Remove water from wet natural gas to meet pipeline quality specs

Gas Dehydration processes utilize glycol solvents to remove water from wet natural gas to meet pipeline quality specifications or condition the gas for condensate liquids removal. The wet gas is contacted with lean glycol in the contactor tower. The rich glycol then flows to a regenerator, where heat separates the used glycol and the water, regenerating the glycol for re-use. The water vapour exits the top of the regenerator to atmosphere while the lean glycol is recirculated back to the contactor in a recirculating loop.

Through this process, the Gas Plant can achieve:

• A higher gas production quota via reliable treatment of wet gases.
• Process reliability for consistency of production and minimization of downtime.
• Consistent on-spec sales gas quality for water content.
• Minimization of operating and maintenance costs due to fouling and corrosion.

Although this ensures your dehydration reliably meets your daily production quotas and environmental protection needs, there are certain critical challenges faced:

• Foaming and lower production rates and high-water content sales gas due to hydrocarbon liquid and particulate ingression into the glycol loop is a common problem. With effective liquid and solid removal upstream of the contractor, the glycol loop can be protected from foaming and fouling.
  
  KO pots, mesh pads, cyclonic devices and conventional filter-separators may not effectively remove aerosol sized liquid hydrocarbon droplets or fine solids. High efficiency SepraSol liquid/gas coalescers and Medallion HP liquid/gas coalescers provide 99.999% removal at 0.3 microns per the DOP test and 1 ppb downstream per the modified ANSI/CAGI-400-1999 test procedure.
  
  High efficiency coalescers can also be used downstream of the contractor on the dry gas to recover glycol mechanical losses and prevent carryover of glycol downstream.
•  

• Foaming, poor dehydration performance and increased maintenance due to fouling of the contractor, lean-rich exchanger and reboiler from dirty glycol is another concern for Gas Plants. Reduction of gaps in productivity, reliability and gas water content through effective solids control in the glycol loop is one plausible solution.
  
  Solid particle contaminants in glycol systems are mostly very fine corrosion products that may not be adequately removed by filters that exhibit unloading, media migration, channeling or poor sealing. A range of absolute and nominal filter elements is available to reduce suspended solids to less than 5 ppmw, keep the glycol clear in color and reduce related foaming and fouling issues.

Key product lines for you to try out:

• For efficient removal of total hydrocarbon and solids upstream of the loop, SepraSol Plus liquid/gas coalescer and Medallion HP liquid/gas coalescer are highly recommended products focused on improving productivity, reliability and on-spec water content via maintained glycol loop efficiency.

• For efficient glycol recovery and reuse in systems exhibiting high mechanical issues, SepraSol liquid/gas coalescer and Medallion HP liquid/gas coalescer are preferred Pall contactor outlet coalescer products that benefit you through downstream process reliability by elimination of glycol carryover.

• For High filtration efficiency, reproducible performance, easy changeout and long filter life to cost-effectively controlling foaming and fouling. Ultipleat HF filters, Coreless filters, Marksman filters, Profile 2 filters, Nexis filters or a range of Pall FSI bag filters are some of the options you can try today. These are sure to improve productivity, reliability and on-spec water content via maintained glycol loop efficiency.

Return to blog main page