logo


LO-CAT® II process for elevated pressure refinery desulfurization

MOL Hungarian Oil & Gas Co. selected a LO-CAT® II Desulfurization System for operation at its production unit in Szeged, Hungary. The unit was custom-designed for direct treatment of sour associated and process gas streams at elevated operating pressures and relatively high CO2 partial pressures.

Recycled process gas and associated gases are collected from the oil fields around the plant and transported via a mixed-phase pipeline, followed by separation in a bank of gas-liquid separators. The associated gas is combined with the recycled processgas stream, compressed to 16–18 barg, and sent to the LO-CAT II. Several technological challenges arose during the project due to process restrictions. Excessive liquid entrainment occurred whenever sour-gas flow exceeded 60,000 normal cu m/hr, so a new, larger separator was retrofitted into the plant. As a result, gas flow up to 80,000 normal cu m/hr was achieved. After startup, it was discovered that considerable condensate was frequently introduced from the process gas and the operation of the two-phase oil-gas pipeline. The presence of excessive liquid hydrocarbons in the LO-CAT II unit caused foaming and floating sulfur. The sour-gas transfer line was modified by retrofitting a simple drainage boot to catch the condensate.

Later, a larger knockout pot replaced the original one, reducing the foaming and floating sulfur and increasing the unit’s effectiveness. The unit’s catalyst recirculation pump was replaced when the LO‑CAT II capacity exceeded the pump’s design. A new pump with the required capacity was installed and continues to operate successfully. The unit operates with a gas flow of 60,000 to 100,000 normal cu m/hr, with a sulfur load of about 50 kg/day (due to low H2S concentration in the gas). Current H2S removal efficiency is 90%, producing gas suitable for pipeline quality.

DOWNLOAD LITERATURE

View More

  • Caustic services

    For 65 years, Merichem has provided environmentally responsible handling of spent caustics and other secondary materials that result from refining, natural gas and petrochemical processing. Merichem Caustic Management Services safely transports your secondary materials to Merichem manufacturing facilities ...

  • LO-CAT - the green solution to sulfur recovery

    The LO-CAT process, available exclusively from Merichem, is a patented liquid redox system that uses a proprietary chelated iron solution to convert H2S to innocuous, elemental sulfur. It does not use any toxic chemicals and does not produce any hazardous waste byproducts. The environmentally safe catalyst ...

  • FIBER FILM - Non-dispersive hydrocarbon treating

    Introduced in 1974, the FIBER FILM® Contactor is the foundation for a variety of caustic, amine and acid treating processes. Merichem processes using FIBER FILM Contactors have been licensed worldwide and successfully applied to treating problems throughout the hydrocarbon processing industries. ...

  • NAPFINING™ Naphthenic acid removal

    NAPFINING™ technologies were first licensed in 1977 and to date Merichem has granted 78 unit operating licenses world-wide. The non-dispersive FIBER FILM® Contactor achieves reduced capital expenditure and less plant space requirements compared to most treating alternatives, making NAPFINING™ ...

  • THIOLEX™ caustic extraction of acid gas

    THIOLEX™ technology was rst licensed in 1980 and to date Merichem has granted 224 unit operating licenses world-wide. The non-dispersive FIBER FILM® Contactor achieves reduced capital expenditure and less plant space requirements compared to most treating alternatives, making THIOLEX™ ...

  • MERICON™ spent caustic processing

    MERICON™ technology provides an on-site solution for the processing of spent caustics to reduce their biological oxygen demand (BOD) and chemical oxygen demand (COD), control odor, adjust acidity and destroy phenolics. Merichem Company’s patented technology produces a neutral brine effluent ...

  • MERICAT™ H2S & mercaptan sweetening

    MERICAT™ technologies were first licensed in 1977 and to date Merichem has granted 194 unit operating licenses world-wide. The non-dispersive FIBER FILM® Contactor achieves reduced capital expenditure and less plant space requirements compared to most treating alternatives, making MERICAT™ ...

  • LO-CAT® process for waste water treatment plants

    In 1980, Los Angeles began exploring alternatives to control the H2S concentration in the digester gas produced at the Hyperion Waste Water Treatment Plant (WWTP), which treats nearly 420 MGD, wastewater generating over 475 tons of raw sludge per day. The digester gas H2S concentration had to be controlled ...

  • LO-CAT® process for sulphur recovery / odor control

    The LO-CAT® Hydrogen Sulfide Oxidation System provides economical H2S removal to solve odor problems quickly and effectively. LO-CAT achieves H2S removal efficiencies exceeding 98%. The system also eliminates costly once-through chemicals, offers unique mobile bed contacting material, and reduces ...

  • H2S oxidation system for refinery desulfurization

    The European Union has recently promulgated new directives reducing the amount of residual sulfur in diesel and gasoline. These directives are requiring European refineries to revise both their fuel production processes and their downstream desulfurization strategies. One affected refinery is Irish Refining ...