Liquid CO2 circulating frozen seawater desalination and mineralization equipment system and method

Abstract

The invention relates to a liquid CO2 circulating frozen seawater desalination and mineralization equipment system and method. The liquid CO2 circulating frozen seawater desalination and mineralization equipment system mainly comprises a seawater mineralization solidification desalination device; the seawater mineralization solidification desalination device mainly comprises a tank body, a liquidCO2 vortex release mechanism, a floating ice collection mechanism, a CO2 gas exhaust device and a brine discharge device; the liquid CO2 vortex release mechanism is annularly arranged and fixed on theside wall of the middle lower part in the tank body or is fixed at the middle lower part or the bottom in the tank body; the floating ice collecting mechanism is arranged at the middle upper part inthe tank body; the CO2 gas exhaust device is arranged on the side wall or the top of the upper part of the tank body; and the brine discharge device is arranged at the bottom of the tank body. The equipment system is simple in structure, low in investment, small in occupied area, low in operation energy consumption, low in water production cost and low in operation and maintenance cost. The methodfor desalinating the seawater is wide in adaptability, and the salt content of the seawater is hardly limited.

Description

technical field [0001] The invention relates to the technical field of seawater desalination, in particular to a liquid CO 2 A system and method for circulating frozen seawater desalination and mineralization equipment. Background technique [0002] At present, my country's per capita fresh water accounts for less than 25% of the world's per capita water. It is one of the countries with the poorest per capita fresh water resources in the world, and the spatial distribution of my country's water resources is extremely uneven. It is obvious that there is more in the east and less in the west, and more in the south than in the north. , which is more obvious in North China, Northeast China, Northwest China, and coastal areas (including islands), which not only seriously restricts the rapid development of my country's economy, but also seriously affects the daily work and life of residents. [0003] In order to solve the crisis of fresh water supply, in addition to the convention...

AI Technical Summary

Problems solved by technology

[0007] (1) Low-temperature multiple-effect distillation technology (LT-MED): Fresh water is produced by multiple low-temperature distillation and condensation of seawater, but the outer wall of the heat exchange tube is prone to fouling, and the improvement of thermal efficiency is limited by low temperature (≤70°C). Too big, relatively high investment

[0008] (2) Multi-stage flash technology (MSF): Seawater is condensed after pretreatment and disinfection and multi-stage flash evaporation by steam heating to produce fresh water. High, high project investment, low operating flexibility of equipment, difficult to adapt to projects with large changes in water production, and will cause thermal pollution to the marine environment

[0009] (3) Compressed steam distillation (VC): The steam generated by hot seawater is pressurized twice and condensed into fresh water. This system has high requirements for sealing and seawater pretreatment. It is easy to scale and consumes heat and electricity. High, the equipment volume is also large, the operating cost is high, and it will cause thermal pollution to the marine environment

This method has high requirements for seawater pretreatment, large loss of membrane modules, and the membrane flux is sensitive to temperature. It needs to be equipped with a large number of high-quality corrosion-resistant auxiliary materials (stainless steel pipes, plates and titanium metal pipes), and the cost of fresh water treatment is relatively high.

[0012] (2) Electrodialysis technology (ED): uses potential difference to move and separate salt and water in a directional way, and its operating energy consumption is relatively high (generally 17-20kW·h / m 3 ), and it is difficult to remove salts with low dissociation degree, non-dissociated substances and bacteria, etc., and the product water quality is poor

[0021] The fifth category is oil separation and desalination method, such as mixing coconut oil and seawater to heat up, condensing and separating to remove salt, but the efficiency is low and it is easy to cause secondary pollution

This method increases the cost of mineralization of desalinated water, and cannot achieve good chemical stability, and requires the addition of an alkalinity adjustment process

However, other acidification methods, such as carbon dioxide as the acidification medium, are only found in literature reports and have no practical application.

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