Oxidation, reduction and sulfur recovery multipurpose device
Technical field
The present invention relates to the device that a kind of sulfurous gas that oil refining, chemical industry, Coal Chemical Industry or heat power plant etc. are produced in process of production carries out sulfur recovery, specifically, it is a kind of oxidation, reduction and sulfur recovery multipurpose device.
Background technology
At present, more famous abroad sulfur recovery unit is Crouse (CLAUS) reacting thiourea retrieving arrangement.Referring to Fig. 3, it mainly comprises a roasting kiln G1, a secondary claus reaction device R4, one three grades sulphur cooler E17, molten sulfur pond V1 and a tail gas burning furnace G2.Its technological process is: Sulfur Contained Raw Gas (wherein being rich in hydrogen sulfide) enters roasting kiln G1 through the preheating of preheater E15 and oxygen or air and fuel gas and limits the oxygen incomplete combustion, and its combustion reactions formula is as follows:
H
2S+3/2O
2→SO
2+H
2O
When burning,, make the hydrogen sulfide (H in the reaction generation product by the inlet of control oxygen or air
2S) with sulfurous gas (SO
2) mol ratio equal 2, to satisfy the claus reaction ratio requirement.Enter three grades of sulphur cooler E17 after the cooling of the high-temperature gas passes vapour generator E16 that comes out from roasting kiln G1, molten sulfur and sulfur-bearing non-condensable gas 1 are told in cooling, its sulfur-bearing non-condensable gas 1 removes claus reaction device R4, carries out claus reaction and generates elemental sulfur, and its reaction formula is as follows:
Because above-mentioned reaction is reversible reaction, so the progression that increases the claus reaction device improves the transformation efficiency of elemental sulfur, reactor R4 is a secondary claus reaction device, the reactant flow 1 of coming out from one-level claus reaction device enters three grades of sulphur cooler E17 again, tell molten sulfur and non-condensable gas 2 again, another stage reactor that its non-condensable gas 2 enters among the claus reaction device R4 is again proceeded claus reaction, the reactant flow 2 of coming out enters three grades of sulphur cooler E17 again and tells molten sulfur and sulfur-bearing tail gas, sulfur-bearing tail gas goes incinerator G2 to burn, and enters molten sulfur pond V1 together after three road molten sulfurs that three grades of sulphur cooler E17 tell merge; Blow in the V1 of molten sulfur pond with purifying air, with vapor jet pump P1 molten sulfur pond gas is carried again, thereby the sulfurous gas in the negative pressure gas extract sulphur, molten sulfur after process gas is carried goes out device as product, the sulfurous gas that gas puts forward enters incinerator G2 with the sulfur-bearing tail gas that three grades of sulphur coolers come out, carry out peroxide and burn, it mainly is with the big H of sulfurous gas toxic that this peroxide burns
2S is converted into the less SO of toxicity
2, high-order then emptying simultaneously, also has some other material also to carry out oxidizing reaction in the sulfurous gas, and their reaction formula is as follows:
H
2S+3/2O
2→SO
2+H
2O
COS+3/2O
2→SO
2+CO
2
CS
2+3O
2→2SO
2+CO
2
2S (steam)+2O
2→ 2SO
2
H
2+1/2O
2→H
2O
CO+1/2O
2→CO
2
CH
3OH+3/2O
2→CO
2+2H
2O
NH
3+3/2O
2→1/2N
2+3/2H
2O
……
It more than is exactly traditional Sulfur Recovery Unit production technique.The subject matter that traditional Sulfur Recovery Unit technology exists is: the transformation efficiency of sulphur is desirable not enough; There is sulfurous gas in the discharge tail gas; Roasting kiln G1 limit oxygen incendiary H
2S/SO
2=2 control accuracy is difficult to hold, difficulty that can the control of increase system.
