阅读说明：本技术 用于高有机硫浓度的高炉煤气湿法脱硫系统及工艺 (Blast furnace gas wet desulphurization system and process for high organic sulfur concentration ) 是由 魏振浩 章昌兵 龙志峰 徐庆余 徐华祥 于 2019-12-11 设计创作，主要内容包括：本发明涉及一种用于高有机硫浓度的高炉煤气湿法脱硫系统及工艺。所述的湿法脱硫工艺包括：S1炼铁高炉排出的高炉煤气经过除尘,得到除尘净化后的高炉煤气Ⅰ；S2高炉煤气Ⅰ进入余压透平发电系统(TRT)进行发电并降温降压,得到高炉煤气Ⅱ；S3高炉煤气Ⅱ进入水解吸收塔,将有机硫水解并吸收硫化物,得到净化后的高炉煤气Ⅲ；S4吸收了硫化物的富液进入再生塔,通过加热再生得到贫液和酸性气体,再生后的贫液进入水解吸收塔进行循环使用,酸性气体采用常规Claus硫磺回收工艺回收元素硫；S5高炉煤气Ⅲ进入后续使用工段。本工艺较好地解决了有机硫的脱除净化问题,实现硫资源的回收利用,脱硫过程中脱硫有机溶剂可以循环使用,进一步降低了运行成本。(The invention relates to a blast furnace gas wet desulphurization system and a process for high organic sulfur concentration. The wet desulphurization process comprises the following steps: s1, dedusting blast furnace gas discharged by an iron-making blast furnace to obtain dedusted and purified blast furnace gas I; s2, the blast furnace gas I enters a residual pressure turbine power generation system (TRT) for power generation and temperature and pressure reduction to obtain blast furnace gas II; s3, the blast furnace gas II enters a water desorption tower, organic sulfur is hydrolyzed and sulfide is absorbed, and purified blast furnace gas III is obtained; s4, enabling the pregnant solution absorbing the sulfide to enter a regeneration tower, heating and regenerating to obtain barren solution and acid gas, enabling the regenerated barren solution to enter a water desorption tower for recycling, and recovering elemental sulfur from the acid gas by adopting a conventional Claus sulfur recovery process; and S5, the blast furnace gas III enters a subsequent use section. The process well solves the problem of removal and purification of organic sulfur, realizes the recycling of sulfur resources, and can recycle the desulfurization organic solvent in the desulfurization process, thereby further reducing the operation cost.)

1. A blast furnace gas wet desulphurization process with high organic sulfur concentration is characterized by comprising the following steps:

s1 blast furnace gas I is obtained by dedusting and purifying blast furnace gas discharged by an iron-making blast furnace;

s2, enabling the blast furnace gas I to enter a TRT power generation system for power generation, and reducing the temperature and pressure to obtain blast furnace gas II;

s3, allowing the blast furnace gas II to enter a hydrolysis desulfurization absorption tower, hydrolyzing and converting organic sulfur and absorbing sulfide to obtain purified blast furnace gas III;

s4, enabling the pregnant solution absorbing the sulfide to enter a desorption tower, and heating and regenerating to obtain barren solution and acid gas, wherein the regenerated barren solution enters a hydrolysis desulfurization absorption tower for recycling, and the acid gas adopts a conventional Claus sulfur recovery process to recover elemental sulfur;

and S5, the blast furnace gas III enters a subsequent use section.

2. The wet desulfurization process for blast furnace gas with high organic sulfur concentration according to claim 1, wherein the content of hydrogen chloride in the blast furnace gas with high organic sulfur concentration is 80-300 mg/Nm ³The total sulfur content is 150-300 mg/Nm ³The sulfide mainly comprises carbonyl sulfide (COS) and hydrogen sulfide (H) ₂S) is taken as a main component, wherein COS accounts for about 45-85% of the total sulfur.

3. The wet desulfurization process for blast furnace gas with high organic sulfur concentration according to claim 1, wherein the dust content of the dust-removed and purified blast furnace gas I obtained in the step S1 is controlled to be 5 to 20mg/Nm ³。

4. The wet desulfurization process for blast furnace gas with high organic sulfur concentration according to claim 1, wherein the temperature of the blast furnace gas II in the step S2 is 35 to 90 ℃ and the pressure is 8 to 20 KPa.

5. The blast furnace gas wet desulfurization process with high organic sulfur concentration according to claim 1, wherein the hydrolysis desulfurization absorption tower in the step S3 is a perforated tray tower, a packed tower, a grid tower or an empty tower spray tower; the high-efficiency composite desulfurization organic solvent is one or a mixture of more of monoethanolamine, diethanolamine, N-methyldiethanolamine, six-membered monocyclic oxygen-nitrogen heterocyclic compound, five-membered sulfur-containing heterocyclic compound, water and the like.

