Brine recirculation

Figure 6.29 The influence of brine recirculation within each bank of modules (rriRec/mF = z > 0) on specific cost of RO (spiral-wound).

Electrodialysis, reverse polarity for 4000 mg/L TDS alkalinity to 500 mg/L with minimum pretreatment including brine recirculation pumps, ED stack, electrical equipment, brine discharge facilities, product water treatment and storage, building, intake pipes and transfer pumps. TM cost = 25 000 000 at feed rate = 100 L/s with n = 0.82 for the range 40-1500 L/s. Feed factors 4000 ppm, X 1.00 2000 ppm, X 0.7 850 ppm, X 0.1. 

Figure 11-35 (a) Once through flash evaporator cycle, (b) Brine recirculation flash evar > rdtion cycle. ... 

Seawater or brackish water is used for process applications or as potable water when fresh water is scarce. Six techniques are used for desalination. Five are evaporation processes multiple-effect thermocompression mechanical vapor compression once-through multistage flash and multistage flash with brine recirculation. The sixth process, reverse osmosis, uses membrane technology for desalination. 

Maintenance requirements could be listed in the following order, from lowest to highest maintenance thermocompression once-through multistage flash multistage flash with brine recirculation reverse osmosis multiple-effect evaporation mechanical vapor compression. Several factors are important ... 

Multistage Flash With Brine Recirculation More pumps and controls are needed. Two treatments are used for scale control acid and non-acid. Non-add systems require maintenance similar to once-through systems. Acid addition usually results in corrosion but better material of construction and proper operation can reduce corrosion related maintenance. 

Multistage Flash With Brine Recirculation These systems have economies of 3-12. Greater economy is possible, but more stages are required. The practical maximum number of stages is about 50 where economy is about 12. Low-pressure steam or hot water can be used. 

Once-Through Multistage Flesh These systems also have economies of 3-12 but are generally designed with economies lower than that of brine recirculation systems. 

For large plants, multiple-effect and multistage flash with brine recirculation have lower costs followed by once-through multistage flash (10% higher), thermocompression (40% higher), and reverse osmosis and mechanical compression (both 50% higher). 

Drill fluid pumping Completion brine recirculation CO2 injection initiation CO2 injection shut-in CO2 injection restart Tubing leaking during CO2 injection Tubing leaking during well shut-in Backflush operation. 

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