The raw gas has a high hydrocarbon content; bed temperature rise situation
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This post was last edited by Qianxiafeng on 2010-5-10 at 10:24. The hydrocarbon content in the feed gas is 20–30%; the temperature of the bed is extremely high, as is the temperature of the flue gas furnace. As a result, the sulfur production furnace had to increase its air supply, but with little effect. The high temperature in the exhaust furnace is due to a high hydrocarbon content, which results in the formation of large amounts of COS and CS2; these substances cannot be properly hydrolyzed, leading to an excess of sulfides in the exhaust gases that enter the furnace and cause its temperature to rise. But why does the bed temperature rise by so much? Could it be due to the hydrolysis reaction? Hydrolysis reactions are endothermic reactions. Is it because the reaction in the sulfur production furnace is poor, which leads to intensified reaction in the bed? Then why isn’t the bed temperature increase that high no matter how it’s adjusted? It’s still because. . . . . . . . ?
May I ask if the bed layer you are referring to is the bed layer of the Claus reactor or that of the hydrogenation reactor? If an increase in the bed temperature of the hydrogenation reactor is normal. The increase in temperature in the exhaust flue is not caused by an excess of sulfides, but rather by the incomplete combustion of hydrocarbons in the reaction furnace, leading to secondary combustion in the flue.
This post was last edited by Qianxiafeng on 2010-5-10 at 10:04. What you mean by the bed temperature is probably the temperature of the sulfur converter. It’s normal for this temperature to rise, as there are hydrocarbons present; when the temperature in the sulfur production furnace rises, the temperature of the process gas also increases. Moreover, if the reaction in the sulfur production furnace doesn’t proceed efficiently, more reactants end up reaching the converter, and these two factors combined result in a high temperature in the converter bed! The person upstairs’s claim that the high temperature of the exhaust furnace is due to one factor is one-sided; in fact, both factors are responsible! It is recommended that the poster improve the stability of the upstream processes; excessive amounts of hydrocarbons can affect the quality of sulfur, while carbon deposition in the converter can reduce the activity of the catalysts, thereby affecting the sulfur recovery rate and increasing the pressure throughout the system! It’s a rather troublesome thing!
It is the bed temperature after one rotation. The exhaust section has not been put into operation. The inlet temperature is 270, and the bed temperature reaches up to 390°. The temperature of the exhaust furnace is 700–800°.
This post was last edited by Qianxiafeng on 2010-5-9 at 14:02. How do you manage to keep the bed layer temperature so high? Does this high temperature occur frequently or only occasionally? At such a high level, the catalyst will be ruined after a long time! The answers you’re looking for are in the second and third floors mentioned above. The most important thing is to control the hydrocarbon content upstream; it would be a huge waste to let so much hydrocarbon burn away uselessly! Your main task is to find ways to have the factory recycle this material through its upstream suppliers, and to ensure that the sulfur production furnaces burn hydrocarbons completely, thereby preventing secondary combustion in the exhaust gas furnaces. Finally, it is essential to prevent the converter bed from overheating! ! ! ! ! ! ! !
This post was last edited by Qianxiafeng on 2010-5-10 10:04. It’s just my personal opinion; I couldn’t find enough material to back it up right away. Could it be that the reaction of hydrocarbons with oxygen occurs more frequently than that of hydrogen sulfide with oxygen? As a result, some hydrogen sulfide moved into the reactor, causing the bed temperature to rise. (Just as the probability of a reaction between ammonia and oxygen is lower than that between hydrogen sulfide and oxygen.) Therefore, if the air supply is insufficient, it will lead to incomplete combustion of ammonia, or instead of nitrogen being produced, nitrogen oxides such as nitrogen dioxide will be formed. ) Original poster, may I ask what the pH level is in your quench tower? Is it on the low side? Active participation
This post was last edited by Qianxiafeng on 2010-5-10 10:05. I agree as well; hydrocarbons burn more easily in reaction with oxygen than hydrogen sulfide does. In daily work, by carefully analyzing the air-fuel ratio, it becomes clear that when acidic gases contain significant amounts of hydrocarbons, the following phenomena occur: 1. Even with a very high air-fuel ratio, it is still not possible to reduce the levels of hydrogen sulfide! 2. The furnace temperature keeps rising; if no appropriate measures are taken, the furnace may shut down due to the extremely high temperature. After some time, the temperature of the converter’s bed layer also rises! 3. The exhaust gases may exceed regulatory limits after a certain period of time!
You’re controlling it too much; can the catalyst handle that? ? Is the exhaust furnace temperature that high? ? Is the steam pressure very high? How to deal with it?
5# Light Summer Wind: Under normal conditions, the bed temperature is not like this; it only occurs when the hydrocarbon content is high. Our workplace isn’t as strictly controlled as yours; there are many things we’re forced to deal with, and I can’t go into details. It causes great damage to the equipment. Alas! ! ! ! ! ! ! ! ! !
6# zhezi2009.wang The combustion sequence in the sulfur production furnace is as follows； Hydrogen sulfide, sulfur, hydrocarbons, ammonia. I know this as well; there is information available on it. The reaction of hydrocarbons in the sulfur production furnace consumes a certain amount of oxygen, which has already been taken into account when calculating the theoretical air supply. Oxygen first reacts with hydrogen sulfide to produce SO2, and the excess SO2 serves as an oxidant for hydrocarbons. Actually, it’s the same reaction as with ammonia. When the hydrocarbon content is high, although more air is supplied, the hydrocarbons absorb a large amount of SO2, which results in poor hydrogen sulfide reaction inside the furnace; this in turn causes the reaction temperature in the converter to rise sharply. But I don’t understand how the bed temperature could rise to 390°, right? Our exhaust section hasn’t started operation yet.
8# weihua110 [/ Doesn’t steam pressure have anything to do with furnace temperature? It is related to the steam temperature, but adjusting the amount of deoxygenated water added will suffice.