WO2013067835A1

WO2013067835A1 - Process for oriented synthesis of gasoline and diesel by fischer-tropsch synthesis

Info

Publication number: WO2013067835A1
Application number: PCT/CN2012/079040
Authority: WO
Inventors: 张燚; 陈建峰; 初广文; 邹海魁
Original assignee: 北京化工大学; 北京中超海奇科技有限公司
Priority date: 2011-11-10
Filing date: 2012-07-23
Publication date: 2013-05-16
Also published as: CN102504858B; CN102504858A

Abstract

Disclosed is a process for oriented synthesis of gasoline and diesel by Fischer-Tropsch synthesis. The process belongs to the field of supergravity technology. The process consists in performing oriented synthesis of a syngas into gasoline or diesel under the combined action of a supergravity environment and a catalyst; during the reaction, the catalyst bed is rotated at a certain rotation speed; the reaction materials are coal-based syngas, natural gas-based syngas, coal bed gas-based syngas or biomass-based syngas; the supergravity level of the supergravity reactor is 20-300 g; the reaction temperature is 180°C-500°C; the reaction pressure is 5-100 atm; and the space velocity of the gas is 100-100000h^-1. The process of the present invention has the features of oriented production of gasoline and diesel products, good mass-transfer and heat-transfer performance, and long service life of the catalyst.

Description

Method for synthesizing directional synthetic gasoline diesel by Fischer-Tropsch

Technical field

The invention relates to a method for Fischer-Tropsch synthesis of directional gasoline gasoline. In particular, it relates to a method for directional synthesis of gasoline or diesel by a Fischer-Tropsch synthesis reaction under the action of a supergravity environment and a catalyst by a supergravity reactor. .

Background technique

The Fischer-Tropsch process, also known as FT synthesis, is a process in which a paraffin-based liquid fuel is synthesized from a synthesis gas (CO, a mixed gas of C0 ₂ and 3⁄4) under a suitable condition. The traditional Fischer-Tropsch synthesis products are mainly linear hydrocarbons, olefins, small amounts of aromatic hydrocarbons and aldols, as well as by-product water and carbon dioxide. The product composition is complex, the selectivity is poor, and the light liquid hydrocarbons are less.

The Fischer-Tropsch synthesis has been in existence for more than 80 years, and now Sasol, PetroSA, Shell and Oryx are among the larger Fischer-Tropsch synthesis companies. In recent years, with the gradual depletion of petroleum resources and the increasing demand for new energy and resources worldwide, the way to prepare liquid fuels or high value-added chemicals through Fischer-Tropsch synthesis has been widely recognized. The reactants of the Fischer-Tropsch synthesis reaction, syngas, can be converted from coal, natural gas, biomass by gasification or reforming. The chain growth of the Fischer-Tropsch synthesis product follows the polymerization mechanism and the selectivity of the product follows the Anderson-Schultz-Flory distribution. In addition to the higher selectivity of formazan and heavy hydrocarbons, the selectivity of other products is not high. The use of different types of reactors, such as fixed bed, fluidized bed or slurry bed, has little effect on the selectivity of the Fischer-Tropsch synthesis product.

The supergravity separation technique was first proposed by the British Imperial Chemical Industry Corporation (ICI) and was realized by rotating a simulated hypergravity environment with an acceleration of more than 9.8 m/s ² on the earth. It is called Higee (High "g" g is the earth's acceleration, =9.8 m/s ² ) technology, domestic translation is super-gravity technology. . EP0023745 A3 proposes that a supergravity rotating bed can be used for absorption, desorption, steaming and the like. Chinese patents CN1064338A, CN1116146A, CN1116185A break through the limitations of the supergravity separation technology, innovatively propose the supergravity reaction technology, and successfully implement the application of the supergravity rotating bed to the industrial scale oilfield water injection deoxidation process and the preparation of ultrafine calcium carbonate. Chinese patent CN1507940A, CN1895766A proposes a hydrocarbon catalytic reaction in a supergravity reactor and discloses a method for carrying out total hydrogenation and partial hydrogenation of hydrocarbons in a supergravity reactor. Summary of the invention

The object of the present invention is to provide a method for synthesizing gasoline or diesel oil by using a supergravity reactor for Fischer-Tropsch synthesis reaction to synthesize syngas of various sources under the action of a supergravity environment and a catalyst, and specifically, to provide a A method for selectively orienting synthetic gasoline or diesel products using a supergravity reactor to selectively enhance the Fischer-Tropsch synthesis process.

