阅读说明：本技术 一种S-Zorb废吸附剂的酸碱耦合复活方法及复活产品 (Acid-base coupling reactivation method and product of S-Zorb spent adsorbent ) 是由 刘欣梅 吕玉超 孙宗伟 辛颖 于 2019-04-26 设计创作，主要内容包括：本发明提供了一种S-Zorb废吸附剂的酸碱耦合复活方法及复活产品。该方法包括：将S-Zorb废吸附剂在550℃-650℃下焙烧4h-6h；将焙烧后的S-Zorb废吸附剂与无机酸溶液混合搅拌,得到固液混合物；向固液混合物中加入碱试剂搅拌；在80℃-150℃下干燥8h-12h,在400℃-600℃下焙烧4h-6h,得到复活的S-Zorb吸附剂。通过本发明的方法复活的S-Zorb吸附剂的活性位浓度、比表面积及孔容大幅增加,活性组分含量与新鲜吸附剂相似,脱硫活性明显高于再生剂且接近新鲜吸附剂。(The invention provides an acid-base coupling reactivation method and a reactivation product of an S-Zorb waste adsorbent. The method comprises the following steps: roasting the S-Zorb spent adsorbent at 550-650 ℃ for 4-6 h; mixing and stirring the roasted S-Zorb spent adsorbent and an inorganic acid solution to obtain a solid-liquid mixture; adding an alkali reagent into the solid-liquid mixture and stirring; drying at 80-150 deg.c for 8-12 hr, and roasting at 400-600 deg.c for 4-6 hr to obtain reactivated S-Zorb adsorbent. The S-Zorb adsorbent reactivated by the method of the invention has greatly increased active site concentration, specific surface area and pore volume, similar active component content to that of a fresh adsorbent, and desulfurization activity obviously higher than that of a regenerant and close to that of the fresh adsorbent.)

1. An acid-base coupling reactivation method of S-Zorb spent adsorbent, which is characterized by comprising the following steps:

the method comprises the following steps: roasting the S-Zorb spent adsorbent at 550-650 ℃ for 4-6 h;

Step two: mixing and stirring the roasted S-Zorb waste adsorbent and an inorganic acid solution at the temperature of 40-80 ℃ for 2-4 h to obtain a solid-liquid mixture, wherein the mass ratio of the inorganic acid solution to the S-Zorb waste adsorbent is 4:1-11: 1;

step three: adding an alkali reagent into the solid-liquid mixture at the temperature of 40-80 ℃ and stirring for 2-4 h;

step four: drying at 80-150 deg.c for 8-12 hr, and roasting at 400-600 deg.c for 4-6 hr to obtain reactivated S-Zorb adsorbent.

2. The method according to claim 1, wherein the concentration of the inorganic acid solution is 1mol/L to 4 mol/L.

3. The method according to claim 1 or 2, wherein the inorganic acid solution is HNO₃And/or HCl.

4. The method of claim 1, wherein the alkaline agent is NaOH, KOH, Na₂CO₃、K₂CO₃And NH₃·H₂O or a combination of several O.

5. The process of claim 1 or 4, wherein the mass ratio of the basic reagent to the spent S-Zorb adsorbent is from 2:5 to 4: 5.

6. The method of claim 1, further comprising the step of washing and filtering the base treated spent adsorbent of S-Zorb prior to the drying step of step four.

7. The method of claim 6, wherein the washing is performed with deionized water.

8. The method of claim 7, wherein the mass ratio of the deionized water to the spent S-Zorb adsorbent is from 6:1 to 11: 1.

9. An S-Zorb adsorbent obtained by treating an S-Zorb spent adsorbent by the method of any one of claims 1 to 8.

10. The S-Zorb adsorbent of claim 9, wherein the S-Zorb adsorbent has a specific surface area of greater than 130m²Per g, pore volume greater than 0.35m³(ii)/g, desulfurization degree of at least 59%.

Technical Field

The invention relates to a waste treatment method, in particular to a reactivation method of an S-Zorb waste adsorbent, belonging to the field of solid waste treatment.

Background

With the enhancement of environmental awareness of people, environmental regulations put higher demands on the sulfur content in gasoline, and the sulfur content in gasoline is required to be lower than 10 ppm. The S-Zorb process is a process for deep desulfurization of gasoline, and the produced gasoline can meet the requirements of environmental protection regulations. However, the operation of the S-Zorb desulfurization unit can produce large amounts of spent sorbent. The annual processing capacity of the S-Zorb technology in China is over 5000 ten thousand tons, the annual generated waste adsorbent reaches thousands tons, and the adsorbent cost accounts for a considerable proportion of the production cost of low-sulfur gasoline. At present, the treatment mode of the waste adsorbent in China is mainly burying. However, the treatment method not only causes the loss of metal components such as Ni and Zn in the waste adsorbent, but also causes serious pollution to soil and water resources when the metal components enter the soil and water, and seriously threatens the living environment of human beings.

