Every good chemist knows the importance of accurate temperature management for controlled reactions. It underpins key safety and quality parameters and can ultimately mean the difference between a successful or unsuccessful reaction. Reaction vessels often use cooling and/or heating jackets to achieve optimum temperature control: removing heat in exothermic reactions and adding heat in heat-absorbing reactions.

In this article we will discuss some applications of jacketed reactors and how to get the most out of your system.

A reactor (reaction vessel) is a vessel in which chemical reactions take place. Given the wide variety of types of reactions that take place in chemical processes, reactors are made from a wide range of materials and come in a variety of configurations. They have a large number of uses in the chemical industry, such as distillation, API manufacture, crystallisation, extraction and reprocessing. Manufactured in a variety of formats, sizes and materials (usually glass or stainless steel) to suit the chemistry of the end user, the options for customisation are almost limitless.

So, what is a jacket in a reaction vessel?

Temperature control jackets are available in single and double jacket configurations (jacketed or vacuum jacketed). Single jacketed systems use a cooler to circulate liquid around the reactor, while double jacketed systems use a cooler to circulate liquid through the inner jacket. The outer jacket is used as vacuum insulation to ensure that the vessel is maintained at the required temperature - and to prevent condensation/freezing from forming at ultra-low temperatures.

Key uses for jacketed reactors

Jacketed reactors provide enhanced temperature control and thus improved product quality. They are used in a wide range of applications from pharmaceuticals to engine oils. They control the heat of exothermic reactions or reduce the viscosity of highly viscous liquids.

The quality of your reaction may be affected by the type of stirring used, the size and shape of the reactor and the addition of baffles, as all these conditions affect the mixing capacity. You should also consider other conditions that may affect your reaction, such as photosensitivity - it may be necessary to paint your jacketed reactor vessel with an amber colour.

Many jacketed reactors can be connected to laboratory automation software, providing the user with precise control of reactor temperature and process, computerised data and reports.

Stainless steel and glass

There are both positives and negatives to using steel and glass in jacketed reactors. Ultimately, you must decide what you need the vessel for. When using reflux as described above, stainless steel is usually used (or you may need an alloy such as Hastelloy for improved chemical resistance) and this type of reactor is usually more expensive than a glass reactor when pressurised conditions are required and no reaction visibility is possible.

Jacketed Glass Reactors

A jacketed vessel is a vessel designed to control the temperature of its contents by using a cooling or heating 'jacket' around the vessel through which a cooling or heating fluid is circulated.

The jacket allows for a uniform heat exchange between the fluid circulating in it and the vessel walls.

Jacketed glass reactors are designed to react and mix different types of materials under specific adjustable temperature and vacuum conditions. The reaction lids have different functional ports allowing the user to perform different purposes such as adding material to the vessel at a controlled rate, measuring the temperature of the material, adding powder or solids to the vessel, recovering distilled material, etc. The lids can be fully customised according to customer requirements.