(AEP) Advance Exhaust Gases Cleaning Plant

Services Details

Design to remove SOX from exhaust gas stream on ships
Dual Water scrubber system is based on exhaust gas cleaning with seawater in open loop utilizing the natural alkalinity found in seawater.
The system can also be operated using fresh water together with added alkali in a close loop mode, it is also possible to combine these two methods in a hybrid mode.

In all operating modes the scrubbing water is released back to the sea after it has been processed in water treatment units. However, in close loop operation, the scrubbing water is recycled several times within the system and the amount of effluent flow of closed loop operation, a zero discharge mode, where no discharge to sea exists, is possible by directing the effluent flow to a holding tank.

By- passing of the scrubber is possible with a by- pass damper. The by-pass arrangements permit the operation of the engines when the scrubber is not needed.

The exhaust gas enters the scrubber through the radial inlet and exits the scrubber through the vertical outlet at the top. In the scrubber, the SOX components are washed from the exhaust gas flow with scrubbing water (FW or SW). Before the cleaned exhaust gas exits the scrubber it passes through droplet separators where entrained water droplets are removed from the gas. Each scrubber is equipped with electrical exhaust gas fan with variable speed drive (VSD). Fan is located above the scrubber unit. The backpressure of the scrubber unit is totally compensated by the fan, this minimizing the exhaust gas backpressure.

Scrubbing water, seawater or freshwater with alkali added, is sprayed to the upper and lower sections and drained through the bottom of each section. The scrubbing water also absorbs heat and other components from the exhaust gas stream. To minimize the environmental impact, the effluent is processed and the quality monitored before releasing the cleaned effluent to sea. In open loop, the amount of effluent is equal to the amount of seawater used, while in close loop system, the amount of effluent depends on the amount of SO2 being absorbed.

Guidelines for exhaust gas-cleaning systems.

• IMO Marine environmental protection committee has adopted (guidelines for exhaust gas cleaning systems), IMO resolution MEPC. 184(59), in July 2009.
• The guidelines include e.g. rules for certification, verification and documentation of scrubbers and regulations for monitoring and discharge of wash water.
• The wash water discharge criteria set to quality requirements for the concentration of PH, PAH turbidity, nitrates and additives. Also wash water monitoring and recording requirements are specified in the guidelines.
• Residues generated by a scrubber should be delivered ashore to port facility.

Such residues are not allowed to be discharged to sea or incinerated onboard.

Approval of Scrubber.

Statutory scrubber documentation during certification.

• International air pollution prevention (IAPP) certificate.
• SOX emissions compliance plan for ship (SECP)
• EGCS-SOX technical manual (ETM)
• SOX Emissions compliance certificate (SECC)
• EGCS-SOX record book
• Onboard monitoring manual (OMM)

Classification.

• Scrubber components and systems.
• Safety concept.