SU1287925A1 - Method of cleaning gases from hydrogen sulphide and sulphur dioxide - Google Patents

Abstract

This invention relates to catalytic gas cleaning processes for sulfur compounds. The aim of the invention is to increase the degree of purification. Gas removal from hydrogen sulphide and sulfur dioxide is carried out by contacting with an aqueous solution containing a catalyst — a solution of aluminum oxide or aluminum or silicon hydroxide in hydrofluoric acid and a buffer solution — an ammonium phosphate solution, or sodium, or potassium in a ratio of 2.5-3.5 t2 in phosphoric acid. In this case, the buffer solution is pre-mixed with the catalyst and the resulting mixture is held at 0-20 ° C for 20-50 hours. The sorption capacity of the solution is 31-32 g of sulfur / 1 l-h. 2 tab. (L with U 1чE 00 with to

Description

The invention relates to catalytic methods for the purification of waste gases containing sulfur compounds, in particular the waste gases of Claus plants, and can be used in gas, petrochemical industries and as well as for cleaning exhaust gases of metallurgy and power plants.

The aim of the invention is to increase the degree of purification.

Example 1. A method of cleaning gases was carried out in a laboratory setup, including a glass absorber, gas cylinders, rheometers, manometers, thermometers.

In the gas entering the absorber and the purification of hydrogen sulfide and sulfur dioxide, contained wt.%;

HgS 1-3

SO 0.5-1.5

 Up to 100

The linear velocity of the gas in the absorber was maintained at a level of 0.1-0.2 m / s. The process was carried out at atmospheric pressure., 1 MPa and) ° C.

An absorption solution for cleaning gas from hydrogen sulphide and sulfur dioxide is prepared as follows. Preparation of the catalyst. The catalyst solution is prepared and oxides or hydroxides of aluminum or silicon by dissolving them in hydrofluoric acid in a manner similar to that of a known method and at the same concentration.

Preparation of phosphate buffer. K 3 n. a solution of phosphoric acid was added 3 n. ammonium or sodium or potassium phosphate solution and diluted with distilled water so that the concentration of phosphate and phosphoric acid is 1-35%, and the ratio of these components is 2.5-3.5 / 2.

The prepared catalyst and buffer solutions can be introduced into the absorber separately. However, to further increase the activity of the absorption solution, it is advisable to mix them by the following method.

The catalyst is metered into the buffer solution, stirred and the resulting mixture is kept at -10-30 ° C for 5,10,20,50 and 120 h. The resulting solutions are tested for gas purification.

- Different modes of activation of absorption solutions by the method of aging are presented in Table 1. The sorption capacity of the solution was determined from the material balance of the gas and from the sulfur yield.

Analyzing the data of table 1, we can conclude that the activation of the solution is advisable to carry out

0-20 ° C for 20-50 h (examples 2,4,6), when going beyond these limits, the activity of the solution decreases. The sorption capacity of the absorption solution, i.e. his activity at

aging, increased by 30-40%. When the temperature is above 20 ° C (Example 7), the maximum sorption capacity decreases (up to 22 g of sulfur / liter h). At temperatures below 0 ° C (example 1)

maximum sorption capacity is reduced to 20 g sulfur / 1. With an increase in the holding time of the CBbmie solution for 50 h (Example 5), the maximum sorption capacity does not increase. When reducing the exposure time to less than 20 hours (example 3), the maximum sorption capacity decreases to 20 g of sulfur / 1 l-h.

Data on the process for

the method of example 1 are presented in table 2.

When going beyond the proposed concentrations in the direction of decreasing the activity of the solution decreases to the level known (example 10), with increasing concentration above the proposed activity of the solution does not change significantly. For buffer solutions, containing sodium and potassium phosphates and

phosphoric acid, the concentration change is similar.

With an increase in the ratio of ammonium phosphate and phosphoric acid in a buffer solution of more than 3.5 activity

the solution drops to 4 g of sulfur / l.h

(Example 5), and with a decrease in the ratio, the activity of the solution remains at the level of the lower limit. For solutions containing Na, K, and

phosphoric acid, the dependence of the solution activity on the ratio of the components of the buffer solution is similar.

Claims (1)

Formula due to shadow The method of purification of gases from hydrogen sulfide and dioxide, sulfur with obtaining elemental sulfur by their absorber312879254 water in the presence of a catalyst as a buffer solution using a solution of oxide or hydroxide is a solution of ammonium phosphate, or aluminum or silicon in sodium fluoride, or potassium in phosphoric acid and a buffer solution, taken in the ratio 12.5-3.5: 2, pa, characterized in that, which is pre-mixed with in order to increase the degree of purification, the catalyst and the mixture is kept when for 20-50 hours Table 1 Activation Modes Examples inLLTLlTL LTJriL Holding temperature  € -10 o -10 10 10. 20 30 Optimum holding time, h50 25 5 20 60 50 120 Maximum sorption capacity, g sulfur / 1 l-h 20 30 20 31 32 32 22 table 2 Content in Absorption Solution Relation Activity 1phosphate am-solution oxide / hydroxide of a mixture of phosphate moni or - (sorption aluminum or ammonium or three or ka-capacitance) cut in fluorine or potassium and phosphorus hydrogen hydrogen or phosphoric acid at acid, mol / l acid, wt.% 20 C, g sulfur / l r-ra. h A1,0z NH ten 2 A1.0, NH. ten -3 3 A1.0, NH ten 4 A1.0, NH ten -four 12 16 19 18 17 20 19 18 22 21 23 25 24 5 A1.0, t ten -3 12 6, NH ten 12 7 A1.0, 10 NH 35 8 A1.0 10 -3 NH ;; 35 NH 10AH OZ NH, ten , -3 11А1 „0 NH, Continuation of table 2 0.5 12 AIA ha t14 Na 15 AIjOj Na sixteen AH.OZ TO 17 A1aOz 18 A1A 19 A1 (OH) j, 20 A1 (OH) NH 2Ji AKOHV NH. 22 AI (OH) NH, 23 AI (OH) NH 24 Sic. NH 25 SiO, NH; 26 810 „ NH) ten . -I 27 Sio NH: The continuation of the table, 2, 2.5 / 2 24 12