In order to improve the sulfur conversion rate of traditional claus sulphur recovery units, follow-on claus reaction sulfur recovery unit has appearred again.If before the tail gas of traditional claus sulphur recovery units burns, add A reactor again, just form super claus sulphur recovery units, in the reactor of this increase, the hydrogen sulfide selective oxidation is become elemental sulfur, reaction formula is as follows:
H
2S+0.5O
2→S+H
2O
This reaction is the thermodynamics complete reaction, therefore can obtain very high elemental sulfur transformation efficiency.If further before super claus reaction device, add A reactor again, just formed super excellent claus sulphur recovery units, in super excellent claus reaction device, claus reaction device section, catalytic reduction section and selective oxidation section are arranged, in this reactor, sulphur reaches higher sulfur recovery rate by following three kinds of reactions:
1, in a large amount of recovery sulphur of claus reaction section: promptly load claus catalyst in the claus reaction section of super excellent claus reaction device upper strata, generate sulphur according to famous claus reaction, reaction formula is as follows:
2H
2S+1SO2→
3/
nS
n+2H
2O
2, to the SO of remnants
2Carry out the selective hydrogenation catalytic reduction: promptly in the catalytic reduction section, remaining SO
2By the H in the process gas
2Be reduced to sulphur steam and H with CO
2S, reaction formula is as follows:
SO
2+2H
2→1/nS
n+2H
2O
SO
2+3H
2→H
2S+2H
2O
SO
2+2CO→1/nS
n+2CO
2
3, selective oxidation H
2S becomes sulphur: for fear of the limitation of Crouse's balanced reaction, H
2S is oxidized to sulphur steam in the selective oxidation section, and reaction formula is as follows:
H
2S+0.5O
2→
1/
nS
n+H
2O
This shows that the improvement of claus reaction sulfur recovery unit is to carry out towards putting forward doctor positive rate of recovery direction by increasing reaction order always, and technical process and device are taken advantage of in complicated.
At present, also have a kind of claus reaction sulfur recovery unit that adds vent gas treatment abroad, be called the spy of Cisco (SCOT) technology, promptly on above-mentioned traditional claus reaction sulfur recovery unit, be added with the vent gas treatment part again.Referring to Fig. 4, it produces SO in the tail gas with above-mentioned common claus reaction
2Become H by hydrogenator R5 hydrogenating reduction
2S enters absorption tower T4 solvent absorbing H
2S, tail gas enters incinerator G2 from the T4 cat head, with the H of high poison
2S is oxidized to SO
2High-order emptying.The sulfur-bearing rich solution of absorption tower T4 bottom enters regenerator column T5 middle part, the thermal regeneration solvent, and generate H
2S, H
2S comes out from the T5 cat head, enters return tank V2 after the condensation, and the sulfur-bearing non-condensable gas that comes out from return tank V2 returns roasting kiln G1, carries out sulfur recovery once more.The sulfur recovery rate of this device is higher, can reach 99.9%, and can satisfy present GB emission request.This flow process can not be said under the competent situation of hydrogen source and not be an effective means, but it sends all tail gas into hydrogenator, load is big, investment is high, the more important thing is from operational path it is reasonably not near, promptly in the operational path of sour gas → limit oxygen burning → claus reaction → hydrogenating reduction → absorption and regeneration → burning emptying, carried out secondary combustion, and owing to existing H in the claus reaction tail gas discharged
2S has SO again
2, it is difficult to accomplish both absorbed H
2S absorbs SO again
2So, be with SO in the tail gas
2Hydrogenating reduction become H
2S absorbs and separates sucking-off H
2Return roasting kiln G1 behind the S, carry out sulfur recovery once more, therefore, its hydrogenating reduction is not to be able to and the operation that increases, makes the technical process complexity, and device gross investment and process cost are higher.
In sum, existing Crouse's class (comprise super and super excellent and add vent gas treatment) sulfur recovery unit is to increase technical process, to increase to be operable to and obtain higher sulfur recovery rate and tail gas qualified discharge originally.Have, they all not too consider the over-all properties of device again, only handle the Sulfur Contained Raw Gas that is rich in hydrogen sulfide basically, if the concentration of hydrogen sulfide in the unstripped gas is less than 20% of unit volume, just are difficult to limit the oxygen burning, cause claus reaction to carry out.
Summary of the invention
The objective of the invention is at the problem that exists in the prior art, a kind of oxidation, reduction and sulfur recovery multipurpose device is provided, it can have higher sulfur recovery rate under the condition of simplifying technical process, simultaneously, can also control the concentration of sulphur in the tail gas well, make its qualified discharge, moreover, it also has the good comprehensive processing power, is suitable for handling multiple Sulfur Contained Raw Gas.
