Table 1.
Recent studies on the performance of membrane distillation systems using feed water preheating systems
| Refs | Nature | Improvement-techniques | Results | Remarks |
|---|---|---|---|---|
| Shafieian et al. (2019) | Experimental + Simulation | Feed preheating using electric heater | Permeate water increase by 52 g/m2 min for increasing feed temperature from 30 to 60 °C | It is more efficient to heat the feed water stream to improve water productivity than to use the same amount of energy to cool the permeate stream |
| Shafieian and Khiadani (2019) | Experimental | Feed preheating using evacuated tube solar water collector + Electrical heater |
• Permeate water productivity reached 3.81 L/m2 h with cooling unit • Maximum thermal efficiency of the solar system reached 78% • Exergy efficiency varying between 4 and 5% • Overall system efficiency improved from 46.6 to 61.8% for using the cooling unit in the permeate flow loop • Solar working fluid temperature varying between 37 and 58 °C |
Except 15 min in the morning, the heat pipe solar collector was able to operate the desalination system independently without any additional required thermal energy |
| Elminshawy et al. (2020) | Experimental + Simulation | Electric heater + V-trough solar concentrator PV panels with cooling + Buried water heat exchanger | For feed water of 80 and 144 kg/h, the permeate flux is 0.76 kg/ h, Specific thermal energy consumption is 103 kWh/m3, GOR is 1.36, and produced water cost reached 22.48 $/m3 | The hybrid system has the capacity to produce 19.58 m3 of freshwater per year at a cost of 22.48 $/m3 and to reduce CO2 emissions by 136.82 kg |
| Wang et al. (2019) | Experimental | Solar PV with thermal recovery integrated with MD | Pure water productivity reached 3.25 kg/m2.h for utilizing 5-stage MD integrated with PV | This device can transform an electric power plant from a water consumer to a pure water producer |
| Ding et al. (2005) | Experimental + Simulation | Feed preheating using evacuated tube solar water collector | About 23.5 l/h average water productivity for 0.8 l/min feed flow rate and feed temperature 70 °C | - |
| Elzahaby et al. (2016) | Experimental + Theoretical | Feed preheating using evacuated tube solar water collector + Electrical heater |
• The daily productivity of pure water reaches 40.587 kg/day for 20 L/min feed flow rate and feed temperature 70 °C • Daily efficiency and Gain output ratio reached 60.06% and 0.624 |
- |
| Kabeel et al. (2017a) | Experimental | Feed preheating using evacuated glass tube solar water collector + Evaporative cooler |
• Maximum productivity reached 33.55 L/day • System efficiency reached 49.01% and gain output ratio reached 0.49 • Feed temperature ranged 55–70 °C |
Use of the cooling unit on permeate flow loop improved the system productivity almost 1.25 |
| Soomro and Kimc (2018) | Theoretical | Solar power tower plant to produce the electricity and preheated the seawater before supplied to MD |
• The maximum permeate flux 29.05 kg/ h was achieved at feed temperature 45 °C • The average freshwater produced up to 40,759 L/day • Estimated water cost 0.392 $/m3 |
• Increasing the feed temperature increased the permeate flux • The effect of the feed flow rate is not significant compared to permeate flow rate |
| Siefan et al. (2022) | Experimental | Feed preheating using flat plate solar collector + Solar-powered PV collectors | • Solar powered was a better option for membrane distillation in terms of an environmental footprint | - |
| Sandid et al. (2021) | Experimental and simulation | Feed preheating using flat plate and evacuated tube collectors + electric heater |
• The specific thermal energy consumption ranged from 158.83 to 346.55 kWh/m3 • The hot feed inlet temperature ranged 50–65 °C • The maximum gain output ratio reaches 4.4 • Thermal efficiency reached 72% • Cost of fresh drinking water reached 14.73 $/m3 |
Using solar energy reduces carbon dioxide emissions by 7274.45 kg/year |
| Chang et al. (2022) | Practicality | Feed preheating using evacuated tube solar collector | Permeate flux reached 5.2 kg/m2 h at feed temperature 52 °C | This system is very effective for remote areas and especially for coastal fishery communities |
| Usman et al. (2021) | Economic feasibility | Feed preheating using thermal solar collector and waste heat recovery |
• Increase the membrane permeability for using solar-thermal and waste heat • Reduced the rate of external power required to operate the system from 40 to 60% • Decreased water price from 6.80 $/m3 (the cost of operating the system with the electricity only) to only 1.6 $/m3 |
The contribution of solar heat and waste heat used in the operation of the process leads to a lower cost of water production as well as making the desalination system more competitive, sustainable and economically viable for small and remote applications |
| Gustafson et al. (2018) | Theoretical | Waste heat + Chiller | Permeate water flux reached 22.9 L/m2 h at feed inlet temperature 64 °C and distillate temperature of 30 °C | Membrane productivity depends strongly on waste heat source characteristics |
| Abdelkader et al. (2019) | Experimental | Electrical heater | Permeate flux reached 13 kg/m2 h at a water temperature difference of 30 °C | - |