UECC seeks to end the burning of separated oil

Incinerators? days are numbered. So says Jeff Argent, environmental projects manager at Norwegian-headquartered roro operator United European Car Carriers (UECC).

The pressures of environmental stewardship – to reduce air borne emissions – are likely to lead international regulators to outlaw the burning of waste oil produced during the treatment of bilge water. In addition, many ship operators? customers want to be seen to be employing environmentally friendly companies.

The outlawing of incineration would leave ship operators like UECC with two alternatives for separating oil from bilge water: employing biological methods of separation; or non-biological treatment. Both methods require that waste sludge produced by separators is held in a tank for later disposal ashore, while the separated water can be disposed of overboard. UECC is currently experimenting with both techniques, in order to move away from the need to burn waste oil and take the oil content of bilge water for discharge below 15 ppm.

Non-biological

The company will shortly have a Marinfloc flocculent unit and sludge de-watering device retrofitted onto the 9,693g Swedish-flag vessel, Autorunner. This will replace the ship?s existing conventional system for the separation and disposal of oily bilge water. Earlier this year it had the same Swedish-designed equipment retrofitted to its other Swedish-flag ship, Autoracer, a sistership of Autorunner.

Both ships? Swedish crew are familiar with the operation of the proven system, explains Argent. The flocculent unit treats the bilge water. Oil and other impurities removed are channelled into the sludge tank for later disposal. Water removed by the de-watering device from sludge in the holding tank is channelled into the bilge water holding tank.

Bugs eat oil

In May, UECC had a less-proven biological system fitted to another ship, the 11,591g Autopremier. EnSolve Biosystems PetroLiminator 100 oily water separator was installed during a drydock in Poland. It is the first European application of the US-company?s biotechnology-based system, although it is being used on a number of Great Lakes carriers in North America.

For now, Autopremier?s original Hamworthy separation system, including its incinerator, is being retained and used. The two systems are completely separate apart from the suction line, explains Argent. When UECC is completely happy that the PetroLiminator works in all possible operating scenarios (including establishing whether the bugs that eat the oil get seasick or not), thus making the original system obsolete, it will consider removing the equipment.

“The [PetroLiminator] system will allow us, in confined waters, to recirc[ulate] bilge water back into the bilge tanks,” he says. “It is forever cleaning what is in the bilge tanks. In unconfined waters we can put [the treated] water overboard.”

PetroLiminator contains bugs – non-pathogenic bacteria – that absorb the oil and other hydrocarbons contained in the bilge water. It works 24 hours a day and in its first month of operation, says EnSolve, treated for discharge over 12,000 gallons (45m3) of bilge water. Argent says engineers? time is freed up compared with running a conventional bilge water separator.

UECC has ISO 14000 environmental management certification. The replacement of the conventional oily water separators is only partly related to its environmental commitments under this certification though. “Its great to be altruistic, but its to save money as well,” admits Argent.