The back-absorption problem of hydrogen chloride
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I would appreciate some guidance from experts: Our company produces hydrogen chloride mainly for the conversion process to produce VCM. Under normal operating conditions, the production volume is 5500 NM3/h. In the event of a conversion failure, all the hydrogen chloride is directed to the absorption system to be used as acid; this process is controlled manually, but it has never been operated before. The concern is that rapid pressure fluctuations during shutdown could lead to hyperchlorination and cause an accident. I would appreciate some guidance from experienced experts. This post was last edited by 181128425 on 2009-4-11 11:20]
This design has major flaws. 1. During a conversion accident, all the hydrogen chloride is directed to the absorption system to be used as acid, which is very dangerous and could lead to problems in the hydrochloric acid system. 2. Inhaling back air, with acetylene entering the hydrochloric acid system, can also cause accidents. In our facility, there is no such thing as complete absorption of hydrogen chloride in the event of a conversion accident. There is indeed an automatic nitrogen filling system in the mixing and dehydration system.
During a conversion accident in our plant, the acetylene supply is immediately cut off, and the hydrogen chloride flow is reduced rapidly leading to the shutdown of the furnace; this prevents all of the acid from being discharged. If the equipment used for discharging acid has a large capacity, and the pressure of the discharged acid is higher than the pressure of the gas being supplied, then the formation of perchlorine may occur. If, on the other hand, the acid-discharging capacity is limited, and the pressure of the discharged acid is lower than the pressure of the gas being supplied, then the formation of hydrogen may occur
It is said that PVC in western Ningxia undergoes automatic reverse absorption; does anyone know anything about this? This post was last edited by Qicai Shuizhizi on 2009-4-8 19:33.]