CN102059156A - Denitration catalyst regenerating solution and regenerating method thereof - Google Patents

Abstract

The invention discloses a cellular denitration catalyst regenerating solution for a coal fired power plant and a regenerating method thereof. The regenerating solution comprises a cleaning solution and an activated replenishing solution, wherein the cleaning solution contains H2SO4 and an emulsifying agent S-185; the activated replenishing solution contains VOSO4 and ammonium paratungstate; and ultrasonic cleaning is adopted in the cleaning method. The regenerated catalyst has relative activity (K/Ko) of 0.95-0.99 and SO2/SO3 conversion rates of both less than 1 percent and meets the requirement on the engineering; and the regenerating process is simple in operation and is suitable for industrialized massive regeneration.

Description

Denitrating catalyst regenerated liquid and renovation process thereof

Technical field

The present invention relates to the denitrating catalyst field, particularly coal-burning power plant's denitrating catalyst regenerated liquid and renovation process thereof.

 

Background technology

In the recent period, Chinese Ministry of Environmental Protection has externally announced the exposure draft of " thermal power plant's nitrogen oxide Prevention Technique policy ", the comprehensive preventive health measures that advocate that reasonable use fuel combines with pollution control technology, combustion control technology and denitrating flue gas control technology combines is to reduce the discharging of coal-burning power plant's nitrogen oxide.The suggestion original text proposes especially that " spent catalyst should adopt regeneration techniques as far as possible, and the spent catalyst that can't regenerate can carry out landfill by " hazardous waste security landfill pollute control criterion " requirement (GB18598)." " encourage high performance catalyst raw material, new catalyst, the regeneration of spent catalyst and the development and application of safe disposal technology." under the normal condition, a 600MW unit, finish " 2+1 " after, the discarded amount of annual is about 100 sides, the employing land-fill method easily causes environmental pollution.Make catalyst return to 95～100% of original activity by regeneration, catalyst can reuse, and cost only is the 40-50% of catalyst changeout cost more.Therefore, carrying out catalyst regeneration promptly reduces SCR denitration cost and meets national industrial policies again.

Use ammonium metatungstate and ammonium paratungstate as the active supplementation material (V of make-up catalyst among the Chinese patent application 200910031206.X and 200510117054.7 ₂O ₅And WO ₃).Because ammonium metavanadate is an extremely toxic substance, need chemical breakdown reaction generation vanadic anhydride is taking place more than 250-300 ℃; The ammonium paratungstate dissolubility is relatively poor: in the time of 20 ℃, solubility is less than 2% in the water, and desired concn solution is disposed in inconvenience.Therefore, adopt above-mentioned solution to carry out regenerated catalyst, operation easier is bigger.Simultaneously, only point out the denitration rate of catalyst contrast situation before and after the regeneration, the not relative activity (K/Ko) and the SO of catalyst before and after the explanation regeneration in the patent ₂/ SO ₃The conversion ratio situation.It is pointed out that relative activity (K/Ko) is the important indicator of catalyst regeneration, simultaneously in the SCR denitrification process, the SO of catalyst ₂/ SO ₃Conversion ratio generally requires less than 1%.Therefore, above-mentioned patent does not illustrate the catalyst regeneration effect better.

Summary of the invention

In view of this, one of purpose of the present invention is to provide a kind of denitrating catalyst regenerated liquid, its hypotoxicity, and regeneration effect is good, and the process time is short.

For achieving the above object, technical scheme of the present invention is:

The denitrating catalyst regenerated liquid is made up of cleaning fluid and the active liquid that replenishes, and contains sulfuric acid and emulsifying agent S-185 in the described cleaning fluid, and described activity is replenished liquid and contained vanadic sulfate and ammonium metatungstate.

Further, described denitrating catalyst regenerated liquid is composed as follows:

Cleaning fluid: emulsifying agent S-185 mass fraction is 0.005～1%, and the sulfuric acid molar concentration is 0.2～0.8mol/L.

The active liquid that replenishes: the vanadic sulfate molar concentration is 0.2～0.8mol/L, and the ammonium metatungstate molar concentration is 0.2～0.8mol/L.

Two of purpose of the present invention is to provide a kind of denitrating catalyst renovation process, and this method only needs to be used simple device, can avoid complicated calcination steps, can comparatively fast finish the regeneration of catalyst.

For achieving the above object, technical scheme of the present invention is:

The denitrating catalyst renovation process, concrete steps are: at first, catalyst to be regenerated is at first used cleaning fluid in service sink, adopt the ultrasonic wave mode to remove the hole inside ash of catalyst; Then, in the activation pond, the catalyst soakage that has cleaned is replenished liquid in activity, carry out active component and replenish; At last, will in drying box, carry out drying with the catalyst that has replenished active component.Finally, just obtain the denitrating catalyst of regenerating.

