阅读说明：本技术 一种催化油脂定向加氢脱氧制备氢化生物柴油的方法 (Method for preparing hydrogenated biodiesel by catalyzing grease directional hydrodeoxygenation ) 是由 刘朋 蒋剑春 周铭昊 徐俊明 王奎 李静 夏海虹 叶俊 赵佳平 王瑞珍 于 2019-11-25 设计创作，主要内容包括：本发明公开了一种催化油脂定向加氢脱氧制备氢化生物柴油的方法,属于氢化生物柴油的制备技术领域。采用分子筛负载型催化剂,催化油脂原料加氢脱氧反应以加氢脱羧/脱羰方式进行,获得氢化生物柴油,所述氢化生物柴油中十五烷和十七烷的总含量大于85％；所述催化剂活性组分为Ni<Sub>2</Sub>P,催化剂的用量为反应油脂原料重量的5％-10％；所述氢化生物柴油的主要成分为以十五烷、十七烷,且本发明定向加氢脱羧/脱羰选择性大于80％,减少反应水分的生成,避免催化剂的遇水易失活缺陷,延长催化剂的使用寿命；本发明制备氢化生物柴油的反应转化率大于95％,且大大降低油脂加氢脱氧反应温度和时间,显著降低反应能耗和成本。(The invention discloses a method for preparing hydrogenated biodiesel by catalyzing grease directional hydrodeoxygenation, belonging to the technical field of hydrogenated biodiesel preparation. Catalyzing the hydrodeoxygenation reaction of the grease raw material by adopting a molecular sieve supported catalyst in a hydrodedecarboxylation/decarbonylation mode to obtain hydrogenated biodiesel, wherein the total content of pentadecane and heptadecane in the hydrogenated biodiesel is more than 85%; the active component of the catalyst is Ni 2 P, the dosage of the catalyst is 5-10% of the weight of the reaction grease raw material; the main components of the hydrogenated biodiesel are pentadecane and heptadecane, and the directional hydrogenation decarboxylation/decarbonylation selectivity of the invention is more than 80 percent, thereby reducing the generation of reaction water, avoiding the defect that the catalyst is easy to be activated when meeting water, and prolonging the service life of the catalyst; the reaction conversion rate of the hydrogenated biodiesel prepared by the method is more than 95 percent, the temperature and the time of the hydrodeoxygenation reaction of the grease are greatly reduced, the energy consumption of the reaction is remarkably reduced, andand (4) cost.)

1. A method for preparing hydrogenated biodiesel by catalyzing oil and fat directional hydrodeoxygenation is characterized in that a molecular sieve supported catalyst is adopted, the hydrodeoxygenation reaction of a catalytic oil and fat raw material is carried out in a hydrodedecarboxylation/decarbonylation mode, and the reaction is carried out for 2-4h at the temperature of 280-320 ℃ to obtain the hydrogenated biodiesel, wherein the total content of pentadecane and heptadecane in the hydrogenated biodiesel is more than 85%; the active component of the molecular sieve supported catalyst is Ni₂The mass of the P and the Ni elements is 5-15 wt.% of the carrier; the dosage of the molecular sieve supported catalyst is 5-10% of the mass of the grease raw material.

2. The method for preparing hydrogenated biodiesel by catalytic grease directional hydrodeoxygenation according to claim 1, characterized by comprising the following steps:

(1) adding a grease raw material into a hydrocarbon solvent, and uniformly stirring to obtain a mixed solution; the hydrocarbon solvent is one or two of cyclohexane or normal hexane, and the grease raw material accounts for 15-30% of the mass of the solvent;

(2) transferring the mixed solution into a high-temperature high-pressure reaction kettle, adding a molecular sieve supported catalyst, replacing the internal air, introducing 2-4MPa of hydrogen from the outside, stirring, heating for reaction, and obtaining the hydrogenated biodiesel after the reaction is finished.

3. The method for preparing hydrogenated biodiesel by catalytic directional hydrodeoxygenation of grease according to claim 1 or 2, wherein the grease raw material is waste grease, jatropha oil, xanthoceras sorbifolia oil, litsea cubeba oil or pistacia chinensis oil.

4. The method for preparing hydrogenated biodiesel by catalytic grease directional hydrodeoxygenation according to claim 2, wherein the hydrocarbon solvent is cyclohexane, and the grease raw material is 20% of the solvent by mass.

5. The method for preparing hydrogenated biodiesel by catalytic directional hydrodeoxygenation of grease according to claim 1 or 2, wherein the molecular sieve supported catalyst is Ni₂P/SAPO-11, the mass of Ni element is 15 wt.% of the SAPO-11 carrier.

