阅读说明：本技术 一种转化煤焦油中酚类化合物的催化剂的制备及催化方法 (Preparation and catalysis method of catalyst for converting phenolic compounds in coal tar ) 是由 邱泽刚 李志勤 尹婵娟 于 2019-10-24 设计创作，主要内容包括：本发明公开了一种转化煤焦油中酚类化合物的催化剂的制备及催化方法,催化剂由活性成分、载体以及助剂组成,活性成分为氧化钴和氧化钼,载体为单斜晶相氧化锆和氧化铝的复合物,助剂为磷,其中,活性组分以钼和钴单质计分别占催化剂重量的2.35wt％～5.54wt％和0.62wt％～2.84wt％,助剂磷以单质计占催化剂总重量的1.0wt％～2.0wt％,其余为载体,制备方法包括制备载体以及利用载体和活性组分溶液制备催化剂,催化方法包括催化剂预硫化、催化剂活化以及利用催化剂对酚类化合物进行催化反应,本发明可将酚类化合物选择性转化为高值化的芳烃,酚类化合物脱氧率接近100％,芳烃收率可达87.72％。(The invention discloses a preparation and catalysis method of a catalyst for converting phenolic compounds in coal tar, the catalyst comprises active components, a carrier and an auxiliary agent, the active components comprise cobalt oxide and molybdenum oxide, the carrier is a compound of monoclinic phase zirconium oxide and aluminum oxide, the auxiliary agent is phosphorus, wherein the active components respectively account for 2.35 wt% -5.54 wt% and 0.62 wt% -2.84 wt% of the weight of the catalyst in terms of simple substances of molybdenum and cobalt, the auxiliary agent phosphorus accounts for 1.0 wt% -2.0 wt% of the total weight of the catalyst in terms of simple substances, the rest is the carrier, the preparation method comprises the steps of preparing the carrier and preparing the catalyst by utilizing a carrier and an active component solution, the catalysis method comprises the steps of presulfurizing the catalyst, activating the catalyst and utilizing the catalyst to carry out catalytic reaction on the phenolic compounds, the invention can selectively convert the phenolic compounds into high-value aromatic hydrocarbons, the deoxidation rate of the phenolic compounds is close to 100%, the yield of the aromatic hydrocarbon can reach 87.72 percent.)

1. The catalyst for converting phenolic compounds in coal tar is composed of an active component, a carrier and an auxiliary agent, and is characterized in that the active component is cobalt oxide and molybdenum oxide, the carrier is a monoclinic phase zirconia-alumina compound, the auxiliary agent is phosphorus, wherein the active component accounts for 2.35-5.54 wt% and 0.62-2.84 wt% of the weight of the catalyst respectively based on simple substances of molybdenum and cobalt, the auxiliary agent phosphorus accounts for 1.0-2.0 wt% of the total weight of the catalyst based on the simple substances, and the balance is the carrier.

2. The catalyst for converting phenolic compounds in coal tar according to claim 1, wherein the monoclinic phase zirconia has a specific surface area of 60-90m²Per g, pore volume of 0.140-0.20cm³(ii)/g, the average pore diameter is 8-13 nm; the precursor of the aluminum oxide has the specific surface area of 350-450m²Per g, pore volume of 0.6-1.0cm³(ii) pseudoboehmite with an average pore diameter of 6-8 nm.

3. A preparation method of a catalyst for converting phenolic compounds in coal tar is characterized by comprising the following preparation steps:

s1, preparing a zirconium oxide and aluminum oxide composite carrier: weighing a certain amount of zirconium oxychloride octahydrate (ZrOCl)₂·8H₂O) and urea are respectively dissolved in distilled water, then the urea solution is slowly dripped into the zirconium oxychloride octahydrate solution under stirring, the solution is uniformly mixed by fully stirring, then the mixed solution is moved into a stainless steel reaction kettle lined with PPL (p-polyphenylphenylene), the temperature is firstly increased to 80 ℃ and kept for 2h, the temperature is continuously increased to 200 ℃ and kept for 8h, the temperature is cooled to room temperature, and the product is repeatedly washed by distilled water until no Cl is detected^-And dried at 60 ℃ for 8 hours to obtain ZrO₂Followed by the alumina precursors pseudo-boehmite, ZrO2 anduniformly mixing the extrusion aid sesbania gum to obtain a mixture, adding distilled water into the mixture according to the water-powder ratio of 0.6-0.8:1, kneading in a kneader for 80-120min, putting the mixture into a strip extruder for extrusion molding, drying at 15-40 ℃ for 6-8h, drying at 100 ℃ for 10-12h, heating to 450-650 ℃ at the heating rate of 2-6 ℃/min, and roasting for 4-6h to obtain the zirconium oxide and aluminum oxide composite carrier;

s2, preparation of a catalyst: adding cobalt oxide precursor cobalt nitrate and molybdenum oxide precursor ammonium molybdate into distilled water, stirring at room temperature to completely dissolve the cobalt oxide precursor cobalt nitrate and the molybdenum oxide precursor ammonium molybdate, then adding phosphoric acid, continuously stirring for 1h to obtain an active component solution, then dipping the zirconium oxide and aluminum oxide composite carrier into the obtained active component solution by a saturated dipping method, drying for 10h at 100 ℃, then heating to 500 ℃ at the heating rate of 5 ℃/min, and roasting for 3h to obtain the finished catalyst.

4. The method for preparing the catalyst for converting the phenolic compounds in the coal tar according to claim 3, wherein the weight percentage concentration of the cobalt nitrate, the ammonium molybdate and the phosphoric acid in the active component solution is 12.79-14.82%, 11.07-23.27% and 3.0-6.0%.

5. A catalytic process for a catalyst for converting phenolic compounds in coal tar, characterized in that the catalytic process comprises the steps of:

1) and (3) pre-sulfurizing the catalyst: adding ammonium thiosulfate solid into distilled water, stirring at room temperature for 1h, then impregnating the catalyst prepared in claim 3 with an aqueous solution of ammonium thiosulfate for 4h, and then drying the catalyst at 100 ℃ for 6h to obtain a pre-vulcanized catalyst;

2) and activating the catalyst: putting the vulcanized catalyst into a kettle type reactor to activate the catalyst under the activation condition of H₂The pressure is 3MPa, the temperature is 300 ℃, and the time is 50 min;

3) and carrying out catalytic reaction on the phenolic compound by using a catalyst: putting the catalyst and the phenolic compound into a kettle type hydrogenation reactorCatalytic reaction under the condition of H₂The pressure is 2MPa to 4MPa, the temperature is 280 ℃ to 340 ℃, and the time is 3h to 8 h.

6. The catalytic method of claim 5, wherein the phenolic compound is a mixed phenol separated from coal tar.

Technical Field

The invention relates to the technical field of coal tar deep processing, in particular to a preparation method and a catalysis method of a catalyst for converting phenolic compounds in coal tar.

Background

Coal tar is one of the main products of coal thermal processing, and is a black or blackish brown viscous liquid with pungent odor. Coal tar can be divided into high temperature (900-1000 ℃), medium temperature (700-900 ℃) and low temperature (500-700 ℃) according to the carbonization temperature.

The high-temperature coal tar is black, has high density, contains a large amount of asphalt, is a complex mixture consisting of aromatic compounds, has low content of alkyl hydrocarbon, more high-boiling-point substances and good thermal stability, so the main processing mode of the high-temperature coal tar in China is to separate and refine to obtain various chemical raw materials, thereby providing very important basic raw materials for industries such as medicines, pesticides, fibers, plastics, dyes, spices, materials and the like. The high-temperature tar contains more than 10 compounds with the mass fraction of more than or equal to 1.0 percent, and the compounds are mainly three isomers of naphthalene, phenanthrene, fluoranthene, pyrene, acenaphthylene, fluorene, anthracene, 2-methylnaphthalene, carbazole, indene, dibenzofuran, cresol and the like. Many of these organic compounds are plastics, synthetic fibers, dyes, synthetic rubbers, pesticides, building materials, high temperature resistant materials and valuable raw materials for the defense industry. The content of phenolic compounds in the high-temperature coal tar is about 1 to 2.5 percent of the content of the tar, wherein 6 percent of the phenolic compounds are low-grade phenols, the rest phenolic compounds are mainly high-grade phenols, and the low-grade phenols mainly refer to phenol, cresol and xylenol. Lower phenol in the high-temperature coal tar can be separated out for utilization, but higher phenol basically has no application value, and high-value conversion is urgently needed.