For achieving the above object, technical scheme of the present invention is as follows:
It comprises incineration oxidation unit, Sulfur Recovery Unit unit, desulfurizing and purifying unit and hydrogenating reduction unit, the unstripped gas of sulfur-bearing is divided into A, B two-way, the A road is divided into C, D two-way again by valve F1, send into the incineration oxidation unit behind sulfur-bearing non-condensable gas that comes out by first variable valve and Sulfur Recovery Unit unit in the C road and the road, send into the incineration oxidation unit behind required air or oxygen and fuel gas and the road during incineration oxidation unit oxygen-excess combustion, the sulfur dioxide gas that is rich in that the incineration oxidation unit comes out is sent into the desulfurizing and purifying unit; The high-order discharging of the purified gas that the desulfurizing and purifying unit comes out, by the desulfurizing and purifying unit select to absorb and the sulfur dioxide gas that desorbs be assigned to D road and Sulfur Contained Raw Gas by valve F5 and road after send into the Sulfur Recovery Unit unit, be provided with the proportioning detector of hydrogen sulfide and sulfurous gas at the unitary feed-pipe of Sulfur Recovery Unit place, the liquid sulfur that the Sulfur Recovery Unit unit process generates is as the product caterpillar, enters the incineration oxidation unit behind the sulfur-bearing non-condensable gas that the Sulfur Recovery Unit unit comes out and Sulfur Contained Raw Gas that is assigned to the C road and the road; The Sulfur Contained Raw Gas that is assigned to the B road enters the hydrogenating reduction unit by behind valve and second variable valve and hydrogen feed by the 3rd variable valve and the road, and what the hydrogenating reduction unit came out is rich in hydrogen sulfide and receives the unitary opening for feed of Sulfur Recovery Unit.
Further improved technical scheme of the present invention is as follows:
This device also is provided with a cracking hydrogen production unit with the methanol-water hydrogen, and its hydrogen manufacturing outlet is joined with unitary unstripped gas inlet of described hydrogenating reduction and road.
The unitary sulfur dioxide gas outlet of described desulfurizing and purifying is divided into E, F two-way, and the E road is by valve F4 and D road Sulfur Contained Raw Gas and the road of passing through valve F5, and the F road is by valve F3 caterpillar.
Characteristics of the present invention are as follows:
One, the present invention compares with existing Crouse's class sulfur recovery unit, and it is not both significantly: it is not the sulfur-bearing tail gas that traditional claus reaction desulfurization is come out to be sent into that incinerator carries out oxygen-excess combustion and H that will be wherein
2S changes into SO
2Gaseous emission carries out oxygen-excess combustion but this sulfur-bearing non-condensable gas is delivered to incinerator with a part of Sulfur Contained Raw Gas, and wherein contained sulfide all is converted into SO as far as possible in oxygen-excess combustion
2, obtain purer SO by the unitary absorption and desorption of desulfurizing and purifying then
2Gas is again with this purer SO
2Form H with the hydrogen sulfide in another part Sulfur Contained Raw Gas
2S/SO
2=2 mole proportioning turns back to traditional claus reaction device again and carries out desulphurization reaction, thereby forms the round-robin sulfur recovery process.So the present invention need not too pursue the sulphur transformation efficiency of claus reaction, only need the SO of sulfide in the burning of control peroxide
2The poor degree of the internal circulating load of sweetening agent and regenerated thereof in turnover ratio and the desulfurizing and purifying (this control ratio is pursued the sulphur transformation efficiency of claus reaction merely and wanted simple and much easier), the rate of recovery that just can significantly surpass super excellent claus sulphur recovery units, the rate of recovery of the present invention and existing sulfur recovery unit and SO
2Emission concentration is compared as follows:
Device name |
Rate of recovery % |
SO
2Emission concentration mg/Nm
3 |
Super excellent Cross unit |
99.2~99.5 |
≤550 |
The Cross unit that adds vent gas treatment |
99.7~99.9 |
≤20 |
The present invention |
99.6~99.99 |
≤10~150 |
As can be seen from the above table, the present invention has still obtained very high sulfur recovery rate and lower SO under the condition of simplifying technical process and control
2Discharging.This result has changed the improvement direction of simple pursuit claus reaction sulphur transformation efficiency.
