Slurry Reactor

What is a slurry reactor?

A slurry reactor is a particular continuous flow reactor which has the capability to mix solids, liquids and gases simultaneously. The solid is primarily the catalyst and is typically suspended in a liquid with gas pumped through it.

The ‘slurry’ is what is referred to as the suspended solid, whereby fine solid particles are suspended in a liquid to catalyse the reaction of a gas with a liquid. A slurry reactor allows for all three phases to occur continuously in a reactor system.

What is an example of a slurry reactor?

Slurry reactors have a wide number of uses within the fine chemical and pharmaceutical industries. In order for flow reactors to replace the majority of batch reactor usage, they must have the capability to handle reactions that involve suspended solids.

Examples include heterogenous chemistry that involves solid slurries, such as hydrogenations, oxidations, chlorinations and reductions. This also includes reductions with metal catalysts and reactions that form a precipitate.

Continuous flow slurry reactor

In a continuous flow reactor, solid particles which are part of the chemical process need to be able to flow through the system without risking blocking, bridging, fouling or settling. Standard flow methods used for handling homogenous fluid rarely work well when solids are present in the reactor.

The way the flow reactor is designed is integral to it functioning as a slurry reactor. This is why a continuous slurry reactor is usually engineered to have simple internal geometry and large channel diameters, which lead to good mixing.

Good mixing is required to keep solids suspended in horizontal transfer lines, with turbulent flow assisting in keeping the slurry at high axial velocity.

The versatility of the Coflore ACR cell block is a clear example of why a flow reactor is an ideal host for slurry reactions. With various injection sites available for the gas to be pumped in, in-between the various CSTR agitator stages, meaning the Coflore systems can be modelled to exact reaction requirements.

The Coflore range, including the Coflore ACR and ATR have been engineered to accommodate a wide range of slurries with different attributes, including fast-settling solid slurries, slow-settling slurries and varying solid particle sizes.

Check out some of the technical notes and publications our systems have been involved in, including a phosphorylation reaction and deoxygenation.

A suspended solid slurry

Slurry Handling Within the Coflore

Effective Phosphorylation of 2,2′-Methylene-bis(4,6-di-tert-butyl) Phenol in Continuous Flow Reactors

Calcium Carbonate Slurry Recycling

Flow chemistry in the multi-step synthesis of natural products

Flow chemistry in pharmaceuticals: Slurry hydrogenation

Using Coflore’s answer to the slurry reactor, we recently tested our flow reactor for another pharmaceutical application. Slurry reactors are a fundamental aspect of catalytic hydrogenation reactions, with the presence of a solid catalyst such as nickel, platinum or another material required to complete the reaction.

We recently executed some development work with Hydregen and their biocatalyst. In our most recent publication, members of the AM Technology team proved Coflore's slurry reactor adaptions can easily adopt biocatalytic hydrogenation reactions. With improved gas-liquid mass transfer rates, the publication focused on reducing 3-quinuclidinone to (3R)-quinuclidinol, which is a key component in approved antimuscarinic drugs.

The biocatalytic system operates at mild conditions, achieving conversion rates without requiring additional optimisation. This new route for pharmaceutical APIs can replace the use of traditional metal catalysts whilst providing energy efficiency and safer chemistry perks of a flow chemistry-slurry reactor.

Flow reactors play a key role in pharmaceutical production, find out how their slurry handling capabilities have been adopted for streamlined API manufacturing here.