Desalination method by membrane vaporization absorption

Abstract

The invention provides a desalination method by membrane vaporization absorption. The method provided by the invention is characterized by comprising the following steps of: using a hydrophobic millipore membrane as a separation device and allowing two side surfaces of the hydrophobic millipore membrane to respectively contact with a processed liquid and an absorbent; absorbing water molecules in the processed liquid by the absorbent, wherein the temperature of the processed liquid is the same as or similar to that of the absorbent; separating the absorbent and water after absorption of the water molecules by the absorbent, so as to obtain desalinated water. The invention has the following effects: high-quality desalinated water is obtained at low cost; membrane pollution is slight; the yield of seawater desalination is high, and the discharge of concentrated water is minimized after seawater desalination so as to cause no unfavorable influence on the ecological environment; comprehensive utilization of seawater chemical resources can be realized, the technology is optimized to extract potassium, bromine and magnesium chemical products, and consumption of acid, alkali and chlorine chemical medicines is minimized during the technological process; and seawater only undergoes simple sand filtration as a pretreatment. In comparison with a reverse osmosis technology, the pretreatment is simple, and the quality of the desalinated water by the pretreatment is much better than that of product water by reverse osmosis.

Description

technical field [0001] The invention relates to a membrane desalination method, especially a method suitable for seawater desalination. Background technique [0002] With the rapid development of society and the rapid increase of population, the shortage of fresh water resources has attracted the attention of all countries in the world. According to statistics from the United Nations, nearly 700 million people in 43 countries around the world often face "water stress" and water shortages. About one-sixth of the people have no clean drinking water, and one-third of the people have difficulty in living with water. In 2009, drought victims The number is several times the number of migrants due to armed conflict. In the context of global warming, "water security" has become a top global issue, and water resources have become a country's strategic resource. The competition for fresh water resources such as rivers will lead to armed conflicts and wars among countries. In fact, t...

AI Technical Summary

Problems solved by technology

There are two main problems in reverse osmosis technology: one is the low recycling rate of reverse osmosis fresh water, which generally can only reach about 40%, and about 60% of the concentrated water is still discharged

If the reverse osmosis treatment of concentrated seawater is continued, the operating pressure will be greatly increased and the cost will be increased

Second, reverse osmosis seawater desalination technology cannot fully remove boron in natural seawater, far exceeding the standards set by the World Health Organization

[0022] In recent years, for large-scale seawater desalination projects, the cost of desalinated water has been reduced to 6-7 yuan / t, but it is still too expensive for poor and underdeveloped countries and regions

Although the membrane distillation method produces good water quality, it requires additional energy to condense the steam, consumes phase change heat, and consumes a lot of energy.

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