CS9101241A2 - Method of hydrogen sulfide and carbon dioxide containing gas purification - Google Patents

Abstract

Purificn. of a gas contg. combustible components, CO2 and S cpds. (esp. H2S) is carried out by scrubbing with a scrubber soln. which is regenerated by expansion, stripping and hot regeneration, H2S-rich off-gas from the hot regeneration being processed to elementary S and an H2S-contg. residual gas which is contacted with scrubber soln. The novelty comprises (i) partially combusting the H2S-rich off-gas with oxygen(-contg. gas) or air in a combustion chamber to produce a gas mixt. at 1000-2000 deg.C contg. at least 30 mol.% of the introduced sulphur as elementary S and contg. H2S and SO2 in the molar ratio 4-1:1; (ii) cooling the gas mixt. to below the dew point of elementary S and separating the condensed S; (iii) heating the gas mixt. to 180-200 deg.C and subjecting it directly to catalytic hydrogenation and/or hydrolysis to convert residual SO2 into H2S; and (iv) contacting (part of) the treated gas, as H2S-contg. residual gas, with scrubber soln.

Description

-1-

A method for purifying hydrogen sulfide-containing gas and the like

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for the purification of a gas comprising a combustible component as well as carbon dioxide, and a sulfur compound, such as E2S, in the wash zone by a solution that is regenerated and reused. ... wherein the regeneration wash solution is released from the pressure, stripped and heated for hot recovery, H2S-rich exhaust gas. from regeneration for. hot, working. The elemental sulfur and residual gas-containing H2Sa residual gas are contacted with the scrubbing solution. In the European patent 0 054 772, a method of this kind is described, wherein the off-gas supplied to the Claus apparatus comprises. HgS and large amounts of CO 2 · This waste gas further processes in a relatively expensive Claus plant which exhibits two or three catalytic stages. the waste gas after partial combustion of EgS to SO 2 is converted catalytically by a Claus reaction of "2 H 2 S + SO 2 -> 3 S + 2 E 2 O" and "... as imperfect as elemental sulfur and water". Forward and beyond each of these catalytic grades. Elemental Sulfur Allows Gaseous Snow to Condense and Separates · The catalytic reaction steps are followed at a known stage by hydrogenation, before the waste gas is returned to the scrubber.

These catalytic steps of the process cause considerable costs and have the drawback that. expensive starting, equipment. There is also the danger that catalysts will lose their activity quickly when the device is started and stopped frequently and extreme load changes occur.

The invention is based. the essential task of carrying out the treatment of the waste gas rich in H 2 S-regeneration, however, that the start-up of the plant can be effected. to be a simple one. and even more frequent. rotation rotation is no-problem. According to the invention, this is achieved by the above process. by getting waste gas ... rich in. HgS-z regeneration after, heat burns, partly in. a combustion chamber with oxygen containing oxygen or air and a combustion chamber is produced, a gaseous mixture having a temperature in the range of 1000-2000C, which contains no name. 30. mol%. sulfur introduced into the combustion chamber as elemental sulfur. and components E2S and SOg .v. mole ratio 4: 1 to. 1: 1, then. se. the gaseous mixture cools the melting point. sulfur, the condensed elemental sulfur is separated off, gaseous, the mixture is heated to ISO 280 ° C, and is produced directly by catalytic hydrogenation and / or hydrolysis, the residual SO 2 content being recovered. to K2S. and at least a portion of the gas so treated. as the H2S-containing residual gas is fed to. contact with washing equipment. In particular, the process according to the invention is suitable for de-sieving; In the process according to the invention, care is taken to ensure that the H2S-rich waste gas fed to the combustion chamber is enriched with H2S, in this case, the combustion chamber and in the immediate connection react with it a reaction of H2S + 02 = S + K20 with a high proportion of hydrogen sulphide on the elemental sulfur, Troto may refrain from further processing of the gas mixture by catalytic -3-reaction of E2S and SO2 in / with the Claus reaction EgS + SO 2 + 3 S + 2 H 2 O

It is contemplated that there is less reactivity of the H2S that it has. The result is an increased need for hydrogenation, cooling of the hydrogenation catalyst necessary due to the higher hydrogenation yield. The process according to the invention can be achieved by means of a cooling gas supply, through which the missing hydrogenation hydrogen can also be supplied.

