Does anyone have experience with using nitrogen to cool down an SRU train for shutdown? What factors should be considered? What are the pros and cons? How much nitrogen is typically needed to cool a 300LTPD train?
I am familair with N2 cooldown in a Sulfur Train. One of the benefits is you can cool the unit down more quickly, thereby shortening your down time. But one of the considerations is how much N2 does your plant have available and what other units might be using it if it was a multi unit turnaround. This can be resolved by bringing in N2 trucks, but that costs $$$, so that is always a consideration. I’ve included a link that discusses a case of using CO2 along with N2.
We have used N2 trucks more often than not to cool down our Claus processes after SD. The main advantage is the cool down process time is cut drastically. The main guidelines we follow is no more cool down than 100 deg per hour on our cat beds at the claus. The main thing you have to watch while cooling with nitrogen is the affect on your TGU. You will see an initial cool down of your In line heater/burner and a usual quick SO2 hit at your thermal oxidizer. I dont know how much N2 we use total but the temps can get below 0.