【Help Request】To all dxjm colleagues in the desulfurization workshop: safety issues regarding the rich amine solution

If there is a large-scale leak, things will definitely get very bad – the reflux system is the worst in this regard, followed by the rich liquid stream, with the lean liquid stream being in a better condition. 1. In the event of a large-scale leak, it’s best to stop operations immediately; this is the best choice both from an environmental perspective and from an economic standpoint. 2. Regarding the issue of hazard, from the perspective of H2S leakage, as long as it is properly controlled, the concentration will not be very high. As you said, the release rate isn’t fast, and the space isn’t sealed, so the possibility of H2S poisoning is still low. However, after dealing with the accident, flushing the site is still essential; if substances seep into the ground, nothing will be able to grow there. 3. During maintenance, chemical cleaning, water flushing, and steam purging are certainly used, but the odor inside the equipment remains strong anyway

Thank you. I contacted the company’s refinery workshop after starting work, and it seems to be the same situation. But what was said upstairs about \"not a single plant being able to grow there\" – well, that’s because the pipelines might have to pass through farmers’ land... :( Is an environmental impact assessment necessary?

When we stopped the operation of the equipment to recover the solution, we encountered a situation in which the hydrogen sulfide concentration in the low-level tank area exceeded the allowable limit when its level reached 1 g/L. If there is a leak during the long-distance transport of the concentrated liquid, hydrogen sulfide will be released upon depressurization, which certainly poses safety risks. It is recommended to use stainless steel for the pipelines, and to install hydrogen sulfide detectors along them.

I’m not very familiar with this process, but I’ve been doing simulations related to it recently. The smell of H2S is extremely strong; back in Hefei, there was a Jianghuai Fertilizer Factory that emitted a strong smell of rotten eggs every day. I guess sulfur factories must also have a very strong odor

The situation described by the poster, such as a large-scale leak of rich liquid, must absolutely not occur; if it does happen, it must be handled in accordance with the emergency procedures for H2S leaks. Because the H2S concentration in the rich liquid is very high, a large-scale leak will lead to catastrophic consequences. Here I would like to provide you with some figures: the maximum allowable concentration of H2S in the facility is 10 ppm. When the H2S concentration reaches 200 ppm, a person’s sense of smell is impaired, and when it reaches 700 ppm, exposure can lead to fatal electric shock-like effects. Therefore, everyone must pay close attention to H2S leaks.

Based on the liquid richness level you mentioned, the hydrogen sulfide concentration that could occur in such an environment is around 500 ppm, with wind speeds of about level 2 to 3. Two points should be noted: 1. Emergency response mechanisms should be employed as much as possible in the case of large-scale leaks, and this is absolutely correct. 2. The leakage rate of the rich liquid pipeline is extremely low, as corrosion of the rich liquid proceeds slowly when the flow rate is controlled. 3. In the event of a leak in the rich liquid, no major accidents similar to those that occurred in Sichuan will take place, but the hydrogen sulfide concentration detected will be far above **the standards. In large groups of people, inhalation reactions to hydrogen sulfide can occur

Under what conditions was this 500ppm produced? How large is the coverage area? There are a few words in your sentence that I can’t understand (:lol). And this is also quite important – could you provide some evidence? If it’s 500 ppm, the range is quite large, which is somewhat concerning. :( This post was last edited by Uemaki on 2009-3-18 12:37 )

If it is considered as “H2S”, then no further discussion is possible; the key issue is the leakage of rich liquid and its degree of harm to the environment.

The data I have provided above is by no means intended to scare people, as the H2S content in rich liquid is usually around 20 g/l; a leak of such rich liquid implies a large release of H2S, which is therefore extremely dangerous. Of course, the probability of such things happening is very low, but in our facility, there was indeed an incident where personnel almost lost their lives due to H2S poisoning during the maintenance of a liquid-rich pump. Therefore, this must be given due attention.

The low-level tank area we mentioned is used for recovering solutions when the plant is shut down; its location is lower than that of the main plant area, so hydrogen sulfide does not spread easily. It is also recommended to use HYSYS to conduct a simulation of liquid-rich pressure reduction on the first floor, so as to determine the maximum concentration of hydrogen sulfide in the air. Calculating the distance over which it can spread is rather complex.

Some people have done simulations: 25 tons of leakage would produce 1 kg of gas, which includes some water; moreover, the release rate wouldn’t be instantaneous, and the affected area wouldn’t be confined to a small space... In fact, it seems that people are intimidated by H2S. On the list of toxic substances, it isn’t considered highly toxic – it’s just very smelly and has a poor reputation, **(it’s all about perception!)** :) This post was last edited by Uwaki on 2009-3-19 09:29 ]

It’s normal for the levels in this environment to exceed the standard; the standard seems to be 10PPM, which is the point at which a strong odor becomes noticeable :) Check the simulation results above

I’m looking at this post after a long time – the results from that design institute showed a pipeline rupture resulting in a leakage rate of 25 tons per hour… 1 kg of gas per hour. It seems that as long as one doesn’t deliberately go near it to smell it, there shouldn’t be any major problems; the main concern is perhaps the accumulation of large amounts of gas in low-lying areas where there’s no wind :(A mechanism for comparing traffic at both ends can be set up; once there is a difference, an alarm or routine inspection can be triggered… Well, I’m a bit ‘disappointed’ about this issue. Is that the right word to use?) :Lol, at the beginning of the invention of cars, trains, high-voltage electricity… and also at the inception of pipeline gas… :) Hehe, I’m used to posting replies in other forums and thinking that such posts don’t count; I thought this post would just disappear without a trace, but to my surprise it still came back to the surface! :P This post was last edited by Uwaki on 2009-4-9 20:45 ] This post was last edited by adsl121 on 2009-4-10 02:04 ]

At low temperatures, the rich liquid seems to be relatively safe. Under normal conditions, at atmospheric pressure and below 45°C, the amine solution reacts in a direction that facilitates the absorption of hydrogen sulfide; above 60°C, it reacts in a direction that facilitates desorption. Usually, when collecting samples of the rich liquid, we simply use bottles to take samples at the sampling port, and no problems have occurred. Of course, experienced workers know to stand upwind when taking samples, and if there is no wind, they try to hold their breath while sampling. This post was last edited by adsl121 on 2009-4-11 00:50.]