Method for producing semi-synthetic protective and reaction gases especially for heat treatment of steels and metals composed of a mixture of differently selectable amounts of nitrogen, hydrogen, carbonmonoxide, carbondioxide and steam

摘要

In this process, the cracked gases hydrogen and carbon monoxide obtained from a catalytic methanol cracking process and carbon dioxide are admixed to the nitrogen gas or a nitrogen/hydrogen gas mixture and the methanol is admixed to the nitrogen preheated as a carrier gas and/or carbon dioxide, hydrogen or cracked gas, the mixture is completely evaporated in a evaporator and the resulting methanol vapour/nitrogen mixture is cracked in a reactor filled with a catalyst at a process temperature of 270 - 300 DEG C to give mainly CO and H2. Before admixture, the cracked gases pass through a heat exchanger for preheating the nitrogen carrier gas and, in order to remove CO2, two heat exchangers which can be switched on and off alternately and are operated with liquid nitrogen and in which alternately carbon dioxide can be frozen out in one heat exchanger, while the other can be dried and flushed with preheated nitrogen can be incorporated in the process sequence. IMAGE