Two, since tail gas of the present invention contain internal circulating load that sulphur concentration is controlled by sweetening agent with and the poor degree of regenerated, therefore, be easy to reach 150mg/Nm
3Discharge index, theoretical value can be less than 10mg/Nm
3Simultaneously, the present invention can also be by the control sweetening agent internal circulating load with and the poor degree of regenerated regulate the sulphur concentration that contains of tail gas, because this adjusting is relevant with the working cost of device, promptly increase the solvent cycle amount and will strengthen solvent cycle pump load, power consumption is increased; Improve the poor degree of solvent reclamation, can increase steam consumption.Therefore, the present invention can be according to the emission standard of different areas, with tail gas contain sulphur concentration adjust to can qualified discharge, make working cost minimum again.
Three, the present invention has cancelled the preposition limit oxygen of the claus reaction incomplete combustion workshop section of operational condition harshness, burns and be improved to peroxide, i.e. the required H of claus reaction
2S/SO
2=2 proportioning raw materials is not to burn by limit oxygen to obtain, but obtain needed sulfurous gas behind perfect combustion by part Sulfur Contained Raw Gas (the sulfur-bearing non-condensable gas of discharging comprising the Sulfur Recovery Unit unit) and the desulfurizing and purifying, and then forming the proportion relation of claus reaction with the hydrogen sulfide proportioning in this sulfurous gas and the unstripped gas, this is more much easier than the burning of control limit oxygen.
Four, the present invention is to the H of Sulfur Contained Raw Gas
2S concentration does not require, if the mol ratio of hydrogen sulfide and sulfurous gas does not reach 2 in the Sulfur Contained Raw Gas, and then can be by the hydrogenating reduction unit with the part SO in the Sulfur Contained Raw Gas
2Be reduced into H
2S; If hydrogen feed is burst weary, this device can also be made raw material with the methanol-water that is easy to get, and makes hydrogen by the cracking hydrogen production unit, makes its restriction that is not subjected to hydrogen source, and therefore, the present invention has that raw material is easy to get, flexible operation and the strong characteristics of comprehensive treatment capability.
Five, products scheme of the present invention is flexible.Because desulfurizing and purifying unit resulting sulfurous gas purity height, therefore, it both can return the sulfur recovery unit recovery sulphur, and direct carrying device is used to produce sulfuric acid again.
Six, hydrogenation operation of the present invention is different with the spy's of Cisco hydrogenation, hydrogenation operation of the present invention is not the necessary operation on the operation process main road line, only when too much or only containing the unstripped gas of sulfurous gas, processing sulfurous gas just can increase the expense of this this operation and this operation, therefore, it does not make process complications, but has improved the comprehensive treatment capability of device.
Description of drawings
Fig. 1, structural principle sketch of the present invention.
Fig. 2, concrete structure synoptic diagram of the present invention.
The structural representation of Fig. 3, traditional claus sulphur recovery units.
The structural representation of Fig. 4, the special sulfur recovery unit of Cisco.
Embodiment
Referring to Fig. 1,2, which comprises at least incineration oxidation unit 1, Sulfur Recovery Unit unit 2, desulfurizing and purifying unit 3 and hydrogenating reduction unit 4.Described incineration oxidation unit 1 mainly is made of an incinerator G, described Sulfur Recovery Unit unit 2 mainly is made of claus reaction device R1, sulphur cooler E3, molten sulfur pond V, wherein claus reaction device R1 can be one-level or secondary claus reaction device, sulphur cooler E3 can be secondary or three grades of sulphur coolers, described desulfurizing and purifying unit 3 mainly is made of quench tower T1, absorption tower T2 and regenerator column T3, described hydrogenating reduction unit 4 mainly is made of a hydrogenator R2, and described cracking hydrogen production unit 5 mainly is made of cracking hydrogen production reactor R3.The concrete parts composition of device and annexation describe in detail by the technological process of following embodiment.This device can come recovery sulphur with three kinds of Sulfur Contained Raw Gas, promptly be rich in the hydrogen sulfide unstripped gas, be rich in the sulfurous gas unstripped gas and only contain the sulfurous gas unstripped gas, simultaneously, can also produce sulfurous gas with the unstripped gas that contains sulfurous gas, the embodiment division is as follows.
