Glycol dehydration has stood the test of time as the preferred way to remove water from natural gas. The design of glycol systems
is unique for each application as the overall package design will vary to meet the specified moisture content of the gas at the process conditions.
Ethylene glycols (mono, di and tri ethylene glycols)are commonly used for dewatering applications due to their ability to absorb water (hygroscopic liquid)and leave pipelines etc dry ready for carrying oil, gas, or produced fluids. GLYCOL WATER mixes (supplied in all ratios up to 80% MEG) can be used as a cheaper alternative to 100% Glycol, dependent on the amount of water expected in the line.
ETHYLENE GLYCOLS are also commonly used to remove water from gas streams, which significantly reduces the risk of hydrate formation. In addition glycol can be used to remove existing hydrate deposits within a system
KASRASVAND custom designs and builds each system as a complete turn-key package with particular emphasis given to:
- Discharge gas moisture content
- High gas dehydration capacity
- Minimum glycol losses
- Minimum power consumption
- Optimum plant efficiency and design integrity
- Compliance with SHEQ requirements
KASRASVAND DETAIL PROCESS:
Wet gas to be dehydrated enters the glycol contactor is brought into close contact with the glycol by means of bubble cap trays. Bubble cap trays have become the standards as this type of trays hold its liquid seal both at the low liquid loadings inherent in a glycol unit and under turn down conditions as regards gas flow rate. (Low liquid loadings are a characteristic of the glycol dehydration process since the glycol circulation is a foundation of the water content of the gas being dehydrated rather than the total gas stream.
- The number of trays used in the glycol contactor as well as the glycol loading and glycol concentration are determined according to the degree of dehydration required. The glycol loading and concentration are established the duty for the glycol regenerator is established
- The bubble cap tray used in our Glycol Dehydration unit employs a bubble cap specifically designed for the purpose and its performance characteristics such as tray efficiency are well proven so that dehydration performance can be confidently predicted and guaranteed.
- A glycol regenerator can be used in conjunction with a glycol contactor when the glycol circulation rate and concentration are determined by the glycol contactor design or in conjunction with dehydrate inhibition units when the duty is set by th hydrate inhibition requirements
- In the case where a glycol contactor is used, tri-ethylene glycol is the most suitable type of glycol, whereas for dehydrate inhibition schemes mono-ethylene glycol is more suitable. Tri-ethylene glycol is normally regenerated to greater than 99% concentration for return to the glycol contactor whereas mono-ethylene glycol is generally regenerated to a concentration within 60-80% level.
Natural gas is dehydrated to avoid corrosion or pipeline plugging due to ice or hydrate formation. The traditional way to dehydrate natural gas is by absorption in triethylene glycol (TEG). Normally, the water is removed from the (rich) glycol by distillation, and then the regenerated glycol is recycled back to the absorption
KASRAVAND custom designs glycol regeneration packages to recondition glycol used for processes such as hydrate inhibition and gas dehydration.
The formation of gas hydrates can lead to significant production and safety issues in drilling operations as the solid hydrate material can plug flow lines and equipment.
Therefore, to supress the formation of hydrates glycol, typically monoethylene glycol (MEG), is injected into the well
The MEG that returns from the well is termed Rich MEG and contains significant quantities of water, dissolved salts and other contaminants. KASRAVAND custom designs glycol regeneration systems to strip the absorbed water, salts, and contaminants from the Rich MEG to produce Lean MEG that can be recycled to storage tanks and production wells.
After absorption, soluble gases like CO2 are first released from the glycol in a flash tank, and then the glycol is heated before it flows to a distillation (regeneration) column. The regeneration column has a reboiler and a condenser. Regeneration of the glycol by atmospheric distillation at about 200 °C achieves about 1 weight % water in regenerated glycol. The regenerated glycol is pumped back to the absorption column and heat exchanged against the rich glycol and cooling water.
The simplest way to reduce the water content in the glycol, is to introduce stripping gas to the regeneration column The stripping gas can be nitrogen, recycled natural gas or flash gas (from the flash tank after the absorption column). Traditionally, the stripping gas is added to the liquid in the reboiler. The additional feed of stripping gas compared to the HYSYS simulation .(The apparent feed of stripping gas to the middle of the column is due to the HYSYS graphics. The actual stripping gas feed is to the reboiler.)
And so on other process will be done (incase needed more information please contact to our technical department .