DE2738610A1 - Catalytic solid bed reactor - with one coaxial zone filled with catalyst and the other with inactive material - Google Patents

Abstract

A catalytic solid bed reactor for the performance of exothermic and endothermic reactions in the gas/gas, gas/liq. or liq./liq. phase is not filled entirely with the catalyst. In the radial direction, only the central core is filled with the catalyst (when the reactor is wall-cooled) or only the peripheral zone (when the reactor is externally heated). The remainder is charged with catalytically inactive material. The arrangement saves the zones of a reactor where a catalyst is utilised very imperfectly. The reactor achieves the same throughput as when it is completely filled with catalyst.

Description

description

to the patent application relating to the catalytic fixed bed reactor.

The invention relates to a catalytic fixed bed reactor for implementation exothermic and endothermic chemical reactions. Such reactors can be opened Reactions in the gas-gas phase, the gas-liquid phase and the liquid-liquid phase use. Fixed bed reactors are either total or in superimposed layers Filled with a catalyst over the entire radius. Especially with cooled reactor designs are significant between the hot interior of the reactor and the cooled wall Temperature differences exist, which can be seen as a radial temperature profile in the Way noticeable that the catalyst in the cooler edge zones at the chemical Reaction of the low temperature hardly involved and therefore in terms of sales is insufficiently used.

To illustrate this, Fig. 1 shows those determined from experiments axial temperature profiles of the exothermic reaction of ethane and oxygen in one recorded to 590 Kelvin cooled tubular reactor with a diameter of 5 cm. Curves 2, 3 and 4 are the temperature profiles at a radius of 13t20 and 24 mm. Curve 5 is the wall temperature of the cooled reactor. According to the temperatures the sales are also decreasing distributed over the radius of the reactor.

The catalyst located in the colder edge zones therefore only carries contributes to sales to a very small extent.

The object of the invention is to reduce the underutilized part of the Save catalyst and at the end of the reaction zone to the same conversion achieve that would be obtained in a fully catalytic reactor.

This is achieved in that only the warmer one in the radial direction Zone of the reactor filled with catalyst and the colder zone with inert material is. To distinguish, the reactor, which is completely filled with catalyst, should be used as fully catalytic reactor and the reactor according to the invention as a partially catalytic reactor Reactor.

Fig. 2 and 3 show two possible versions of partially catalytic Fixed bed reactors, of which the one according to Fig. 2 is cooled on the outer wall and the one after Fig. 3 is heated on the outer wall. The wall-cooled reactor is inside lying warmer zone 6 with the catalyst and the outer lying colder zone 7 filled with a catalytically inactive material. With the wall-heated reactor conversely, the warmer outer zone 6 with catalyst and colder inner zone 7 with Inert material filled. Laboratory tests have shown that with sufficient reactor length with the partially catalytic reactor type at the outlet of the reactor under otherwise same Conditions the same conversion is achieved as with a fully catalytic reactor. In these experiments, almost half of the catalyst was saved. This surprising This fact can be explained by the fact that the radial concentration differences present in the reactor of the flowing media through diffusion and other exchange processes with increasing Flow length are compensated. The reactive gas mixture mA + mB gets out of the catalytically inactive zone 7 during the flow (Fig. 2) into the active catalyst zone 6 (Fig. 2), while the end product mC from zone 6 to Zone 7 is exchanged. The inactive zone 7 thus gives the initially saved reactive gas mixture mA + m B with increasing reactor length to the catalyst zone and absorbs the end product mC from this to the same extent. In an adiabatence-cooled or the reactor heated from the outside, the inactive edge zone in the reactor acts as a storage tank and Exchange zone for the still reactive gas and for the end product.

So that the reactive gas mixture enters the catalyst zone even faster baffles or baffles can be installed in the inactive zone.

The catalyst filling can be separated from the inert filling different grain diameters between the two or by installing a net between the hatalyeator and the inert layer can be facilitated.

The technical progress of the invention is that by Saving of very expensive catalyst with wall-cooled, adisbatic or heated Fixed bed reactors, the catalyst used is better and more evenly stressed and thereby a considerable saving in Koaten is possible.

Claims (5)

Claims 1. Catalytic fixed bed reactor is characterized that in the radial direction only part of the reactor with catalyst, the other part is filled with catalytically inactive material. 2. Catalytic fixed bed reactor according to claim 1 is characterized characterized in that with wall-cooled reactors only the core zone, with from the outside heated reactors only the edge zone, in adiabatically operating reactors only the The core or edge zone is filled with catalyst, but the rest with catalytically inactive Material. 3. Catalytic fixed bed reactor according to claim 1 is characterized characterized in that baffles are installed in the catalytically inactive zones. 4. Catalytic fixed bed reactor according to claim 1 is characterized characterized in that the catalyst and inert material have different diameters. 5. Catalytic fixed bed reactor according to claim 1 is characterized characterized in that the catalyst and inert filling by a heat-corrosion-resistant and the catalytic converter-safe network is disconnected.