The most desirable method of disposal for the spent S-Zorb adsorbent is to recycle it to the S-Zorb plant after rejuvenation. For example, publication No. CN104923193A discloses an acid-base treatment reactivation method of an S-Zorb spent adsorbent, which refers to a molecular sieve desiliconization method, and uses an alkali to treat the spent adsorbent, and removes zinc silicate on the surface of the spent adsorbent through alkali treatment; simultaneously, alkali treatment is carried out on SiO carrier₂Causing some destruction to generate secondary pores, thereby exposing the unreacted active components covered with the inert components in the spent adsorbent and partially restoring its desulfurization activity. The acid treatment is to convert zinc silicate into soluble salt by using acid, and then remove the soluble salt, and simultaneously the acid can be mixed with carrier Al₂O₃And reacting to play a pore-forming role and improve the exposure rate of the active components in the waste adsorbent. It can be seen that both the alkali treatment and the acid treatment in the reference 1 are to remove the inert zinc silicate component on the surface of the waste adsorbent or to form pores in the carrier to improve the accessibility of the active component by destructive action on the waste adsorbent, thereby partially recovering the desulfurization activity of the waste adsorbent. However, this method causes a large amount of Zn loss, and the alkali treatment and the acid treatment are performed sequentially, and the intermediate product needs to be filtered and washed, which is a complicated process.

Disclosure of Invention

In order to solve the above-mentioned technical problems, it is an object of the present invention to provide a method which can effectively reactivate an S-Zorb spent adsorbent without causing loss of active components.

In order to achieve the technical purpose, the invention provides an acid-base coupling reactivation method of an S-Zorb spent adsorbent, which comprises the following steps:

the method comprises the following steps: roasting the S-Zorb spent adsorbent at 550-650 ℃ for 4-6 h;

step two: mixing and stirring the roasted S-Zorb waste adsorbent and an inorganic acid solution at the temperature of 40-80 ℃ for 2-4 h to obtain a solid-liquid mixture, wherein the mass ratio of the inorganic acid solution to the S-Zorb waste adsorbent is 4:1-11: 1;

step three: adding an alkali reagent into the solid-liquid mixture at the temperature of 40-80 ℃ and stirring for 2-4 h;

step four: drying at 80-150 deg.c for 8-12 hr, and roasting at 400-600 deg.c for 4-6 hr to obtain reactivated S-Zorb adsorbent.

The method of the invention fundamentally changes the composition and the structure of the waste adsorbent, and enables the waste adsorbent to be reactivated. Compared with the regenerated adsorbent, the activated site concentration, the specific surface area and the pore volume of the reactivated S-Zorb adsorbent are greatly increased, the content of active components is similar to that of the fresh adsorbent, and the desulfurization activity of the reactivated S-Zorb adsorbent is obviously higher than that of the regenerated adsorbent and is close to that of the fresh adsorbent.

S-Zorb sorbent during use, the active component (e.g., ZnO) of the S-Zorb sorbent interacts with the support to form zinc silicate. The zinc silicate has high thermal stability and cannot be converted in the regeneration process. Therefore, the content of zinc silicate continuously increases, the content of ZnO decreases, and the adsorbent gradually deactivates. Zinc silicate is preferentially formed on the surface of ZnO, and active ZnO is covered so that the active ZnO cannot be contacted with reactants to deactivate the adsorbent.

In one embodiment of the present invention, the process of the present invention comprises the step of calcining the spent S-Zorb adsorbent at 550 ℃ to 650 ℃. The purpose of this step is to remove the carbon deposit on the surface of the spent S-Zorb adsorbent while converting ZnS and NiS on the surface into ZnO and NiO.

For example, the calcination may be carried out at 600 ℃ for 6 hours.

In one embodiment of the present invention, the method of the present invention comprises the step of mixing and stirring the calcined spent adsorbent of S-Zorb with an inorganic acid solution. Mixing the roasted waste adsorbent with inorganic acid solution, and converting the inert zinc silicate into Zn by the reaction of the acid and the zinc silicate on the surface of the waste adsorbent²⁺Dissolved in an aqueous solution. Also, the acid treatment process may be applied to the support (e.g., Al)₂O₃) The structure causes certain destruction effect to generate secondary pores, the specific surface and pore volume of the reactivated S-Zorb spent adsorbent are increased, and the diffusion of reactants and products is accelerated; the destructive effect can also generate a large number of defect sites on the surface of the carrier, so that the amount of Lewis acid is increased, and the increase of the amount of Lewis acid is beneficial to the adsorption of the alkaline sulfur-containing compound and the acceleration of the conversion of the sulfide.

In one embodiment of the invention, the concentration of the inorganic acid solution used is 1mol/L to 4 mol/L. For example, the concentration of the inorganic acid solution may be 2mol/L, 2.5mol/L, 3mol/L, 3.5 mol/L.

