Adding chlorine to cooling water in short controlled bursts is a highly effective method to prevent mussels from colonizing the cooling water systems at power plants and other industrial installations. Ten years after the first implementation of Pulse-Chlorination at a Dutch power plant, this Best Available Technology - developed by KEMA - has proved to be a very cost-effective chlorine dosing method, from both an environmental and economical point of view. After successful tests carried out at two Dutch Shell plants, KEMA is starting the test for implementation of this technology at the Shell Pulau Bukom refinery in Singapore.
The colonization of cooling water systems by mussels and other macro fouling species is a major problem at power plants and other industrial sites. Without effective anti-fouling measures, the pipe work, condensers and heat exchangers soon are lined with the organisms, which reduces production capacity and increases the risk of leakages due to pitting corrosion. To investigate the technical and operational possibilities, Shell Eastern Petroleum Pte Ltd. (SEPL) has contracted KEMA for its services regarding optimization of chlorine dosing at its refinery at Pulau Bukom in Singapore. The main goal is to obtain the optimal dosing regime according to the Pulse-Chlorination principle, a method combining optimal fouling control with minimal chlorine discharge, while retaining safe plant operation. The optimal dosing regime will be used to design a new chlorination plant.
SEPL Pulau Bukom
Shell Eastern Petroleum Pte Ltd. (SEPL) operates the largest Shell refinery in the world in terms of crude distillation capacity at Pulau Bukom, an island located 6.5 km southwest of Singapore. It is the first refinery in Southeast Asia to receive ISO 14001 certification. The main chemicals produced are propylene, chemical solvents and hydrocarbon solvents. The refinery consists of eight main process installations. Pulse-Chlorination will be introduced in three phases. At the end of 2008 an inventory visit and study was carried out. Mid-January 2009 the tests on site were started up, using the KEMA Mobile laboratory.
Pulse chlorination
KEMA has developed the Pulse-Chlorination method to substantially mitigate the problems of effective fouling control as well as the environmental impact of the discharge of chlorination residues. Essentially, Pulse-Chlorination involves introducing chlorine at intervals and in concentrations adapted to the colonization behavior of the mussels. The method has been used successfully in operation at power plants and industrial sites in the Netherlands, Australia, Korea and the Middle East for several years now, with chlorine consumption rates as low as 50% compared with the previous regimes.
Information
More information on the project at SEPL can be obtained at contact.tos@kema.com or from Mr Peter Oortwijn of the Pulau Bukom SEPL Refinery.
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