A method for enabling gas exchange and chemical reactions with one or more liquid streams contained in a reactive process vessel are provided. One or more exchange layers within the process vessel can be composed of both collector media and releaser media. The exchange layers allow elements to facilitate increased performance of vessel operations by promoting gas component mixing and diffusion. Improved rates of gas component exchange mean less coking and more gas components available for reaction.

A reactor may have a catalyst bed for the catalytic treatment of a gas stream, with the catalyst bed extending substantially over a cross section of the reactor. Gas to be treated may axially fly through the catalyst bed. A carrier structure for the catalyst bed that is at least partly floatingly mounted in the reactor may include a sieve element and, radially outwardly, carrier elements fixedly joined to the reactor wall below the sieve element. The sieve element provides a resting surface for the catalyst bed. The sieve element terminates, radially outwardly, at a distance from the reactor wall. The carrier structure also includes support elements for the sieve element that are floatingly mounted in the reactor. An improved floating mounting is thus provided where not only the sieve element itself but also further parts of the carrier structure are mounted to prevent stresses due to thermal expansion.