CN1237471A

CN1237471A - Application of chrome-contained waste catalyst as desulfurizing agent

Info

Publication number: CN1237471A
Application number: CN 98109074
Authority: CN
Inventors: 刘振宇; 刘守军; 朱珍平; 牛宏贤
Original assignee: Shanxi Institute of Coal Chemistry of CAS
Current assignee: Shanxi Institute of Coal Chemistry of CAS
Priority date: 1998-06-02
Filing date: 1998-06-02
Publication date: 1999-12-08
Anticipated expiration: 2018-06-02
Also published as: CN1089018C

Abstract

The application of chromium-contained waste catalyst as desulfurizing agent includes the steps of breaking waste catalyst, sieving, boiling in water, drying, activating, absorbing and regeneration, etc.. Said invention greatly reduces the cost for desulfurization.

Description

Contain the application process of chromium dead catalyst as desulfurizing agent

The invention belongs to a kind of method of flue gas dry desulfurization, be specifically related to a kind of application process that contains the chromium dead catalyst as desulfurizing agent.

Fossil fuel combustion waste gas (or claiming flue gas) contains SOx, and adopting dry desulfurization is present development trend.Environmental project (1995.10, VOL 13, NO5) one piece " fluid bed CuO flue gas desulfurization experimental study " disclosed, desulfurization principle is that CuO and SOx generate sulfate, absorbent CuO is the fixed bed state in reactor, also can adopt fluid bed CuO technology, absorbent is the fluid bed state in reactor.Recycle after the regeneration of gas such as the absorbent CuO available hydrogen that lost efficacy, methane carbon monoxide.In this regenerative process, obtain being rich in SO ₂Gaseous mixture so that the recovery of sulphur.Its shortcoming is the CuO cost height as absorbent.

The objective of the invention is to develop a kind ofly reduce cost, with useless smelting useless to contain the application process of chromium dead catalyst as desulfurization absorbent.

It is as follows as the application process of desulfurization absorbent to contain the chromium dead catalyst:

1. look and contain chromium dead catalyst granule size decision and whether need fragmentation procedure, no matter whether pass through fragmentation, all need remove the efflorescence part, to reduce bed pressure drop by screening;

2. look poisoning type and degree, select suitable pre-treating method and activation condition for use, generally can adopt poach to remove SiO ₂/ K ₂O/Na ₂Surface coverings such as O, dry then, activation;

3. through pre-treatment, the dead catalyst of activation and flue gas contact catalysis remove the SOx in the flue gas;

4. adsorb saturated desulfurizing agent and regenerate, the both available reducibility gas of regeneration gas, sulphur is with SO ₂Or the form of S emits, also available oxidizing gas, and sulphur is with SO ₃Form emit;

5. desulfurization and the both available fixed bed of regeneration, also available moving bed needs two groups when adopting fixed bed and is used alternatingly, one group of desulfurization, another organizes regeneration, and the number of every group of bed depends on the flow of the flue gas of handling and the volume of catalytic bed; When adopting moving bed, the speed that moves in moving bed by the control desulfurizing agent can guarantee certain desulfurization degree.

The described middle temperature transformation Fe of chromium dead catalyst that contain for losing efficacy ₂O ₃/ Cr ₂O ₃Catalyst, the hts catalyst of different model composed as follows:

Fe ₂O ₃ Cr ₂O ₃ MgO K ₂O CaO

B104 50-60 7-9 17-20 0.5-0.7

B106 65-70 12-14 3.5-4.5 0.2-0.9 0.7-0.9

B107 70-72 10-12

WB-I 66-70 10-12 2.5-2.5 0.5-0.8

The activation temperature of above-mentioned dead catalyst is 300-650 ℃, and the reaction temperature of SO2 is 250-500 ℃ in desulfurizing agent and the flue gas, and the desorption and regeneration temperature is 400-650 ℃.Regeneration atmosphere both can be used reducibility gas, also available oxidizing gas.Reducibility gas (CO, H ₂, CH ₄Or the like) when regenerating, need be equipped with steam protection (H ₂The O/CO=3-5 mol ratio), or adopts inert gas, prevent that CO from becoming elemental iron with iron oxide reduction towards rare.Sulphur is with SO ₂Discharge, but both production high concentrations SO ₂, also can convert it into SO ₃, or be reduced into elementary sulfur.During oxidizing gas (as air, oxygen or the like) regeneration, sulphur is with SO ₃Discharge, available water or dilute sulfuric acid absorb system sulfuric acid.

Fig. 1 is the flow chart of moving bed desulfurization.

As shown in the figure, 1 is reactor, and 2 is regenerator, and A is flue gas before purifying, and B is flue gas after purifying, C is fresh desulfurizing agent, and D is regeneration tail gas, and E is regeneration gas.

