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CN-117861732-B - Regeneration method of deactivated denitration catalyst

CN117861732BCN 117861732 BCN117861732 BCN 117861732BCN-117861732-B

Abstract

The invention relates to the technical field of catalyst regeneration, and discloses a regeneration method of an inactivated denitration catalyst. The regeneration method comprises the following steps of (1) carrying out at least one heat treatment on an inactivated denitration catalyst monomer, (2) placing the inactivated denitration catalyst monomer subjected to the heat treatment in an electrolyte solution for electrochemical treatment, then rinsing, and (3) sequentially placing the rinsed inactivated denitration catalyst monomer in a mechanical reinforcing liquid and an active component supplementing liquid for impregnation, (4) carrying out oxidation calcination on the impregnated inactivated denitration catalyst monomer, and then carrying out reduction. The method can integrally regenerate the denitration catalyst deactivated by metal elements such as Fe, pb, cu, as, organic matters such as COD and the like and ammonium bisulfate mixed salt, and the obtained regenerated denitration catalyst can maintain the structural integrity, has higher mechanical strength and catalytic activity and can be directly put into use.

Inventors

  • WU YIHAO
  • LI NIANHUA
  • WEI JINJIA
  • MA GUOQIANG

Assignees

  • 国能龙源内蒙古环保有限公司
  • 国能龙源环保有限公司

Dates

Publication Date
20260505
Application Date
20231121

Claims (9)

  1. 1. A method for regenerating an inactivated denitration catalyst, characterized by comprising the steps of: (1) Carrying out at least one heat treatment on the inactivated denitration catalyst monomer; (2) Placing the heat-treated deactivated denitration catalyst monomer into an electrolyte solution for electrochemical treatment, and then rinsing; (3) Sequentially placing the rinsed deactivated denitration catalyst monomer into a mechanical reinforcing liquid and an active component reinforcing liquid for soaking; (4) Oxidizing and calcining the impregnated deactivated denitration catalyst monomer, and then reducing; The electrolyte in the electrolyte solution is one or more than two of citric acid, oxalic acid, lactic acid, tartaric acid, ammonium citrate, ammonium oxalate, ammonium lactate and ammonium tartrate; the electrochemical treatment conditions comprise a current density of 10-50 mA/cm 2 and a time of 0.5-3h; The mechanical reinforcing liquid is one or more than two selected from ethoxy tantalum solution, nano silicon dispersion liquid and aqueous polyurethane; The electrolyte solution also contains an initiator, wherein the initiator is selected from one or more than two of hydrogen peroxide, sodium hypochlorite and sodium persulfate.
  2. 2. The method for regenerating an inactive denitration catalyst according to claim 1, wherein the concentration of the electrolyte in the electrolyte solution is 0.01 to 0.5mol/L.
  3. 3. The method for regenerating an inactive denitration catalyst according to claim 1, wherein the concentration of the initiator in the electrolyte solution is 1 to 5wt%.
  4. 4. The method for regenerating an inactivated denitration catalyst according to claim 1, wherein the heat treatment conditions include a temperature of 300 to 500 ℃ for 2 to 5 minutes; and/or the number of heat treatments is 2-3.
  5. 5. The method for regenerating an inactive denitration catalyst according to claim 1, wherein when the mechanical reinforcing liquid is an ethoxytantalum solution, the concentration of ethoxytantalum in the ethoxytantalum solution is 10 to 60wt%; And/or, when the mechanical reinforcement liquid is a nano silicon dispersion liquid, the concentration of SiO 2 in the nano silicon dispersion liquid is 20-50wt%; And/or, when the mechanical reinforcing liquid is aqueous polyurethane, the concentration of polyurethane in the aqueous polyurethane is 20-50wt%.
  6. 6. The method for regenerating an inactive denitration catalyst according to claim 1, wherein the active component replenishment liquid contains an active component and an auxiliary agent, the active component is one or two or more of a tungsten source, a molybdenum source and a vanadium source, and the auxiliary agent is one or two or more of cerium salt, manganese salt, cobalt salt, antimony salt, copper salt and holmium salt.
  7. 7. The method for regenerating an inactive denitration catalyst according to claim 6, wherein the content of the active component is 0.1 to 3% by weight and the content of the auxiliary agent is 0.1 to 3% by weight based on the total weight of the active component replenishment liquid.
  8. 8. The method for regenerating an inactive denitration catalyst according to claim 1, wherein the condition of the oxidative calcination includes a constant temperature of 240 to 300 minutes after heating to 250 to 350 ℃, a constant temperature of 150 to 200 minutes after heating to 420 to 460 ℃, and a constant temperature of 100 to 150 minutes after heating to 520 to 570 ℃.
  9. 9. The method for regenerating an inactive denitration catalyst according to claim 1, wherein the temperature of the reduction is 250 to 350 ℃ and the time of the reduction is 4.5 to 7 hours.

