How do you keep plant reactions cold?

Close-up image of a large stainless steel pressure filter at the CalaChem processing plant Grangemouth, Scotland

Source: © Lewis Houghton / Science Photo Library

When a really big tub of ice just doesn’t cut it

It’s probably one of the first tasks you ever set about in the laboratory: making a 50% sodium hydroxide solution. It’s terribly simple – to a clamped-down Erlenmeyer flask containing water, you add your sodium hydroxide and start stirring. As the sodium hydroxide dissolves, the heat released can be intense enough that you need to cool it. If you’re making a litre or two of this solution, you’ll need a tub full of ice to absorb the exotherm.

What happens when you need to cool more than a couple of litres? Depending on where you work, it’s not really that different. But when it comes the plant, a big tub of ice just won’t cut it.