The Fischer-Terring process is a process in which the crude syngas obtained by converting coal, natural gas, coalbed methane and biomass into raw materials is desulfurized and deoxygenated, and then subjected to water gas shift reaction according to the Fischer-Tropsch synthesis reactor. Adjusting the H ₂ /CO ratio to the appropriate syngas enters the reactor to synthesize various 'hydrocarbons. Replacement page (Article ₂₆ ) Although the classical ASF law can give a good product distribution description within a certain range, and is widely used in the original analysis of kinetic data. However, a large number of experimental facts in recent years indicate that the product distribution of FT synthesis does not completely follow the ASF distribution law. During the reaction, high-boiling liquid products such as paraffin remain in the catalyst pores and the catalyst bed, hindering the product from diffusing out of the reaction environment, promoting secondary reactions such as olefin re-adsorption and chain growth, thereby further increasing the yield of heavy hydrocarbons and reducing the yield. The selectivity of gasoline and diesel. Increasing mass transfer and heat transfer efficiency in the Fischer-Tropsch synthesis reaction can have the following advantages: (1) It can effectively reduce local overheating of the reactor, thereby reducing the selectivity of formazan; (2) Conducive to primary reaction products Leaving the reaction environment, thereby reducing the influence of secondary reaction on product selectivity, thereby improving the selectivity of gasoline and diesel; (3) facilitating the introduction of heavy hydrocarbons from the catalyst pores and the catalyst bed, thereby reducing the wax in the catalyst pores. Deactivation of the catalyst caused by the accumulation in the catalyst increases the service life of the catalyst.

The Fischer-Tropsch synthesis catalyst typically comprises the following three types of components: a primary metal, a support or a structural auxiliary, and various other adjuvants and additives. Among them, the main metal is mainly composed of the eighth group elements Fe, Co, Ni, Ru and Rh. Fe and Co are industrially proven catalysts which are ideal for Fischer-Tropsch synthesis and have been successfully applied in the industry. Ru is the most catalytically active metal in CO hydrogenation reaction, especially for high molecular weight linear terpene hydrocarbons. However, due to its high price, it can only be used as an auxiliary agent to improve the activity and selection of catalysts. Sex. The hydrogenation activity of Ni is second only to Ru, but it mainly produces formazan. Rh is easy to form oxygenates.

The Fischer-Tropsch reaction catalyst of the present invention comprises a catalyst such as a pelletized, honeycomb or plate type Co-based, Ru-based or Fe-based prepared by various methods.

The process conditions of the method for Fischer-Tropsch synthesis using the supergravity reactor of the present invention are as follows: Fischer-Tropsch synthesis reaction is carried out in a supergravity reactor, the supergravity level of the supergravity reactor is 20-300 g; the reaction temperature is 180 °C-500'C, reaction pressure is 5-100atm, gas space velocity is lOO-lOOOOh'^

The supergravity reactor described in the method of the present invention means that the gravitational acceleration of the supergravity field is greater than the gravitational acceleration of the earth.

Various types of supergravity reactors (g = 9.8 m / s ² ). Hypergravity technology is one of the first key technologies in process enhancement technology that has received much attention. The easiest way to implement supergravity on Earth is to simulate it using a centrifugal acceleration environment created by rotation. By changing the rotation speed and the rotor radius to control the centrifugal acceleration, that is, the level of the simulated super-gravity level, the value reaches several hundred or several thousand times of the earth's gravitational acceleration (g). At this time, the fluid is subjected to a simulation super that greatly exceeds the gravity of the earth. Gravity control. People can study super-gravity science and develop and utilize super-gravity technology by rotating experiments to obtain a continuous, stable and controllable centrifugal force field. The supergravity technology is a process intensification technology that strengthens the transfer and micro-mixing process, which can greatly improve the efficiency of the reaction and separation process, and significantly reduce the volume of the reaction and separation device. The demonstration practice of industrial applications in China for many years shows that the super-gravity device It has outstanding advantages such as large operation flexibility, easy opening and closing, small floor space, small space, high production efficiency and high production intensity.

The process of the present invention performs a Fischer-Tropsch synthesis reaction in a manner completely different from a fixed bed, a fluidized bed and a slurry bed reactor.

2

Replacement page (Article 26) A Fischer-Tropsch synthesis reaction method for the targeted production of gasoline and diesel products.