6. The high organic sulfur concentration blast furnace gas wet desulfurization process according to claim 1, wherein the hydrolytic conversion in the step S3 is a hydrolysis reaction of COS, and most of COS is converted into H by the hydrolytic conversion ₂S。

7. The wet desulfurization process for blast furnace gas with high organic sulfur concentration according to claim 1, wherein the sulfide in the pregnant solution in the step S4 is mainly H ₂S, and a small amount of COS. In addition, it also contains chlorides and a small amount of dust.

8. The high organic sulfur concentration blast furnace gas wet desulfurization process according to claim 1, characterized in that the regeneration tower in the process S4 is a perforated tray tower, a packed tower, a grid tower or an empty tower spray tower; the heating regeneration temperature is 95-180 ℃.

9. The wet desulfurization process for blast furnace gas with high organic sulfur concentration according to claim 1, wherein the regeneration loss rate of the efficient composite desulfurization organic solvent in step S4 is 6 to 20 ppm.

10. The blast furnace gas wet desulphurization system with high organic sulfur concentration is characterized by comprising the following components in sequence through pipelines:

the dust remover comprises a gravity dust remover and a dry dust remover which are sequentially connected through a pipeline and is used for removing dust and purifying blast furnace gas generated by a blast furnace to obtain blast furnace gas I;

the TRT power generation system is used for generating power by using the blast furnace gas I and reducing the temperature and pressure of the blast furnace gas I to obtain blast furnace gas II;

the hydrolysis desulfurization absorption tower is used for carrying out organic sulfur hydrolysis conversion on the blast furnace gas II and absorbing sulfides to obtain purified blast furnace gas III and then outputting the purified blast furnace gas III;

and the desorption tower is used for heating and regenerating the pregnant solution absorbing the sulfide to obtain barren solution and acid gas, wherein the regenerated barren solution enters the hydrolysis desulfurization absorption tower for recycling, and the acid gas adopts the conventional Claus sulfur recovery process to recover the elemental sulfur.

Technical Field

The invention belongs to the technical field of blast furnace gas desulfurization, and particularly relates to a blast furnace gas wet desulfurization system and process for high organic sulfur concentration.

Background

The blast furnace gas is a byproduct gas of blast furnace smelting in iron and steel enterprises, is an important secondary energy source of the iron and steel enterprises, and plays a significant role in energy structure of the iron and steel enterprises. Because the prices of coke and coal dust have an important influence on the smelting cost of ton iron, in order to reduce the smelting cost of the blast furnace, some enterprises can select coke with poor quality grade and coal dust with high sulfur content, thereby causing the content of sulfur in blast furnace gas to exceed the standard. The sulfide in the blast furnace gas is carbonyl sulfide (COS) and carbon disulfide (CS) ₂) Hydrogen sulfide (H) ₂S), thiol and thioether, mainly COS and H ₂S、CS ₂Mainly comprises COS accounting for about 45-85% of the total sulfur. The high organic sulfur content not only causes the corrosion of gas pipelines, equipment and the like to be intensified, but also causes SO in the flue gas of users of gas power plants, blast furnace hot blast stoves, steel rolling heating furnaces and the like ₂The emission is seriously out of limits (about 150-250 mg/Nm) ³). Therefore, SO in flue gas after the combustion of blast furnace gas without desulfurization and purification treatment ₂The emission index can not reach 50mg/Nm recommended by national ultra-low emission ³(hot-blast stove, heating furnace, etc.) and 35mg/Nm ³(boilers, gas turbines, etc.).

At present, the process route of blast furnace gas desulfurization is as follows: gravity dust removal and dry dust removal for blast furnace gas>Organic sulfur hydrolytic conversion system->Residual pressure turbine power generation system (TRT) ->Dry or wet desulfurization system>Pipe network. The process flow has the following disadvantages: (1) h is generated after hydrolysis and transformation of organic sulfur ₂S which results in H in blast furnace gas ₂The content of S is increased, which can greatly aggravate the corrosion of TRT facilities and auxiliary pipelines thereof and shorten the service life of the generator; (2) the system has complex equipment, poor stability and large floor area; (3) the desulfurization catalyst can not be recycled, the sulfur element is difficult to recover, and the operation cost is high.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a blast furnace gas wet desulphurization system and a process for high organic sulfur concentration, and aims to solve the problems in the prior art that the corrosion of a TRT facility and auxiliary pipelines thereof is aggravated, the system equipment is complex, the stability is poor, the occupied area is large, a desulphurization catalyst cannot be recycled, sulfur elements are difficult to recover, and the operation cost is high.