6. The method for preparing hydrogenated biodiesel by catalytic directional hydrodeoxygenation of grease according to claim 1 or 2, wherein the hydrodeoxygenation reaction temperature is 300 ℃ and the reaction time is 4 hours.

7. The method for preparing hydrogenated biodiesel by catalytic grease directional hydrodeoxygenation according to claim 1 or 2, wherein the dosage of the molecular sieve supported catalyst is 6% of the weight of the grease raw material.

8. The method for preparing hydrogenated biodiesel by catalytic grease directional hydrodeoxygenation according to claim 5, wherein the catalyst Ni is₂The preparation method of the P/SAPO-11 comprises the following steps:

(1) adding SAPO-11 into an aqueous solution of a nickel source and a phosphorus source, and performing ultrasonic impregnation, drying and calcination to obtain a catalyst precursor; the phosphorus source is one or a mixture of ammonium dihydrogen phosphate and diammonium hydrogen phosphate; the nickel source is nickel nitrate hexahydrate;

(2) adding a catalyst precursor into a tubular furnace, introducing hydrogen to carry out temperature programming reduction, and carrying out passivation treatment after the reduction is finished and the temperature is reduced to room temperature to obtain a catalyst Ni₂P/SAPO-11；H₂The flow rate is 100-150 mL/min; the temperature programmed processThe process is as follows: heating to 250-300 ℃ at a speed of 10-12 ℃/min, heating to 350-400 ℃ at a speed of 5-7 ℃/min, heating to 600-650 ℃ at a speed of 1-2 ℃/min, maintaining the constant temperature of 600-650 ℃, and reducing for 2-3 h, wherein the temperature is 1% O at normal temperature₂/N₂Passivating for 0.5-1 h.

9. The method for preparing hydrogenated biodiesel by catalytic directional hydrodeoxygenation of grease according to claim 1 or 2, characterized by comprising the following steps:

(1) adding a carrier SAPO-11 into an aqueous solution of nickel nitrate hexahydrate and diammonium hydrogen phosphate, wherein the mass of a Ni element is 15 wt.% of the carrier, ultrasonically dipping for 30min, drying for 12h at 80 ℃, transferring to a muffle furnace at 550 ℃ to calcine for 4h, and crushing and screening by using an 80-mesh screen to obtain a catalyst precursor; adding a catalyst precursor into a tubular furnace, introducing hydrogen to carry out temperature programming reduction, and carrying out passivation treatment after the reduction is finished and the temperature is reduced to room temperature to obtain a catalyst Ni₂P/SAPO-11；H₂The flow rate is 150 mL/min; the temperature programming process comprises the following steps: heating to 250 deg.C at 10 deg.C/min, heating to 350 deg.C at 5 deg.C/min, heating to 650 deg.C at 1 deg.C/min, and maintaining the constant temperature of 650 deg.C for reduction for 3 h; at room temperature at 1% O₂/N₂Passivating for 0.5 h;

(2) the catalyst Ni₂Adding P/SAPO-11 and 20% pistacia chinensis bunge oil cyclohexane solution into a high-temperature high-pressure reaction kettle, displacing internal air, introducing 2.5MPa of hydrogen from the outside, stirring and heating, reacting for 4 hours at 320 ℃, and obtaining hydrogenated biodiesel after the reaction is finished; the catalyst Ni₂The dosage of the P/SAPO-11 is 6 percent of the weight of the Pistacia chinensis oil.

Technical Field

The invention belongs to the technical field of preparation of hydrogenated biodiesel, and particularly relates to a method for preparing hydrogenated biodiesel by catalyzing oil and fat to perform directional hydrodeoxygenation.

Background

With the rapid development of the world economy, the energy supply required by the human society is rapidly increased, the normal survival and development of human beings are seriously threatened by the imminent exhaustion of the traditional fossil energy and the ecological environmental problem generated in the use process, and the urgent need of finding the alternative energy of the petrochemical energy is urgent. For a long time, research and use of biodiesel having green, low carbon, clean, renewable properties has been of great interest. The first generation biodiesel is fatty acid methyl ester, has mature process and application, has many advantages as a substitute fuel, but also has certain defects and limitations, high cold filter plugging point, high viscosity and poor oxidation stability, and limits the popularization and application of fatty acid methyl ester biodiesel.

