2 replies to this topic

[Rahimzadeh]

Dear:

In our gas refinery , cooling system (compressor)  get not ready , some people proposed we cool down propane by flaring for loading to tank.

Please tell us your idea about this

Regards

[gegio1960]

not sure what they have in mind but... flaring is an emergency practice, only!

[Neelakantan]

i understand the query because we have done a similar exercise when our turbine drive for our propane compressor failed and the new one took more than 90 days to come in place. but remember, this will result in a huge loss of propane to do that and also the temperature that you get will not be deep. also the amount of propane flashed will be vented!

 

you should have an insulated propane hold-up (sphere of much larger capacity and i am not talking about the accumulator), you need low temperature hoses (normally condenser and accumulator are at higher temperature and only from first high pressure flash  LTCS may be present; so you need to connect the cold propane liquid to the flash drum

 

finally you need a local recompressors (typical screw  compressors of low capacity)

 

procedure:

start "flaring" the propane sphere to the flare; you can start in the evening or late night; next day morning you may find the prssure is low; dont worry that the propane is lost you will find that almost major amount of propane self-cools due to boiling and the storage achieves a low temperature matching the equilibrium of the flare pressure.

 

this could be -10 to -15 deg C.  this cold propane is taken to the first flash drum and the chilling happens;  we added three screw compressors at three stages and the performance of the whole system depends on the capacity and running of these compressors,

 

if i remember, (it was in 1989) we ran like this for almost two months with 30 to 50% duty;  we could do it because we worked with a government major in india where running of the plant is more important than the economics of the run!

 

regards

neelakantan