Those facts are implicit in the name of an innovative project – Project Landlord – where CDE Process scope was to head up the project by treating an existing effluent stream by means of softening, ion exchange and membrane technologies for re-use as highpurity boiler feed in the factory.
The client decided to use the term ‘landlord’ because without high purity water, the Synfuels Catalytic Cracker (SCC) could not operate. The SCC is the ‘tenant’, with its operation dependent on the water purification process.”
CDE Process focus was to develop and implement the treatment process of cooling tower blowdown water undergoes initial cold lime softening to reduce the hardness and silica components. From the softening process the water is directed to the submerged Zenon ultrafiltration submerged membranes after pH correction. Here, by means of a vacuum process the permeate is produced with suspended solids removed by a backpulsing and air scouring process.
The process would basically be to what happens when you suck on a straw when drinking a milkshake: “All the suspended matter gets stuck onto the straw and the liquid permeates the straw.”
The water is then treated with ion exchange softeners, to reduce the residual hardness, before going through spiral reverse osmosis membranes. This removes the majority of dissolved solids from the water.
Final purification is provided by the mixed bed demineralisation process. The water is then re-incorporated into the plant’s processes, saving approximately 20 million litres of water a day.
The project became an overall winner of the 2009 Department of Water affairs water conservation and demand management sector awards in the industry mining and power sector category.
Impressive though it is, the project was just one small part of the clients strategic approach to water.
“Going forward, we are ensuring that water considerations are being incorporated into business decision-making particularly in the design and planning for new projects”, comments the client.