maintenance of batch and semi-batch reaction systems. In this book the terms batch and semi-batch are used interchangeably for simplicity. The objectives of the book are to ... 

The book does not focus on occupational safety and health issues, although improved process safety can benefit these areas. Detailed engineering designs are outside the scope of this work. This book intends to identify issues and concerns in batch reaction systems and provide potential solutions to address these concerns. This should be of value to process design engineers, operators, maintenance personnel, as well as members of process hazards analysis teams. While this book offers potential solutions to specific issues/concerns, ultimately the user needs to make the case for the solutions that provide a balance between risk... 

All of these issues make batch reaction systems unique, in terms of the challenges they pose for managing process safety. 

Each chapter starts with a description of the topic covered in the chapter. This is followed by a short example highlighting a reported incident involving a batch reaction system. The case study is followed by a listing of key issues and process safety practices unique to the topic. The issues and concerns presented in this book, as well as potential design solutions and sources of additional information are presented in the tables. This format concisely conveys the necessary and relevant information in a familiar and convenient format. The organization of the tables is described below. 

Understanding the behavior of all the chemicals involved in the process—raw materials, intermediates, products and by-products, is a key aspect to identifying and understanding the process safety issues relevant to a given process. The nature of the batch processes makes it more likely for the system to enter a state (pressure, temperature, and composition) where undesired reactions can take place. The opportunities for undesired chemical reactions also are far greater in batch reaction systems due to greater potential for contamination or errors in sequence of addition. This chapter presents issues, concerns, and provides potential solutions related to chemistry in batch reaction systems. 

The fact that batch processes are not carried out at steady state conditions imposes broad demands on the control system. The instrumentation and control system have to be selected to provide adequate control for a wide variety of operating conditions and a wide variety of processes. In addition, basic process control and shutdown systems have to deal with sequencing issues. This chapter presents issues and concerns related to safety of instrumentation and control in batch reaction systems, and provides potential solutions. 

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. 

Guidelines for Process Safety in Batch Reaction Systems (2000)... 

Figure 12-40. Process A Batch reaction with all reactants added at the beginning of the reaction. There is a considerable amount of flammable and hazardous material in the reactor at the beginning. (Source S. M. England, Inherently Safer Plants Practical Applications," Process Safety Progress, Vol. 14, No. 1, pp. 63-70, AlChE, 1995.)...

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. 

General Considerations The following should be taken into account whenever designing or operating a chemical process that involves intended chemical reactions (Hendershot 2002). CCPS (1999) also details many key issues and process safety practices to consider that are oriented toward the design and operation of batch reaction systems. 

Designing and Operating Safe Chemical Reaction Processes (HSE 2000). Published by the U.K. Health and Safety Executive and directed to small to medium-sized chemical manufacturing companies using batch and semi-batch processes. It addresses chemical reaction hazards and inherently safer processes, hazards assessment, preventive and protective measures, and management practices. 

Analysis and Safeguards Lees, Loss Prevention in the Process Industries ISBN 0750615478 Guidelines for Safe Storage and Handling of Reactive Materials Guidelines for Process Safety in Batch Reaction Systems Guidelines for Hazard Evaluation Procedures, Second Edition with Worked Examples... 

A reaction simulation program, REACTION, which will run on a personal computer, and which is specifically adapted for the non-steady states prevailing in batch reactions, is described and illustrated by a typical reaction model. Among uses of the program for rapidly studying reaction engineering, process optimisation, control systems, scale-up and staff training requirements, are included thermal stability and process safety studies. 

Optimal feed profile for a second order reaction in a semi-batch reactor under safety constraints, Experimental study. Journal of Loss Prevention in the Process Industries, 12 (11), 485-93. 

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