The technical scheme adopted by the invention for solving the technical problems is as follows: a blast furnace gas wet desulphurization process for high organic sulfur concentration comprises the following processes:

in order to achieve the above object, the present invention provides a wet desulfurization process for blast furnace gas with high organic sulfur concentration, comprising the steps of:

s1 blast furnace gas I is obtained by dedusting and purifying blast furnace gas discharged by an iron-making blast furnace;

s2, enabling the blast furnace gas I to enter a TRT power generation system for power generation, and reducing the temperature and pressure to obtain blast furnace gas II;

s3, allowing the blast furnace gas II to enter a hydrolysis desulfurization absorption tower, hydrolyzing and converting organic sulfur and absorbing sulfide to obtain purified blast furnace gas III;

s4, enabling the pregnant solution absorbing the sulfide to enter a desorption tower, and heating and regenerating to obtain barren solution and acid gas, wherein the regenerated barren solution enters a hydrolysis desulfurization absorption tower for recycling, and the acid gas adopts a conventional Claus sulfur recovery process to recover elemental sulfur;

and S5, the blast furnace gas III enters a subsequent use section.

Preferably, the content of hydrogen chloride in the blast furnace gas with high organic sulfur concentration is 80-300 mg/Nm ³The total sulfur content is 150-300 mg/Nm ³The sulfide mainly comprises carbonyl sulfide (COS) and hydrogen sulfide (H) ₂S) is taken as a main component, wherein COS accounts for about 45-85% of the total sulfur.

Preferably, the dust content of the blast furnace gas I subjected to dust removal and purification in the step S1 is controlled to be 5-20 mg/Nm ³。

Preferably, the temperature of the blast furnace gas II in the step S2 is 35-90 ℃, and the pressure is 8-20 KPa.

Preferably, the hydrolysis desulfurization absorption tower in the step S3 is a porous tower plate tower, a packed tower, a grid tower or an empty tower spray tower; the high-efficiency composite desulfurization organic solvent is one or a mixture of more of monoethanolamine, diethanolamine, N-methyldiethanolamine, six-membered monocyclic oxygen-nitrogen heterocyclic compound, five-membered sulfur-containing heterocyclic compound, water and the like.

Preferably, the hydrolytic conversion in the step S3 refers to a hydrolysis reaction of COS, and most of COS is converted into H by the hydrolytic conversion ₂S。

Preferably, sulfide in the pregnant solution in the step S4 is mainly H ₂S, and a small amount of COS. In addition, it also contains chlorides and a small amount of dust.

Preferably, in the process S4, the regeneration tower is a porous tower plate tower, a packed tower, a grid tower or an empty tower spray tower; the heating regeneration temperature is 95-180 ℃.

Preferably, the regeneration loss rate of the efficient composite desulfurization organic solvent in the step S4 is 6-20 ppm.

In order to achieve the purpose, the blast furnace gas wet desulphurization system with high organic sulfur concentration comprises the following components in sequence through pipelines:

the dust remover comprises a gravity dust remover and a dry dust remover which are sequentially connected through a pipeline and is used for removing dust and purifying blast furnace gas generated by a blast furnace to obtain blast furnace gas I;

the TRT power generation system is used for generating power by using the blast furnace gas I and reducing the temperature and pressure of the blast furnace gas I to obtain blast furnace gas II;

the hydrolysis desulfurization absorption tower is used for carrying out organic sulfur hydrolysis conversion on the blast furnace gas II and absorbing sulfides to obtain purified blast furnace gas III and then outputting the purified blast furnace gas III;

and the desorption tower is used for heating and regenerating the pregnant solution absorbing the sulfide to obtain barren solution and acid gas, wherein the regenerated barren solution enters the hydrolysis desulfurization absorption tower for recycling, and the acid gas adopts the conventional Claus sulfur recovery process to recover the elemental sulfur.

The invention has the beneficial effects that:

1. the hydrolysis desulfurization absorption tower is arranged behind the TRT system, so that the problem of aggravating corrosion of TRT facilities and auxiliary pipelines thereof does not exist;

2. the high-efficiency composite desulfurization organic solvent can be recycled, so that the operation cost is reduced;

3. the system has simple equipment and small occupied area, and realizes the recycling of sulfur resources.

Drawings

FIG. 1 is a schematic view of the wet desulfurization process for high organic sulfur concentration blast furnace gas according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The invention is further illustrated by the following examples, without limiting the scope of the invention to the following.