Beyond buckets and batches

Readers of this column know a fine chemical plant’s faithful friends: its stirred tank reactors. While they are covered in steel and bristling with protrusions, they’re not too different from a laboratory chemist’s 3-necked flask. And while plant reactors have motor-driven agitators instead of enormous magnetic stirrer bars, the concept is the same: a container for running reactions in, with a tool to mix the chemicals. Reactants are fed in until the reactor is full, and the whole thing is heated or cooled to manufacture a new compound, then the product mixture is crystallised and filtered. Each batch is manufactured the same way, week in, week out. But there are other ways to make chemicals, beyond old-fashioned stirring.