Method of cleaning exhaust gases of sulphur production
(57) Abstract:The invention relates to a method for cleaning exhaust gases of the production of sulfur containing H2S, SO2COS, CS2. The essence of the method lies in the fact that the cleaned gas is passed at 250-350°C over a catalyst consisting of either titanium dioxide or titanium dioxide, containing 1-20 wt.% sulphate of calcium, or strontium, or barium, followed by cooling of the gas and its processing method Claus at 100-160°C and a molar ratio of H2S : SO2= 2:1 to produce elementary sulfur. 2 C.p. f-crystals, 1 tab., 1 Il. The invention relates to the purification of sulfur-containing industrial gases.More specifically, the invention relates to the purification of the residual gases in the production of sulfur containing from 0.2 to 4% vol. H2S, SO2and at least one of the compounds COS and CS2.A known method of cleaning gases production of sulfur containing COS, CS2and SO2including gidrogenizirovanii and catalytic hydrolysis of sulfur-containing gases, cooling the residual gas and the subsequent catalytic processing it according to the method Claus at a temperature of 100-160aboutC and a molar ratio of N2S: SO2=2:1 with polyclonality, associated with the implementation of gidrogenizirovanii sulfur-containing gases and intermediate stages of cooling gas flows and oxidation of hydrogen sulfide.The purpose of the invention is to facilitate the method.This goal is achieved by the proposed method to obtain purification of the residual gases in the production of sulfur containing water vapor and sulfur compounds from 0.2 to about 4. % consisting of H2S and SO2and at least one of the compounds COS and CS2including hydrolysis OS and CS2at a temperature of from 250 to 350aboutWith the hydrolysis catalyst, cooling the residual hydrolyzed gas and the subsequent processing is cooled in the presence of a catalyst Claus at a temperature of from 100 to 160aboutC and a molar ratio of N2S:SO2equal to 2:1 with obtaining sulfur, and characterized in that the hydrolysis of COS and CS2carry on the catalyst based on titanium dioxide, or consisting only of titanium dioxide, or of titanium dioxide containing from 1 to 20 wt.% sulphate of calcium, strontium or barium.The contact time of the residual gas with the catalyst of hydrolysis, i.e. the duration of the hydrolysis is mainly from 0.5 to 10 C. These values are given for standard conditions poverhnosti, measured by the method of WET constituting from 5 to 300 m2/g, and the total porous volume defined by the method of mercury penetration, of 0.05 to 0.6 cm3/,For heating the hydrolyzed residual gas to the temperature required for purification method Claus, mainly, you can use indirect heat exchanger with an agent having an appropriate temperature.Keeping the molar ratio of N2S: SO2equal to 2:1 in gidrolizovannogo residual gas supplied to the treatment, may be known for this regulatory methods, for example, by varying the ratio of expenses acid gas and gas containing free oxygen introduced to the sulfur plant with this change, primarily, by maintaining a constant flow rate of sour gas fed to the sulfur plant, and by changing the flow rate of gas containing free oxygen.The method is described below with reference to the diagram, as shown on the accompanying drawing, which schematically represents a consistently United sulfur plant Claus 1, hydrolysis reactor 2, the catalytic purification unit 3, a furnace for sigonius, which can be selected from such compounds as bauxite, aluminum oxide, silicon dioxide, natural or synthetic zeolites, which are usually used for the formation of sulfur between H2S and SO2.Sulfur plant 1 includes, on the one hand, the combustion chamber 6, which contains the burner 7, provided with a pipe 8 for supplying an acidic gas and a pipe 9 for supplying air, the latter pipe provided with a valve 10 with an adjustable valve, and which has an exit 6A for gases, and, on the other hand, the first catalytic Converter 11 and the second catalytic Converter 12, each of which has one input, respectively, 11a and 12A, and one output, respectively 11b and 12b separated by a fixed catalyst bed reactor. The combustion chamber 6 and the catalytic converters 11 and 12 are set sequentially so that the output 6A of the combustion chamber was connected to the input 11a of the first Converter 11 through the first sulfur condenser 13, then the first heater 14, and the output 11b of the specified first Converter was connected to the input 12A of the second Converter 12 through the second sulfur condenser 15, then the second heater 16, and the output 