Condenser for Natural Gas

I am a process engineer working with some concept studies for a customer.
We are looking in to one solution where we need a direct contact condenser to liquefie natural gas by “mixing” it with subcooled LNG. The LNG containing the liquefied natural gas will be routed to a regasification plant. Is there anyone with with experience with that kind of direct condensing of natural gas and who maybe now any manufactures of this kind of equipment?

 

[dcasto]

let me give you series of numbers and you decide.

If you take 60 moles per hour of natural gas at 60 degress and 50 psig, it would take 100 moles per hour of LNG at a minus 450 F.

At -250 F and 50 psig, 100 moles per hour on LNG will absorb 7.5 moles of natural gas.

 

Hi dcasto

I agree that we need quite a lot of LNG to condensate the gas, but I think that your case with minus 450 F is a little to cooled (may be a typo). Our gas will be quite cold about -60 F and the liquid will be around -240 F and the pressure will be 50 psig.
There is a high LNG flow specified in the project but we are on the borderline for cooling capacity.
Our customer is not interested in a complex system with a nitrogen cooling circuit or something like that, so we are looking in to solve the problem with a relatively simple system.
One way of solving it could be to compress the gas to our send out pressure but the compressor for compressing the gas up to 1500 psig will be quite complicated and expensive.

 

[dcasto]

Without exact composition of the LNG, i can not see where your LNG is subcooled very much. Pure methane at 50 psig has a boiling point of -220. On pure methane you would need 100 moles of your LNG per every 6 moles of -60 NG at 50 psig. Remember, the critical pressure of methane is 673 psig

there is fairly simple refrigeration system that you can set up for small quanities of LNG. It involves a refrigeration loop with 15% N2 and the rest in methane. This allows you to have a high pressure suction on the refrigeration compressor.