SU1447395A1 - Catalyst for oxidizing sulfuric compounds - Google Patents

Description

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The invention relates to the production of heterogeneous catalysts for the liquid-phase oxidation of sulfur compounds and can be used in the purification of natural hydrogen sulfide containing. waters of the mining industry, as well as during the regeneration of waste absorption solutions of the process of purification of process gases from hydrogen sulfide with obtaining elemental sulfur as the final product, in the gas processing, oil refining, and chemical industries.

The purpose of the invention is to increase the selectivity for sulfur, the catalytic activity and stability of the catalyst due to the content of an additional component, coke crumb, and a certain ratio of components.

Example to Catalyst of composition, May,%: ash 15: water-insoluble cobalt phthalocyanine (FCC) 1; coke crumb 5; polyethylene else, prepared on laboratory rolls by mixing 7.5 g of coal ash — ash, removed from electrostatic precipitators, 0.5 g of powdered FCF, 2.5 g of coke crumb and 39.5 g of granulated high-pressure polyethylene (LDPE) at the melting point of polyethylene to obtain a homogeneous catalyst mass, followed by formation in the form of a round bar.

Coke crumb is a waste from the vortex combustion of coal in PK-24 boilers; CHP when generating power steam and has the following characteristics: fractional composition 0.25-1.25 mm; total pore volume 1,5-t, 6 cm / g, specific surface area 600-700 pore radius up to 100 nm 10%; 100-500 nm 20%, 500-1000 nm 30%, the rest 1000 nm.

All metals in the coke crumb according to the X-ray diffraction analysis are in the oxide form.

The technical and elemental composition of coke chips are presented in table. 1 and 2.

Chip 5 mm wide and 0.5 mm thick is cut from a catalyst mass on a lathe.

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In a similar way, catalysts containing ashes, coke chips, APC and LDPE are produced in various mass ratios.

All the catalysts thus obtained are used both for the regeneration of the soda absorption solution used to purify the process gases from hydrogen sulfide and for the purification of natural waters.

Example 2. Experiments on the regeneration of soda solution and the purification of process gases from hydrogen sulfide were carried out on an installation consisting of two glass columns with a height of 700 mm and a diameter of 30 mm filled with a catalyst. One of them plays the role of an absorber, where the catalyst plays the role of nozzles to increase the mass transfer between the absorbing liquid and the process gas, as well as to nucleate the primary catalyst-oxygen-hydrogen sulfide complexes - polysulfides, and the other column - the regenerator. Untreated process gas is supplied to the absorber, and air for oxidation of hydrogen sulfide to almost elemental sulfur is fed to the regenerator. The process is carried out as follows: 350 ml of the spent soda absorption solution of the composition: 20 g / l, 350-400 mg / l of hydrogen sulphide, pH 8.5, comes from the adsorber, where gas is continuously cleaned from the countercurrent. hydrogen sulfide in the regenerator, which is loaded with 35 g of catalyst, containing, wt.%: ash 15, coke 5; FCC 1.0; LDPE the rest, prepared according to example 1, the residence time of the spent absorption solution in the regenerator is 15 minutes, where air is continuously supplied to oxidize hydrogen sulfide at a volumetric rate of 60 l / h at atmospheric pressure. The stripping air passes through the hydrogen sulfide control absorber system. To assess the catalytic selectivity for sulfur and the activity of the prepared catalyst, the residual concentration of hydrogen sulfide at the exit from the regenerator is determined by the method according to GOST 22985-78, as well as the oxidation products — thiosulfates, sulfites, sulfates and total sulfur, in the absorption solution.

and then elemental sulfur according to known methods.

Comparative data on the determination of catalytic activity

sulfur lectures of the obtained catalysts for various ratios of the active components are presented in Table. 3

Example 3. The installation described in example 2 was used to test the stability of the proposed catalyst under pressure in comparison with the prototype in the process of regenerating soda absorption absorber used to purify gas from hydrogen sulfide up to 0.5%.

Regeneration is carried out with an air supply of 60 l / h5 atmospheric pressure.

