Special thread for handling urgent issues in production facilities
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Haichuan is a platform for everyone to communicate. The leaders have always emphasized the importance of such communication, and those who come to Haichuan are all elites from various petrochemical companies; they come here to exchange ideas and learn from their peers, so as to apply new technologies and good practices to their own facilities. When problems arise in their facilities, they think first of turning to Haichuan and its members for help. For these reasons, a special thread for urgent issues has been created: 1. This thread is intended solely for Haichuan members to use when there are emergency situations in their production facilities; it must not be used for other purposes, otherwise the post will be deleted. 2. Experts from various fields are encouraged to actively post questions to help resolve them. 3. All moderators and members should give higher scores to posts.
It’s very timely; I really need my gasoline hydrogenation unit. A few days ago, I noticed an increase in the system pressure drop. Upon closer inspection, it was found that the pressure drop in the high-pressure heat exchanger was high. The pressure drop across the inlet and outlet of the high-pressure heat exchanger was 1.05 MPa. What could be the cause of this, and how should it be addressed? The general operating conditions of the plant are a system pressure of 3.0 MPa; the cycle hydrogen compressor is a reciprocating compressor with a processing capacity of 150,000 tons per year. The amount of cycle hydrogen is 10,000 cubic meters. Hydrogen is produced by dry gas method, the temperature before the heat exchanger ranges from 200 to 260 degrees, and 2.5 T/H of water is injected into the pipe bank prior to the heat exchanger before the high-pressure section. It is mainly used for processing coker gasoline. The device can no longer hold up; operations will have to stop soon. I’m not sure what can be done at home to address this issue. Thank you! ! ! ! ! ! ! ! ! ! ! ! ! ! This post was last edited by zhuyitou8 on 2008-7-16 23:50.]
Are you using reformed hydrogen? What is the Cl- content in the recycled hydrogen? Is water injected before the high-pressure heat exchanger? What is the inlet temperature of the heat exchanger? Based on the phenomena you described, they are quite similar to those that occurred in our plant’s hydrocracking unit. Last year, ammonium salt crystallization led to an increase in system pressure drops in our plant’s hydrocracking unit; a large amount of ammonium salt also accumulated on the impellers of the hydrogen recirculation pump, which forced us to shut down the unit for maintenance. My experience is limited, and this is just my personal opinion; I hope it can be helpful to you :)
How did you handle it? Was the water injection point modified later? Is this phenomenon still existing today?
The liquid carryover phenomenon with circulating hydrogen should be quite noticeable. I’m not sure what the operating temperature in your system is; if it’s 150 degrees, then hydrogen sulfide-amine salts are involved, while if it’s above 180 degrees, then chloroamine salts are the main concern. It is recommended to increase the amount of water injected and to check whether the quality of that water meets the required standards
Check the water supply pipes as well to see if there are any blockages
Increase the water injection volume and monitor the high-ammonia concentration.
We keep the cold water temperature between 40 and 50 degrees, and we use deionized water for this purpose
If the reformed hydrogen contains chlorine, it is necessary to dechlorinate the reformed hydrogen; modifying the water injection point is not sufficient. By how much should the temperature at your water injection point be higher? Also, is the tube-side pressure difference high after the reactor outlet due to high heat transfer?
The temperature at the water injection point is around 190 degrees. Initially, the differential pressure was not very high; however, it increased significantly after detection. Just changing the pipe layer to 102 resulted in a differential pressure of 0.5 MPa