Initial startup heating
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In fixed-bed reactions in chemical plants, there are liquid-phase and gas-phase methods. What are the main differences in the heating process? For example, in some liquid-phase methods, the reaction can be carried out with cyclic feeding followed by cyclic heating, while in gas-phase methods nitrogen is generally used for heating. I’m a bit confused; please explain it based on your understanding. Thank you
The temperature increase in the gas phase is intended for water removal and drying; drainage at multiple low points is required, while it is the liquid phase that undergoes the actual temperature increase
In liquid-phase reaction processes such as hydrogenation in oil refining, the reaction takes place in a liquid phase inside the reactor and heating furnace; therefore, it is possible to directly start the furnace and circulate the feed material to increase the temperature. In gas-phase processes such as those for styrene and ethylbenzene, nitrogen is used to raise the temperature; feeding begins only when the temperature reaches 200–300 degrees Celsius. The feed is in gas form, meaning that the liquid phase must be vaporized before it enters the heating furnace, and any liquid phase inside the heating furnace or reactor is not allowed. I want to compare these two types of reactions to see what the fundamental differences are in the heating process
Oh, I misunderstood then; I’ve never been in contact with styrene plants