amount of energy needed to desalinate water
At a pilot facility in Singapore, Siemens has cut the energy needed to desalinate seawater by more than 50 percent. The plant processes 50 cubic meters of water per day, consuming only 1.5 kilowatt-hours of electricity per cubic meter. The thermodynamic minimum energy for desalination (the energy required for separating an infinitely small amount of fresh water from salt water) is the same for all processes. Energy differences between processes are due to the difference in efficiency of the process. The method used to extract fresh water from saline does not matter. The thermodynamic minimum energy for desalination (the energy required for separating an infinitely small amount of fresh water from salt water) is the same for all processes. 0.66 kcal / liter is the minimum energy required to desalination of one liter of seawater, regardless of the technology applied to the process. It is interesting to compare this energy to the heat required to boil one liter of water and condense its vapors. Figure 1. Energy require to convert saline water to fresh water for a range of salinity and recovery levels. 1 kJ/kg (1.05 kWh/kgal). Seawater is 3.5% dissolved salts by weight. Energy require to convert saline water to fresh water for a range of salinity and recovery levels. 1 kJ/kg (1.05 kWh/kgal). Seawater is 3.5% dissolved salts by weight. Energy is the largest single expense for desalination plants, accounting for as much as half of the costs to make drinking water from the sea, according to a report. Thus, energy costs go up with each recovery reiteration. As a bit of water is removed and purified, the rest of the water has a higher salt concentration and thus, more energy is needed to separate the next unit of water.The figure shows the energy needed to desalinate water with higher and higher percentages of salt. The energy that's required and the pressure that's required to filter salt is approximately 100 times less, Stetson added. The amount of work it takes to squeeze that water through the torturous path of today's best membranes is gone for Perforene. One kilocalorie (kcal) is equal to about 4200 Joules, therefore, the work is 2780 / 4200 = 0.66 kcal / liter. 0.66 kcal / liter is the minimum energy required to desalination of one liter of seawater, regardless of the technology applied to the process.
1.5 kilowatt-hours