Embodiment 1
This routine Sulfur Contained Raw Gas is rich in hydrogen sulfide, does not therefore need with hydrogenating reduction unit (4), and the technological process of its recovery sulphur is as follows:
1, referring to Fig. 2, Open valve F1, F4, F5, valve-off F2 and F3, Sulfur Contained Raw Gas is after preheater E1 preheating, F1 is divided into C by valve, the D two-way, the D road is mixed the back and is entered Sulfur Recovery Unit unit 2 (hereinafter to be referred as sulfur recovery unit) by preheater E13 with the sulfur dioxide gas that desulfurizing and purifying unit 3 comes out, the C road with enter incineration oxidation unit 1 after the sulfur-bearing non-condensable gas that returns from sulfur recovery unit 2 mixes, in incinerator G, add excess air or oxygen, if the concentration of hydrogen sulfide of gas is lower in the stove, it is combustion-supporting to add fuel gas, and incinerator G carries out oxygen-excess combustion at 850 ℃ ± 50 ℃, with the H in the sulfurous gas
2S, COS, CS
2Change into SO with sulphur steam etc.
2, CO
2, CO, H
2, NH
3Deng gas, the reaction formula of essential substance is as follows in the sulfurous gas:
H
2S+3/2O
2→SO
2+H
2O
COS+3/2O
2→SO
2+CO
2
CS
2+3O
2→2SO
2+CO
2
2S (steam)+2O
2→ 2SO
2
H
2+1/2O
2→H
2O
CO+1/2O
2→CO
2
CH
3OH+3/2O
2→CO
2+2H
2O
NH
3+3/2O
2→1/2N
2+3/2H
2O
……
From incinerator G come out be rich in sulfur dioxide gas and enter vapour generator E2 byproduct steam after, enter desulfurizing and purifying unit 3.
2, the sulfur dioxide gas that is rich in that enters desulfurizing and purifying unit 3 is introduced into interchanger E12, enter quench tower T1 after being cooled to them about 200 ℃, with coming out to enter absorption tower T2 from the T1 cat head after the water for cooling dedusting, in the T2 of absorption tower, absorb sulfurous gas with absorption agent, cat head comes out to remove gas behind the sulfurous gas as the high-order emptying of purified gas, the rich solution that has absorbed sulfurous gas comes out at the bottom of the still of absorption tower T2, with enter regenerator column T3 middle part from the regeneration lean solution of regenerator column T3 tower still after by poor rich liquid heat exchanger E5 heating, reboiler E8 is by low-pressure steam or hot water heating at the bottom of the T3 tower still, the rich solution that enters in the tower is evaporated, vaporization temperature is 90 ℃ ± 20 ℃, pressure is 0.15MPa ± 0.04MPa, the absorption agent of a large amount of sulfur dioxide gas that the evaporation of T3 cat head desorbs and a spot of water vapor and trace enters condenser E7, after under 50 ℃ ± 10 ℃ water vapor and absorption agent condensation being got off, enter return tank V0, the phlegma total reflux of coming out from return tank V0 is to the T3 cat head, the sulfur dioxide gas that comes out from return tank V0 is through after the foam removal, enter interchanger E12 preheating by valve F4 again, enter sulfur recovery unit 2 through preheater E13 then with after the partial raw gas that is assigned to the D road mixes, absorption agent then is reproduced into lean solution and comes out from the tower still, through poor rich liquid heat exchanger E5 cooling, return T2 top, absorption tower after being cooled to 40 ℃ ± 5 ℃ through lean solution water cooler E6 again, form the absorption agent circulation.Contain internal circulating load and the poor degree thereof that sulphur concentration QC1 is controlled by absorption agent in the cleaning of off-gas that the T2 cat head comes out, (thermal load is big more and poor degree is controlled by the thermal load of regenerator column T3 tower still, poor degree is big more, otherwise, more little), so, the internal circulating load of absorption agent can be controlled by regulating variable valve FC4, can regulate the size of T3 tower still thermal load by regulating variable valve FC5, with the poor degree of control absorption agent.
