Overview
Multi-stage flash (MSF) and multi-effect distillation (MED) plants operate at high brine temperatures where scale formation, foaming, and corrosion are the primary threats to production capacity and heat transfer efficiency. In LNG and petrochemical facilities with co-located desalination, treatment chemistry must be compatible with both the thermal process and downstream use of the distillate as boiler makeup or process water.
Antiscalants
Threshold inhibitors that prevent precipitation of calcium carbonate, calcium sulphate, and magnesium hydroxide on heat transfer surfaces at elevated brine temperatures.
- Polymeric (Polycarboxylic)
- Phosphonate-based
- High-temperature Polymer Blend
Antifoams
Control foam formation in flash chambers and evaporators caused by organic contamination and high Total Dissolved Solids in recirculating brine.
- Silicone-based Antifoam
- Polyglycol-based Antifoam
Corrosion Inhibitors
Protect carbon steel and copper alloy components from acidic conditions and dissolved gas attack in brine heaters, tube bundles, and condensers.
- Acid Dosing (H₂SO₄ for pH control)
- Benzotriazole (copper alloy protection)
Oxygen Scavengers
Remove dissolved oxygen from feedwater and brine to prevent pitting corrosion on carbon steel surfaces throughout the desalination train.
- Sodium Sulphite
- Hydrazine alternative