Description

Regeneration method of deactivated denitration catalyst Technical Field The invention relates to the technical field of catalyst regeneration, in particular to a regeneration method of an inactivated denitration catalyst. Background Selective Catalytic Reduction (SCR) denitration technology is the most mature flue gas denitration technology at present, and has been applied in large scale in ultra-low emission reformation in multiple industries. As a core of the SCR denitration technology, the employed SCR denitration catalyst is deactivated by clogging, abrasion, sintering, chemical poisoning, loss of active components, and the like during use, so that it cannot be used continuously. If the inactivated denitration catalyst is not properly disposed, serious resource waste and environmental pollution are caused. At present, the country greatly promotes the regeneration of the deactivated denitration catalyst, thereby realizing the efficient recycling of the deactivated denitration catalyst. At present, aiming at the collected inactivated denitration catalyst (vanadium-titanium system), the whole regeneration is taken as a priority principle for the good structure and the excellent mechanical strength, so that the regenerated denitration catalyst is obtained, and the valuable metals in the inactivated denitration catalyst with the damaged whole structure are recovered. However, at present, the regeneration treatment of many deactivated denitration catalysts does not follow the recovery principle, so that the original integral structure is often damaged and the mechanical strength is reduced in the regeneration process, so that the deactivated denitration catalysts cannot be continuously used, and the service life of the regenerated denitration catalysts is severely restricted. In addition, aiming at the inactivated denitration catalyst which contains various heavy metal elements and has high heavy metal content, organic matters, ammonium bisulfate and other hetero salts, the whole regeneration difficulty is high, and at present, no proper method is available for completely removing the substances which cause the inactivation of the denitration catalyst, so that the requirement of the actual working condition on the activity of the regenerated denitration catalyst can not be met. Disclosure of Invention The invention aims to solve the problems of high heavy metal content, high integral regeneration difficulty of the deactivated catalyst with a plurality of impurity types, low mechanical strength and catalytic activity of the regenerated catalyst and the like in the prior art, and provides a regeneration method of the deactivated denitration catalyst, which can be used for the regeneration method with high heavy metal content, the inactivated denitration catalyst containing various organic matters and ammonium bisulfate is integrally regenerated, the structural integrity of the obtained regenerated denitration catalyst can still be maintained, the integral structure of the regenerated denitration catalyst is not damaged, the obtained regenerated denitration catalyst has higher mechanical strength and catalytic activity, and the regenerated denitration catalyst can be directly put into use, so that the efficient recycling of the inactivated denitration catalyst is realized. In order to achieve the above object, the present invention provides a regeneration method of an inactivated denitration catalyst, the regeneration method comprising the steps of: (1) Carrying out at least one heat treatment on the inactivated denitration catalyst monomer; (2) Placing the heat-treated deactivated denitration catalyst monomer into an electrolyte solution for electrochemical treatment, and then rinsing; (3) Sequentially placing the rinsed deactivated denitration catalyst monomer into a mechanical reinforcing liquid and an active component reinforcing liquid for soaking; (4) Oxidizing and calcining the impregnated deactivated denitration catalyst monomer, and then reducing; The electrolyte in the electrolyte solution is one or more than two of citric acid, oxalic acid, lactic acid, tartaric acid, ammonium citrate, ammonium oxalate, ammonium lactate and ammonium tartrate; the electrochemical treatment conditions comprise a current density of 10-50mA/cm 2 and a time of 0.5-3h; the mechanical reinforcing liquid is one or more than two selected from ethoxy tantalum solution, nano silicon dispersion liquid and aqueous polyurethane. Preferably, the concentration of the electrolyte in the electrolyte solution is 0.01 to 0.5mol/L. Preferably, the electrolyte solution further contains an initiator; and/or the initiator is selected from one or more than two of hydrogen peroxide, sodium hypochlorite and sodium persulfate. Preferably, the concentration of initiator in the electrolyte solution is 1-5wt%. Preferably, the heat treatment conditions include a temperature of 300-500 ℃ for 2-5min; and/or the number of heat treatments is 2-3. Prefer