A trickle-bed reactor (TBR) is a

chemical reactor A chemical reactor is an enclosed volume in which a chemical reaction takes place. In chemical engineering, it is generally understood to be a process vessel used to carry out a chemical reaction, which is one of the classic unit operations in chem ...

that uses the downward movement of a liquid and the downward (co-current) or upward (counter-current) movement of gas over a packed bed of (

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

) particles. It is considered to be the simplest reactor type for performing catalytic reactions where a gas and liquid (normally both reagents) are present in the reactor and accordingly it is extensively used in processing plants. Typical examples are liquid-phase

hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organ ...

, hydrodesulfurization, and hydrodenitrogenation in refineries (three phase hydrotreater) and

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

of harmful chemical compounds in wastewater streams or of

cumene Cumene (isopropylbenzene) is an organic compound that contains a benzene ring with an isopropyl substituent. It is a constituent of crude oil and refined fuels. It is a flammable colorless liquid that has a boiling point of 152 °C. Near ...

in the

cumene process The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was i ...

.
Also in the treatment of waste water trickle bed reactors are used where the required biomass resides on the packed bed surface.

Kinetics

Although the physical reactor is relatively simple, the hydrodynamics in the reactor are extremely complex. It is for this reason that TBRs have been extensively studied over the past five decades and currently the amount of open literature publications on TBRs is increasing, hinting that the understanding of the hydrodynamics is still limited. A good introduction to the hydrodynamics of TBR can be found in the classic article by Satterfield. Rate of reaction and mass transfer equations are derived by Fogler.

References

{{Reflist Chemical reactors

Kinetics

See also

References