| CPC C02F 1/445 (2013.01) [C02F 2101/10 (2013.01); C02F 2103/08 (2013.01); C02F 2301/063 (2013.01)] | 13 Claims |
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1. A water desalination method that uses forward osmosis, comprising:
(a) creating a vacuum in a water desalination system;
(b) after creating the vacuum in the water desalination system, flowing salt water or contaminated water to be desalinated through a feed side of a forward osmosis (FO) membrane housing, wherein the salt water or the contaminated water to be desalinated is at ambient temperature;
(c) after step (b), while flowing the salt water or the contaminated water through an inlet of the feed side of the FO membrane housing, flowing a concentrated ammonium bicarbonate solution through an inlet of a draw side of the FO membrane housing, wherein the feed side and the draw side of the FO membrane housing are separated by a FO permeable membrane,
wherein the concentrated ammonium bicarbonate solution functions as a draw solution in the FO membrane housing,
wherein a temperature of the concentrated ammonium bicarbonate solution is also at ambient temperature;
(d) as a result of osmotic pressure, allowing a minimum period of time for the concentrated ammonium bicarbonate to pull a percentage of desalinated product water from the feed side through the FO permeable membrane to the draw side of the FO membrane housing;
(e) flowing brine or other extracted contaminant solutes pulled through the FO membrane housing in the feed side of the FO membrane housing to a collection point for the brine or the other extracted contaminant solutes, further comprising flowing the brine or the other extracted contaminant solutes to a first vacuum tank and pumping the brine or the other extracted contaminant solutes one or more time in and out of the first vacuum tank before redirecting the brine or the other extracted solutes to another location for further processing or collection;
(f) flowing a resulting solution through the draw side of the FO membrane housing from the draw side of the FO membrane housing, wherein the resulting solution is a combination of the percentage of the desalinated product water and the concentrated ammonium bicarbonate solution and wherein the resulting solution is a diluted ammonium bicarbonate solution;
(g) pumping the resulting solution to a water heat pump, wherein the water heat pump has a load side and a source side, wherein the load side is divided from the source side of the water heat pump;
(h) flowing the resulting solution through the load side of the water heat pump, further comprising, using the water heat pump to heat or raise a temperature of the resulting solution as the resulting solution is flowing through the load side of the water heat pump;
(i) after step (h), flowing the heated resulting solution to a feed side of a hydrophobic membrane housing, wherein the hydrophobic membrane housing comprises a hydrophobic membrane that permits gases to flow through the hydrophobic membrane from the feed side of the hydrophobic membrane housing to a draw side of the hydrophobic membrane housing, wherein the gases are ammonia, carbon dioxide, and water vapor;
(j) allowing the heated resulting solution to be filtered through the hydrophobic membrane of the hydrophobic membrane housing, wherein any ammonium bicarbonate ions in the heated resulting solution are converted or dissociate into the gases in the feed side of the hydrophobic membrane housing, wherein the gases pass through the hydrophobic membrane from the feed side of the hydrophobic membrane housing to the draw side of the hydrophobic membrane housing, leaving behind freshwater product water to flow out of the feed side of the hydrophobic membrane housing without ammonium bicarbonate ions present in the freshwater product water;
(k) flowing the freshwater product water from the feed side of the hydrophobic membrane through a first dividing valve;
(l) after passing through the first dividing valve, directing a first amount of the freshwater product into an inlet of the source side of the water heat pump and re-directing a second amount of the freshwater product water directly to a second vacuum tank;
(m) directing the freshwater product from the water heat pump to a second dividing valve further comprising dividing up the first amount of freshwater product that has been cooled into a first amount of cooled freshwater and a second amount of cooled freshwater;
(n) directing the first amount of the freshwater product to the second vacuum tank; and
(o) directing the second amount of cooled freshwater to the draw side of the hydrophobic membrane so that the cooled freshwater interacts with the gases of the converted ammonium bicarbonate ions and the gases reform or reassociate as ammonium bicarbonate ions that exit the draw side of the hydrophobic membrane and flow out of the draw side of the hydrophobic membrane as a concentrated ammonium bicarbonate solution.
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