阅读说明：本技术 用于异戊二烯产品中二硫化碳超深度脱除方法 (Ultra-deep removal method for carbon disulfide in isoprene product ) 是由 秦玉才 宋丽娟 毕研峰 王焕 李冠泓 翟鹏 于 2020-07-21 设计创作，主要内容包括：本发明属脱硫技术领域,尤其涉及一种用于异戊二烯产品中二硫化碳超深度脱除方法,包括如下步骤：(1)吸附剂前驱体的制备：取多孔二氧化硅粉体、碱土金属氧化物粉体及助剂,添加一定量的粘结剂、润滑剂及扩孔剂,混合均匀,经熟化、干燥,再进行焙烧,然后冷却降温,得到吸附剂前驱体；(2)异戊二烯中二硫化碳的超深度脱除：将吸附剂前驱体在吸附床内原位活化处理备用,在一定操作条件下,将含硫异戊二烯产品以一定空速通过吸附床进行吸附脱硫,待吸附床出口总硫含量达到穿透点,切换物料到另一台吸附床。本发明可最大限度减少高活性的二烯烃发生副反应,处理量和吸附选择性高,操作周期长,生产成本低,废渣排放量少。(The invention belongs to the technical field of desulfurization, and particularly relates to a method for ultra-deep removal of carbon disulfide in isoprene products, which comprises the following steps: (1) preparation of adsorbent precursor: taking porous silicon dioxide powder, alkaline earth metal oxide powder and an auxiliary agent, adding a certain amount of a binder, a lubricant and a pore-expanding agent, uniformly mixing, curing, drying, roasting, cooling and cooling to obtain an adsorbent precursor; (2) ultra-deep removal of carbon disulfide from isoprene: the adsorbent precursor is activated in situ in an adsorption bed for standby, under certain operation conditions, sulfur-containing isoprene products are adsorbed and desulfurized through the adsorption bed at a certain airspeed, and when the total sulfur content at the outlet of the adsorption bed reaches a breakthrough point, the materials are switched to another adsorption bed. The invention can reduce the side reaction of high-activity alkadiene to the utmost extent, and has the advantages of high treatment capacity and adsorption selectivity, long operation period, low production cost and little waste residue discharge.)

1. A method for ultra-deep removal of carbon disulfide in isoprene products is characterized by comprising the following steps:

(1) preparation of adsorbent precursor:

taking porous silicon dioxide powder, alkaline earth metal oxide powder and an auxiliary agent, adding a certain amount of a binder, a lubricant and a pore-expanding agent, uniformly mixing, curing, drying, roasting, cooling and cooling to obtain an adsorbent precursor;

(2) ultra-deep removal of carbon disulfide from isoprene:

the adsorbent precursor is activated in situ in an adsorption bed for standby, under certain operation conditions, sulfur-containing isoprene products are adsorbed and desulfurized through the adsorption bed at a certain airspeed, and when the total sulfur content at the outlet of the adsorption bed reaches a breakthrough point, the materials are switched to another adsorption bed.

2. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 1, wherein: in the step (1), the mixture is cured at 50-150 ℃, dried for 0-12 hours and then roasted at 350-600 ℃ for 0.5-12 hours.

3. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 2, wherein: in the step (1), the mass percentage of the porous silicon dioxide powder in the adsorbent is 0-50%; the mass percentage of the alkaline earth metal oxide powder in the adsorbent is 0-70%; the mass percentage of the auxiliary agent in the adsorbent is 0-30%; the mass percentage of the binder in the adsorbent is 0-10%; the mass percentage of the lubricant in the adsorbent is 0-2%; the pore-expanding agent accounts for 0-1% of the adsorbent by mass.

4. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 3, wherein: in the step (1), the porous silicon dioxide powder is one or a combination of more than two of white carbon black, silica gel, molecular sieve and aerogel; the alkaline earth metal oxide powder is one or the combination of more than two of magnesium oxide, calcium oxide and barium oxide.

5. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 4, wherein: in the step (1), the auxiliary agent is one or a combination of more than two of calcium hydroxide, magnesium hydroxide, calcium oxalate and magnesium oxalate.

6. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 5, wherein: in the step (1), the binder is one or a combination of more than two of magnesium hydroxide, nitric acid, polyethylene glycol and starch.

7. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 6, wherein: in the step (1), the lubricant is one or a combination of more than two of polyethylene glycol and graphite; the pore-enlarging agent is one or the combination of more than two of polyethylene glycol, starch, magnesium carbonate and calcium carbonate.

8. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 7, wherein: in the step (2), the in-situ activation treatment condition is that the activation is carried out for 2-12 hours at the temperature of 150-350 ℃ in a nitrogen atmosphere.

9. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 8, wherein: in the step (2), the operating temperature in the operating condition is 25-150 ℃, and the operating pressure is 0.1-0.5 Mpa; calculated by mass airspeed, the airspeed range is 1-20 h^-1。

10. The method for ultra-deep removal of carbon disulfide from isoprene products according to claim 9, wherein: when the total sulfur content of the isoprene product at the outlet of the adsorption bed reaches 0.1-10 ppm of a set breakthrough point, carrying out regeneration treatment operation on the desulfurization adsorbent; the regeneration treatment operation comprises in-situ regeneration in an adsorption bed and regeneration outside the adsorption bed, and the specific operation conditions are as follows: regenerating for 4-12 hours in a nitrogen atmosphere at 200-550 ℃, and cooling for later use in the nitrogen atmosphere.

Technical Field

The invention belongs to the technical field of desulfurization, and particularly relates to a method for ultra-deep removal of carbon disulfide from an isoprene product.

Background

Isoprene is an important chemical raw material, is an important monomer for synthesizing rubber, is mainly used for synthesizing isoprene rubber, is used as a comonomer for synthesizing butyl rubber, is also used for synthesizing resin, liquid polyisoprene rubber and the like, and is also used in the fields of fine chemical production such as pesticides, medicines, spices, adhesives and the like. The isoprene product is mainly derived from a byproduct carbon five fraction (cracking C for short) in the ethylene cracking process by extractive distillation₅About 15-25%). Carbon disulfide is an important harmful impurity in ethylene cracking gas, and due to physicochemical characteristics, the boiling point (46.2 ℃) is superposed with the carbon five fraction, the carbon disulfide is mainly enriched in the carbon five fraction, and is difficult to effectively separate in the isoprene extractive distillation separation and purification process, for example, an isoprene product of a certain plant, although the purity of the separated isoprene product is as high as more than 99.9%, the total sulfur content of the isoprene product still reaches 40-50 ppm, the carbon disulfide mainly accounts for about 95% of the total sulfur content, and a small amount of thioether, mercaptan and thiophene. Since sulfur-containing compounds not only poison the catalyst during processing of the isoprene downstream products, but also affect the quality of the isoprene downstream products, a total sulfur content of less than or equal to 5 ppm (wt%), or even less than or equal to 0.1ppm (wt%) is generally required. Therefore, ultra-deep desulfurization of isoprene, especially deep removal of carbon disulfide, becomes a key technology for high value-added utilization of isoprene.

Generally, the oil product desulfurization technology is mainly divided into hydrodesulfurization technology, extraction desulfurization technology, complex desulfurization technology, oxidation desulfurization technology, adsorption desulfurization technology and other non-hydrodesulfurization technologies. However, due to the high reactivity of isoprene and the high stability of carbon disulfide, it is not feasible to remove carbon disulfide from isoprene by chemical conversion methods such as hydrogenation, oxidation, biological desulfurization, etc., and extractive desulfurization and adsorptive desulfurization techniques are two feasible ultra-deep desulfurization schemes for isoprene. The extraction desulfurization is to use a proper extracting agent to realize the removal of sulfide in raw materials by high dissolution selectivity of sulfur-containing compounds, and the technology has the problems of insufficient desulfurization depth, difficulty in realizing ultra-deep desulfurization (less than 1 ppm), large using amount of the extracting agent, easiness in generating waste liquid, complex subsequent purification treatment process, high production cost and the like. The adsorption desulfurization technology realizes selective adsorption and removal of sulfide by utilizing the excellent adsorption performance of the adsorbent on the sulfide, is a desulfurization technology with low operation cost and small influence on product quality, and is an ultra-deep desulfurization technology with great popularization and application prospects.

