MEG Reclaiming Process Technology Review.pptx

Summary of current MEG reclaiming process technologies available in the market.
MEG is monoethilene glycol.
MEG injection is widely used in upstream gas production to prevent hydrate formation in wellheads and subsea export pipelines to gas processing plants.

Sources of salts are formation water, pipeline corrosion and well completion fluids. Salts accumulate in the MEG loop. Other contaminants are also present: lube oil, HC, decomposition products.

1. MEG RECLAMATION 22/03/2013

2. MEG RECLAMATION MEG injection is widely used in upstream gas production to prevent hydrate formation in wellheads and subsea export pipelines to gas processing plants . Sources of salts are formation water, pipeline corrosion and well completion fluids . Salts accumulate in the MEG loop . Other contaminants are also present : lube oil, HC, decomposition products . MEG Regeneration = reconcentration to 80-90wt% MEG MEG Reclamation = salt / solids removal

3. MEG RECLAMATION – SALT CHEMISTRY Low soluble salts : Calcium (Ca 2+ ) and other divalent metal cations form low soluble salts (Ca 2+ , Mg 2+ , Fe 2+ , CO 3 2- , CHCO 3 - ) -> Precipitation by pH increase and heating High soluble salts : Sodium ( Na + ) and other monovalent metal cations form high soluble salts ( Na + , K + , Cl - ) -> Precipitation by super saturation ( vacuum flash separation )

4. Semi-continuous slip stream reclaiming PRETREATMENT RECONCEN-TRATION RECLAMATION VACUUM UNIT MEG + salts water Rich salty MEG Lean low salt content MEG Hydro-carbons Conventional reconcentration process at nearly atmospheric pressure The reclaimer operation ( salts removal ) is performed on a slip stream of the regenerated lean MEG - Discontinuous salts removal

5. Continuous slip stream reclaiming PRETREATMENT RECONCEN-TRATION RECLAMATION SOLIDS TREATMENT VACUUM UNIT MEG + low soluble salts MEG + high soluble salts water rich salty MEG lean low salt content MEG salts Hydro-carbons MEG return Chemical injection Conventional reconcentration process at nearly atmospheric pressure The reclaimer operation (high solubility salts removal ) is performed on a slip stream of the regenerated lean MEG - Continuous salts removal

6. Continuous full stream reclaiming PRETREATMENT RECLAMATION RECONCEN-TRATION SOLIDS TREATMENT VACUUM UNIT MEG + low soluble salts MEG + high soluble salts water Rich salty MEG Lean salt free MEG salts Hydro-carbons MEG return Chemical injection The entire feed stream is vaporized Reconcentration and reclamation in one operation Continuous salts removal

7. MEG RECLAMATION – PROCESS COMPARISON Comart Aker Kvaerner Cameron Process configuration Semi-continuous slip stream reclaiming Continuous full / slip stream reclaiming Continuous full / slip stream reclaiming Pre-Treatment HC removal HC removal Low soluble salt removal HC removal Low soluble salt removal Heating Immersed heater bundle MEG r ecycle stream with external spiral plate HE (hot oil) MEG r ecycle stream with external spiral plate HE (hot oil) Removed salt stream MEG recovery - Centrifuge -> Salt cake with max. 10wt% of 97wt% MEG Membrane Filter Press ( Pre-Treatment ) Brine displacement method & Centrifuge ( Reclaiming ) (MEG losses of only 0.03wt% achievable ). -> Spec is salt cake with max 10wt% water and 10wt% MEG

8. NEXT STEPS Step1 Develop the continuous slip stream reclaiming This is more similar to what we are currently doing . Main modifications required : - Add a pretreatment to remove divalent salts - Recycle heating - Continuous solids Treatment - Study the Flash Separator and the brine column Step 2 Develop the continuous full stream reclaiming

9. HOW TO PROCEED? Option 1 – R&D Realization of a pilot plant ( possible cooperation with university to study the chemistry ) Option 2 – Proposal preparation Study the modification to our system while developing a proposal for a real project. Gather some of the missing information from common suppliers Option 3 – Consultants Cooperation with people involved in the development and design of reclaimers operating on a continuous basis Option 4 - …… .