Air electrode for producing alkaline hydrogen peroxide and preparation method thereof
The present invention belongs to the field of preparing inorganic compounds by electrochemical methods. The invention relates to a quinone-containing air electrode for industrial preparation of alkaline hydrogen peroxide and a preparation method thereof. The multi-component electrode group of the present invention is assembled by unit plates. Each pair of electrodes is composed of a cathode plate, a quinone-containing air cathode carbon core, an ion exchange diaphragm, a plastic support net and an anode plate. Fluid distribution is provided at the upper and lower ends of the electrode working area. The chamber and collection chamber are equipped with throttling holes at the fluid inlet. The multi-component electrodes are connected in series with limited dipoles, and the plastic hose used for circulating alkaline water in the anode is extended to more than 5 meters. The present invention can prepare alkaline hydrogen peroxide under the condition of directly using low-pressure air and obtain satisfactory working indicators, and does not have the disadvantage that the electrode is soaked by alkaline water and becomes ineffective. Quinone-containing air electrodes for producing alkaline hydrogen peroxide are characterized in that each pair of electrodes is composed of an anode plate, a plastic mesh, a cation separator and a quinone-containing air cathode. A distribution chamber and a distribution chamber for incoming fluid are provided at the upper and lower ends of the electrode working area. The collection chamber for discharging fluids has an orifice at the fluid inlet. The multi-component electrodes adopt a limited dipole series connection method. The plastic hoses used for the inlet and outlet of the anode circulating alkaline water are lengthened and then connected to the liquid collection main pipe. , the multi-component electrode group is assembled from unit plates.
Neutralizing the aqueous sodium peroxide solution with phosphoric acid
The present invention relates to the field of preparation of inorganic compounds, in particular to the aqueous sodium peroxide solution of the cathode product obtained from the patent application No. 871 03988 Method for preparing hydrogen peroxide. Use phosphoric acid or sodium dihydrogen phosphate to neutralize the sodium peroxide aqueous solution to pH 9.0~9.7 to generate Na2HPO2 and H2O2. Cool the Na?HPO? and H2O2 aqueous solution to +5~-5℃ to make it insulated. Most of Na2HPO2 is precipitated in the form of Na2HPO2 ·10H2O hydrate, and then the mixture containing Na2HPO2 ·10H2O hydrate and peroxide oxygen aqueous solution is separated in a centrifugal separator, and the hydrate is separated, and then the mixture containing a small amount of Na?HPO? The aqueous hydrogen peroxide solution is evaporated and fractionated to obtain approximately 30% H2O2 product. ---------------------------------------- Claims: Method for preparing hydrogen peroxide , which is characterized in that it is prepared from sodium peroxide aqueous solution using the following steps: (1) Use phosphoric acid or sodium dihydrogen phosphate NaH2PO2 to neutralize the sodium peroxide aqueous solution to 9.0~9.7 to generate Na?HPO? and H ?O? aqueous solution, (2) Cool the Na2HPO2 and H2O2 aqueous solution to +5~-5℃, so that most of the Na2HPO2 is precipitated in the form of Na2HPO2 ·10H?O hydrate, (3) In the centrifugal separator Separate the mixture containing Na2HPO2·10H2O hydrate and hydrogen peroxide aqueous solution, so that the Na2HPO2·10H2O crystals are separated from the hydrogen peroxide aqueous solution containing a small amount of Na2HPO2, (4) The aqueous hydrogen peroxide solution containing a small amount of Na2HPO2 Evaporate in the evaporator to obtain steam containing H2O2 and H2O, while the concentrated Na2HPO2 salt solution containing hydrogen peroxide flows out from the bottom and returns to the neutralization tank. (5) Put the steam containing H2O2 and H2O in the fractionation tower Carry out vacuum fractionation to obtain about 30% H2O2 product.
Electrolyzed sulfuric acid
Use electrolysis of 60% sulfuric acid to obtain peroxydisulfuric acid, which can then be hydrolyzed to obtain hydrogen peroxide with a concentration of 95%.
2-Ethylanthraquinone (EAQ) method
At present, the main method for industrial scale production is the 2-ethylanthraquinone (EAQ) method.
2-Ethylhydroanthraquinone reacts with hydrogen under the action of a catalyst at a certain temperature and pressure to form 2-ethylhydroanthraquinone, and 2-ethylhydroanthraquinone undergoes an oxidation-reduction reaction with oxygen at a certain temperature and pressure, and 2-ethylhydrogen The reduction of anthraquinone produces 2-ethylanthraquinone and hydrogen peroxide (H2O2) --------------------------------- -------------------------------------------------- -------------------------------------------------- ------------------ Packing: Packed in polyethylene barrels, there should be vent holes on the container cover, wrapped in wooden boxes, net weight per barrel 20kg. Precautions for storage and transportation: This product is a first-class inorganic acidic corrosive product. This product should be stored in a cool, clean and ventilated warehouse. The temperature should not exceed 30°C and avoid sunlight. The container should be tightly closed, but the ventilation holes should be clear to prevent dust from clogging it, which would easily decompose and deteriorate if it falls into it. Isolate heat sources and fire, and do not store or transport it with organic matter or metals such as iron, copper, chromium and their salts. Wear work clothes, masks, and gloves when handling. If it accidentally touches the skin, rinse with water. If it touches the eyes, rinse with warm water. This product should not be stored for a long time. Inspect the product regularly and replace it promptly if a leaking barrel is found. If the dunnage wood smokes, the smoking dunnage wood should be moved out of the warehouse immediately or poured with water to save it. In case of fire, water, sand or carbon dioxide fire extinguishers can be used to put out the fire.
Laboratory preparation method:
In the laboratory, hydrogen peroxide can be prepared by reacting dilute sulfuric acid with BaO2 or Na2O2: BaO2 H2SO4==== BaSO4↓ H2O2 Na2O2 H2SO4 10H2O == == Na2SO4 ·10H2O↓ H2O2 The filtered solution contains 6~8 H2O2