Chinese patent (application number: 201510076936.7) discloses a desulfurization method for cracking carbon five, which relates to a desulfurization method for cracking carbon five, firstly adding a desulfurizing agent into a cracking carbon five raw material to react for a period of time under certain pressure and temperature, then separating sulfur-free cracking carbon five at the tower top by a filtration and distillation method, and placing the sulfide obtained by the reaction in a tower kettle, wherein the desulfurizing agent comprises the following components: 3-8% of triethanolamine, 3-8% of acetonitrile, 3-8% of aniline, 3-8% of acetone, 8-12% of benzene, 25-35% of saturated ammonia water, 8-12% of butyronitrile, 8-12% of cyclohexane, 10-20% of aniline and 3-8% of 2-ethyltoluene diamine. The method provided by the invention has good desulfurization effect, the desulfurization product does not introduce a byproduct, the composition of cracking carbon five is not changed, and the desulfurizer has low toxicity and is nonflammable.

The desulfurization technology related to the invention belongs to the extraction desulfurization technology, the extracting agent has more components, the preparation process is complex, the generation amount of desulfurization waste liquid is large, and the desulfurized C₅In addition, the residual extractant in the product is mainly aimed at mercaptan and thioether in cracking carbon five from the viewpoint of the components of the desulfurizer provided by the invention, and the removal effect of carbon disulfide is not considered, so that the method is not suitable for ultra-deep desulfurization of carbon disulfide in high-purity isoprene products.

U.S. patent (US 9981889B 2) discloses a method of achieving removal of CS2 from petroleum hydrocarbons using a combined treatment comprising at least one carbon disulfide scavenger and at least one phase transfer catalyst. The disulfideThe carbon scavenger may include at least one polyamine having the general formula H₂N-(R₁-NH)x-R₂-(NH-R₃)y-NH₂Wherein R is₁、R₂、R₃May be the same or different and includes H, aryl, C₁-C₄An alkyl group; x and y may be integers between 0 and 10. This embodiment can realize a hydrocarbon compound comprising CS in isoprene₂Is reduced.

The desulfurization technology related to the invention still belongs to the category of extraction desulfurization technology, and CS is selected₂The synthesis of the remover is complex, a compound phase transfer catalyst is needed to play a role in desulfurization, the operation process is complex, and the problem of high production cost exists; in addition, the invention does not quantify the deep removal effect of the proposal on carbon disulfide with the content of tens ppm in isoprene; moreover, the regeneration and purification process of the desulfurizer provided by the invention is too complex.

The technical core of ultra-deep adsorption and removal of carbon disulfide in isoprene is the development of a high-efficiency adsorbent. Chinese patent (publication number: CN 103182291A) discloses a preparation method and application of deep desulfurization adsorbent for cracking carbon five distillate oil, which is characterized in that: the process comprises the following steps: 1) preparing a carrier: taking pseudo-boehmite powder, adding a binder and an extrusion aid, extruding into strips or granulating in a rotating way, drying and roasting to obtain strip-shaped or spherical gamma-Al₂O₃A carrier; 2) impregnation of Zn, Cu, group IA or group IIA metals: loading metal salt by adopting a co-impregnation method; dipping and filtering at room temperature, taking out, drying and roasting, and then naturally cooling; wherein ZnO accounts for 5-15% of the adsorbent by mass, CuO accounts for 2-8% of the adsorbent by mass, the content of the metal oxide of the IA group or IIA group is 1-5%, and the balance is an alumina carrier; the at least one group IA or IIA metal is any one of potassium, sodium, calcium, and/or combinations thereof. The application is the application of the prepared desulfurization adsorbent in deep desulfurization reaction of cracking carbon five distillate oil.