In one embodiment of the present invention, the inorganic acid solution may be HNO₃And/or HCl.

In one embodiment of the present invention, the method of the present invention comprises the step of mixing and stirring the acid-treated spent adsorbent of S-Zorb with an alkali agent. Adding excessive alkali to make Zn in the solution²⁺Precipitated and deposited on the adsorbent surface.

In one embodiment of the invention, the mass ratio of the alkaline reagent to the spent S-Zorb adsorbent is from 2:5 to 4: 5. For example, the mass ratio of the alkali agent to the spent adsorbent of S-Zorb may be 3:5, 3.5:5, etc.

In one embodiment of the present invention, the alkali agent is NaOH, KOH, Na₂CO₃、K₂CO₃And NH₃-H₂O or a combination of several O.

In one embodiment of the present invention, the process of the present invention comprises the steps of washing and filtering the spent S-Zorb adsorbent after the alkali treatment.

In one embodiment of the invention, the washing is carried out with deionized water. Wherein the mass ratio of the deionized water to the S-Zorb spent adsorbent can be 6:1-11: 1.

For example, the mass ratio of deionized water to spent S-Zorb adsorbent can be 7:1, 8:1, 9:1, 10:1, and the like.

In one embodiment of the present invention, the method of the present invention comprises the step of drying and calcining the S-Zorb spent adsorbent after washing and filtering.

The precipitate on the surface of the adsorbent can be converted into ZnO as an active component by washing, filtering, drying and roasting the S-Zorb spent adsorbent.

The present invention also provides an S-Zorb adsorbent obtained by treating an S-Zorb spent adsorbent by the above-described method of the present invention.

The S-Zorb adsorbent has the advantages that the surface ZnO active species are increased, the grain size is smaller, the acid site concentration, the specific surface area and the pore volume are greatly increased, and the gasoline desulfurization activity can be almost comparable to that of a fresh agent. The S-Zorb adsorbent has a specific surface area of more than 130m²Per g (typically 130 m)²/g-180m²Per g) pore volume of more than 0.35m³Per g (typically 0.35 m)³/g-0.5m³In terms of a/g) and a desulfurization rate of at least 59% (generally 59% to 65%). Compared with the regenerant, the acid site concentration of the S-Zorb adsorbent is increased by 2-3 times, the specific surface area is increased by 4-6 times, the pore volume is increased by 2-4 times, and the gasoline desulfurization rate of the S-Zorb adsorbent is remarkably higher than that of the regenerant and almost comparable to that of a fresh agent.

The acid-base coupling reactivation method of the S-Zorb waste adsorbent comprises the steps of roasting the waste adsorbent to remove carbon deposition on the surface of the waste adsorbent, and simultaneously converting ZnS and NiS on the surface into ZnO and NiO. Then, the roasted waste adsorbent is mixed with an acid solution, and the inert zinc silicate is converted into Zn by the reaction of the acid and the zinc silicate on the surface of the waste adsorbent ²⁺Dissolved in an aqueous solution. Subsequently, an excess of base is added to the solution to make the Zn in the solution²⁺Precipitated and deposited on the adsorbent surface. The precipitate on the surface of the adsorbent can be converted into the active component ZnO by washing, filtering, drying and roasting the adsorbent. At the same time, the acid is on the carrier Al₂O₃The corrosive action of (2) can produce a large number of wormsThe shape of mesopores, namely the pore-forming function; meanwhile, the corrosion action also makes the surface of the S-Zorb spent adsorbent become very rough, the structure is looser, the specific surface and pore volume are increased, and the diffusion of reactants and products is accelerated; the destructive effect can also generate a large number of defect sites on the surface of the carrier, so that the amount of Lewis acid is increased, and the increase of the amount of Lewis acid is beneficial to the adsorption of the alkaline sulfur-containing compound and the acceleration of the conversion of the sulfide.

According to the acid-base coupling reactivation method of the S-Zorb spent adsorbent, acid treatment and alkali treatment are continuous processes, intermediate products do not need to be filtered and washed, and the process is simple.

The acid-base coupling reactivation method of the S-Zorb spent adsorbent can remove the inert component zinc silicate on the surface of the spent adsorbent, recover the element Zn and convert the element Zn into the active component ZnO again, and hardly causes the loss of the active component in the whole reactivation process. In addition, the grain diameter of the regenerated ZnO particles in the revival process is smaller than that of ZnO in the fresh agent, which is beneficial to promoting the transfer of sulfur from the Ni surface to ZnO; meanwhile, the smaller particle size is beneficial to the exertion of the sulfur storage performance of ZnO, the utilization rate of ZnO is increased, and the sulfur storage performance is enhanced.

By the acid-base coupling reactivation method of the S-Zorb waste adsorbent, waste can be recycled, environment is protected, and the treatment pressure of three wastes of an enterprise is reduced.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.