Residual gas. hydrogenation and / or hydrolysis containing H 2 S-may be carried out, for example, by washing. or even regeneration; Next, the possibility-lies in that being. this residual gas flows directly into the combustion chamber, which is especially recommended when it is not. the combustion chamber supplies oxygen to the off-gas enriched with high E2S. Waste gas is generated in hot recovery. low in CO2 with CO 2 content max. more if the exhausted washing solution of the wash zone is released from the strain prior to regeneration in the least two generating columns. in this case, it is advisable to deliver the released gas at least partially to the previous stage as a shear gas. In addition, it is possible to strip the hot gas with inert gas, • The process is particularly well suited. for desulphurisation of high performance gases for gas turbine and turbine power plants. Such high-temperature gases can, for example, be produced in a manner known per se by gasifying solid fuels.

Different washing, solutions, selective for H2S are suited for gas purification. known, for example, by means of a physical treatment solution such as methanol, 1-methylpyrrolidone, methyldiethanolamine or dimethyl polyethylene glycol. The gas is most often carried out at pressures in the range of 5 to 100 bar and known for the wash solution.

AND

temperatures ranging from 80 ° C to + 100 ° C. open. At pressures of about -1 to 10 bar, pressures may be higher. Today, pressures of 1 to 10 bar are acceptable.

The method editing options are explained using a drawing. List of drawings in the drawing

FIG. Figures 1, 3 and 4 show block diagrams of different variants in a manner and Fig. 2 shows an example. The Claus device used according to the invention, in a simplified representation. Examples of the Invention i. In the method of Fig. 1, the gas to be desulphurised by conduit 1 to the wash zone 2 is provided. to which. The treated gas is fed through the recovered washing solution. The purified gas is drawn off through a 4. The spent washing solution, which contains E2S and CO 2, is passed. management £ for partial. release from voltage to re-absorber 6. Reabsorber.6 ... is. a regenerative column comprising a known substance exchange element, for example, liquid and gas permeable bottoms. In the reabsorption, the C02 is most desiccated, however, HgS-is maintained as far as possible by treating the solution. For this purpose, a regenerated washing solution is fed to the reabsorption head 6, which absorbs the rising gases, preferably the sulfur compounds. . The area of reabsorption 6 is fed from the line. 10 and 11. HgS containing gases which act as stripper gases in the reabsorption 6 and expel. in particular CO 2. The CO2-rich waste gas can be coupled to the gas, from line 4 for the most frequent uses, since it is desulfurized as completely as possible.

The scrubbing solution recovered in the conduit 13 first reaches the heat exchanger. 14, there is heated and flowed through the 15 k. Regeneration-16 hot. the cooker 17 is necessary to increase the temperature so as not to contaminate the washing solution, in particular. In addition, the stripping gas can be fed additionally by stripping gas stripped gas 18 through the stripping gas. it can be, for example, hydrogen, nitrogen, but also desulphurized waste gas.

Regenerated by work, the solution leaves the reneration. / 16 lead. 20, in the heat exchanger 14 is cooled, and through conduit 21 is. returns back to the wash area. 2 and to. reabsorberu 6. Waste gas rich, naphtha se. pulls off ..... on head 16 regeneration. The heat of the .23 and the partial flow is conducted through the conduit 24 to the Claus apparatus which consists of a portion of the burner B and a portion of the hydrogenation connected thereto. The details of the portion of the burner B and the hydrogenation portion H are explained below with reference to FIG. it explains that the hydrogenation part. H includes hydrogenation. and / or hydrolysis. 23z-Regeneration 16th heat, is passed through condenser 26 and conduit 11 and reabsorbed 6.

