The natural solution for thermal storage and heat transfer in Concentrated Solar Power (CSP) plant.
SQM is the largest producer of 100% natural nitrate salts in the world. SQM has access to abundant reserves of raw materials. SQM owns mines and installations that allow production with the lowest possible CO2 emissions.
SQM has a Worldwide sales network which allows to cover the needs of each specific market in the globe.
Most renewable technologies suffer from a discontinuous energy supply and an unpredictable output due to altering weather conditions and/or energy demands. CSP plants, equipped with a Molten Salts Storage System, store excess heat and stay operational also during evening hours and cloudy days, which significantly increases their electricity output. An environmentally friendly solution from SQM that optimizes the efficiency of your CSP plant.
KEY ADVANTAGES OF SQM’s THERMO-SOLAR SALTS
• 100% natural nitrate salts
• Virtually maintenance free
• High specific heat
• High chemical stability
• Non-flammable
• Non-toxic
• Produced with much lower CO2 emissions and far less environmental impact compared to synthetically produced salts
• Highly refined, low in impurities grades
SQM’s Sodium Nitrate + Potassium Nitrate:
The natural solution for thermal storage and heat transfer.
Annually, SQM produces around 1 million MT (more than 50% of the world market quantities!) of sodium and potassium nitrate from Caliche Ore and Salar Brines, two natural resources found in Northern Chile. Caliche is extracted from surface deposits in the Atacama Desert; derived products including Sodium Nitrate and Iodine. The Salar Brines are pumped from underground brines in the Salar de Atacama (Atacama Salt Flat) after which they are deposited in large solar evaporation ponds to separate the desired elements. Products derived from Salar Brines include Lithium Chloride Brine, Potassium Chloride, Magnesium Chloride Hexahydrate, Boric Acid and Potassium Sulphate.
To produce nitrates, the caliche mineral is crushed and then subjected to a leaching process with water. Sodium Nitrate is obtained from this leached solution by crystallization. Part of the obtained Sodium Nitrate goes through another stage of processing during which Potassium Chloride, from the Salar de Atacama is added. The mixture is then subjected to ion exchange, crystallization, refining and drying processes to yield Potassium Nitrate. Control of stoichiometry of the reaction and crystallization process allows for a controlled mix of Sodium Nitrate and Potassium Nitrate.
Physical properties of SQM’s Thermo-Solar Salts.
Reference: A.V. Zavoico, SAND2001-2100 Solar Power Tower Design Basis Document - Courtesy of Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 - July 2001).For this specific application, Sodium Nitrate and Potassium Nitrate are mixed in 60%/40% by weight ratio. The mixture is stable in air and has a low vapour pressure.
SQM’s Thermo-solar salts specifications
SQM offers to the CSP industry high quality Sodium Nitrate and Potassium Nitrate grades to match the specific requirements of each CSP power plant developer. The composition of these grades is described in the individual specifications sheets and is summarized in the table here below.
(1) The product does not contain other relevant sources of halogen compounds (iodide, bromide, iodate, bromate or any other).
(2) Moisture measured at SQM production site. Some absorption of moisture may occur during transportation.
Particle size guaranteed: 2mm. Insoluble particles between 0.85 mm and 2 mm represent typically less than 0.05% of the product.
SQM, the worldwide market leader in the production and the commercialization of Specialty Plant Nutrition, Potassium, Industrial Chemicals, Iodine and Lithium, is also a global key provider of natural, high quality thermo-solar salts used for thermo-solar energy storage and as heat transfer fluid. An environmentally friendly solution from SQM that optimizes the efficiency of your CSP plant.
Experience about corrosion
SQM Thermo-solar salts have given positive results on corrosion already many years ago during the Solar Two project. In more recent measurements, Sandia National Laboratories in USA has concluded that at 600°C bulk molten salt temperature, the corrosion rate ranged was on average less than 16.5 microns of metal loss per year for 13 different alloys after 3000 hours of tests (table below) with only one alloy exceeding 25 microns. Most industrial applications would label that as excellent corrosion performance (ref. SAND 2013-2526, March 2013). Below a snapshot table extracted from this report summarizing the results.
termosolar, Concentrated Solar Power, Concentrating Solar Power, CSP, Concentrated Solar Thermal Power, Fresnel, SQM, solar power, solar energy, Energy Storage, Storage