As a new generation of biological liquid fuel capable of replacing petroleum diesel, hydrogenated biological diesel is proposed, which is directly converted into a C15-C18 alkane compound by grease (triglyceride) through catalytic hydrodeoxygenation reaction, has the same molecular structure as petroleum diesel, has good oxidation stability and higher cetane number, and can be mixed with the petroleum diesel for use. However, the process of converting the grease into the hydrogenated biodiesel through catalytic hydrogenation has high requirements on catalytic activity, and generally uses a noble metal catalyst, which is expensive and has high cost; the common transition metal sulfide catalyst has certain improved catalytic activity, is not environment-friendly, is easy to cause sulfur pollution to the prepared biodiesel, and simultaneously, sulfur in the catalyst is easy to lose, so that the active center structure of the catalyst is changed, and a sulfur source needs to be continuously supplemented in the reaction process. The catalytic hydrogenation reaction path in the preparation process of the hydrogenated biodiesel is undefined, so that the defects of more hydrogenated product components, lower alkane content in the product and the like are caused, the catalytic hydrogenation reaction of the oil mainly generates reactions such as double bond hydrogenation saturation, direct deoxidation by hydrogenation, hydrogenation decarboxylation, hydrogenation decarbonylation and the like, and the reaction process is as follows:

firstly, double bond hydrogenation saturation is generated, double bond functional groups in triglyceride side chains are eliminated, and the stability of the product is further improved; the direct deoxidation by hydrogenation is to make all oxygen atoms in the grease to generate H₂Removing O in a form, and generating alkane compounds with hexadecane and octadecane as main components; the hydrodedecarboxylation is to convert oxygen atoms in the fats and oils to CO₂Formally removed and produces alkane compounds with pentadecane and heptadecane as main components; the hydrogenation decarbonylation is to convert oxygen atoms in the grease into CO and H₂The O form is removed, and alkane compounds with pentadecane and heptadecane as main components are produced. The direct hydrodeoxygenation consumes a large amount of hydrogen sources, and the hydrogen sources are completely converted into water, so that the catalyst is easy to deactivate along with the enrichment of the water; the hydrogenation decarboxylation and the hydrogenation decarbonylation consume less hydrogen, only generate trace moisture and even no moisture, and prolong the service life of the catalyst. The existing problems are how to improve the directional selectivity of catalytic hydrogenation decarboxylation and hydrogenation decarbonylation of the grease, so as to define the main path of catalytic hydrogenation reaction, improve the total content of pentadecane and heptadecane in the product, reduce the content of other alkane byproducts and obtain high-quality hydrogenated biodiesel with concentrated component content.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for preparing hydrogenated biodiesel by catalyzing oil and fat directional hydrogenation and deoxidation, which catalyzes oil and fat directional hydrogenation and decarboxylation and hydrogenation and decarbonylation reactions, greatly reduces the generation of reaction water, prolongs the service life of a catalyst, greatly reduces the temperature and reaction time of the catalytic hydrogenation reaction, and reduces the reaction energy consumption.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a method for preparing hydrogenated biodiesel by catalyzing grease directional hydrodeoxygenation adopts a molecular sieve supported catalyst, the catalytic grease raw material hydrodeoxygenation reaction is carried out in a hydrodedecarboxylation/decarbonylation way, and the reaction is carried out for 2-4h at the temperature of 280-320 ℃ to obtain the hydrogenated biodiesel, wherein the total content of pentadecane and heptadecane in the hydrogenated biodiesel is more than 85%; the active component of the molecular sieve supported catalyst is Ni₂The mass of the P and the Ni elements is 5-15 wt.% of the carrier; the dosage of the molecular sieve supported catalyst is 5-10% of the weight of the reaction grease raw material. The method specifically comprises the following steps:

(1) adding a grease raw material into a hydrocarbon solvent, and uniformly stirring to obtain a mixed solution; the hydrocarbon solvent is one or two of cyclohexane or normal hexane, and the grease raw material accounts for 15-30% of the mass of the solvent;

(2) transferring the mixed solution into a high-temperature high-pressure reaction kettle, adding a molecular sieve supported catalyst, replacing the internal air, introducing 2-4MPa of hydrogen from the outside, stirring, heating, and obtaining the hydrogenated biodiesel after the reaction is finished.

According to the method for preparing the hydrogenated biodiesel by the catalytic oil directional hydrodeoxygenation, the oil raw materials are waste oil, jatropha oil, xanthoceras sorbifolia bunge oil, litsea cubeba oil or pistacia chinensis oil.

According to the method for preparing the hydrogenated biodiesel by catalyzing the oil and fat to carry out directional hydrodeoxygenation, the hydrocarbon solvent is cyclohexane, and the oil and fat raw material accounts for 20% of the mass of the solvent.

The method for preparing the hydrogenated biodiesel by catalyzing the grease directional hydrodeoxygenation comprises the step of preparing the hydrogenated biodiesel by using Ni as the molecular sieve supported catalyst₂P/SAPO-11, mass of Ni element 15 wt.% of support.