Wherein, ultrasonic cleaning is 10～30 minutes; The active time of replenishing the liquid dipping is 20～60 minutes; Adopt under 80～150 ℃ of hot-air conditions when dry, dried the denitrating catalyst of to regenerate 2～5 hours.

 

Beneficial effect of the present invention is: since in the cleaning fluid except sulfuric acid solution and emulsifying agent S-185, cleaning process adopts the ultrasonic wave cleaning way simultaneously, therefore, scavenging period only needs 10～30 minutes, only is 1/2 of existing technology; Adopt vanadic sulfate and ammonium metatungstate that catalyst is carried out active component simultaneously and replenish, promptly avoided the severe toxicity of ammonium metavanadate to cause unsafe factor, avoided the complicated technology of the repeatedly roasting of catalyst again.Adopt the denitrating catalyst after this method is regenerated: activity can return to 95～99% of original activity; SO ₂/ SO ₃Conversion ratio all satisfies the engineering design requirement less than 1%; Simultaneously, regeneration technology is simple to operate, is applicable to industrial scale regeneration.

 

The specific embodiment

In order to make the purpose, technical solutions and advantages of the present invention clearer, below the preferred embodiments of the present invention are described in detail.

Embodiment 1

One, the preparation of regenerated liquid

1, the preparation of cleaning fluid

In the ultrasonic wave service sink, configuration emulsifying agent S-185 mass fraction is 0.005%, and the molar concentration of sulfuric acid is the mixed solution of 0.8mol/L.Carry out ultrasonic wave and handled 10 minutes, it is mixed, placed aging 1 hour, amount to 200L.

2, the active preparation that replenishes liquid

In the activation pond, the configuration molar concentration is the mixed solution of the ammonium metatungstate of the vanadic sulfate of 0.8mol/L and 0.8mol/L.Carry out mechanical agitation 5 minutes, it is mixed, placed aging 1 hour, amount to 200L.

Two, denitrating catalyst regeneration technology flow process

Discarded catalyst is immersed in the service sink that cleaning fluid is housed, carried out ultrasonic cleaning 10 minutes; Then, catalyst soakage is replenished liquid in activity, flooded 60 minutes; Take out catalyst and be placed in the drying box, 80 ℃ of dryings 5 hours.Catalyst regeneration finishes.

 

Embodiment 2

One, the preparation of regenerated liquid

1, the preparation of cleaning fluid

In the ultrasonic wave service sink, configuration emulsifying agent S-185 mass fraction is 1%, H ₂SO ₄Molar concentration is the mixed solution of 0.2mol/L.Carry out ultrasonic processing 10 minutes, it is mixed, placed aging 1 hour, obtain cleaning fluid, amount to 200L.

2, the active preparation that replenishes liquid

In the activation pond, the configuration molar concentration is the mixed solution of the ammonium metatungstate of the vanadic sulfate of 0.2 mol/L and 0.2mol/L.Carry out mechanical agitation 5 minutes, it is mixed, placed aging 1 hour, obtain the active liquid that replenishes, amount to 200L.

Two, denitrating catalyst regeneration technology flow process

Discarded catalyst is immersed in the service sink that cleaning fluid is housed, carried out ultrasonic cleaning 30 minutes; Then, catalyst soakage is replenished liquid in activity, flooded 20 minutes; Take out catalyst and be placed in the drying box, 150 ℃ of dryings 2 hours.Catalyst regeneration finishes.

Embodiment 3

One, the preparation of regenerated liquid

1, the preparation of cleaning fluid

In the ultrasonic wave service sink, configuration emulsifying agent S-185 mass fraction is 0.5%, H ₂SO ₄Molar concentration is the mixed solution of 0.4mol/L.Carry out ultrasonic processing 10 minutes, it is mixed, placed aging 1 hour, amount to 200L.

2, the active preparation that replenishes liquid

In the activation pond, the configuration molar concentration is the VOSO of 0.8 mol/L ₄Mixed solution solution with the ammonium metatungstate of 0.8mol/L.Carry out mechanical agitation 5 minutes, it is mixed, placed aging 1 hour, amount to 200L.

Two, denitrating catalyst regeneration technology

Discarded catalyst is immersed in the service sink that cleaning fluid is housed, carried out ultrasonic cleaning 20 minutes; Then, catalyst soakage is replenished liquid in activity, flooded 30 minutes; Take out catalyst and be placed in the drying box, 120 ℃ of dryings 3 hours.Catalyst regeneration finishes.

