Читать книгу Introduction to Desalination - Fuad Nesf Alasfour - Страница 24

Recall that feed type, characteristics, and quality play a major role in selecting desalination system. In addition potable water purity, type of energy consumption, water production cost, and emissions are also factors that play a role during desalination technology selecting; engineers must evaluate all the mentioned parameters to optimize his or her selection process.

For example, if we take a case of 45 000 ppm feed seawater, thermal system can be used, while in other cases such as brackish water with 8000 ppm salinity, membrane system is recommended. In certain applications using two different combined desalination system, thermal and membrane, which is called hybrid (Chapter 10), is another option of selection.

Table 1.1 shows the range operational energy requirement for main desalination systems.

Table 1.1 Energy requirement for main desalination systems.

Source: Alkaisi et al. 2017 [4]. Reproduced with permission of Elsevier.

	MEE	MSF	MEE‐TVC	MVC	RO	ED
Typical unit size (m3/d)	5000–15 000	50 000–70 000	10 000–35 000	100–2500	24 000	−145 000
Steam pressure (atm)	0.2–0.4	2.5–3.5	0.2–0.4	—	—	—
Electrical energy consumption (kWh/m3)	1.5–2.5	4–6	1.5–2.5	7–12	3–7	2.6–5.5
Thermal energy consumption (kJ/kg)	230–390	190–390	145–390	None	None	None
Electrical equivalent for thermal energy (kWh/m3)	5–8.5	9.5–19.5	9.5–25.5	None	None	None
Total equivalent energy consumption (kWh/m3)	6.5–11	13.5–25.5	11–28	7–12	3–7	26–5.5