Abstract
Feed gas from KLD fields has mercury content with around 125 micro g/Nm3. Mercury Removal Unit (MRU) will be designed to reduce the mercury content well below 5.5 micro g/Nm3 and meet export spec. The mercury removal unit (MRU) is located upstream of GSU, unlike other PDO plants as well as other places in oil& gas processing facilities where MRU is located downstream of GSU. The optimized location of MRU is to avoid contamination of GSU equipment with high Hg content.
Before entering the mercury bed the gas is heated approximately 10 °C above its water and HC dewpoints in the superheater to avoid liquid formation in the mercury bed due to pressure drop across the adsorbent. The superheater upstream of MRU ensures that gas to MRU is at single vapour phase. However, due to hydrocarbon carryover from the inlet KOD which mostely heavy components will increase significantly the gas dew point and thus higher superheater duty.
As a further optimization in order to remove liquids carryover and reduce the superheater duty, filter coalescer is added upstream of MRU superheater.
This paper demonstrate how this new approach and lineup was engineered overcoming various challenges.