1, it is indicated that oxygen or air or oxygen-enriched air is fed, via line 28, to the exhaust gas, rich, H2S supplied. line 30 se. it discharges the elemental sulfur through the exhaust gas it contains. The ε-S 2 -SO 2 is fed to the hydrogenation portion Eα of the residual gas containing HgS from the hydrogenation. Part H. is returned to the temperature control line 10a in the hydrogenation reactor. The washing zone 2, the seab sorber 6 and the hot regeneration 16 may comprise the self-known substance exchange enhancing elements, e.g., the bottom.

The Claus device shown in detail in FIG. 2, which essentially consists. from the burner portion B / between. The reference numerals 24 and 40 and the hydrogenation portion between the reference numerals 45 and 50 operate as follows. The off-gas from the process 24, together with the oxygen-containing gas coming out of line 28, is separated. first brings .ke. The details of such a combustion apparatus are disclosed in DE-OS 37 35 002, as well as in U.S. Pat. No. 4,632,819. . with temperatures ranging from 1000 to 2000 ° C, while the oxygen ratio in the process 28 is adjusted to a molar ratio of εgSk. The SO 2 in the gaseous mixture was between 4: 1 to 1: 1, preferably about 2 µl in the indirect heat sink. 32. which. is provided with a power supply 34 for the power supply. water. and the vapor recovery line 33, the gaseous mixture is cooled below the sulfur melting point, so that the condensate elemental sulfur is passed through the conduit 30a to the collecting tank 35.

The cooled gaseous mixture flows through line 37 to another, non-direct cooler 22, and the yield of elemental sulfur, lato, is improved. elemental sulfur flows through the conduit. The gas inlets 40 now have glazing temperatures of about 125 ° C to 135 ° C. For heating, a 43 ° lath preheated gas mixture is passed through an indirect heat exchanger and passed at an ISO temperature of 280 ° (to a catalytic hydrogenation line 45 of 46 ° C). whereby a hydrogen-containing gas is fed through the conduit 46a if the hydrogen produced in the combustion chamber 31 is hydrogenated, in particular the SO2 to EgS, in a known manner. For this purpose, for example, cobalt-molybdenum catalysts are used. The gaseous mixture coming from the hydrogenation 46 is first precooled in the condenser 47 and then fed to a direct condenser 48 to remove water. the water supplied in the cycle through the indirect condenser 49. The instantaneous water is withdrawn by the conduit 22. In the conduit 10, the residual gas comprising EgS with temperatures of about 20 to 40 ° The coolant 48 is a partial stream of this residual gas, guided 10a back to the hydrogenation 46 to regulate the temperature in the hydrogenation. and 46a may also be provided by line 45. The residual gas in line 10, as shown in FIGS. 1, 3 and 4, is further processed.

Method variants according to. FIGS. 3 and 4 correspond in part to the guidance of the method of FIG. 1, so that the same reference numerals are used. markers and references, se-. the explanation given below, with FIG. Fig. 3 is the gas to be. Desulfurizing, it is conducted via line 1a and after mixing with gas from line 10 through conduction. ! wash areas ... 2. In the process of FIGS. 3 and 4, the regeneration is similarly carried out with two regenerative columns 7 and 51 in which the washing solution is partially released from the tension and treated with the same stripping gas. Stripping .gas. from column 7, there is a waste gas from the conduit 32 which comes from the regeneration column. 31 and flows. Referring to FIG. -3, the exhaust gas is fed from the column. 7 lines.60 partially; to work in area 2, the rest is flowing through the management. 61. to the hydrogenation part of the EClaus device. Hydrogen-containing gas is added via line 46a. . for example, it can be vented from pure flow 4 if this is appropriate.

