A glycol dehydration unit helps to remove water from natural liquids and gas generated from a reservoir. In a glycol dehydration unit, the glycol fluid must be clean and as close to its original, pure state as possible. Contamination due to hydrocarbons and other particulates reduces its ability to absorb water from the gas stream. It also adversely impacts the performance of the glycol regeneration process. This is why filters are typically used to remove the impurities. Activated carbon filter and a particulate filter are the two common types typically used in the device. Read on to learn more about them.
Glycol Particulate Filter Used in a Dehydration Unit
As the name indicates, this filter helps to remove any solids that the glycol picks up from the trays and contact with the gas stream. It is the first filter the glycol comes into contact after leaving the glycol contactor. A particulate filter is installed between the activated carbon filter and the glycol reboiler accumulator coil. It is a sock or pleated cartridge type filter that has a simple operation.
Indication of Poor Performance of Glycol Particulate Filter
When the differential pressure increases across the filter, it is a sign that it is loading up with solids. Thus, it is essential to regularly monitor it to avoid plugging it off and blocking the flow of glycol.
Glycol Carbon Filter for a Dehydration Unit
Activated carbon is a type of treated or processed carbon that has small pores to help increase the area available for the adsorption process. Due to the high microporosity, the surface area of one gram of activated carbon is more than 32,000 sq ft or 3,000 m2.
Glycol carbon filters are installed between the glycol reboiler still column and the glycol particulate filter. The activated carbon is used to remove the contaminants that were in an emulsion or solution form in the glycol. Heavy hydrocarbons, as well as emulsified contaminants or other liquids in the system, are removed by adsorption.
Activated carbon filters are of two styles:
- Cartridge – for low flow rate systems
- Bulk Bed – for higher liquid flow rates
Indication of Poor Performance of Glycol Carbon Filter
Monitoring the canister’s differential pressure does not solely indicate the performance of the carbon filter. This is what makes it different from the operation of the particulate filter. Fluid samples must be drawn from the system and compared to the original lean glycol solution. Clean glycol should only be a slight discoloration from the original solution. Cloudy or dark glycol means that the activated carbon needs replacement or regeneration. The high differential pressure across the activated filter canister indicates that it is filling with contaminants, indicating that the filter is not working correctly.
The high differential pressure across the glycol contactor is another indication of inadequate filter performance. This may be a result of glycol foaming due to contamination. The final indication of poor glycol solution cleanliness is when the glycol dehydration unit cannot remove the water required to meet the pipeline water content specification.
We Deliver Reliable Oil & Gas Equipment
Glycol filters are easily installed, and when correctly maintained, become the most economical method of purification of a glycol system. Crimtech Services Ltd. has more than 25 years of experience in fabrication, engineering, and design services to the oil and gas industry. We have the resources and expertise to troubleshoot and optimize glycol dehydration units. We also carry an extensive inventory, including wellsite separators, pressure vessels, glycol line heaters, glycol dehydrators for sale.
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