Chemical reactor safety

Principles of Chemical Reactor Safety Applied to Polymerization... 

General In comparison with design information on blowdown drums and cyclone separators, there is very httle information in the open technical hterature on the design of quench tanks in the Chernies industry. What is available deSs with the design of quench tanks (Sso called suppression pools) for condensation of steam or steam-water mixtures from nuclear reactor safety vSves. Information and criteria from quench tanks in the nuclear industry can be used for the design of quench tanks in the chemicS industry. There have been sev-... 

Once a decision to use QRA has been made, you must decide whether frequency and/or consequence information is required (Steps 6 and 7). In some cases you may simply need frequency information to make your decision. For example, suppose you wish to evaluate the adequacy of operating procedures and safety systems associated with a chemical reactor. The main hazard of concern is that the reactor could experience a violent runaway exothermic reaction. You believe that you know enough about the severe consequences of a runaway and nothing more will be gained by quantifying the consequences of potential run-... 

Knowledge of the rate is important to design chemical reactors for industrial production. It is also important for optimizing the production and to define the safety limits of operation. As was mentioned in the introduction, various transfer processes can influence chemical rates. The recognition of such interference is of primary importance during any study of kinetics, especially in those studies that will serve as the basis of design for production reactors. 

There had been small-scale probabilistic risk studies, but the first in-depth study v, as initiated by the U.S, Atomic Energy Commission in September 1972 and completed by the Nuclear Regulatory Commission (NRC). This was known as the Reactor Safety Study, W. SH-(400, Ociuher 1975) that set the pattern for subsequent PSAs not only nuclear, but chemical md tniii portation, PSA had it beginnings in nuclear power because of the unknown risk and the large amounts of funds for the investigation. 

I am a physicist who switched to nuclear engineering for my Ph D. My introduction to PSA was as an original participant in the Reactor Safety Study in 1972. Material for this book was first gathered in 1974 for a workshop on what to expect in WASH-1400 (the results of the Reactor Safety Study). Materials were gathered over the years for EPRI, Savannah River Laboratory, and other workshops. A culmination was in 1988 with "Probabilistic Risk Assessment in the Nuclear Power Industry" with Robert Hall as coauthor. This book updates these materials and adds material on PSA in the chemical process industry. I prepared the material for printing using a word processor... 

Chapter 3 concerns the dynamic characteristics of stagewise types of equipment, based on the concept of the well-stirred tank. In this, the various types of stirred-tank chemical reactor operation are considered, together with allowance for heat effects, non-ideal flow, control and safety. Also included is the modelling of stagewise mass transfer applications, based on liquid-liquid extraction, gas absorption and distillation. 

Taylor, B. T. et al. (2000) HAZOP A Guide to Best Practice (Institution of Chemical Engineers, London). USAEC (1975) Reactor Safety Study, WASH-1400 (United States Atomic Energy Commission). 

Economic and safety considerations encourage minimal stockpiling of chemicals and avoiding transportation of hazardous substances. These increasing demands offer many opportunities for microwave chemistry in the development of environmentally benign methods for the preparation of intermediates, specialty chemicals and pharmaceuticals [6[. It appears likely that within the next few years, individual chemical reactors will be required for diverse tasks and will need to be easily relocated... 

Steel, C. B. and P. F. Nolan, "Scale-up and Heat Transfer Data for Safe Reactor Operation" in Proceedings of the International Symposium on Runaway Reactions, p. 597, Center for Chemical Process Safety/AIChE, New York, NY (1989). 

Chemical interaction considers the unwanted reactions of process substances with materials in the plant area. These reactions are not expected to take place in the reactor and therefore they are not discussed in the side reaction subindex. The Inherent Safety Index has utilized EPA s matrix (Hatayama et al., 1980) to classify the hazards of the chemical interaction in a process. The worst interaction that appears between the substances present in the plant area is used in the calculations for the Chemical Inherent Safety Index. 

In this third edition we have revised the theoretical part and introduced a number of new simulation examples. Some examples deal with safety problems in chemical reactors and others are related to modelling of environmental systems and are located in a new Environmental Process section. 

Guide for the Identification and Control of Exothermic Chemical Reactions" (TAA-GS-05 1994). A document in German by the Technischer Ausschuss fur Anlagensicherheit (Technical Committee for Plant Safety) of the Federal Ministry of the Environment, Nature Conservation and Reactor Safety. Addresses safety assessment of reactions during both normal operations and excursions, as well as selection and extent of measures to be adopted. An English translation of this document is provided on the CD-ROM included with this publication. 

Kammel, U., S. Schluter, A. Steiff, and P.-M. Weinspach (1996). "Control of Runaway Polymerization Reactions by Injection of Inhibiting Agents - A Contribution to the Safety of Chemical Reactors." Chemical Engineering Science 51, 10, 2253-59. 

A great deal can and should be said about safety, but we have only been able to outline the principles by which chemical reactors may go out of control. We will conclude our discussion of safety by listing some of the notorious accidents that have occurred in the chemical industry. 

The greatest safety hazard in chemical engineering operations is without question caused by uncontrolled chemical reactions, either within the chemical reactor or when flammable chemicals escape from storage vessels or pipes. Many undergraduate students are never exposed to the extremely nonlinear and potentially hazardous characteristics of exothermic free radical processes. 

---