The stripping gas is also fed through the line 18 to the hot gas and part of the exhaust gas from the hot gas. getting over. a control valve 66 and a conduit 67 as a stripping gas for the second regeneration column 51 ' solution from line ... 1 ^. flowing through the relief valve 15a, before it enters the column. Residual gas-containing H 2 S. from the hydrogenation section. H is passed through line 10 to the gas to be treated in line 1, which is similar to the embodiment of FIG. Fig. 3 uses residual gas containing S 2 S from conduit 10 as an additional stripping gas in the first regeneration column 6 and waste gas X 1 of the colony is passed through conduit 60 through the gas purge zone 2. hot regeneration 16 with feed 24 all into the apparatus and in the housing. The second regenerative column 51 is used as a stripping gas, for example, nitrogen, which is fed through line 62. The hydrogenation component E, usually a hydrogen source, is supplied as a hydrotreating agent. gas via line 46a. It is also possible to use part of the washed gas stream from line 4 as hydrogenation gas, for example 1. In carrying out the method of FIG. 3 with a Claus device. correspondingly, FIG. 2-gaseous product is deprotected. Dusting · Gasification of Coal Processes as. The amounts, pressures, and gaseous constituents in the various lines are shown in the following tables. All the amounts, and components, are in all examples given in kmol / h.

Leading '' ..... lá ----- 4 - '5' '10 60 61 amount 10000 10039,4 395,7 192, -5 247 119,9 pressure. / bar / 37 '36 37 1.1 1.4 1.4 Components: co2 1650 1656.4 294 104.3 196.3 95.7 E' S 33 - 75 22.7 19.3 9.4 E2 4317 4314.4 11, 2.8 7.5 3.5 CO 4000. 3993.6 15.5 0.4 10.5 5.0 V -...... .....-; . .75. 0.2. 62.3 12.9 6.3

Line '13' 24 46a '' 52 '54 67 Amount 124.4 103.8 4.4 95.6 65.9 37.1 Pressure / bar / 1.5 - 1.8 36 1.6 1.8 1.8 components: • co2 49.2 1.5 0.7 47.7 2 0.5 V .. 74.9 '46.3 -. 28.6 63 16.7 H2 - - 1.9 ** - co * - 1.8 - - · - H2 .......... .0.3 .. 56. ... - 19 , 3 · 0.9 19.9 -9-

As a stripping gas. conducting nitrogen in quantity. 75 kmol / run 18, is fed to the combustion chamber 31 via line 28. 21 kmol / h-pure oxygen. Washed-out solution. The line has a temperature of 37 ° C. 22 in the amount of 33 kmol / h, in the hydrogenation 46 the co-ball-molybdenum is used. In addition, a partial purge gas stream is fed to the conduit-4 through the catalyst 46a with activated activated carbon support. By line 50, 35.6 kmoles of water at 70 ° C are removed. Example 2. In the embodiment of FIG. 4, the gas is co-treated with the Claus apparatus of FIG. from - gasification, coal and feed, to line 1a. 45, 45 kmol / h oxygen is used. 62, the combustion in the combustion chamber 31 is carried out at 12.1 km / h of pure 02.19 kmol / h of elemental sulfur is fed into the tank. 35 a. 24.2. kmol / h water. are included, in the following tables (all-by-quantities, also all components) are in kmol / h /. knowledge ...... 1 ........ 4 '5 ........ 10 13 24 quantity 10000 10026, -8 372,6 9 · 128,1 27,2 pressure / bar / '37 36 37 1.4 1.5 1.8 temperature / ° c / 30 38 36 30 31 elephants: co2 1650 1650 300. 27 - e2s 19' 46.3 6.3 100.5 25.3 h2 + co 8331 3331,3 '26,3 0,8 - - K2 ....... · ...... - -45- ........ ... 1.9. .0,6 1,9 -10- veleni '' 46a 52 '' 54 60 quantity 6 .. 145,9 27,2 399,4 pressure / bar / 2,5 1,4 1,8 1,3 temperature / ° 0/30 30 31 components: CO, e2sh2- + Kl '' co 27- -. 300. 75.2 25.3 27.3 - -. 27.1 43.7 "" 1.9 "45.0

