SU48244A1 - Method of absorption of sulfur dioxide - Google Patents

Description

Cartbin is spread {% by the way of Shvlezeni SO, from pyritic gases "whose is the Gönich Schröder Method. It consists in TOMi that cold gases flow from bottom to top in a tower filled with coke, cold water flows down to meet them, which absorbs SO2 from gases. Other gases — nitrogen and oxygen — are not retained with water and are released into the atmosphere. The aqueous solution obtained in this way contains in 1 liter 10 to 15 g of F30. Out of 6% of gas, water cannot absorb more (Henry-Dalton's law). From the SOj solution it is distilled off with live steam. The mixture of steam and SOa enters the cooling column, the steam condenses, and the concentrated SO2 is first dried with sulfuric acid, then enters the gas tank, and from there to the compressor.

Other methods, such as the absorption of SOg by organic substances, as well as the adsorption of SOj by activated carbon and silica gel in the technique, are not yet used because of the serious difficulties encountered. In Germ. pat K2 160940 describes a method for absorbing SO2 with dicalcium phosphate, but due to the insolubility of the latter, scrubber nozzles are unavoidable and the process cannot be continuously carried out. Using the Genish-Schroeder method, SO2 can only be extracted from gases.

with a content of at least SOj. For stripping off SOa from the solution, you spend a lot of steam, despite the use of heat exchangers. Gases with an SOi content less than 5–6% (water-batching 1–2% SOa) are no longer profitable for extracting SO2 from them, since water absorbs little SOa from them (Henry Dalton's law) and excessive steam will be required to release SO from these weak solutions.

The author's research in the field of absorption of ZOZ from gases showed that there is an absorbent that extracts SOa from gases containing more than 0.5 - 0.25 / o SOj, which until now was considered impossible, and 1 liter of absorbent can be absorbed from such a gas 120 - 150 g of SOa- By heating with hot or deep vapor, SO2 is released from this absorbent. Dbosbent after it is cooled to ordinary temperature goes back into the cycle; however, it does not deteriorate and may serve for absorption for a long time.

The absorbent consists of a solution of sodium phosphate, potassium, or ammonium, alone or in a mixture. The reaction is carried out according to the following formula:

1 NaaHPO, + SOg -f NZO: ManH2PO4 +

+ NaHSOs

1) at ordinary temperature, 2) when heated.

In the cold and at ordinary temperatures, the solution absorbs SOg, and when heated, SOg is released from the solution. For a more complete separation of the SOE and the solution, it is useful in the initial solution, in addition to NagHPOi (diphosphate), to have some more MaH2PO4 (monophosphate), for example, 90-70% diphosphate and 10-30% monophosphate. This is explained by the law of action of the masses. With an excess of acidic monosalt, the reaction is:

NaHSOs + NaHgPOi NagHPO -f

-j-SOa + HgO

goes better than with equimolecular quantities.

The present method has the following advantages over the Genish Schroeder method:

1. Heat consumption for the release of SO2 from the solution will be significantly less, since the proposed solution contains a 10 times more SOg (120-150 g

in 1 l) than the aqueous solution of Genish-Schroeder (10-15 g SOa in 1 l).

2. The described absorbent can extract SOj sales from weak gases containing 0.5-0.25% SOg, which is unprofitable by the Genish-Schröder method.

The subject matter of the invention.

Claims (2)

1. A method of absorbing sulfuric anhydride in the cold from the gas mixture containing phosphate with its subsequent release when heated, characterized in that the absorption is produced by solutions of a mixture of sodium, potassium or ammonium mono-diphosphates followed by separation of the sulfuric anhydride from solutions at 90 and above. 2. A method according to claim 1, characterized in that a mixture of sodium di-monophosphate and a sodium monophosphate is used in the absorption of phosphoric acid diphosphate from 90 to monophosphate and from 10 to 30% to absorb sulfur dioxide.