CN111961497B - Method for directly converting low-carbon chain hydrocarbon into long-carbon chain hydrocarbon - Google Patents

Abstract

The invention discloses a method for directly converting low-carbon chain hydrocarbons into long carbon-chain hydrocarbons. Direct synthesis of long carbon chain hydrocarbons; the catalyst includes an active component and a carrier, the active component is one or more of transition metals in Group VIII, and the carrier is one of oxides, carbon materials, and molecular sieves or several, the content of active components in the catalyst is 1-20%, so that the process from synthesizing methyl to synthesizing long carbon chain hydrocarbons in the traditional Fischer-Tropsch synthesis process is transformed into directly from low-carbon chain hydrocarbons. The process of long carbon chain hydrocarbons greatly shortens the reaction process. And the product has good low carbon chain hydrocarbon conversion, C5+ hydrocarbon selectivity and low methane selectivity. Effectively alleviate the shortage of oil resources.

Description

A method for directly converting low carbon chain hydrocarbons into long carbon chain hydrocarbons

technical field

The invention belongs to the catalysis field of petrochemical industry, and particularly relates to a method for directly converting low-carbon chain hydrocarbons into long-carbon chain hydrocarbons.

Background technique

With the global shortage of oil resources and the increasingly serious environmental pollution problems, people pay more and more attention to finding a clean energy that can replace oil. Biomass energy is the only natural carbon source in renewable energy and has broad development prospects. . In terms of the utilization of biomass energy, developed countries such as the United States and Europe have achieved relatively mature application systems, but the application technology of biomass energy in developing countries such as China needs to be further improved. In order to effectively alleviate the energy crisis, in addition to seeking renewable energy, the existing energy structure should also be optimized to improve the utilization efficiency of existing energy.

Fischer-Tropsch synthesis is one of the key technologies that can directly convert energy such as coal, natural gas and biomass into clean oil products.

The Fischer–Tropsch process is a process for producing clean hydrocarbon fuels or chemicals from synthesis gas (CO and H ₂ ) under heterogeneous catalysts and appropriate conditions. In a typical Fischer-Tropsch synthesis reaction, synthesis gas is mainly derived from non-petroleum feedstocks, such as natural gas, coal or biomass; the main products of the reaction are alkanes, olefins, and by-products are methane, a small amount of alcohols and other oxygenated hydrocarbons. Generally, elements with CO hydrogenation activity can be used as active components of Fischer-Tropsch synthesis catalysts. Typical Fischer-Tropsch synthesis reaction catalysts mainly use transition metals Fe, Co, Ni and Ru of Group VIII as active components. Metals can activate CO with moderate activation ability.

The traditional Fischer-Tropsch synthesis process is to pass the synthesis gas into the Fischer-Tropsch synthesis catalyst to synthesize long carbon chain hydrocarbons, only the chain growth reaction of carbon monoxide in the synthesis gas is carried out, and the resource utilization rate is low.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems and alleviate the shortage of petroleum resources and the imperfection of the biomass energy utilization system, the present invention provides a method for directly preparing long-carbon chain hydrocarbons from low-carbon chain hydrocarbons. Syngas, under the action of catalyst, directly synthesizes long carbon chain hydrocarbons, which makes the traditional Fischer-Tropsch synthesis process from synthesizing methyl to synthesizing long carbon chain hydrocarbons to directly change from low carbon chain hydrocarbons to long carbon chains The process of chain hydrocarbons greatly shortens the reaction process. And the product has good low carbon chain hydrocarbon conversion, C5+ hydrocarbon selectivity and low methane selectivity. The present invention not only utilizes carbon monoxide, but also adds low-carbon chain hydrocarbons. my country has abundant and abundant low-carbon resources, and there are also a large number of low-carbon chain hydrocarbons in the refining and chemical industries. The present invention utilizes these resources and solves the problems of resource shortage and environmental pollution to a certain extent.

The technical scheme of the present invention is as follows:

A method for directly converting low carbon chain hydrocarbons into long carbon chain hydrocarbons. Carbon chain hydrocarbons; the catalyst includes an active component and a carrier, the active component is one or more of transition metals in Group VIII, and the carrier is one or more of oxides, carbon materials, and molecular sieves , the content (mass percentage) of active components in the catalyst is 1-20%.

Preferably, the active component is one or more of Fe, Co, Ni and Ru.

Preferably, the content of the active component in the catalyst is 5-20%.

Preferably, the low-carbon chain hydrocarbon is one or more of methane, ethane, ethylene, propane, propylene, isobutane, n-butane, maleic butene, f-butene, isobutene and n-butene.

Preferably, the hydrogen-to-carbon ratio of the synthesis gas is 0.5-6, and further, the hydrogen-to-carbon ratio of the synthesis gas is 1-4.