The effective adsorption active components of the desulfurization adsorbent prepared by the invention are ZnO and CuO, and the active components can be inevitably chemically combinedActive isoprene has strong action, and the carrier is gamma-Al₂O₃Because the surface of the carrier contains acidity which can cause isoprene to be polymerized, the invention adds metals (potassium, sodium and calcium) in group IA or IIA to neutralize the acidity of the surface of the carrier.

Chinese patent (publication No. CN 104230626A) discloses a method for desulfurizing isoprene separated from ethylene cracking carbon five; feeding ethylene cracking carbon pentaraw materials into a thermal polymerization kettle for thermal polymerization, wherein cyclopentadiene in the raw materials is thermally polymerized into dicyclopentadiene; the hot polymeric material enters a pre-separation tower, dicyclopentadiene components in the material are removed, further purified isoprene is obtained at the tower top, the pre-separated material enters an extraction tower for extraction and separation, components with a boiling point close to that of the isoprene in the material are removed, the extracted material enters an analytical tower for analytical rectification, a concentrate mainly containing isoprene is obtained at the tower top, an extracting agent mainly containing acetonitrile and water is obtained at the tower bottom, the analyzed material enters a washing tower, pure isoprene is obtained at the tower top, the pure isoprene separated by washing enters an isoprene storage tank, and the pure isoprene is pumped into a fixed bed reactor through a pump for catalyst adsorption desulfurization; the method can reduce the sulfur content in the isoprene to less than 5 mu g/g, and has simple process conditions and easy control.

The catalyst used for the adsorption desulfurization of the catalyst in the fixed bed reactor disclosed by the invention mainly comprises 15-85% of nano-alumina, 5-25% of zinc oxide, 5-75% of silicon oxide, ZnO as an effective active component, and alumina or silicon oxide as a carrier. The invention needs to carry out multi-step separation and purification treatment on the raw material before adsorption desulfurization, and aims to avoid the cyclopentadiene with higher activity in the raw material from generating strong chemical action with the adsorbent.

According to the research on deep desulfurization of isoprene, the Jilin university (Xuyang. adsorption desulfurization research of sulfide in isoprene [ D ]. Jilin university, 2015.) selects adsorbents prepared by Tianjin university, Zhongkoyao large union institute, Shanghai Di Yang corporation, Beijing trimerization environmental protection company and the like, and dynamic desulfurization experiments show that the desulfurization effect of the activated carbon and molecular sieve compound adsorbent provided by Tianjin university and the desulfurization effect of the activated carbon and zinc oxide compound adsorbent provided by large union corporation are obvious, the influence on isoprene raw materials is small, the optimal desulfurization rate can be reached is 91.51%, and the sulfur penetration capacity is 1.97%; however, this adsorbent has a relatively large problem in regeneration, and the desulfurization degree is reduced from 91.51% to 59.55% after 2 regenerations, and large-scale industrial application cannot be achieved. Therefore, the development of an adsorbent which has excellent carbon disulfide adsorption performance, can be repeatedly regenerated and used and has little influence on the properties of isoprene products is very important.

In summary, the core of the ultra-deep carbon disulfide removal technology in isoprene products is to develop a high-efficiency adsorbent, and the main challenges are: firstly, the carbon disulfide adsorption selectivity is excellent; secondly, the material can be repeatedly regenerated and used; thirdly, the side reaction of the isoprene with high reactivity is not caused.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the ultra-deep removal method for the carbon disulfide in the isoprene product, which can reduce the side reaction of high-activity diene to the maximum extent, has high treatment capacity and adsorption selectivity, long operation period, low production cost and small waste residue discharge.

