cryogenic unit n.
Skip this Video
Loading SlideShow in 5 Seconds..
Cryogenic Unit PowerPoint Presentation
Download Presentation
Cryogenic Unit

Loading in 2 Seconds...

play fullscreen
1 / 7

Cryogenic Unit - PowerPoint PPT Presentation

  • Uploaded on

Cryogenic Unit. Recovery of NGL’s. “ Chillin ”. Extreme cooling of the inlet gas is necessary prior to entering the Demethanizer (cryogenic tower) How is this accomplished? Two inlet gas Routes: 1) 1 st gas/gas exchanger 2) Side Exchanger 1. 1 st Gas/Gas Exchanger.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Cryogenic Unit' - bridget-ireland

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
cryogenic unit

Cryogenic Unit

Recovery of NGL’s


Extreme cooling of the inlet gas is necessary prior to entering the Demethanizer (cryogenic tower)

How is this accomplished?

Two inlet gas Routes: 1) 1st gas/gas exchanger 2) Side Exchanger

1. 1stGas/Gas Exchanger.

-Inlet gas travels through this exchanger on the tubesidepromoting cooling of the gas before entering the 2nd Gas/Gas Exchanger. 

-Notice that another colder gas returning from the side exchanger is used to further cool our gas stream.

2. Side Exchanger

-This inlet gas flow is cooled by the natural gas liquids within the demethanizer tower (cryogenic tower) operating at extremely cold temperatures (- 160 C).

-Due to the very low operating temps of the tower we are able to cross exchange with the temperatures in that column. 

-Allows inlet gas to leave at a much lower

Causes liquids in the side exchanger to be heated.(Thermodynamics anyone?)

are you kidding me cold
Are You Kidding me Cold

Inlet gas streams from the 1stGas/Gas exchanger and Side -Exchanger rejoin before streaming through the 2nd Gas/Gas heat exchanger.

2nd Gas/Gas Exchanger will further cool the gas stream. Once again our gas stream is on the tubeside.

- Notice that in both Gas/Gas heat exchangers that the residue gas from the top of the demethanizer tower provides the cooling in both of them. 

-Inlet gas comes out of the 2nd Gas/Gas heat exchanger at a very cold temperature causing NGL’s within the gas to condense and end up in the inlet separator.

inlet separator turbo expander
Inlet Separator/Turbo-Expander

The purpose of the inlet separator is to trap condensed liquidsfrom the gas stream and prevents them from entering Turbo-Expander.

NGL collected here are routed to the cryogenic tower

The Turbo-Expander is designed to sharply drop the pressure of vapors which will cause an extreme temperature decrease of the gas stream.

Cold gas stream enters the cryogenic tower

The Turbo-Expander provides a secondary service as well: it is also performing work. 

Notice that as the turbo-expander turns it causes the compressor to turn. This provides rotational energy for the compressor. 

demethanizer cryogenic tower
Demethanizer/Cryogenic Tower

The function of demethanizer tower is to heat up the inlet gas feed just enough to release methane and condense the remaining NGLs. 

Areboilerlocated at the bottom of the tower provides the heat needed to release methane from the rest of the NGLs. 

follow the methane
Follow the Methane

Residue (methane) gas leaves the top of tower

-Used as coolant in gas/gas exchanges (shell side). This in turn heats up the methane.

-Methane enters expander-compressor increasing the pressure of the methane allowing it to be sent down the sale’s pipeline.

*Remember that the compressor is able to do work because the turboexpanderprovides rotational energy.No other drivers! Very efficient!

-Methane leaving the compressor enters a condenser.

Some methane liquifys and collects in the accumulator. 

The liquid methane returns to the tower as reflux for improved product.

-The remaining methane travels to arecompressorfurther increasing the pressure of the gas.

-The residue gas also travels through the reboiler providing heat to the demethanizer tower and also cooling itself down further.

-Finally, Residue gas flows through a cooler before going to the sale’s pipeline. 

ngl s
  • The NGL’s are going to leave the system too.
  • NGL’s exit the bottom of the reboiler.  Because they were not vaporized by the column.
  • These natural gas liquids (demethanized product)and are an excellent revenue source.
  • Often times, the NGL’s continue on to a fractionation unit where they can be separated individual components such as ethane, propane, butane and even natural gasoline.