Preferably, the reaction temperature for directly synthesizing long carbon chain hydrocarbons from low-carbon chain hydrocarbons is 210-400° C., the reaction pressure is 0.1-3 Mpa, and the reaction space velocity is 1000-6000 h ⁻¹ .

Preferably, the catalyst further includes an auxiliary agent, which is one or more of Re, Ce, La, Sc, Pr, Li, Na, K, and Cs, and the content of the auxiliary agent in the catalyst is greater than 0 and less than 30% .

The preparation method of the catalyst comprises the following steps:

S1 supports the active component precursor on the carrier, and obtains the catalyst precursor by standing, drying and calcining;

The S2 catalyst precursor is then activated to obtain a catalyst.

Preferably, S1 also includes loading the auxiliary agent precursor on the carrier (mixing the active component precursor and the auxiliary agent precursor, and loading the auxiliary agent precursor on the carrier).

In the present invention, the active component precursor and the auxiliary agent precursor are preferably one or more of nitrates, carbonates and sulfates.

Preferably, during the activation treatment in S2, the activation gas is one or more of hydrogen, ammonia, carbon monoxide, hydrazine and organic amine.

Preferably, the activation gas space velocity in S2 is 500-4000 h ^-1 , the activation temperature is 0-600° C., the activation pressure is 0.1-4 Mpa, and the activation time is 4-20 h. Furthermore, the activation gas space velocity is 500-2500h ^-1 , the activation temperature is 200-500°C, the activation pressure is 0.1-2Mpa, and the activation time is 6-10h.

The carrier is Al ₂ O ₃ , SiO ₂ , TiO ₂ , activated carbon, carbon nanofibers, carbon nanotubes, carbon spheres, ordered mesoporous carbon, mesoporous carbon, ZSM-5, Beta molecular sieve, MCM-41, SBA -15. One or more of Y-type molecular sieves.

Preferably, the carrier has a specific surface area of 100-1200 m ² /g, and an average pore diameter of 0.1-10 nm.

Preferably, the size of the carrier ranges from 0.05 to 1 cm.

The beneficial effects of the present invention are: the present invention feeds low-carbon chain hydrocarbons into the synthesis gas, and directly synthesizes long carbon-chain hydrocarbons under the action of the catalyst, thus making the traditional Fischer-Tropsch synthesis process from synthesizing methyl to synthesizing long carbon The process of chain hydrocarbons is transformed into the process of directly changing from low-carbon chain hydrocarbons to long-carbon chain hydrocarbons, which greatly shortens the reaction process. And because it is a chain growth reaction based on low-carbon chain hydrocarbons, it has high C5+ hydrocarbon selectivity and low methane selectivity, and the product also has a good low-carbon chain hydrocarbon conversion rate, which can effectively alleviate the the shortage of oil resources.

Description of drawings

FIG. 1 is a process flow diagram of Embodiment 1 of the present invention.

Detailed ways

The endpoints of the ranges disclosed herein and any values are not limited to the precise ranges or values, which are to be understood to include values near those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

Example 1

Dissolve 2.19g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of the catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The active components in the catalyst The content of Co was 10%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. After the reaction was stable for 28 h, the results are shown in Table 1. The conversion of propylene was 99.00%, the conversion of CO was 47.95%, the selectivity of methane was 0.98%, and the selectivity of _C5 ⁺ was 96.86%.

Example 2

Dissolve 2.19g of cobalt nitrate hexahydrate, 0.04g of chloroplatinic acid and 0.06g of potassium carbonate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 36 hours, kept at 80° C. for 12 hours in a drying oven, and then calcined at 550° C. for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of the catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 0.1MPa, hydrogen with a flow rate of 60ml/min was introduced for activation treatment for 8h to obtain a finished catalyst. The active components in the catalyst The content of Co was 10%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 400° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, butene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of flow rate F=1mL/h. After the reaction was stable for 24 h, the butene conversion reached 31.40%, the CO conversion reached 94.51%, the methane selectivity was 41.33%, and the _C5 ⁺ selectivity was 18.30%.

Example 3

Dissolve 3.22g of ferric nitrate nonahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Fe in the catalyst is 10%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. Propylene conversion was 97.18%, CO conversion was 48.09%, methane selectivity was 3.78%, and _C5 ⁺ selectivity was 86.54%.

Example 4

Dissolve 1.03g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 5%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. Propylene conversion was 95.82%, CO conversion was 39.48%, methane selectivity was 2.36%, and _C5 ⁺ selectivity was 85.97%.

Example 5

Dissolve 4.94g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 20%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. The propylene conversion was 97.52%, the CO conversion was 51.66%, the methane selectivity was 5.46%, and the _C5 ⁺ selectivity was 84.88%.

