Nitric Acid Plant

[24hrs]

is it better to buy a nitric acid plant economiser made of carbon steel than one made of zirconium.?
if the temperatures in the economiser are about 120C

 

[unclesyd]

What are the compositions of the streams enter the economizer?

 

[24hrs]

This is the likely composition of the stream that enter into the economiser

Inlet gas 250C ,40psig
compositon : Nitrogen 65% ,water 15% ,NO2 13% ,O2 7%

Boiler water treatment :
Pre-treatment
Lime softened
Base exchanged
Dearation
Mechanical (Vacuum)
Chemical-sodium sulphate
Composition
Chloride: 10-20ppm
Max. O2 : 20ppb
NaOH : 100-300ppm
Shut Down: 1 week


Thanks

 

[BenThayer]

i am not going to do the detailed math but this does not look good.

what is the temp of the inlet water? it looks like you could hit the dew-point and start absorbing NO2 and making acid in this application.

the only carbon steel i have seen in nitric acid units for heat exchangers was right after the NH3 converter/burner where you are running 1650-1720°F and then there relatively serious procedures and interlocks to ensure the boiler feed water was hot enough to allow the ammonia burning at the gauze to take place.

and then there would be a higher alloy (e.g., zirc) at the acid condenser stages.

who's design and what vintage acid plant is this? are you part of the Nitric Acid Producers Meeting or the Ammonium Nitrate Producers Study Group (actually, i think they combined a few years ago)?