Table 2
Chemical cleaning in place (CIP) procedures applied at the three locations studied.
| Location | Location I Sas van Gent, Netherlands | Location II Dordrecht, Netherlands | Location III Veendam, Netherlands |
| Linear flow velocity | 0.184 m s−1 | 0.202 m s−1 | 0.202 m s−1 | Feed pressure | 1 bar | 1 bar | 1 bar | Total duration | 8 hours | 24 hours | 6.5 hours | Step1 | Circulation with NaOH 60 min; T = 35°C; pH = 12 | Circulation with NaOH 120 min; T = 35°C; pH = 12 | Prerinsing with demi water | Step2 | Soaking with NaOH 30 min; T = 35°C; pH = 12 | Soaking (overnight) with NaOH T = 20°C; pH = 12 | Soaking with demi water 30 min | Step3 | Circulation with NaOH 60 min; T = 35°C; pH = 12 | Rinsing with demi water | NaHSO3; pH = 10.5 (adjust pH with NaOH) 60 min; T = 35°C; C = 1–1.5% v/v | Step4 | Soaking with NaOH 30 min; T = 35°C; pH = 12 | Circulation with Divos 2 90 min; T = 35°C; pH = 1.6 | Soaking with NaHSO3 120 min; T = 20°C; pH = 10.5 | Step5 | Circulation with NaOH 60 min; T = 35°C; pH = 12 | Final rinsing with demi water | Rinsing with demi water | Step6 | Soaking with NaOH 30 min; T = 35°C; pH = 12 | | Divos 2 30 min; T = 35°C; pH = 2.5 | Step7 | Rinsing with demi water | | Soaking with Divos 2 60 min; T = 20°C; pH = 2.5 | Step8 | Circulation with HCl 60 min; T = 35°C; pH = 2.1 | | Final rinsing with demi water | Step9 | Soaking with HCl 30 min; T = 35°C; pH = 2.1 | | | Step10 | Circulation with HCl 60 min; T = 35°C; pH = 2.1 | | | Step11 | Soaking with HCl 30 min; T = 35°C; pH = 2.1 | | | Step12 | Final rinsing with demi water | | |
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demi water = dimineralized water (RO permeate); Divos 2 = mixed acid detergent descaler (JohnsonDiversey, UK).
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