3, the sulfur dioxide gas that desorbs from desulfurizing and purifying unit 3 is with after the Sulfur Contained Raw Gas on D road is mixed, and through interchanger E13 heat exchange to 230 ± 10 ℃, enters claus reaction device R1 again, carries out claus reaction and generates elemental sulfur, and reaction formula is as follows:
Enter the sulfur dioxide gas of claus reaction device and the hydrogen sulfide in the D part sulfur-bearing raw material and will form H
2S/SO
2=2 mole proportioning, this proportional quantity is detected by detector RC1, and the Sulfur Contained Raw Gas tolerance that enters incinerator G by variable valve FC1 control, thereby the sulfurous gas quantum of output of control desulfurizing and purifying unit 3 finally makes the gas that enters the claus reaction device satisfy described H
2S/SO
2=2 mole proportion relation.The temperature of reaction of claus reaction device R1 is 220 ℃ ± 20 ℃.The simple substance gaseous sulfur that claus reaction device R1 produces becomes liquid sulfur after sulphur cooler E3 condensation, this liquid sulfur enters fluid cell V and carries out steam negative pressure gas and carry, unstripped gas with the C road after the sulfur-bearing non-condensable gas that sulfurous gas that gas puts forward and sulphur cooler come out mixes returns incineration oxidation unit 1, and the liquid sulfur after gas is carried goes out device as sulfur product.
Embodiment 2
This routine unstripped gas is rich in sulfurous gas and other sulfide gas, the content of hydrogen sulfide wherein is lower, the claus reaction proportion relation that not enough formation hydrogen sulfide and sulfurous gas mol ratio equal 2, so will the sulphur dioxide reduction in the unstripped gas be become an amount of hydrogen sulfide by hydrogenation, sulfurous gas in this hydrogen sulfide and the unstripped gas matches and satisfies the claus reaction proportion relation, thereby finish sulfur recovery, its production process is as follows:
1, referring to Fig. 2, valve-off F1, Open valve F2 and FC2, be rich in the sulfurous gas unstripped gas and after the heat exchange of preheater E1 preheating and interchanger E11, all enter hydrogenator R2, simultaneously, by the regulating and controlling valve FC3 adding hydrogen of limiting the quantity of, unstripped gas and hydrogen carry out incomplete hydrogenation reduction in reactor R2, and its reaction formula is as follows:
SO
2+3H
2→2H
2O+H
2S
COS+H
2→CO+H
2S
CS
2+4H
2→CH
4+2H
2S
RSR+H
2→RH+H
2S
……
R represents alkyl in the following formula.
When not having sources of hydrogen, methanol-water can be passed through respectively and send into cracking hydrogen production reactor R3 after preheater E9 and the interchanger E10 heat exchange to 250 ℃ ± 20 ℃ and produce hydrogen, its reaction formula is as follows:
CH
3OH+H
2O→CO
2+3H
2
The temperature of reaction of this reaction is 230 ℃ ± 20 ℃, and reaction pressure is 1.1MPa ± 0.4MPa.
2, valve-off F3 and F5, Open valve F4, the gas that contains hydrogen sulfide that generates from hydrogenator R2 and mix from the sulfur dioxide gas that desulfurizing and purifying unit 3 comes out after, after interchanger E13 heat exchange to 230 ℃ ± 10 ℃, enter claus reaction device R1 again, in this reactor R1, carry out claus reaction and generate elemental sulfur, temperature of reaction is 220 ℃ ± 10 ℃, wherein the needed H of claus reaction
2S/SO
2=2 mole proportioning is controlled by the growing amount of hydrogen sulfide in the hydrogenation reduction, and this growing amount is controlled by the hydrogen add-on of hydrogenator R2, and this add-on is controlled by variable valve FC3.The simple substance gaseous sulfur that the claus reaction device produces in sulfur recovery unit 2 through after condensation and the stripping process similarly to Example 1, the liquid sulfur that obtains goes out device, the sulphur cooler comes out the sulfur-bearing non-condensable gas and the sulfurous gas that puts forward from molten sulfur pond gas is sent into incineration oxidation unit 1 after merging, in incineration oxidation unit 1 through entering desulfurizing and purifying unit 3 after the burning disposal similarly to Example 1, after in desulfurizing and purifying unit 3, handling through the absorption and desorption identical with embodiment 1, the high-order emptying of the purified gas that comes out from desulfurizing and purifying unit 3, the sulfur dioxide gas that desorbs from this unit 3 mixes with sulfurous gas and road that hydrogenating reduction unit 4 comes out, forms the round-robin sulfur recovery process through entering claus reaction device R1 behind the interchanger E13 again.
