Lecture 12 Water Desalination Lecture 12 Water Desalination

Lecture (12): Water Desalination

Lecture (12): Water Desalination Lecture (12): Lecture objectives: By the end of this lecture students should be able to: 1. To know the description of desalination stages. 2. To know the desalination technologies classification 3. To know desalination plants in KSA.

Introduction • Many regions in the world do not have easy access to fresh drinking water • Desalination process helps remove salts from sea water to make it drinkable • Pros: Brings drinking water to many dry regions • Cons: Expensive – In some parts of Middle East, a liter of water is more expensive than a liter of gasoline

Description of desalination stages 4

Desalination technologies classification based on the separation process adopted 5

Desalination technologies classification based on the type of energy used 6

PROCEDURES • Reverse Osmosis • Distillation – Multistage flash (MSF) – Multiple effect distillation (MED) – Vapor compression • Electro dialysis • Vacuum freezing

Reverse Osmosis • • Water pressure increased Pumped through permeable membranes Salts separated from water due to membranes Most desalination plants utilize this technology

Multi Stage flash • Steam is used to heat tubes of saline water • Heated water flows into “stages” that are at lower pressure • Water boils rapidly and “flashes” into steam

Existing Plants # Location Plant Name Year of Commission Installed Capacity (m 3/day) Installed Capacity MW Type of Technology 1 Alwajih (3) 2009 9, 000 - Single Purpose (MED) 2 Khafji (2) 1986 22, 886 11 Single Purpose (MSF) Umlujj (2) 1986 4, 400 - Single Purpose (RO) Umlujj (3) 2009 9, 000 - Single Purpose (MED) 3 4 Umlujj 5 Farasan (2) 2009 9, 000 - Single Purpose (MED) 6 Rabigh (2) 2009 18, 000 - Single Purpose (MED) 7 Duba (3) 1989 4, 400 - Single Purpose (RO) 8 ALBirk 1983 2, 270 - Single Purpose (MSF) 9 ALAzizih 1987 4, 500 - Single Purpose (MED) 10 Haql 1990 4, 400 - Single Purpose (RO) 11 ALQunfutha 2008 9, 000 - Single Purpose (MED) 12 ALlith 2009 9, 000 - Single Purpose (MED) Khobar (2) 1983 223, 000 710 Dual Purpose (MSF) Khobar (3) 2000 280, 000 479 Dual Purpose (MSF) 13 14 Khobar

Existing Plants Plant Name Year of Commission Installed Capacity (m 3/day) Installed Capacity MW Type of Technology Jubail (1) 1982 137, 729 360 Dual Purpose (MSF) Jubail (2) 1983 947, 890 1225 Dual Purpose (MSF) 17 Jubail (RO) 2000 90, 909 - Single Purpose (RO) 18 Yanbu (1) 1981 108, 074 357 Dual Purpose (MSF) Yanbu (2) 1998 144, 000 150 Dual Purpose (MSF) 20 Yanbu (RO) 1998 128, 182 - Single Purpose (RO) 21 Jeddah (3) 1979 88, 357 256 Dual Purpose (MSF) 22 Jeddah (4) 1982 221, 575 590 Dual Purpose (MSF) Jeddah (RO 1) 1989 56, 800 - Single Purpose (RO) 24 Jeddah (RO 2) 1994 56, 800 - Single Purpose (RO) 25 Jeddah (RO 3) 2013 240, 000 - Single Purpose (RO) Shoaiba (1) 1989 223, 000 263 Dual Purpose (MSF) Shoaiba (2) 2001 454, 545 520 Dual Purpose (MSF) Shoqaiq 1989 97, 014 108 Dual Purpose (MSF) # Location 15 16 19 23 26 27 28 Jubail Yanbu Jeddah Shoaiba Shoqaiq

Water Demand in KSA – Main Figures 2010 2025 Population (Million) 27. 2 34 (*) Water demand (Million m 3/day) 6. 8 8. 5 (*) Desalination share in water 53% (3. 3 Million m 3/day) 63% (5. 2 Million m 3/day) * ( ): assuming an average annual growth rate of 1. 5%

Multi Stage flash (cont…) • Generally, only a small amount converts to steam since rapid vaporization results in cooling of water • Thus water is flashed multiple times in different stages at lower pressures, requiring no extra heat • But, multi stage flashing reduces thermal efficiency • 85% of world’s desalinated water is generated through MSF • Recently the equipment has become cheaper

Shoaiba Desalination Plant • Largest desalination plant in the world • Produces 450, 000 m³/day • Per year – 150 million m³ of water is desalinated – Total cost is $1. 06 billion • To increase thermal efficiency of this plant, the maximum number of stages is set to 25 (MSF) • Research in the field is resulting in more plants coming up in Florida and California

Reverse Osmosis https: //www. youtube. com/watch? v=m. Z 7 bgk. Fgq. JQ https: //www. youtube. com/watch? v=a. Vd. Wqbpbv_Y