12b UDC 17b for gases, which is output from the sulphur plant.The catalytic purification unit 3 contains two catalytic reactor 18 and 19, mounted in parallel and having, each, on the one hand, the inlet pipe for the purified gas, respectively 20 and 21, and the specified inlet pipe fitted with a valve, respectively 20A and 21A, and the injection pipe, respectively 22 and 23 of the regeneration gas and cooling, with the specified injection pipe provided with a valve, respectively, 22A and 23a, and, on the other hand, the output pipeline purified gas, respectively 24 and 25, and the output pipe fitted with a valve, respectively 24A and 25A, and an outlet pipe, respectively 26 and 27 eluent regeneration and cooling, with the specified outlet pipe provided with a valve, respectively, 26a and 27A. Input pipelines, respectively 20 and 21, catalytic reactors 18 and 19 are connected through appropriate valves 20A and 21A, to the pipe 28, which forms the entrance of the catalytic purification unit 3. Similarly, outlet pipes, respectively, 24 and 25, these catalytic reactors 18 and 19 are connected through appropriate valves 24A and 25A, to the pipe 29, obraz and injection pipelines separated from the output holes and outlet pipes fixed bed catalyst Claus. Insectine pipelines 22 and 23 of the reactors 18 and 19 set in parallel through the respective valves 22A and 23a at one end 30A of the conduit 30 is circulating regeneration gas and cooling and discharge pipes 26 and 27 of these reactors also installed in parallel at the other end 30b of these reactors also installed in parallel at the other end 30b of the specified pipe 30. This conduit 30 is set from the end 30b by the end of 30A, sulphur condenser 31, the fan 32, valve 33, a heater 34 and the outlet 35, provided with a valve 35A, and the ends of the specified challenge facing the pipe 30, one between the fan 32 and the valve 33 and the other below the heaters 34. The fan 32 is mounted on the pipe 30 so that the suction hole of the fan is connected with a sulfur condenser 31. The pipe 29, which forms the output of the cleaning unit 3, is connected through line 45, to the furnace combustion 4, which is connected, through line 46 to the chimney 5.Hydrolysis reactor 2 has one input 2A out 2b separated from one another a fixed layer hydrolytic catalyst. Exit 17b sulfur plant 1 is connected by a pipe 36, through the heater 37 type indirect theres cooling system 39 type indirect heat exchanger, to the pipe 28, which forms the entrance of the unit clean.The analyzer 40, for example, type interferential spectrometer installed with the bend on the pipe 38 below the cooling system 39, and the specified analyzer carries out the determination of the molar content of N2S and SO2in the gas circulating in the pipe 38, and sends a signal 41 representing the instantaneous value of the molar ratio of N2S:SO2in the specified gas. The signal 41 is served by a computer 42, which generates a signal 43 representing the adjustment of the air flow to bring the instantaneous molar ratio of H2S:SO2to the target value, and the specified signal 43 serves on the flow regulator 44, which regulates the opening of the valve 10, which provides regulation of the air flow introduced to the sulfur plant through a pipeline 9.In this setting, the implementation of the method can schematically be represented as follows.It is assumed that the reactor 18 is in phase reaction, and the reactor 19 is in a regeneration phase, the valves 20A, 24A, 23a, 27A and 33 are open at the same time as the valves 21A, 22A, 25A, 26a and 35A are closed.
2S and SO2and elemental sulfur. This effluent, after separation of the contained sulfur in the first sulfur condenser 13, is heated in the first heater 14 and is directed to the first Converter 11. Upon contact with the Claus catalyst contained in the Converter, connect the H2S and SO2available in gas afluente, react with sulphur. The reaction mixture is received from the Converter 11, after the separation of the contained sulfur in the second capacitor 15, followed by heating in the second heater 16, is sent to the second Converter 12, in which is formed a new amount of sulfur by catalytic reaction between H2S and SO2. The reaction mixture coming from the Converter 12, exempt from the contained sulfur in the third capacitor 17.Via exit 17b for gases specified capacitor, which forms the output of the sulphur plant, remove residual gas containing water vapor and less than about 4. % in General, the sulfur compounds containing H2S, SO2COS and/or CS2and a very small amount of steam and/or porous sulfur.