Claims (12)

A method for purifying gas comprising / combustible particulates. jekažnintiujiid. ultraviolet and sulfur compounds: washing, washing, washing, washing, scrubbing, stripping, heating, regenerating, hot, waste gas, rich the hydrogen sulphide from hot regeneration is processed into elemental sulfur and residual gas containing hydrogen sulphide residual gas is contacted with the washing solution; n. s e ... by waste gas. bo-na na. hydrogen sulphide, from regeneration, after combustion, partially burns in the combustion chamber with oxygen, an oxygen-containing gas or air, and a gas mixture is produced in the combustion chamber at a temperature of 1000 to 2000. ° C, which contains at least 30 µmol-sulfur fed to the combustion chamber as the sulfur and hydrogen sulfide components; Sulfurous in a molar ratio of 4: 1 to 1: 1, whereupon the gaseous mixture is cooled to below the sulfur temperature, the condensed elemental sulfur is separated off, the gaseous mixture is heated to 180-280 ° C, and is directly catalytic hydrogenated and / or or hydrolysis, the remaining sulfur dioxide content being converted to hydrogen sulfide as much as possible, and at least a portion of the so treated gas as residual hydrogen sulfide-containing gas is added to the wash solution, 2. A process as claimed in claim 1, wherein the hydrogen sulfide-containing residual gas coming from the hydrogenation and / or hydrolysis leads to washing mixtures. A method according to claim 1 or 2, characterized in that it is:. that. the sulfur-rich waste gas from the regeneration of the heat is conducted with a carbon dioxide content of 10% by volume in the combustion chamber. -12-. The method of claim 1 or one of the following. claims. ,. ... y....... se.-partial - current. residual gas. returning from hydrogenation and / or hydrolysis returns prior to hydrogenation or hydrolysis. 5. A method according to claim 1 or one of the following claims. c í. s e tí: .m. ,. . In the process, the solution coming from the washing zone and containing the impurities releases, partly from the tension in the first regenerating column containing the elements for the metabolism, and the diomide-carbon-containing waste gas is drawn off from the first generation column and at least partially led to In the second regeneration column containing the elements for metabolism, it is partially released from the stress and the partially regenerated washing solution from the second regeneration column is fed to the second regeneration column. the regeneration of the burner, the stripping gas is passed to the second regeneration column and the second regeneration column is passed. draws off the second waste gas and passes it as a stripping gas to the first regeneration column » -6. Method according to claim 5 that hydrogen sulfide-containing residual gas is hydrogenated. and / or hydrolysis results in stripping gas into a second recovery column. Method according to claim. '5 »in y start. However, the nitrogen-containing gas is fed to the second regeneration column as a stripping gas. 8. A method according to claim 5, wherein the method is as follows. and. sowing. that the hydrogen sulfide-containing gas coming from the hydrogenation and / or. hydrolysis leads to stripping gas into the first recovery column. -13- 9. Process according to claim 1 or claim 1. one of the following claims. š-n a.ču. The present invention is based on the fact that the the hydrogen sulfide-containing residual gas coming from the hydrogenation and / or hydrolysis leads to the combustion chamber. 10. A method according to claim 5 or one of the following claims. z n. that. se.dílčí. the first-waste gas stream coming from the first recovery column is fed to catalytic hydration and / or hydrolysis. 11. A method according to claim 1 or one of the following claims. z n a n c a n c e ... ... s e t t. - with sulfur of about 30 to 80%, which is contained in the waste gas supplied to the combustion chamber, is obtained as cementitious sulfur. -11- TATEBT CLAIMS so-evwf / ír λ <íÍ-ÍaZi / ^ A- 12. The method of claim. Or one of the following. claims., .. in y. z n s c. s. í m-,. that the cleaned, exhausted gas is fed to the gas or steam turbine plants.