What Went Wrong?

Chapter 22. Reactions—Planned and Unplanned

Famous last words: “I didn't see an exotherm in the lab”; “I only saw a little bit of foaming”; “It goes a bit brown if you leave it in the oven for too long.”—Chilworth Technology

Many accidents, particularly on batch plants, have been due to runaway reactions—that is, reactions that get out of control. The reaction becomes so rapid that the cooling system cannot prevent a rapid rise in temperature, or the relief valve or rupture disc cannot prevent a rapid rise in pressure, and the reactor ruptures. Examples are described in the chapter on human error (Sections 3.2.1e and 3.2.8), although the incidents were really due to poor design, which left traps into which someone ultimately fell.

The number ...