Industrial flue gas A is by desulfurization reactor 1, with the reaction of desulfurizing agent counter current contacting, most SO in the flue gas₂Be absorbed and remove flue gas B emptying after purifying. Regenerate fresh desulfurizing agent C from desulfurization reactor 1 Top adds continuously, at first with exhaust pass gas B reaction, guarantees the low SO of emission₂Concentration is in the descending process of desulfurizing agent, to SO₂Catalytic absorption gradually saturated, arrive outlet, from the top of regenerator 2 Section adds regeneration, decomposes the sulfurous gas that produces and is reproduced gas port and takes and reclaimed, and comes downwards to outlet Contact with the gas of sulfur-bearing not and to guarantee that regeneration fully, goes to the devulcanizer top then, by regulating moving bed The translational speed of middle desulfurizing agent can be kept certain desulfurization degree.

Embodiment 1

The laboratory fixed bed reactors, reactor inside diameter 10mm, the useless synthetic ammonia medium temperature shift catalyst B104 that unloads after 2 years is used in filling, not activation, constant 370 ℃ of temperature of reactor, simulated flue gas contains SO ₂500PPm, O ₂5%, balance N ₂Flow 330ml/min, loaded catalyst 1.5g, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 8.2 hours, 4 hours (580 ℃ of temperature, regeneration gas 5% O thereafter regenerate ₂95% N ₂), after carry out absorbing the second time operation, same exhaust gas components, flow, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 7.1 hours.

Embodiment 2

The laboratory fixed bed reactors, reactor inside diameter 10mm, filling is used and is unloaded useless synthetic ammonia medium temperature shift catalyst B106 after 2 years, at first 1 hour (activated gas 5%O of 450 ℃ of activation ₂+ 95%N ₂).Absorb desulphurization reaction then, constant 370 ℃ of temperature of reactor, simulated flue gas contains SO ₂500PPm, O 25%, flow 330ml/min, loaded catalyst 1.5g, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 10.5 hours, 4 hours (580 ℃ of temperature, regeneration gas 5% O thereafter regenerate ₂+ 95%N ₂), after carry out second time operation, same exhaust gas components, flow, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 9.8 hours.

Embodiment 3

The laboratory fixed bed reactors, reactor inside diameter 10mm, filling is used and is unloaded useless synthetic ammonia medium temperature shift catalyst B107 after 2 years, and at first boiling water boiled 0.5 hour, and 110 ℃ were dried by the fire 2 hours, 1 hour (activated gas 5%O of 450 ℃ of activation ₂+ 95%N ₂), constant 370 ℃ of temperature of reactor, simulated flue gas contains SO ₂500PPm, O ₂5%, balance N ₂Flow 330ml/min, loaded catalyst 1.5g, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 11.1 hours, 4 hours (580 ℃ of temperature, regeneration gas 5% O thereafter regenerate ₂Balance gas N ₂), after carry out absorbing the second time operation, same exhaust gas components, flow, the SO in the catalysis absorbing and removing flue gas more than 85% ₂Can keep 10.7 hours.

Great advantage of the present invention is to greatly reduce desulfurization take discarded chromium-containing catalyst as desulfurization Cost reaches the purpose of the treatment of wastes with processes of wastes against one another.

Claims

1. an application process that contains the chromium dead catalyst as desulfurizing agent comprises preliminary treatment, desulfurization absorption and the desulfurizing agent regeneration of desulfurizing agent, it is characterized in that adopting containing the chromium dead catalyst as desulfurizing agent.

2. the application process that contains the chromium dead catalyst as desulfurizing agent as claimed in claim 1 is characterized in that described method step is:

(1). look and contain chromium dead catalyst granule size decision and whether need fragmentation procedure, no matter whether pass through fragmentation, all need remove the efflorescence part, to reduce bed pressure drop by the screening screening;

(2). look poisoning type and degree, select suitable pre-treating method and activation condition for use, generally can adopt poach to remove SiO ₂/ K ₂O/Na ₂Surface coverings such as O, dry then, activation;

(3). through pre-treatment, the dead catalyst of activation and flue gas contact catalysis remove the SOx in the flue gas;

(4). adsorb saturated desulfurizing agent and regenerate, the both available reducibility gas of regeneration gas, sulphur is with SO ₂Or the form of S emits, also available oxidizing gas, and sulphur is with SO ₃Form emit;

(5). desulfurization and the both available fixed bed of regeneration, also available moving bed needs two groups when adopting fixed bed and is used alternatingly, one group of desulfurization, another organizes regeneration, and the number of every group of bed depends on the flow of the flue gas of handling and the volume of catalytic bed; When adopting moving bed, the speed that moves in moving bed by the control desulfurizing agent can guarantee certain desulfurization degree.

3. the application process that contains the chromium dead catalyst as desulfurizing agent as claimed in claim 1 or 2 is characterized in that described catalyst activation temperature is 300-600 ℃, and the absorption reaction temperature is 250-500 ℃, and regeneration temperature is 400-650 ℃.