In order to solve the technical problem, the invention is realized as follows:

a method for ultra-deep removal of carbon disulfide in isoprene products comprises the following steps:

(1) preparation of adsorbent precursor:

taking porous silicon dioxide powder, alkaline earth metal oxide powder and an auxiliary agent, adding a certain amount of a binder, a lubricant and a pore-expanding agent, uniformly mixing, curing, drying, roasting, cooling and cooling to obtain an adsorbent precursor;

(2) ultra-deep removal of carbon disulfide from isoprene:

the adsorbent precursor is activated in situ in an adsorption bed for standby, under certain operation conditions, sulfur-containing isoprene products are adsorbed and desulfurized through the adsorption bed at a certain airspeed, and when the total sulfur content at the outlet of the adsorption bed reaches a breakthrough point, the materials are switched to another adsorption bed.

In a preferable scheme, in the step (1), the mixture is cured at 50-150 ℃, dried for 0-12 hours and then roasted at 350-600 ℃ for 0.5-12 hours.

Further, in the step (1), the porous silicon dioxide powder accounts for 0-50% of the adsorbent by mass; the mass percentage of the alkaline earth metal oxide powder in the adsorbent is 0-70%; the mass percentage of the auxiliary agent in the adsorbent is 0-30%; the mass percentage of the binder in the adsorbent is 0-10%; the mass percentage of the lubricant in the adsorbent is 0-2%; the pore-expanding agent accounts for 0-1% of the adsorbent by mass.

Further, in the step (1), the porous silica powder is one or a combination of more than two of white carbon black, silica gel, molecular sieve and aerogel; the alkaline earth metal oxide powder is one or the combination of more than two of magnesium oxide, calcium oxide and barium oxide.

Further, in the step (1) of the present invention, the auxiliary agent is one or a combination of two or more of calcium hydroxide, magnesium hydroxide, calcium oxalate and magnesium oxalate.

Further, in step (1) of the present invention, the binder is one or a combination of two or more of magnesium hydroxide, nitric acid, polyethylene glycol, and starch.

Further, in the step (1) of the invention, the lubricant is one or a combination of more than two of polyethylene glycol and graphite; the pore-enlarging agent is one or the combination of more than two of polyethylene glycol, starch, magnesium carbonate and calcium carbonate.

Further, in the step (2), the in-situ activation treatment condition is activation for 2-12 hours at 150-350 ℃ in a nitrogen atmosphere.

Further, in the step (2), the operation temperature in the operation condition is 25-150 ℃, and the operation pressure is 0.1-0.5 Mpa; calculated by mass airspeed, the airspeed range is 1-20 h^-1。

Further, when the total sulfur content of the isoprene product at the outlet of the adsorption bed reaches 0.1-10 ppm of a set breakthrough point, the desulfurization adsorbent is subjected to regeneration treatment; the regeneration treatment operation comprises in-situ regeneration in an adsorption bed and regeneration outside the adsorption bed, and the specific operation conditions are as follows: regenerating for 4-12 hours in a nitrogen atmosphere at 200-550 ℃, and cooling for later use in the nitrogen atmosphere.

The key of the preparation and application technology of the adsorbent for deeply removing the carbon disulfide from the isoprene product is that firstly, the adsorbent can be used for adsorption desulfurization under mild operation process conditions, normal temperature and pressure and non-hydrogenation conditions, and the side reaction of high-activity diene can be reduced to the maximum extent; secondly, the treatment capacity and the adsorption selectivity of the adsorbent are improved, the operation period is prolonged, and the production cost is reduced; and thirdly, the developed adsorbent can be regenerated and reused, and is beneficial to reducing waste residue emission.

Compared with the prior art, the invention has the following beneficial effects:

1) the provided adsorbent can realize ultra-deep removal of carbon disulfide in isoprene products, and the sulfur content is lower than 0.1 ppm.

2) The desulfurization process adopts a fixed bed adsorption process, is operated at normal temperature and normal pressure, has no loss of an adsorbent and is low in operation cost.

3) The adsorbent is non-toxic and harmless to human bodies, and has no environmental pollution.

4) The adsorbent can be repeatedly regenerated and used, the activity can be well recovered, long-period operation is facilitated, and the production cost is reduced.

Detailed Description

The present invention will be further described with reference to the following specific examples. The scope of the invention is not limited to the following expressions.

