United Arab Emirates University College of Engineering Chemical Engineering Department Graduation Project II

1. United Arab Emirates UniversityCollege of Engineering Chemical Engineering DepartmentGraduation Project II Designing an Effective Dehumidification Method to Produce Fresh Water From AirFaculty Advisor: Dr. Ali AL Marzouqi

2. Outline • Introduction • Summery of Achievement in GP1 • Updated Background Theory • Detailed Design • Economical, Ethical and Contemporary Issues • Project Management • Conclusion and Way Forward

3. Introduction • Problem Statement and Purpose • Shortage of water. • UAE the water resources have been depleted due to: • Increased tourism. • Construction activities. • Population growth [1]. Table1: Population for year 2008 and 2009

4. Major Productions of Fresh Water Consumption of water produced by desalination plants in UAE is 98 % [2]

5. Desalination Plant Disadvantages • High cost • High energy consumption • Environmental impacts

6. Project and Design Objectives • Obtain fresh water from the atmosphere using an efficient and economic way. • Selection criteria • Cost • Effectiveness • Simplicity • Safety • Ethics • Practicality for large scale operation • Minimization of Environmental impacts

8. Heat Exchanger Water Pump Outlet Reservoir Inlet Reservoir Seawater Water Wheel Detailed Design Alternative The proposed design for the air dehumidification process to produce water is a modification of a patent by a US inventor Richard J. Bailey [3] Figure 1: Schematic diagram for water production system by Bailey

9. Summary of Design Process Figure 2: Schematic diagram of the proposed dehumidification process.

10. Summary of achievements of GP1 Table 2: Comparison between different technologies

11. Tasks • The tasks required for GPII were as follows: • Design of a commercial-scale dehumidification unit. • Mass and energy balance. • Process flow diagram using HYSYS and Visio. • Sizing. • Material of construction/Cost. • Instrumentation. • Health, safety and environmental impact (HSE). • Economic analysis and business plan. • Reports and presentations.

12. 5 4 E-100 A1 w1 Material and Energy Balance • Heat exchanger : condense water vapor. • Material balance • and • Liquid water condensed • Air

13. Energy balance • Air • Water

14. Storage tank • Material balance • Valve =0

15. Pump • Material balance = • Energy balance =0 • Power of the pump (kW)= * • Head loss = ∆P/ρwg • Blower

16. Updated Background Theory • Relevant literature for GP 2 • Weather conditions in the UAE including the humidity. • Dubai [4] • Material of construction Table 3: Dubai temperatures in summer Table 4: Dubai temperatures in winter

17. Temperature of seawater at different depths of the sea[5] Figure 3: Seawater temperatures at different depths

18. Environmental Issues for New Literature • Decreasing the humidity of air. • Rejecting heat to the seawater from the downstream.

19. Detailed Design

20. Detailed Design Absolute Humidity • Based on the average temperature and relative humidity obtained from Dubai forecasting for three months: Table 5: Temperature, relative humidity and absolute humidity in summer and winter seasons [4]

21. Detailed Design Dew Point Temperatures Table 6: Dew Point Temperatures Figure 4:Dew-RH Chart [6]

22. Detailed Design List of Process Variables • The dehumidification process is affected by many variables. These variables can be adjusted and manipulated to achieve the highest water production. Table 7: List of Process Variables

23. Detailed Design Design Criteria for the Process Variables Table 8: Comparison between Middle East & Worldwide water production [7] Average capacity for plants in the Middle East is higher than that of all plants worldwide. For the purpose of our calculations a capacity of 200,000 m3/day, which is between these two average values was used.

24. Process Flow Diagram (PFD) Air 5 4 A1 w1 8 3 1 2 Figure 5: PFD for air dehumidification unit

25. Main Equipment Design (Manual Design)

26. Main Equipment Design (Manual Design) • Pipe Sizing Table 10: Pipe dimensions and properties • Based on pipe limitations, the maximum flow rates for both seawater and air that could be achieved are 4.16x106 kg/hr

27. Design in Hysys Program Figure 6: Design of the dehumidification process in Hysys program

28. Comparison between Simulators including Hysys and Detailed Manual Design Table 11: Manual and Hysys design comparisons for summer and winter seasons

29. Bench Scale Design Figure 7:Air Dehumidification Prototype

30. Experimental Results for the Dehumidification Prototype Table 12: Experimental conditions

31. Experimental Results for the Bench Scale Prototype Figure 8:Condensed amount of water for the experimental runs.

32. Piping and Instrumentation Diagram (P&ID) Figure 9:P&ID for the dehumidification unit

33. Types of equipment (Heat Exchanger) Table 13: Comparison of different types of heat exchanger [8] Plate-Fin HE

34. Types of equipment (Valves) Table 14: Comparison of different types of valves [9] Throttling valve Non-return valve On-Off valve

35. Types of equipment (Pump) Table 15: Comparison of different types of pumps [10] Centrifugal Pump Positive displacement Pump

36. Types of equipment (Blower) Table 16: Comparison of different types of blowers [11] Positive Displacement Blower Centrifugal Blower

37. Material of Construction (MOC) • The dehumidification plant must be safe, completely free of any harmful contaminants, toxins and bacteria. • All equipment must be protected from corrosion. • Therefore it is important to choose the best and the safest material to be used in the construction of the dehumidification plant.

38. MOC Table 17: Comparison of different types of stainless steel [12]

39. Economic Analysis

40. Capital Cost of the Plant • Total module cost for one unit: [13] Where: is the capital cost (total module) of the plant is the bare module equipment cost which • Bare Module cost: Where: FBM is the bare module cost factor is the purchase cost for base conditions.

41. Table 18:Bare module cost calculation for each equipment. For the year 2001, total module cost is $ 5,950,414 For the year 2009, total module cost is $ 7,983,183

42. CAPCOST program results: Table 19: Comparing the cost using equations and CAPCOST program. • For the heat exchanger: the specified heat transfer area was too large ; maximum is 1000 m2 and in the process is 1300 m2. • For the pump:the specified power was too large; maximum is 300 KW, and in the process is 1190 KW. • For the storage:the diameter (12.2m) is too large in the process.

43. Manufacturing Cost of the Plant: Cost of Manufacture (COM) = Direct Manufacturing Costs (DMC) + Fixed Manufacturing Costs (FMC) + General Expenses (GE) • DMC = CRM + CWT + CUT + 1.33COL + 0.03COM + 0.069FCI • FMC = 0.708COL + 0.068FCI+ depreciation • GE = 0.177COL + 0.009FCI+ 0.16COM • TC = CRM + CWT + CUT + 2.215COL + 0.190COM + 0.146FCI + depreciation

44. Utilities cost (CUT):This is associated with different heating or cooling media. Table20:Total cost of utilities

45. Operating labor cost (COL) Table 21: Operating labor costs

46. Table 22: Cost of manufacturing Table 23:Additional cost for the process

47. Total Cost • The total cost is equal to $ 2,470,758,238. • Although the cost of this process seems high, it is less than the cost of producing water from desalination plant for the same capacity, the cost is $ 3,033,600,000.

48. Cast Flow Analysis Figure 10 : Cash flow diagram for the project

49. Ethics • Reducing the humidity may affect human health which may lead to dryness of the skin. • Putting the plant near a community may scare the society. • People have the right to know that: • No chemicals will be used. • No harmful wastes will be dumped into the sea.

50. HAZOP • The objective of HAZOP is to minimize the effect of unusual situation by: • Ensuring that the control and other safety systems are in place. • Ensuring that people who use and operate can do so without risk of personal injury.