FIELD: gas replacement.
SUBSTANCE: group of inventions is related to a gas replacement method, a gas replacement installation and the use of a gas replacement method or installation in a nitro compound hydrogenation reaction method. A gas replacement method in a hydrogenation reaction of nitro compounds includes the first step of replacing the gas of a stream to be replaced in the presence of a first replacement gas, called the first gas replacement step. Then the second step in which the gas is replaced in the presence of a second replacement gas, called the second gas replacement stage. The reduced velocity of the first replacement gas, which is an absolute value, unit of measurement is m/s, is equal to V1. The reduced velocity of the second replacement gas, which is an absolute value, unit of measurement is m/s, is equal to V2, and V2/V1 ≥ 1.5. A gas replacement unit used in the method, a system for carrying out the hydrogenation reaction of a nitro compound and a method for carrying out the hydrogenation reaction of a nitro compound are also claimed.
EFFECT: group of inventions provides gas replacement efficiency (in particular, degassing efficiency) in general, which can reach 90% or higher, preferably 94% or higher, and also provides a controlled amount of carbon deposition on the catalyst in a fluidized bed reactor.
32 cl, 30 ex, 7 tbl, 6 dwg
