AB Separator

AB Separator
Kigsz · CC BY-SA 4.0 · source
Name	AB Separator
Caption	Industrial AB Separator unit
Inventor	Telefon AB L.M. Ericsson?
Introduced	20th century
Application	Liquid-liquid separation
Industry	Petrochemical industry, Oil refinery, Water treatment

AB Separator

The AB Separator is an industrial liquid-liquid separation device used to remove dispersed phases from continuous phases in process streams. It has been employed in Petrochemical industry installations, Oil refinery operations, and municipal Water treatment facilities where compact footprint, ease of maintenance, and reliable phase disengagement are required. Developed and refined through cross-industry practice, the AB Separator integrates principles from classical coalescers, gravity settlers, and vortex separators to deliver controlled separation performance.

Overview

The AB Separator functions by promoting coalescence and phase disengagement between immiscible liquids under controlled hydraulic and geometric conditions. Operators in Shell plc, ExxonMobil, BP, Chevron Corporation, and TotalEnergies SE installations have adapted AB Separator variants to treat feeds from units such as distillation column overheads, hydrotreating effluents, and produced water from offshore platforms. Engineering firms including Bechtel Corporation, Fluor Corporation, KBR, Inc., and Jacobs Engineering Group specify AB Separators where space constraints and modular construction are prioritized. The design draws on research reported at conferences organized by AIChE and SPE and standards discussed by ASME and API committees.

Design and Construction

Typical AB Separator geometry includes a cylindrical or rectangular vessel with an internal energy dissipation zone, a coalescing medium, and a quiescent separation zone. Materials selection often references suppliers such as DuPont and ArcelorMittal for corrosion-resistant alloys, with linings specified by Saint-Gobain or 3M for aggressive service. Internals may incorporate structured packings akin to those from Sulzer Ltd. and demisting elements inspired by designs used in air separator technology. Fabrication is contracted to yards with experience building pressure-retaining equipment, including Samsung Heavy Industries, Daewoo Shipbuilding & Marine Engineering, and Wärtsilä. Instrumentation integrates transmitters from Emerson Electric Co. and flowmeters from Siemens or Honeywell International Inc. to monitor level, temperature, and differential pressure. Design calculations reference methodologies published by API separators committees and case studies in journals circulated by IChemE.

Operation and Performance

Performance metrics for AB Separators include separation efficiency, residence time, throughput, turndown ratio, and pressure drop. Operators calibrate demisting and collection using test data from pilot rigs at research centers such as National Physical Laboratory (United Kingdom) and SINTEF laboratories. Onshore terminals operated by Shell plc and ExxonMobil report achieved droplet size removal consistent with predictions from population balance models used in studies at Imperial College London and Massachusetts Institute of Technology. Start-up and transient behavior is influenced by feed temperature, interfacial tension modifiers (e.g., surfactants supplied by BASF SE), and shear introduced by upstream pumps manufactured by Sulzer or KSB. Control strategies often employ logic developed in ABB and Schneider Electric programmable controllers and model-based tuning from research groups at Georgia Institute of Technology and University of Cambridge.

Applications and Industries

AB Separators see broad use across sectors including Petrochemical industry, Oil and Gas Industry, Chemical industry, Marine industry, Power station feedwater treatment, and municipal Water treatment works. In offshore-produced water treatment on platforms developed by Transocean and Statoil (Equinor) projects, AB Separators handle oil-in-water emulsions before discharge governed by permits modeled after guidelines from OSPAR Commission. Refinery process units at ExxonMobil Baton Rouge Refinery-scale facilities apply AB Separators to light hydrocarbon-water separations, while chemical plants operated by Dow Chemical Company and DuPont use them to recover solvents. AB Separators are also integrated into closed-loop cooling water circuits at facilities built by General Electric and Siemens Energy.

Maintenance and Safety

Maintenance protocols emphasize access for inspection, internals removal, and non-destructive examination per standards set by American Petroleum Institute and ASME Boiler and Pressure Vessel Code. Turnarounds coordinated by contractors such as SNC-Lavalin and McDermott International include cleaning of coalescer media, replacement of demister pads, and verification of level-control instrumentation supplied by Rosemount (Emerson) or Endress+Hauser. Safety practices align with procedures promoted by International Labour Organization and OSHA for confined-space entry and hot-work permits; emergency response planning references guidance from National Fire Protection Association standards and training programs offered by International Association of Oil & Gas Producers.

Environmental and Regulatory Considerations

Discharge quality from AB Separators must meet regional regulatory limits established by authorities such as the Environmental Protection Agency in the United States and the European Environment Agency in the European Union. Compliance for produced water is often demonstrated against guidelines from the OSPAR Commission and national regulations enforced by agencies like Norwegian Environment Agency for offshore fields developed by Equinor. Environmental impact assessments for installations specify monitoring programs that reference analytical laboratories accredited under schemes run by UKAS or ANSI National Accreditation Board. Lifecycle considerations include end-of-life recycling of metallic shells with firms in the scrap metal trade and management of coalescer media waste per hazardous-waste rules administered by EPA-equivalent bodies.

Category:Separation processes