The specific process of the method of the invention comprises: carrying out the Fischer-Tropsch reaction in a supergravity field, and fixing the Fischer-Tropsch reaction catalyst on the rotor of the supergravity reactor, wherein the catalyst bed is always in a rotating state during the reaction, and the reaction material is The inlet of the supergravity reactor enters, and the syngas undergoes a Fischer-Tropsch reaction through a high-speed rotating catalyst bed. The resulting product is a gasoline or diesel-based hydrocarbon that rapidly leaves the catalyst bed under the action of supergravity. The reactor outlet is discharged and determined by gas chromatography; the reaction material is coal-based syngas, natural gas-based syngas, coalbed methane-based syngas or biomass-based syngas, and its composition is CO+C0 ₂ +H ₂ , CO+H ₂ , C0 ₂ +H ₂ ; The supergravity reactor has a supergravity level of 2-300g _{; the} reaction temperature is 180°C-500°C, the reaction pressure is l-100atm, and the gas space velocity is 100-1 OOOOOh'

The method of the invention regulates the mass transfer process of the reaction product through the regulation of the super-gravity acceleration level in the supergravity reactor, and utilizes the reaction separation synergy to adjust the residence time of the reaction product in the reaction field, thereby controlling or suppressing the second time. The reaction takes place, improves the selectivity of the specific target product, and increases the catalyst life.

The conventional Fischer-Tropsch reaction is limited by the growth and transformation mechanism of the synthesis process chain. The target product has relatively low selectivity and more synthetic by-products. The normal chain hydrocarbons can range from C1 to C100. Therefore, strengthening the mass transfer of the product and controlling the residence time of different products in the reaction environment can effectively improve the selectivity of the target product. In the synthesis of gasoline and diesel, select the appropriate super-gravity acceleration, so that the generated low-carbon olefins quickly leave the reaction environment, inhibit the secondary reaction such as hydrogenation or chain growth, reduce the probability of heavy hydrocarbon generation, and thus improve the selectivity of gasoline and diesel. . In addition, a reduction in the partial pressure of the gasoline and diesel products in the reaction environment will cause the reaction to move toward the formation of lower olefins to further enhance the selectivity of the lower olefins.

In addition, too long residence time of the product and intermediate product on the catalyst is one of the causes of carbon deposition of the catalyst, and carbon deposition is one of the important reasons for the deactivation of the Fischer-Tropsch catalyst. Therefore, the present invention can effectively suppress the surface area carbon generation of the catalyst and increase the life of the catalyst.

Because of the advantages of the supergravity reactor:

Strengthen mass transfer. The mass transfer process between the reactants and the product and the catalyst in the above reaction is strengthened under the action of supergravity, effectively reducing or eliminating the influence of the diffusion process on the above reaction, so that the produced product can quickly leave the reaction environment and improve the target product. The selectivity and the yield effectively inhibit the carbon deposition deactivation of the catalyst and accelerate the movement of the reactants toward the product, thereby improving the reaction efficiency.

Enhance heat transfer. The above reaction is an exothermic reaction. In the exothermic reaction process, it is crucial to eliminate the heat of reaction in time. When an exothermic reaction is carried out in a conventional fixed-bed reactor, if heat is not taken out in time, the reaction temperature is liable to be out of control. In the supergravity reactor, since the product rapidly leaves the catalyst bed under the strengthening of the supergravity, the reaction exotherm is quickly taken out of the reaction zone by the product, so that it is easy to control the reaction temperature and is suitable for the above reaction.

Accordingly, the present invention utilizes a supergravity reactor for Fischer-Tropsch synthesis to selectively synthesize specific target products, including gasoline and diesel. 3

Replacement page (Article 26) The method of the invention has the characteristics of high conversion rate of reaction materials, targeted production of gasoline and diesel products, good mass transfer, good heat transfer performance and long catalyst life.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a supergravity reactor employed in the present invention.

The reactor includes:

Reactant inlet

2. Catalyst bed

3. Rotor

4. Product export

detailed description

The Fischer-Tropsch synthesis catalyst is installed in the rotor of the supergravity reactor, and the catalyst bed is always in a high-speed rotation state during the reaction. Syngas enters the inlet of the supergravity reactor through a high speed rotating catalyst bed. The resulting product was discharged from the outlet of the supergravity reactor and determined by gas chromatography analysis. In the case where the space velocity is constant, the time at which the product leaves the reaction environment can be controlled by adjusting the rotational speed of the catalyst bed, thereby controlling the selectivity of the product.

Example 1

The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / 2. The cobalt-based Fischer-Tropsch catalyst particles are placed in a mesh support and fixed to the rotor of the supergravity reactor.