Example 6

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1, and pass carbon monoxide with a flow rate of 30ml/min at 400℃ and 2.0MPa for activation treatment for 6h to obtain the finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed-bed reaction device shown in Fig. 1, at 2.0 MPa, 210 °C, the synthesis gas space velocity of 1000 h ^-1 , the synthesis gas volume ratio H ₂ :CO:N ₂ =16:8:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 16, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. The propylene conversion was 60.01%, the CO conversion was 62.90%, the methane selectivity was 15.84%, and the _C5 ⁺ selectivity was 48.78%.

Example 7

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1, and at 500°C and 2.0MPa, pass hydrogen with a flow rate of 30ml/min for activation treatment for 6h to obtain the finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 6000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =128:64:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 260, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. The propylene conversion was 7.26%, the CO conversion was 46.14%, the methane selectivity was 6.39%, and the _C5 ⁺ selectivity was 79.87%.

Example 8

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1, and at 500°C and 2.0MPa, pass hydrogen with a flow rate of 30ml/min for activation treatment for 6h to obtain the finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 240° C., the synthesis gas space velocity of 1500 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =16:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. The propylene conversion was 58.52%, the CO conversion was 56.28%, the methane selectivity was 2.21%, and the _C5 ⁺ selectivity was 88.77%.

Example 9

Dissolve 2.19g of cobalt nitrate hexahydrate and 0.01g of chloroplatinic acid in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 300°C and 0.1MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 10%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 280° C., the synthesis gas space velocity of 2400 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:11:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 43, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=0.5mL/h. The reaction was stable after 24h. Propylene conversion was 99.99%, CO conversion was 99.91%, methane selectivity was 34.59%, and _C5 ⁺ selectivity was 48.64%.

Example 10

Dissolve 2.19g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 500°C and 0.1MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 10%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 350° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas Introduce low-carbon chain hydrocarbons, the molar ratio of carbon monoxide to low-carbon chain hydrocarbons is 130, propylene is used as the representative raw material of low-carbon chain hydrocarbons, and the reaction is carried out under the reaction conditions of propylene flow rate F=1mL/h. The reaction was stable after 24h. The propylene conversion was 55.88%, the CO conversion was 68.42%, the methane selectivity was 26.80%, and the _C5 ⁺ selectivity was 58.87%.

Example 11

3.49g of cobalt nitrate hexahydrate and 0.01g of chloroplatinic acid were dissolved in 4.20g of deionized water to form a solution, and then 4.00g of alumina carrier was added for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas The low-carbon chain hydrocarbon is introduced, and the molar ratio of carbon monoxide to the low-carbon chain hydrocarbon is 130. Taking propylene as the representative raw material of low-carbon chain hydrocarbons, the reaction was carried out under the reaction conditions of propylene flow rate F=1 mL/h. The reaction was stable after 24h. The propylene conversion was 40.11%, the CO conversion was 46.77%, the methane selectivity was 11.52%, and the _C5 ⁺ selectivity was 81.62%.

Example 12

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of the catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The active components in the catalyst The content of Co was 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 250° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas The low-carbon chain hydrocarbons were introduced, and the molar ratio of carbon monoxide to the low-carbon chain hydrocarbons in the synthesis gas was 130. Taking propylene as the representative raw material of low-carbon chain hydrocarbons, the reaction was carried out under the reaction conditions of propylene flow rate F=1 mL/h. After the reaction was stable for 24 h, the propylene conversion was 95.82%, the CO conversion was 39.48%, the methane selectivity was 2.36%, and the _C5 ⁺ selectivity was 85.97%.

Example 13

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 2.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas The low-carbon chain hydrocarbon is introduced, and the molar ratio of carbon monoxide to the low-carbon chain hydrocarbon is 130. Taking propylene as the representative raw material of low-carbon chain hydrocarbons, the reaction was carried out under the reaction conditions of propylene flow rate F=1 mL/h. After the reaction was stable for 24 h, the propylene conversion was 90.59%, the CO conversion was 50.18%, the methane selectivity was 10.87%, and the _C5 ⁺ selectivity was 80.38%.

Example 14

Dissolve 3.49g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 15%. Finally, in the fixed bed reaction device shown in FIG. 1 , at 3.0 MPa, 230° C., the synthesis gas space velocity of 3000 h ⁻¹ , the synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5, in the synthesis gas The low-carbon chain hydrocarbon is introduced, and the molar ratio of carbon monoxide to the low-carbon chain hydrocarbon is 130. Taking propylene as the representative raw material of low-carbon chain hydrocarbons, the reaction was carried out under the reaction conditions of propylene flow rate F=1 mL/h. After the reaction was stabilized for 24 h, the propylene conversion was 95.64%, the CO conversion was 27.20%, the methane selectivity was 11.51%, and the _C5 ⁺ selectivity was 79.69%.