The composition and properties of the medium-low temperature coal tar are greatly different from those of the high-temperature coal tar, the medium-low temperature coal tar contains more oxygen-containing compounds and chain hydrocarbons, wherein the content of phenolic compounds can reach about 30 percent, and the balance of nitrogen-containing compounds, sulfur-containing compounds and colloidal compounds mainly containing pyridine. The main technology for processing and utilizing the medium-low temperature coal tar is to produce fuels such as gasoline, diesel oil and the like by catalyst hydrogenation. At present, phenol-containing coal tar is mostly directly fed into a hydrogenation device in industry to produce fuel, and the serious problem of the scheme is that the value of low-grade phenol is not improved, and the low-grade phenol and the high-grade phenol are both excessively hydrogenated, so that phenol, a valuable compound with outstanding available characteristics, is actually wasted; meanwhile, the hydrogen consumption is increased and the energy consumption is increased in the whole process, and the water generated by phenol hydrogenation seriously influences the catalyst, so that the performance of the catalyst is reduced and the service life of the catalyst is shortened. In view of the constitutional characteristics of the low-temperature coal tar rich in phenols, a route combining chemicals and fuel oil should be adopted for high-value and high-efficiency utilization of the low-temperature coal tar. Therefore, the catalytic conversion and utilization of phenols in the medium-low temperature coal tar, especially high phenols, have important significance, and it needs to be noted that low phenols and high phenols can be catalytically converted together, but the processing of high phenols has more economic value.

The current research on the conversion of phenols in coal tar is relatively deficient. In recent years, researches on the conversion of phenolic compounds are basically directed to biomass-derived oil, the used catalyst mainly comprises supported reduced metal and also relates to nitride, phosphide and carbide, and the sulfur-state catalyst used in the petroleum and coal tar processing industry is not regarded as important because sulfur can be introduced into the biomass-derived oil product. Among various catalysts, for coal tar phenol fractions containing sulfur, nitrogen, metal impurities and high oxygen, a reduced metal catalyst is easy to poison and expensive (for noble metals), phosphide, carbide and nitride are easy to poison and have poor stability, a non-supported transition metal sulfurized catalyst has the problem of difficult large-scale preparation and storage, and the formability and mechanical strength of the catalyst when the catalyst is used in a fixed bed face great challenges. In contrast, the supported transition metal sulfidation catalyst has better toxicity resistance and stability, and is easy to be butted with the existing large-scale coal tar industrial hydrogenation device and the catalyst production device. Accordingly, provided herein is a transition metal sulfided catalyst.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method and a catalysis method of a catalyst for converting phenolic compounds in coal tar so as to realize high-value utilization of the phenolic compounds in the coal tar.

The purpose of the invention is realized by the following technical scheme:

the catalyst for converting phenolic compounds in coal tar is composed of an active component, a carrier and an auxiliary agent, and is characterized in that the active component is cobalt oxide and molybdenum oxide, the carrier is a monoclinic phase zirconia-alumina compound, the auxiliary agent is phosphorus, wherein the active component accounts for 2.35-5.54 wt% and 0.62-2.84 wt% of the weight of the catalyst respectively based on simple substances of molybdenum and cobalt, the auxiliary agent phosphorus accounts for 1.0-2.0 wt% of the total weight of the catalyst based on the simple substances, and the balance is the carrier.

Further, the monoclinic phase zirconia has a specific surface area of 60-90m²G, the pore volume is 0.140-0.20cm3/g, and the average pore diameter is 8-13 nm; the precursor of the alumina is pseudo-boehmite with the specific surface area of 350-450m2/g, the pore volume of 0.6-1.0cm3/g and the average pore diameter of 6-8 nm.

