Developed by Merichem Technologies, MERICON^™ I, II, III and Neutralization systems are on-site treatment technologies used in the processing of spent caustics for BOD/COD reduction, odor control and/or pH adjustment.

These solutions employ either wet air oxidation (WAO) or acidification—along with the option of final neutralization—to yield a treated brine effluent stream acceptable for disposal to wastewater treating facilities, evaporation ponds or waterways.

MERICON^™ I Advantages

• Best for sulfidic spent caustics treatment with less demanding COD specs
• Oxidizes sulfides to sulfate and thiosulfate; oxidizes mercaptides to disulfide oils
• Built from stainless steel, reducing capital expenses

Low Pressure Variant

• Operates at 5 barg @ 100°C
• Reduces sulfidic chemical oxygen demand (COD) by 75%
• Uses plant air—no dedicated air compressors required—reducing operating expenses

Medium Pressure Variant

• Operates at 20 barg @ 150°C
• Higher performance. Reduces sulfidic COD by 90-95% along with some organic COD destruction
• Requires dedicated air compressors

MERICON^™ II Advantages

• Effective in treating all mixed refinery and ethylene caustics, including naphthenic and phenolic caustics, to low COD specifications
• Oxidizes spent caustics at high pressures (30-100 barg) and temperatures (200° – 300° C) to reduce COD by 98+%
• Oxidizes all sulfides and thiosulfates to sulfates; destroys phenolics, naphthenics and mercaptides depending on oxidation temperature
• Non-catalyst process
• Minimum contaminates in the final brine

MERICON^™ III Advantages

• Lower cost alternative to WAO for treating sulfidic and naphthenic spent caustics
• Acidifies spent caustics at low pressures and temperatures, releasing most high COD impurities from caustic; reduces COD by 90-95%
• Allows recapture of organic compounds (naphthenates and phenolics) if advantageous
• Flexible operation managing varying compositions and quantities of spent caustic in a timely and responsible manner
• Proven technology for removal of sulfides, mercaptides and naphthenates from caustic streams

MERICON^™ Neutralization Advantages

• Neutralizes spent caustic via acid addition to yield effluents with an adjustable pH
• Lowest cost option for treating spent caustics. Consists of a single vessel
• Best for treating regenerated caustics from REGEN^® systems
• Can be added to any MERICON application or sold as a stand-alone solution where pH adjustment is the only requirement
• Operates at low pressure and temperature
• Variants of this design can rival the performance of MERICON III at a lower cost by removing sulfides, mercaptides and naphthenic acids via acidification followed by stripping using fuel gas or nitrogen and reneutralization – all in a single vessel design