3 replies to this topic

[aanita]

When gas composition is known as dry basis, how can I get ( in HYSYS)
water content in the feed, before water being removed, when temperature and pressure are known.
The gas is saturated condition at given temperature and pressure.
Regards.

[wojtar]

'aanita', on 09 Apr 2010 - 1:30 PM, said:

When gas composition is known as dry basis, how can I get ( in HYSYS)
water content in the feed, before water being removed, when temperature and pressure are known.
The gas is saturated condition at given temperature and pressure.
Regards.

Well, I'm doing something like this (in CHEMCAD but I suppose it is similar in other simulator):
1) Specifying my gas stream (air for example);
2) Specifying water stream (big amount of it);
3) Mixing them together;
4) Resulting stream is going to flash unitop with defined pressure and temperature;
5) In top stream from flash you have saturated gas;
6) Rest of water goes through bottom stream.

Hope this helps

Best Regards

[Srikrishna Chaitanya]

Hi ,

Just add that dry gas stream with another stream having only water (amount start with 100 kg/hr, T & P can be as that of dry gas ) send this mixed stream to a separator , now observe liquid outlet (bottom out of separator )of separator ,
if this stream contains any water (m > 0 kg/hr) that means gas is saturated with water that’s why excess water is going as liquid from separator . Now separator gas out stream can be considered as saturated gas / wet gas .
In case liquid out of separator dosent contain any flow (m <= 0) then amount of water added is not enough to saturate the dry gas . Now add more water till you see some mass of water in the separator liquid out. Once you see water in the liquid out than corresponding gas out is the saturated gas / wet gas .
Note :
In case your gas contains some amount of liquid hydrocarbons , then this liquid is supposed to go through the liquid out . For this case use a 3 phase separator where liquid HC’s comes out as a separate stream (mid ).
This is a crude procedure I normally use , u can use any other simple procedure or check whether any utility / option available to find water required for saturation .good luck
Regards,
Satish

[aanita]

Thank you very much.

Regards.