Embodiment 3
This routine unstripped gas is the gas that only contains sulfurous gas, sulfide hydrogen not wherein, therefore, can not form hydrogen sulfide and sulfurous gas mol ratio and be 2 claus reaction proportion relation, the direct hydrogenating reduction of the part of sulfurous gas unstripped gas can be become an amount of hydrogen sulfide, this hydrogen sulfide and another part sulfurous gas unstripped gas match and satisfy the claus reaction proportion relation, thereby finish sulfur recovery, and concrete production process is as follows:
1, referring to Fig. 2, valve-off F3 and variable valve FC1 open other valve, and unstripped gas is divided into A, B two-way after preheater E1 preheating, and the A road enters the D road by valve F1 and directly removes interchanger E13; The B road is mixed into hydrogenator R2 by valve F2 and variable valve FC2 and hydrogen feed gas, and reaction generates hydrogen sulfide, and described hydrogen feed gas can be sources of hydrogen, also can be the hydrogen that makes by cracking hydrogen production unit 5.Come out to be rich in the unstripped gas that is rich in sulfurous gas on hydrogen sulfide and D road and being rich in of returning from desulfurizing and purifying unit 3 from hydrogenating reduction unit 4 and enter interchanger E13 after mix on sulfur dioxide gas three tunnel and road, after interchanger E13 heat exchange, enter claus reaction device R1, carry out claus reaction and generate elemental sulfur, the needed H of claus reaction
2S/SO
2=2 moles of proportionings are controlled by the tolerance that is rich in the sulfurous gas unstripped gas that enters hydrogenating reduction unit 4, and this tolerance is by variable valve FC2 control, thus the growing amount of hydrogen sulfide in the control hydrogenation reduction.
2, the simple substance gaseous sulfur that claus reaction device R1 produces in sulfur recovery unit 2 through after condensation and the stripping process similarly to Example 1, the liquid sulfur that obtains goes out device, the sulphur cooler comes out the sulfur-bearing non-condensable gas and the sulfurous gas that puts forward from molten sulfur pond gas is sent into incineration oxidation unit 1 after merging, in burning unit 1, enter desulfurizing and purifying unit 3 after through burning similarly to Example 1, in desulfurizing and purifying unit 3 through after the absorption and desorption identical with embodiment 1, sulfur dioxide gas and purified gas come out, the high emptying of purified gas, the unstripped gas on sulfur dioxide gas and D road and hydrogenating reduction unit 4 come out be rich in hydrogen sulfide three tunnel and road after, send into claus reaction device R1 through interchanger E13 again, form the circulation sulfur recovery process.
Embodiment 4,
Referring to Fig. 2, in order to make this device can output sulfurous gas, this example is divided into E, F two-way with the sulfurous gas outlet that desulfurizing and purifying unit 3 desorbs, and on E, F road, set up valve F4, F3, because the sulfur dioxide gas purity of this device output is higher, produce the vitriolic raw material so can be directly used in, otherwise, the outlet of sulfur dioxide gas in the clean unit 3 of desulfurization can be directly and interchanger E12 join, its production process is as follows:
Open valve F1, FC1 and F3, close other valve, Sulfur Contained Raw Gas enters incineration oxidation unit 1 and carries out the oxygen-excess combustion identical with embodiment 1 after preheater E1 preheating, the sulfur dioxide gas that is rich in that comes out from the former unit 1 of incineration oxidation enters desulfurizing and purifying unit 3, carry out the sulfurous gas absorption and desorption identical with embodiment 1, obtain pure sulfur dioxide gas and divide purified gas, sulfurous gas goes out device as the vitriolic raw materials for production by valve F3, the high-order discharging of purified gas.