What is the temperature range for ammonium salt crystallization in hydrocracking units? Will it crystallize at 230 degrees?
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What is the temperature range for ammonium salt crystallization in hydrocracking units? Will it crystallize at 230 degrees?
The crystallization temperature of NH4Cl is 180–200°C, while that of NH4HS is 150°C.
Ammonium chloride levels need to be between 230 and 240 for precipitation to occur
Some say it’s 220°C; if it’s lower, keep it between 180-200°C.
For the high-exchange tube side, the inlet is at 270 degrees and the outlet at 230 degrees – is it necessary to install a water injection point?
For the high-exchange tube side, the inlet is at 270 degrees and the outlet at 230 degrees – is it necessary to install a water injection point?
It needs to be set; we install a water injection point at the high-exchange location
Intermittent water injection will do; we inject for two hours per week!
Based on the inlet and outlet temperatures of the heat exchanger you mentioned, if the sulfur and nitrogen contents are within normal ranges, there is no need to add water. At 230 degrees, even if crystallization occurs, it is minimal; the crystals are washed away by hydrogen and carried to the back, so there is not much need to inject water as in a heat exchanger.
With such temperatures, it’s necessary to install a water injection port; otherwise our factory will suffer losses. At the temperature at which ammonium salts crystallize, crystallization doesn’t occur at all. Over time, crystallization did happen eventually, so we had to stop production and add another water inlet. However, water is injected intermittently – only a small amount is injected when the pressure is high. It is recommended to set one in the initial stage