A preparation method of a catalyst for converting phenolic compounds in coal tar comprises the following preparation steps:

s1, preparing a zirconium oxide and aluminum oxide composite carrier: weighing a certain amount of zirconium oxychloride octahydrate (ZrOCl)₂·8H₂O) and urea are respectively dissolved in distilled water, then the urea solution is slowly dripped into the zirconium oxychloride octahydrate solution under stirring, the solution is uniformly mixed by fully stirring, then the mixed solution is moved into a stainless steel reaction kettle lined with PPL (p-polyphenylphenylene), the temperature is firstly increased to 80 ℃ and kept for 2h, the temperature is continuously increased to 200 ℃ and kept for 8h, the temperature is cooled to room temperature, and the product is repeatedly washed by distilled water until no Cl is detected^-And dried at 60 ℃ for 8 hours to obtain ZrO₂Then uniformly mixing an alumina precursor pseudo-boehmite, ZrO2 and an extrusion aid sesbania gum to obtain a mixture, adding distilled water into the mixture according to the water-powder ratio of 0.6-0.8:1, kneading the mixture in a kneading machine for 80-120min, putting the mixture into a strip extruding machine for extrusion molding, drying the mixture at 15-40 ℃ for 6-8h, drying the mixture at 100 ℃ for 10-12h, heating the mixture to 650 ℃ at the heating rate of 2-6 ℃/min, and roasting the mixture for 4-6h to obtain a zirconium oxide and alumina composite carrier;

s2, preparation of a catalyst: adding cobalt oxide precursor cobalt nitrate and molybdenum oxide precursor ammonium molybdate into distilled water, stirring at room temperature to completely dissolve the cobalt oxide precursor cobalt nitrate and the molybdenum oxide precursor ammonium molybdate, then adding phosphoric acid, continuously stirring for 1h to obtain an active component solution, then dipping the zirconium oxide and aluminum oxide composite carrier into the obtained active component solution by a saturated dipping method, drying for 10h at 100 ℃, then heating to 500 ℃ at the heating rate of 5 ℃/min, and roasting for 3h to obtain the finished catalyst.

Further, the weight percentage concentration of cobalt nitrate in the active component solution is 12.79 wt% -14.82 wt%, the weight percentage concentration of ammonium molybdate is 11.07 wt% -23.27%, and the weight percentage concentration of phosphoric acid is 3.0 wt% -6.0%.

A catalytic method of a catalyst for converting phenolic compounds in coal tar comprises the following steps:

1) and (3) pre-sulfurizing the catalyst: adding ammonium thiosulfate solid into distilled water, stirring at room temperature for 1h, then impregnating the catalyst prepared in claim 3 with an aqueous solution of ammonium thiosulfate for 4h, and then drying the catalyst at 100 ℃ for 6h to obtain a pre-vulcanized catalyst;

2) and activating the catalyst: putting the vulcanized catalyst into a kettle type reactor to activate the catalyst under the activation condition of H₂The pressure is 3MPa, the temperature is 300 ℃, and the time is 50 min;

3) and carrying out catalytic reaction on the phenolic compound by using a catalyst: putting the catalyst and the phenolic compound into a kettle type hydrogenation reactor for catalytic reaction, and controlling the catalytic reaction condition to be H₂The pressure is 2MPa to 4MPa, the temperature is 280 ℃ to 340 ℃, and the time is 3h to 8 h.

Further, the phenolic compound is mixed phenol separated from the coal tar.

The invention has the beneficial effects that: the invention can selectively convert the phenolic compounds into high-valued aromatic hydrocarbons, the deoxidation rate is close to 100 percent, and the aromatic hydrocarbon yield can reach 87.72 percent. In the invention, the active components of cobalt and molybdenum are introduced by an impregnation method, so that the catalyst has proper pore size distribution and good dispersibility. The catalyst of the invention also has good stability, and the catalytic performance of the catalyst is not greatly changed after the catalyst is placed for a period of time.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.