The method for ultra-deep removal of carbon disulfide in isoprene products comprises the following steps:

1) preparation of the adsorbent: taking porous silicon dioxide powder, alkaline earth metal oxide powder and an auxiliary agent, adding a certain amount of a binder, a lubricant and a pore-expanding agent, uniformly mixing, tabletting, extruding or rotating and granulating for molding, curing at 50-150 ℃, drying for 0-12 hours, roasting at 350-600 ℃ for 0.5-12 hours, and then cooling to obtain a flaky, strip or spherical adsorbent precursor.

The mass percentage of the porous silicon dioxide in the adsorbent is 0-50%, the mass percentage of the alkaline earth metal oxide powder in the adsorbent is 0-70%, the mass percentage of the auxiliary agent in the adsorbent is 0-30%, the mass percentage of the binder is 0-10%, the mass percentage of the lubricant is 0-2%, and the mass percentage of the pore-expanding agent is 0-1%.

The porous silicon dioxide powder is any one of white carbon black, silica gel, molecular sieve and aerogel or the combination of the white carbon black, the silica gel, the molecular sieve and the aerogel.

The alkaline earth metal oxide powder is any one or combination of magnesium oxide, calcium oxide and barium oxide.

The auxiliary agent is any one or combination of calcium hydroxide, magnesium hydroxide, calcium oxalate and magnesium oxalate.

The binder is any one or combination of magnesium hydroxide, nitric acid, polyethylene glycol and starch.

The lubricant is any one of polyethylene glycol and graphite and/or a combination thereof.

The pore-expanding agent is any one or combination of polyethylene glycol, starch, magnesium carbonate and calcium carbonate.

2) Ultra-deep removal of carbon disulfide from isoprene:

adopting a multi-fixed bed adsorption process operation, wherein the adsorption operation step comprises: the adsorbent precursor is activated in situ in the adsorption bed for standby before desulfurization, under certain operation conditions, sulfur-containing isoprene product is adsorbed and desulfurized through the adsorption bed at a certain airspeed, and when the total sulfur content at the outlet of the adsorption bed reaches the breakthrough point, the material is switched to another adsorption bed.

The multi-fixed bed adsorption process flow comprises a double-adsorption bed and multi-adsorption bed parallel process, and is specifically determined according to the sulfur content in the material to be treated and the actual capacity requirement.

The in-situ activation treatment condition is that the activation is carried out for 2 to 12 hours at the temperature of 150 to 350 ℃ in a nitrogen atmosphere.

The certain operation conditions include an operation temperature, preferably a temperature range of normal temperature (25 ℃) to 150 ℃, preferably normal temperature (25 ℃), and an operation pressure, preferably a pressure range of normal pressure (0.1 MPa) to 0.5MPa, preferably normal pressure (0.1 MPa).

The certain airspeed is calculated by mass airspeed, and the preferred airspeed range is 1-20 h^-1Preferably 1.0 to 3.0 hours^-1。

The penetration point of the sulfur content is determined (0.1 ppm-10 ppm) according to the specific sulfur content requirement, and the detection method is carried out in an online or offline manner by adopting hydrocarbon sulfide analysis methods such as a coulometer or a gas chromatography-sulfur chemiluminescence detector (GC-SCD).

3) Regeneration of the adsorbent:

according to the technical process for preparing the adsorbent and desulfurizing the isoprene, the regeneration method of the carbon disulfide ultra-deep removal adsorbent in the isoprene is characterized in that when the total sulfur content of isoprene products at the outlet of an adsorption bed is set to a breakthrough point (0.1 ppm-10 ppm), the desulfurization adsorbent is subjected to regeneration treatment operation.

The regeneration treatment operation of the desulfurization adsorbent can be divided into in-situ regeneration in an adsorption bed and regeneration outside the adsorption bed, and the specific operation conditions are as follows: regenerating for 4-12 hours at 200-550 ℃ in nitrogen, air or steam atmosphere, and cooling for later use in nitrogen atmosphere.