What is the role of propylene at the C2 hydrogenation inlet of the ethylene plant?
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I would like to ask: at the inlet of the C2 hydrogenation unit in the Chuanhua ethylene plant, there is an propylene line that runs alongside the ethylene stream, and it returns at the outlet of the C2 hydrogenation unit. What is the purpose of this line, and when will it be put into use?
Is it used for rapid cooling by air flow? Is there a picture? Show a partial view last time
It is a quench line; after the reaction temperature rises excessively, propylene is used to rapidly cool the bed layer in order to restart the operation quickly
Agree with the view above; use it after flying to high temperatures
This post was last edited by Ethylene Novice on 2020-12-13 at 16:51. The file bk15.jpg shows that this method is generally used when the reactor temperature rises excessively or in the event of an emergency shutdown. First, the reactor’s interlock system is activated to release pressure; once the conditions are suitable, nitrogen is used for purging and cooling. Here, it is required that nitrogen bring the bed temperature below 80°C, with propylene being used for further cooling.
Generally, this occurs during the first start-up of the unit or after replacing the catalyst with a new one. Due to the high activity of the catalyst, the hydrogenation (deacetylenation) reaction tends to be intense, resulting in a rapid release of heat and an excessive increase in the bed temperature – commonly known as \"temperature runaway\". Nitrogen is used for cooling, but its effectiveness is usually insufficient; only then is propylene introduced for cooling.
Our company also has this line, but it seems that Feiwen has never used it
I checked our PID and found no propylene line; however, there is a CO injection line designed to prevent excessive hydrogenation, which can effectively reduce catalyst activity