Some comments regarding the system are as follow:

• The NF flux varies considerably. It appears that an average flux of 30 Lmh is reasonable at 50°C and 12 bar. These operating conditions are gentle, and the probability of mechanical membrane damage is quite small. It is most likely that flux stability can be improved by increasing the cross flow. This is one of the parameters that will be investigated on the full-scale system.

• Cleaning every 3 to 4 days is recommended in order to prevent the flux from decreasing too much.

• The concentration ratio is close to 4, meaning that 75% of the feed becomes permeate while the remaining 25% are discharged as concentrate.

The NF shall enable the factory to recycle much more water and therefore consume less fresh water. The bigger the NF system, the more water can be recycled. The full-scale plant will be used to investigate the relationship between water recycling and the impact on the water composition inside the paper machine. UF will make it possible to reduce fresh water consumption from 10m3 per ton pulp to 5m3. NF will make it possible to reduce fresh water consumption to 2m3 per ton pulp possible that is equal to zero discharge. Both are major achievements in water conservation.

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