 

Embodiment 4

One, the preparation of regenerated liquid

1, the preparation of cleaning fluid

In the ultrasonic wave service sink, configuration emulsifying agent S-185 mass fraction is 0.25%, H ₂SO ₄Molar concentration is the mixed solution of 0.6mol/L.Carry out ultrasonic processing 10 minutes, it is mixed, placed aging 1 hour, amount to 200L.

2, the active preparation that replenishes liquid

In the activation pond, the configuration molar concentration is the VOSO of 0.6 mol/L ₄Mixed solution with the ammonium metatungstate of 0.8mol/L.Carry out mechanical agitation 5 minutes, it is mixed, placed aging 1 hour, obtain the active liquid that replenishes, amount to 200L.

Two, denitrating catalyst regeneration technology

Discarded catalyst is immersed in the service sink that cleaning fluid is housed, carried out ultrasonic cleaning 15 minutes; Then, catalyst soakage is replenished liquid in activity, flooded 40 minutes; Take out catalyst and be placed in the drying box, 100 ℃ of dryings 4 hours.Catalyst regeneration finishes.

Embodiment 5

Use the regenerated catalyst and the fresh catalyst of experimental example 1～4 to carry out the catalyst activity contrast, and the SO of test regenerated catalyst ₂/ SO ₃Conversion ratio.Activity of such catalysts, denitration rate and SO ₂/ SO ₃Conversion formula is as follows:

Active K=-AV * ln(1-η);

Denitration rate η=(φ _i(NOx)-φ ₀(NOx))/φ _i(NOx);

Wherein: φ _i(NOx), φ ₀(NOx) be respectively catalyst inlet and exit NOx concentration (ppm)

SO ₂/ SO ₃Conversion ratio

In the formula: -SO ₂/ SO ₃Conversion ratio, %;

The SO of-reactor outlet ₃Concentration, μ L/L;

The SO of-reactor inlet ₃Concentration, μ L/L butt;

The SO of-reactor inlet ₂Concentration, μ L/L butt.

Experiment condition:

The catalyst hole count: 22 * 22, length: 665mm

The catalyst number of plies: 2, catalyst cross section: 150 * 150mm

The engineering Gas Parameters:

Reaction temperature: 380 ℃, flue gas face velocity (AV): 10.55 Nm ³/ (m ²H)

NOx=292ppm，NH ₃=292,

SO ₂=500ppm, O ₂=6%, H ₂O=6%。

The The performance test results of table 1 regenerated catalyst

Catalyst sample Denitration rate (%) Relative activity (K/Ko) SO ₂/SO ₃Conversion ratio (%) Fresh catalyst 92.5 — — Embodiment 1 91.5 0.95 0.81 Embodiment 2 91.7 0.96 0.84 Embodiment 3 92.1 0.98 0.85 Embodiment 4 92.3 0.99 0.87

Result according to embodiment 5 can know that the relative activity of the catalyst after the regeneration (k/Ko) is 0.95-0.99, simultaneously SO ₂/ SO ₃Conversion ratio (%) is all less than 1%, engineering demands.Wherein, the catalyst regeneration best results of embodiment 4.

Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although by invention has been described with reference to the preferred embodiments of the present invention, but those of ordinary skill in the art is to be understood that, can make various changes to it in the form and details, and the spirit and scope of the present invention that do not depart from appended claims and limited.

Claims (4)

1. the denitrating catalyst regenerated liquid is made up of cleaning fluid and the active liquid that replenishes, and it is characterized in that: contain H in the described cleaning fluid ₂SO ₄With emulsifying agent S-185, the active liquid that replenishes contains vanadic sulfate and ammonium metatungstate.

2. denitrating catalyst regenerated liquid according to claim 1 is characterized in that: contained H in the cleaning fluid ₂SO ₄Molar concentration be 0.2～0.8mol/L; The mass fraction of emulsifying agent S-185 is 0.005～1%.

3. denitrating catalyst regenerated liquid according to claim 1 is characterized in that: contained vanadic sulfate molar concentration is 0.2～0.8mol/L in the active additional liquid; The ammonium metatungstate molar concentration is 0.2～0.8mol/L.

4. utilization claim 1 described denitrating catalyst regenerated liquid prepares the method for the denitrating catalyst of regenerating, and it is characterized in that concrete steps are: denitrating catalyst that will be to be regenerated was with described denitrating catalyst cleaning fluid ultrasonic cleaning 10～30 minutes; Adopt the active liquid that replenishes to flood again 20～60 minutes; At last, adopt under 80～150 ℃ of hot-air conditions, dried the denitrating catalyst of to regenerate 2～5 hours.