The research institute, the residence time of the regeneration solution is 15 min in the presence of a catalyst of the following composition, wt%: ash 20; FCC 2 coke crumb 7j polyethylene rest, prepared according to example 1,

The data obtained are presented in Table. four,

Example 4. 300 ml of formation water composition; 100 g / l of salt, 190-110 mg / l of hydrogen sulphide, pH 7.2, is oxidized in the presence of 30 g of catalyst prepared under conditions of example 1. Catalyst chips are loaded into metal III batch reactor thermostat with a water jacket, dispersant plate in the lower part of the reactor, an exemplary manometer to control the working pressure. Air is supplied from a cylinder through a reducer, dosing is carried out using a rheometer at the outlet of the reactor. The stripping gases pass through the absorber system controlling hydrogen sulfide. Hydrogen sulfide produced water is oxidized in a static mode at room temperature, a pressure of 3 MPa for 5 minutes at a supply of 5 liters of air per 1 l of treated water.

All the resulting catalysts (of different composition) are tested according to the above method in comparison with the prototype. The analysis of residual hydrogen sulphide and its oxidation products is carried out according to the methods used in device 3,

The results are presented in Table. five.

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Example 5 o On the unit 5 described in example 4, tests are performed to determine the stability, selectiveness and catalytic activity of the proposed catalyst in a dynamic mode 1700 ml of highly mineralized reservoir water of composition: 100 g / l of salts, 100-110 g / l of hydrogen sulfide, pH 7 , 2, is oxidized in the presence of 170 g of the catalyst; % g ash 20; FCC 2, coke crumb 7, polyethylene rest, prepared according to example 1. The composition of the ash and coke crumb in all samples is the same, i.e. as in examples 2, 3, 4.

Catalyst chips are loaded into the reactor according to example 4. The oxidation of hydrogen sulphide of produced water is carried out at 20 + 2 °, pressure is 3 MPa, temp. stay in the reactor for 5 minutes with the supply of 5 liters of air to 1 liter of treated reservoir, which characterizes the defensive protection oxygen mode. Water and air are fed into the reactor by a flow. In order to evaluate the selectivity, catalytic activity and stability of the proposed catalyst, experiments are compared with the selectivity, catalytic activity and stability of a known catalyst.

The results are shown in Table 6.

The content of coal ash in the proposed catalyst below 15 wt.% Reduces the activity, and above 20 wt.% Increases the activity j but reduces selectivity for sulfur.

The content of phthalocyanine on cobalt below 1 wt.% Reduces the selectivity of the catalyst for sulfur, and an increase in the content of 2 wt.% Does not have a significant effect on the selectivity of the catalyst, as well as on its activity. In addition, an increase in its content increases the cost of the catalyst.

The coke crush below 5 wt.% Reduces the activity and selectivity of the catalyst5 and an increase above 10 wt.% Does not have a significant effect on the activity and on the selectivity of the catalyst, moreover, increasing its content reduces

catalyst strength. I.

The data show that

unlike the known catalyst, the catalyst is more active j, possesses

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increased selectivity for sulfur and exhibits high stability of the catalytic activity and selectivity in the process of regenerating soda absorbent and purifying natural waters with the minimum required amount of oxygen in the air.

The use of the proposed catalyst in the process of regeneration of the sorbent, in particular the soda solution used to purify process gases from hydrogen sulfide, eliminates costly purification methods based on the use of more aggressive absorbents (mouse-soda solution, diethanolamine, dimethylformamide ) and reduces the regeneration time by an average of 1.5 times.

The use of the proposed catalyst in the process of purification of sulfur-containing formation waters allows for

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It is necessary to shorten the oxidation time of hydrogen sulfide by 3 times (instead of 15 minutes to 5) with the same air flow.

Claims (1)

Invention Formula The catalyst for the oxidation of sulfur compounds containing coal ash, cobalt phthalocyanine and a thermoplastic carrier is polyethylene, characterized in that, in order to increase sulfur selectivity and catalytic activity and stability, it also contains coke chips in the following ratio of components, May. %: Hard coal ash15-20 Phthalocyanine cobalt | 2 Koksov kroshka5g10 PolyethyleneErest The technical and elemental composition of coke crumb (May.%) X-ray analysis results Table 1 table 2 T a b l n c a 3 Table 4 1447395 JO Continuation of table 4 n  The proposed catalyst composition, Mac.% J ash 20; FCC 2 coke crumbs 7; LDPE rest; Famous catalyst composition, May. %: ash 50 FCC 5; LDPE rest. 1447395 12 Table 6