A low-chlorine photothermal molten salt production process and production device

Abstract

The invention discloses a low-chloride photothermal molten salt production process and production device. The production process comprises the steps that a, molten salt solution preparation is performed: alkaline liquid and a salpeter solution are used as raw materials to be fed into a neutralizing reactor for neutralization reaction; steam generated through neutralization reaction is subjected toheat recovery; b, a certain concentration of neutralization solution obtained through neutralization reaction is treated by an evaporative crystallization work procedure to obtain molten salt crystals; c, the molten salt crystals are subjected to centrifugal separation and drying to obtain products; centrifugal mother liquid returns to front end work procedures. The alkaline solution is used as raw materials for producing high-quality molten salt; a jet pipe type reactor with a static mixer is used for neutralization reaction; the molten salt solution obtained after the neutralization is usedfor producing solids by evaporation concentration, crystallization or slurry praying drying methods; after the subsequent treatment and package, the solids are used as final molten salt products; thechlorine content can be lower to be 15 to 20 ppm; the corrosion of molten salt products on user equipment can be reduced, so that the service life of equipment is prolonged; the long-period safe operation of a solar photothermal power generation device is ensured.

Description

technical field [0001] The invention belongs to the technical field of photothermal molten salt, and in particular relates to a production process and production device of low-chlorine photothermal molten salt. Background technique [0002] At present, domestic solar thermal power generation is a large-scale utilization of high-temperature thermal energy of solar energy. It can not only reduce the use of fossil fuels, but also achieve the purpose of reducing greenhouse gas emissions and reducing air pollution. It is a rapidly emerging emerging industry. Among them, nitric acid Molten salt series is the most widely used molten salt in this industry, which is suitable for high-temperature thermal power generation of concentrated solar energy. Due to the very strict requirements on the quality of molten salt products in the field of photothermal molten salt, it is also the reason why this technology is proposed. [0003] The components of photothermal molten salt products at h...

AI Technical Summary

Problems solved by technology

[0014] 1. It is mainly used for the production of disodium (sodium nitrite / sodium nitrate=1~2:1) and the technology is mature, but the technology for producing sodium nitrate alone is not yet mature.

[0015] 2. In normal pressure and low pressure operation, large-scale is difficult (the scale of two sodium is 120,000 tons / year, and the largest scale of sodium nitrate is 80,000 tons / year, consisting of 4 production lines, that is, each production line is only 20,000 tons / year sodium nitrate scale)

[0017] 4. Exhaust gas NO x The emission is 600-800ppm, and the tail gas still needs to be treated to meet the emission standards

[0019] 6. Sodium nitrite produced is a toxic substance

[0020] 7. High energy consumption

[0027] 1. At present, the domestic process technology is relatively backward, the neutralization reaction part is non-continuous production, and the tail gas produced is untreated

[0028] 2. The product quality is poor, and the chlorine content cannot meet the requirements of molten salt products

The disadvantage is that the concentration of potassium nitrate in the exchange liquid is low, and the cost of evaporation is high; the concentration of recovered ammonium chloride is low, and the energy consumption of evaporation is high; the requirements for equipment materials are high, and titanium, titanium-molybdenum-nickel alloy or other materials are required, and the manufacturing cost is high.

At the same time, judging from the operation of the domestically built devices, the technology is not mature enough to produce stably

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