How to deal with pipeline blockage caused by ammonium salts in fuel gas
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In benzene hydrogenation units, heat transfer oil is used as the heat source. The heat transfer oil furnace burns gas as well as sulfur-containing exhaust gases generated by the stabilizer tower of the benzene hydrogenation unit (mainly containing ammonia, hydrogen, methane, C4, and C5), which causes ammonium salts to clog the pipes. Do anyone have any good suggestions to address this issue of pipe blockage due to ammonium salts?
Can it be confirmed that it’s an ammonium salt blockage? Since it is a sulfur-containing gas, the ammonium salt is generally ammonium hydrosulfide; such ammonium salt deposits should be eliminated with slight heating. It is recommended to provide steam tracing for the pipelines, or to desulfurize the exhaust gas before it enters the furnace. Additionally, a small amount of oxygen in the pipeline can also cause blockages, and such blockages are caused by the sulfur that precipitates.
When ammonium hydrosulfide crystallizes, keeping the temperature above 150°C generally prevents crystallization.
The key point is that this air is sent to the heat transfer oil furnace for burning, so it’s impossible to maintain such a high temperature
Well, it’s definitely ammonium salts; there are also substances like tar and naphthalene in the gas, but it’s mainly the ammonium salts that cause the problem. Heat tracing may be used, but its effectiveness isn’t very good and needs improvement. There isn’t much sulfur present.
The problem at its source cannot be resolved; it’s difficult to find an effective solution. After all, we can’t just install a purification system for this type of gas, right? PSA can be considered
Sulfur-containing compounds dissolve in water to form acidic solutions that cause severe corrosion of pipelines~~
It is still necessary to control it at the source, by adding appropriate facilities at the early stages of the process; it becomes much more difficult when trying to achieve control through the system.
It’s simple: while strengthening the heat tracing, add a water seal tank before the fuel gas enters the furnace to dissolve the ammonium salts in the gas in water; make sure to replace the water in the water seal tank regularly.
By adding heat tracing and insulation, pipeline design does not require compensators to address stress.