Sodium chlorate

About: Sodium chlorate is a research topic. Over the lifetime, 791 publications have been published within this topic receiving 6844 citations.

Method for preparing high-purity chlorine dioxide by using methanol and hydrogen peroxide as reducing agent

Abstract: The invention discloses a method for preparing high-purity chlorine dioxide by using methanol and hydrogen peroxide as reducing agent. The method comprises: concentrated sulfuric acid and sodium chlorate solution are injected into the generator to form the reaction mother liquid. The reaction mother liquid shall be maintained a certain acidity, temperature and sodium chlorate content, and then it is reacted with the reducing agent (methanol and hydrogen peroxide) to produce chlorine dioxide gas and by-product sodium sulfate. The chlorine dioxide gas is cooled and absorbed by low temperature chilled water to obtain an aqueous solution of chlorine dioxide, and by-products are recycled. The chlorine dioxide solution produced by the aforementioned method has a 60-70% reduction in the Cl2 content and 14-20% reduction in sulfuric acid consumption than that of the chlorine dioxide produced by using a single methanol reducing agent, and the by-product produced is sodium sulfate, not sodium hydrogen sulfate, so neutralization reaction treatment is not required.

Method for producing polycarbonate

Abstract: The invention relates to a method for producing polycarbonate according to the interphase method, the inventive method comprising the following steps: (a) an aqueous sodium hydroxide solution of a disodium salt of at least one dihydroxydiaryl alkane is reacted with phosgene in the presence of at least one organic solvent, a chain stopper and optionally a branching agent; (b) the oligocarbonates produced according to step (a) are condensed in the presence of at least one catalyst; and (c) the organic phase containing polycarbonate and obtained according to step (b) is separated A sodium hydroxide solution containing a maximum of 30 ppm, preferably a maximum of 10 ppm, sodium chlorate, in relation to 100 wt % sodium hydroxide, is used

Preparation method for recovering sodium chloride from sodium chlorate wastewater

Abstract: The invention discloses a preparation method for recovering sodium chloride from sodium chlorate wastewater The preparation method comprises the following steps: firstly, introducing electrolytic wastewater into a wastewater treatment tank for heating and filtering the wastewater by using a filter screen; secondly, adding a metal stabilizer into the filtered wastewater and carrying out chromium metal separation; thirdly, carrying out three-stage continuous evaporation and concentration on the separated wastewater and then carrying out solid-liquid separation through a centrifugal machine to obtain solid sodium chloride; fourthly, carrying out sulfate radical removal on the concentrated wastewater subjected to the solid-liquid separation to obtain barium sulfate precipitation and filteredliquid; fifthly, carrying out secondary evaporation and concentration on the filtered liquid, cooling to room temperature, adding an organic solvent and separating to obtain sodium chloride crystal The method disclosed by the invention has the advantages that the operating temperature is low, so that the service life of the equipment is prolonged; meanwhile, the production efficiency is improvedand the production cost is reduced; in addition, secondary treatment is carried out on the concentrated wastewater, so that the production cost is further reduced

Kinetics and Mechanism Study on Chlorine Dioxide Generation with Hydrogen Peroxide

Abstract: The reaction between hydrogen peroxide and sodium chlorate in presence of aqueous sulfuric acid was studied at various temperatures and molar concentrations of hydrogen peroxide, chlorate and sulfuric acid. The reaction rate law was established by analyzing the consumption of chlorate or hydrogen peroxide. Reaction had been found 0.5 and 1 order with respect to hydrogen peroxide and chlorate concentration, respectively. Reaction order was found about 5.99 with respect to molar concentration of sulfuric acid but it reduced to 1.64 when acidity function, h-, was substituted in place of molar concentration. The temperature dependence of the reaction was also investigated and pre-exponential Arrhenius parameter as well as activation energy were determined. Reaction mechanism compatible with the reaction kinetics was proposed.

Real-Coded Genetic Algorithm for Fixed Structure PID Controller Tuning in Sodium Chlorate Process

Abstract: Sodium chlorate manufacture is among the most energy-intensive industrial electrochemical processes. Industrial manufacture of sodium chlorate crystals will be energy efficient only if the pH of the reactor bulk is controlled. If pH is not within the specific limits, the cell efficiency drops to as low as 66%. This article proposes a fixed structure PID controller for pH in the cell bulk. The fixed structure controller is a solution to issues faced in industrial controller design, such as model uncertainties, nonlinearities, and disturbances. However, a fixed structure controller design results in an optimization problem characterized by multimodality, conflicting constraints, ample pursuit space, and expensive cost function. Traditional optimization methods are inappropriate since a feasible solution set must be computed. Soft computing methods like evolutionary algorithms can handle this problem. This paper attempts to design a fixed structure controller for the pH process in sodium chlorate cells utilizing a real-coded genetic algorithm. The performance of fixed structure controllers is compared with conventional PI and PID controllers empirically. The proposed method’s set-point tracking, disturbance attenuation, and robust stability were found satisfactory.