Marine / Propulsion Systems
Marpol waste oil treatment plant
The plant is owned and operated by Oil One, one of the world’s leading oil waste management companies. A centrifugal separator from GEA Westfalia Separator is used to separate the waste, or slop oil, into three streams: water, which is treated before being delivered to the municipal waste, sludge and solids and recovered oil, which has a high commercial value. Prior to separation, the sludge and waste oils need to be pre-treated. Pantechnic Ltd, leading engineering consultants for marine, oil & gas and power applications, provided a tailor-made – Atex zone 1-designed – pre-treatment installation. They also supplied the balance of plant, an odor handling system and a Scada automatic control system.
As trusted partners of Pantechnic, Kelvion, a world leader in heat exchange technology, provided three plate heat exchangers – two for heating up mixing tank content and one for heating product prior to separation. The two 100 m3 capacity pre-treatment tanks are used to:
- Heat the sludge and waste oils to around 70°C for the demulsifying chemicals to be effective
- Mix the product to disperse the demulsifying chemicals
- Prevent the sludge from settling and clogging the tank
Instead of the traditional method of using steam heating coils and mechanical agitators (propeller mixers) to stop the sludge settling, a specially-designed mixing and heating system, via a recirculation loop was installed. A recirculation pump transports the oil, water and solids through a Kelvion Free Flow plate heat exchanger and a manifold with tank mixing eductors.
The modern Free Flow model has constant width gaps which are ideally suited for products containing solids. The main advantage of this unique tank mixing system is that the tank remains clean of any agitators and the absence of heating coils avoids the slop oil “frying” and leaving carbon deposits. Before entering the centrifuge, the product is heated to 98°C, again using a Kelvion plate heat exchanger. The Marpol/Waste Oil Treatmen Plant, the only one of its kind operating in the east Mediterranean, has worked continuously since August 2015 and delivered 40,000 tons of recovered oil per year. Oil One was so satisfied with the performance that they ordered another centrifuge plant, requiring an additional plate heat exchanger from Kelvion.