Aqua Dynamics

Catalytic Wet Air Oxidation (CWAO)

BGAO

CWAO plant operating at oil refinery

The Aqua Dynamics CWAO is a cost effective process for treating industrial effluents for which conventional chemical, physical and biological processes are inadequate – particularly spent caustic effluent from oil refining and the production of petrochemicals, gas, coal gas, plastics and pharmaceuticals.

The process, developed for over twenty years for coal gasification and oil & gas applications, is a substantial improvement over conventional wet air oxidation technologies, incorporating the use of proprietary heterogeneous catalysts. Air, as the oxidant, is mixed with effluent and passed over a catalyst at elevated temperatures and pressures.

CWAO converts dissolved and suspended organic components to carbon dioxide and water. Oxidisable inorganic components such as ammonia and cyanides are also readily treated. Reductions of Chemical Oxygen Demand up to 99.8% can be achieved.

CWAO is designed for unattended operation and has a small plant footprint.

CWAO units are now being selected for new build oil & gas applications and power stations.

Contaminant reduction of greater than 99.8% can be achieved using the CWAO process, as compared to the leading conventional WAO processes, which only achieve contaminant reductions between 75-90%. CWAO allows the treated product to be discharged directly into the environment or recycled.

Tailored catalysts and system design of CWAO result in considerably lower temperature and pressure operations and running costs than those required for conventional wet air oxidation processes.

Existing plants can be retrofitted to operate as CWAO plants resulting in increased capacity, improved effluent treatment and lower overall operating costs.

CWAO Industrial applications

Many industrial processes produce effluents that cannot be treated fully or economically by conventional technologies.

Aqua Dynamics CWAO process enables operators to meet the most stringent environmental regulations and improve the sustainability of operations.

CWAO provides a very high level of treatment, enabling disposal of the effluent directly to the environment, or for recycling (for example, treated produced water may be used for irrigation).

  • Oil Refinery & Petrochemical Operations

    Oil refinery and Petrochemical operations

    CWAO has been successfully employed at one of the largest oil refineries in Europe for the treatment of spent caustic effluents from the fluidised catalytic cracker and direct coking plants. Enabling the spent caustic to be passed to the site’s waste water treatment plant, COD levels are reduced from 150,000 mg/l to less than 500 mg/l, and total sulphide (including polysulphides) from up to 20,000 mg/l to less than 2 mg/l.

  • Gas Processing

    Gas processing

    Successful trials have been carried out to treat carcinogenic and toxic components in gas processing effluents from amine-based CO2 removal plants, gas field produced water containing hydrate and corrosion inhibitors and dehydration plants.

     

  • Coal Gasification

    Coal Gasification

    Effluents from coal gasification, including synthetic natural gas production and conventional town gas manufacture, are highly concentrated and contain toxic and carcinogenic components, resembling refinery and petrochemical “spent caustics”. CWAO can fully treat the effluents to enable them to be discharged to the environment.

  • Agriculture

    Agriculture

    CWAO can treat pesticides and herbicides to achieve parts per billion discharge limits.

    CWAO can treat produced water for irrigation purposes at a comparable cost to evaporation lagoons with none of the associated toxic solid wastes and harmful air emissions.

  • Plastics, Chemicals & Pharmaceuticals

    Plastics, Pulp and paper industries, Pharmaceuticals

    CWAO has been developed specifically for industrial effluents that cannot be adequately treated by conventional processes. Chemical industries can rely on Aqua Dynamics to create tailored solutions enabling them to cheaply and efficiently treat industrial effluent for safe discharge to the environment.

  • Marine Effluents

    Marine effluents

    A long-term evaluation programme has been successfully completed, to demonstrate the CWAO process for use in submarines and surface ships.

    Key advantages of CWAO in a marine context are the small plant footprint, complete treatment of effluents in one step, robustness and automation and the ability to recover and stabilise the carbon dioxide produced.

Request CWAO Factsheet