In the present invention, the method for Fischer-Tropsch synthesis by directly adding low-carbon chain hydrocarbons into the synthesis gas has good reaction performance under different reaction temperature, catalyst and reaction pressure conditions.

Comparative Example 1

Dissolve 2.91g of cobalt nitrate hexahydrate in 4.20g of deionized water to form a solution, and then add 4.00g of Beta molecular sieve carrier for impregnation. Ultrasonic treatment for 10min makes the active components disperse more uniformly on the surface of the carrier. Then, it was allowed to stand at room temperature for 24 hours, kept at 80 °C for 12 hours in a drying oven, and then calcined at 550 °C for 6 hours in an air atmosphere to obtain a catalyst precursor. Take 1.00g of catalyst precursor and put it into the reaction tube of the fixed-bed reaction device shown in Figure 1. At 400°C and 2.0MPa, hydrogen with a flow rate of 30ml/min was introduced for activation treatment for 6h to obtain a finished catalyst. The content of the active component Co in the catalyst is 10%. Finally, in the fixed bed reaction device shown in Fig. 1, the reaction was carried out under the reaction conditions of 2.0 MPa, 230° C., synthesis gas space velocity of 3000 h ⁻¹ , and synthesis gas volume ratio H ₂ :CO:N ₂ =64:32:5 reaction, and no low-carbon chain hydrocarbons are added. After the reaction was stable for 28 h, the results are shown in Table 1. The CO conversion was 46.42%, the methane selectivity was 2.41%, and the C ₅ ⁺ selectivity was 90.57%.

Table 1 Example 1 and Comparative Example 1 catalytic reaction effect comparison

It can be seen from the data in the table that after adding propylene as the representative raw material of low-carbon chain hydrocarbons to the syngas feed, the CO conversion and C ₅ ⁺ selectivity are improved, and the CH ₄ selectivity is decreased, indicating that the feed The addition of propylene in the feed can effectively improve the performance of the Fischer-Tropsch synthesis reaction.

The preferred embodiments of the present invention have been described above in detail, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, a variety of simple modifications can be made to the technical solutions of the present invention, including combining various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed in the present invention. All belong to the protection scope of the present invention.

Claims (6)

1. a method that low-carbon chain hydrocarbons are directly converted into long carbon-chain hydrocarbons, it is characterized in that: low-carbon chain hydrocarbons are passed into the synthesis gas, and the mol ratio of carbon monoxide and low-carbon chain hydrocarbons is 16～260, and in the catalyst Under the action of directly synthesizing long carbon chain hydrocarbons; the catalyst includes an active component and a carrier, the active component is iron or cobalt, the carrier is one or both of oxides and molecular sieves, and the active component in the catalyst is The content is 1-20%; the low-carbon chain hydrocarbon is one or more of methane, ethane, ethylene, propane, propylene, isobutane, n-butane, maleic butene, f-butene, isobutene and n-butene. species; the reaction temperature for directly synthesizing long carbon chain hydrocarbons from low-carbon chain hydrocarbons is 210-400°C, the reaction pressure is 0.1-3Mpa; the reaction space velocity is 1000-6000h ^-1 ; The preparation method of the catalyst comprises the following steps: S1 supports the active component precursor on the carrier, and obtains the catalyst precursor by standing, drying and calcining; The S2 catalyst precursor is then subjected to activation treatment to obtain a catalyst; during activation treatment, the activation gas is one or more of hydrogen, ammonia, carbon monoxide, hydrazine and organic amine. 2 . The method for directly converting low-carbon chain hydrocarbons into long-carbon chain hydrocarbons as claimed in claim 1 , wherein the hydrogen-to-carbon ratio of the synthesis gas is 0.5-6. 3 . 3. a kind of method that low carbon chain hydrocarbon is directly converted into long carbon chain hydrocarbon as claimed in claim 1, it is characterized in that: described catalyzer also comprises auxiliary agent, and auxiliary agent is Re, Ce, La, Sc, Pr , one or more of Li, Na, K, and Cs, and the content of the auxiliary agent in the catalyst is greater than 0 and less than 30%. 4 . The method for directly converting low-carbon chain hydrocarbons into long-carbon chain hydrocarbons as claimed in claim 1 , wherein: S1 further comprises loading an auxiliary precursor on a carrier. 5 . 5. a kind of method that low carbon chain hydrocarbon is directly converted into long carbon chain hydrocarbon as claimed in claim 4, it is characterized in that, active component precursor and auxiliary agent precursor are nitrate, carbonate and sulfate one or more of them. 6 . The method for directly converting low-carbon chain hydrocarbons into long-carbon chain hydrocarbons as claimed in claim 1 , wherein the activation gas space velocity is 500-4000 h ⁻¹ , the activation temperature is 0-600° C., and the activation The pressure is 0.1～4Mpa, and the activation time is 4～20h.

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