3 replies to this topic

[Poe]

Dear Friends,

 

I am looking about information on how calculate de rate of  injection of Kinetic Hydrate Inhibitor (KHI) which weaken the structure of gas hydrates.

 

Please if anyone could share their experiences calculating or estimating the rate of injection on production system Natural Gas.

 

 

thanks in advance

[Steady]

For natural gas hydrate inhibition, you could use hydrate formation utility that is built in HYSYS  or refer to jmcampbell free guide available on the internet - http://www.jmcampbel...rate-inhibition

 

It is more of an iterative approach that you need to follow to achieve the required hydrate formation temperature in HYSYS utility. Make sure you use the appropriate thermodynamic package.

[paulhorth]

HYSYS can estimate the hydrate formation temperature of a wet gas stream, but it is of no help in estimating the dosage rate for Kinetic Hydrate inhibitors. These chemicals (KHIs) work in a different way to conventional inhibitors, and the concentrations required are much lower. On a recent project we were going to use a concentration of 0.75% wt KHI to water, following study and advice from the chemical vendor. This compares to 30% - 40% typically required with methanol or MEG.

 

You need to contact a chemical vendor to obtain the recommended dosage rate for your fluid and your temperatures.

You need to be able to measure or estimate the flow of water in your system and adjust the injection rate to match. The chemical is expensive so excessive injection should be avoided.

 

I attach an extract from a report that I wrote to assist operators with the KHI dosing system on this recent project. Unfortunately, i do not have any operating data for this project so I cannot confirm if the KHI worked at the recommended concentration.

 

 

Paul

 

Attached Files

•  KHI report extract.docx   16.33KB   20 downloads

[Steady]

yes, i agree with paul..

my apologies, i had the conventional thermodynamic inhibitors in my mind while replying to your query.

For low dosage KHIs, hysys is not an option.