The process conditions of the reaction are as follows:

Syngas air velocity: ZOOOh' ¹ , reaction temperature: 210 ° C, reaction pressure: 1.5 MPa

Catalyst bed supergravity level: 50g

The results of the Fischer-Tropsch synthesis of diesel fuel in a supergravity reactor:

Comparative example 1

A Fischer-Tropsch synthesis of diesel fuel was carried out using a fixed bed reactor. The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / 2 o The cobalt-based Fischer-Tropsch catalyst particles are loaded into a fixed bed reactor.

The process conditions of the reaction are as follows:

Syngas air velocity: 2000h, reaction temperature: 210°C, reaction pressure: 1.5MPa

Fixed bed Fischer-Tropsch reactor for Fischer-Tropsch synthesis of diesel reaction results -

4

Replacement page (Article 26) Selectivity (%)

CO conversion rate (%)

C ₅ + diesel component (C ₉ -C ₁₈ )

48.2% 85 39 Example 2

The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / l. The iron-based Fischer-Tropsch catalyst particles are placed in a mesh support and fixed to the rotor of the supergravity reactor.

The process conditions of the reaction are as follows:

Syngas airspeed: SSOOh- ¹ , reaction temperature: 280'C, reaction pressure: 1.5MPa

Catalyst bed supergravity level: 70g

Diesel reaction results of Fischer-Tropsch synthesis in a supergravity reactor -

Comparative example 2

The Fischer-Tropsch synthesis reaction was carried out using a fixed bed reactor. The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / l. The iron-based Fischer-Tropsch catalyst particles are loaded into a fixed bed reactor.

The reaction conditions are as follows - synthesis gas space velocity: 2500 h, reaction temperature: 280 ° C, reaction pressure: 1.5 MPa

The results of the Fischer-Tropsch synthesis in a fixed bed reactor:

Example 3

The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / l. The iron-based honeycomb Fischer-Tropsch catalyst is placed in a mesh support and fixed to the rotor of the supergravity reactor.

The process conditions of the reaction are as follows:

Syngas airspeed: 250011· ¹ , Reaction temperature: 300 ° C, Reaction pressure: l.OMPa

5

Replacement page (Article 26) Catalyst bed supergravity level: 200g

The results of the Fischer-Tropsch synthesis gasoline reaction in a supergravity reactor:

Comparative example 3

The Fischer-Tropsch synthesis reaction was carried out using a fixed bed reactor. The synthesis gas is a mixture of CO + H ₂ , CO / H ₂ = l / l. An iron-based honeycomb Fischer-Tropsch catalyst is loaded into the fixed bed reactor.

The process conditions of the reaction are as follows:

Syngas airspeed: SSOOh' ¹ , Reaction temperature: 300 ° C, Reaction pressure: l.OMPa

The results of the Fischer-Tropsch synthesis in a fixed bed reactor:

6

Replacement page (Article 26)

Claims

Claim

A method for synthesizing directional synthetic gasoline diesel fuel, characterized in that the reaction of Fischer-Tropsch synthesis of gasoline to gasoline is carried out in a supergravity reactor, the reaction temperature is from 180 ° C to 500 ° C, and the pressure is 5-lOOatm, the volumetric space velocity of syngas is ΙΟΟ-lOOOOh· ¹ ; the syngas is oriented to synthesize gasoline or diesel products under the action of supergravity environment and catalyst.

2 . The method according to claim 1 , wherein the reactants and products of the synthesis reaction are always at an environmental acceleration greater than the gravitational acceleration of the earth before leaving the catalyst bed. = 9.8m / s ² of the reaction environment (ie super-gravity environment).

3 . The method of claim 1 , wherein the reaction material is coal-based syngas, natural gas-based syngas, coal-bed gas-based syngas or biomass-based syngas, Its composition is a CO molar ratio of 20% to 80%.

4. A method of synthesizing directional synthetic gasoline diesel fuel according to claim 1, wherein the catalyst is a ruthenium-based, cobalt-based or iron-based catalyst of various structures prepared by various methods.

5. The method of Fischer-Tropsch synthesis directed gasoline gasoline according to claim 1, wherein the catalyst is in an integrally structured form of a honeycomb or a plate structure, or is fixed in a supergravity in the form of particles. On the reactor rotor.

6 . The method according to claim 1 , wherein the catalyst bed of the method is always in a rotating state during the reaction, and the simulated supergravity level is 20-300 g. 6 . .

7 . The method of claim 1 , wherein the reaction temperature ranges from 180° C. to 500° C., the pressure is from 5 to 100 atm, and the synthesis gas volume has a space velocity of 100. -10000h ^_1 o Replacement page (Article 26)