The method for preparing the hydrogenated biodiesel by the directional hydrodeoxygenation of the catalytic oil has the hydrodeoxygenation reaction temperature of 300 ℃ and the reaction time of 4 hours.

According to the method for preparing the hydrogenated biodiesel by catalyzing the oil and fat directional hydrodeoxygenation, the dosage of the molecular sieve supported catalyst is 6% of the weight of the oil and fat raw material.

The method for preparing hydrogenated biodiesel by catalyzing grease directional hydrodeoxygenation is characterized in that the catalyst Ni₂The preparation method of the P/SAPO-11 comprises the following steps:

(1) adding SAPO-11 into an aqueous solution of a nickel source and a phosphorus source, and performing ultrasonic impregnation, drying and calcination to obtain a catalyst precursor; the phosphorus source is one or a mixture of ammonium dihydrogen phosphate and diammonium hydrogen phosphate; the nickel source is nickel nitrate hexahydrate;

(2) adding a catalyst precursor into a tubular furnace, introducing hydrogen to carry out temperature programming reduction, and carrying out passivation treatment after the reduction is finished and the temperature is reduced to room temperature to obtain a catalyst Ni₂P/SAPO-11；H₂The flow rate is 100-150 mL/min; the temperature programming process comprises the following steps: heating to 250-300 ℃ at a speed of 10-12 ℃/min, heating to 350-400 ℃ at a speed of 5-7 ℃/min, heating to 600-650 ℃ at a speed of 1-2 ℃/min, maintaining the constant temperature of 600-650 ℃, and reducing for 2-3 h, wherein the temperature is 1% O at normal temperature₂/N₂Passivating for 0.5-1 h.

The method for preparing the hydrogenated biodiesel by catalyzing the directional hydrodeoxygenation of the grease specifically comprises the following steps:

(1) adding SAPO-11 into an aqueous solution of nickel nitrate hexahydrate and diammonium hydrogen phosphate, wherein the mass of a Ni element is 15 wt% of that of a carrier, ultrasonically dipping for 30min, drying for 12h at 80 ℃, transferring to a muffle furnace at 550 ℃ to calcine for 4h, and crushing and screening by using an 80-mesh screen to obtain a catalyst precursor; adding a catalyst precursor into a tubular furnace, introducing hydrogen to carry out temperature programming reduction, and carrying out passivation treatment after the reduction is finished and the temperature is reduced to room temperature to obtain a catalyst Ni₂P/SAPO-11；H₂The flow rate is 150 mL/min; the temperature programming process comprises the following steps: heating to 250 deg.C at 10 deg.C/min, heating to 350 deg.C at 5 deg.C/min, heating to 650 deg.C at 1 deg.C/min, and maintaining the constant temperature of 650 deg.C for reduction for 3 h; at room temperature at 1% O₂/N₂Passivating for 0.5 h;

(2) the catalyst Ni₂Adding P/SAPO-11 and 20% pistacia chinensis bunge oil cyclohexane solution into a high-temperature high-pressure reaction kettle, displacing internal air, introducing 2.5MPa of hydrogen from the outside, stirring and heating, reacting for 4 hours at 320 ℃, and obtaining hydrogenated biodiesel after the reaction is finished; catalyst Ni₂The dosage of the P/SAPO-11 is 6 percent of the weight of the Pistacia chinensis oil.

Has the advantages that: compared with the prior art, the invention has the advantages that:

(1) the invention adopts catalyst Ni₂P/SAPO-11 catalyzed grease directional hydrodeoxygenation for preparing hydrogenated biodiesel, and active component Ni₂P shows the catalytic activity of noble metal, the deoxidation conversion rate is more than 95%, the temperature and time of the grease hydrodeoxygenation reaction are greatly reduced, and the reaction energy consumption and cost are obviously reduced.

(2) The invention realizes the preparation of hydrogenated biodiesel by catalyzing the directional hydrodeoxygenation of grease, the catalytic hydrodecarbonylation/decarboxylation directional selectivity is more than 85 percent, the high-quality hydrogenated biodiesel taking pentadecane and heptadecane as main components is obtained, the effective substitution of petroleum diesel can be realized, and the upgrading and updating of biodiesel products are promoted.

(3) The invention prepares the hydrogenated biodiesel by catalyzing the grease directional hydrogenation decarboxylation/decarbonylation reaction path, reduces the generation of reaction moisture, avoids the defect that the catalyst is easy to be activated when meeting water, and prolongs the service life of the catalyst.

Drawings

FIG. 1 shows Ni of example 1₂XRD patterns of the P/SAPO-11 catalyst and the carrier SAPO-11;

FIG. 2 is a diagram showing a gas mass analysis of the reaction product of example 1.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.