System for producing 3.5-valent high-purity vanadium electrolyte and method thereof

Abstract

The invention discloses a system for producing a 3.5-valent high-purity vanadium electrolyte and a method thereof. According to the invention, fluidized bed gas phase hydrolysis is employed for hydrolyzing high-purity vanadium oxytrichloride to vanadic anhydride, vanadic anhydride in a reduction fluidized bed is accurately controlled and reduced to the low-valent vanadium oxide with vanadium average valence of 3.5, under applied microwave field, the 3.5-valent high-purity vanadium electrolyte is dissolved at low temperature by adding water and a sulfuric acid solution, and the electrolyte is directly used in all-vanadium redox flow battery new electric pile. The method for preparing vanadic anhydride through fluidized bed gas phase hydrolysis has the advantages of short flow and high efficiency, arrangement of an inner member in the reduction fluidized bed realizes accurate regulation and control of valence of the reduction products, dissolving of vanadium oxide is promoted and the vanadium ions are activated through special chemical effect of the microwave field, the electrolyte is prepared through dissolving in a low temperature zone, and the electrolyte activity is greatly increased. The system has the advantages of short flow, high efficiency cleaning, and stable product quality, is suitable for large-scale industrial production, and has good economic benefit and social benefit.

Description

technical field [0001] The invention belongs to the fields of energy and chemical industry, in particular to a system and method for producing 3.5-valent high-purity vanadium electrolyte. Background technique [0002] Traditional fossil fuels have always been the main source of energy. Due to long-term mining and extensive use, they are facing the problem of resource depletion, and also bring serious environmental pollution. The development and utilization of clean and renewable energy such as wind energy, water energy, solar energy, and tidal energy has gradually attracted the attention of human society. However, renewable energy is inherently intermittent, and existing energy management systems are difficult to use effectively. [0003] Energy storage technology is one of the ways to solve such problems. Among various energy storage systems, vanadium redox flow battery (VRB) is an attractive energy storage device. The biggest advantage of VRB is its flexibility - the po...

AI Technical Summary

Problems solved by technology

When the impurity concentration in the electrolyte is high, it will bring the following problems: (1) There is a competitive reaction between impurity ions and vanadium ions, reducing battery efficiency

(2) In the positive electrode chamber, impurity ions are deposited on the graphite felt electrode, which blocks the gaps of the graphite felt and reduces the specific surface area of ​​the graphite felt, thereby affecting the charge and discharge efficiency

(3) In the negative electrode chamber, impurity ions will affect the hydrogen evolution overpotential, and gas production will affect the pressure balance inside the battery

(4) Impurity ions reduce the life of the proton exchange membrane

(5) Impurity ions affect the stability of vanadium ions, resulting in premature aging of the electrolyte

The main problem that this patent exists is: no specific reduction process is given, reducing V in hydrogen 2 o 5 Preparation V 2 o 4 The powder is easy to be over-reduced or under-reduced, and it needs precise control to realize it. The measures for accurately controlling the reduction are not listed in the patent; the purity is low; Chinese patents CN101880059A and CN102557134A disclose a process for producing high-purity vanadium trioxide Fluidized reduction furnace and reduction method, by adding heat transfer internal components in the fluidized bed, to achieve enhanced heat transfer; using cyclone preheating to improve energy utilization, to achieve V 2 o 3 Efficient preparation of

The method described in these two patents is only applicable to V 2 o 3 It is not suitable for the preparation of low-valent vanadium oxides in other valence states, because the system does not have the function of precisely controlling the reduction

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