WO2013067834A1

WO2013067834A1 - Method for synthesizing synthesis gas into mixed alcohol

Info

Publication number: WO2013067834A1
Application number: PCT/CN2012/079011
Authority: WO
Inventors: 陈建峰; 张燚; 初广文; 赵宏
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: CN102503769B; CN102503769A

Abstract

Disclosed relates to the field of high gravity technology, and is a method for directly synthesizing a synthesis gas into a mixed alcohol. The present method effectively synthesizes a synthesis gas from different sources into a mixed alcohol with the effect of a catalyst and a high gravity environment. Specifically, provided is a method that uses a high gravity reactor to selectively intensify a synthesis reaction for a mixed alcohol, thereby substantially enhancing the selectivity of the mixed alcohol product. During the reaction process, a catalyst bed layer rotates at a certain rotational speed; the reaction material is a coal-based synthesis gas, natural gas-based synthesis gas, coal bed methane-based synthesis gas, or biomass-based synthesis gas; the high gravity of the high gravity reactor is from 20 to 400g, the temperature is from 200°C to 500°C, the pressure is from 10 to 120 atm, and the gas space velocity is from 100 to 100,000h^-1. The method selectively synthesizes a mixed alcohol product, can produce a targeted a mixed alcohol product, has good mass transfer performance and heat conductivity, and the catalyst thereof has a long service life.

Description

Method for synthesizing mixed alcohol by syngas

Technical field

The present invention relates to a process for synthesizing a mixed alcohol from syngas, and more particularly to a method for synthesizing a mixed alcohol in a supergravity environment and a catalyst fraud using a supergravity reactor.

Background technique

Fischer-Tropsch process, also known as F-T synthesis, is a synthesis of paraffin-based liquid fuels based on synthesis gas (CO, mixed gas of C0 ₂ and H ₂ ) under the catalyst and appropriate conditions. crafting process. The traditional Fischer-Tropsch synthesis products are mainly linear hydrocarbons, olefins, 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 mixed alcohol product can be synthesized primarily under certain reaction conditions using a specific catalyst.

The Fischer-Tropsch synthesis has been in existence for more than 80 years, and now Sasol, PetroSA, Sheil 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 sorghum 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 obeys the polymerization mechanism, and the selectivity of the product follows the Aiiderson-Schuitz-Flory distribution. Since the early 20th century, especially since the oil crisis of the 1970s, countries around the world have done a lot of work in the research of syngas synthesis of mixed alcohols, and have developed a variety of processes for the synthesis of low-carbon mixed alcohols. The use of different types of reactors, such as fixed bed, fluidized bed or slurry bed, has limited selectivity for the product of Fischer-Tropsch synthesis of mixed alcohols.

The supergravity separation technique was first proposed by the British Imperial Chemical Industry Corporation (αα) 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 For Earth acceleration, =9.8 m/s ² ) technology, domestic translation for supergravity technology. . EP0023745 A3 proposes that a supergravity rotating bed can be used for absorption, desorption, distillation and the like. China patent CN1064338A, CN1116146A., CN〗 116] 85A breaks through the limitations of supergravity separation technology, innovatively proposes super-gravity reaction technology, and successfully realizes the application of super-gravity rotating bed to industrial-scale oilfield water injection] 3⁄4 oxygen process and super Preparation of fine 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 mixed alcohol by using a supergravity reactor, and synthesizing a mixed alcohol of various kinds of syngas under the action of a supergravity environment and a catalyst, and specifically, providing A method for selectively enhancing a mixed alcohol synthesis reaction process using a supergravity reactor to significantly improve the selectivity of a mixed alcohol product.

The Fischer-Tropsch synthesis 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 deoxidized, and then adjusted according to the Fischer-Tropsch synthesis reactor. 13⁄4/03 enters the reactor to synthesize various hydrocarbons than a suitable syngas. Mixed alcohol synthesis catalysts have undergone many improvements. To improve the characteristics of different catalyst compositions to improve single pass conversion, alcohol yield and product selectivity. but. However, none of the catalysts are very well suited for each mixed alcohol synthesis process design. In general, the developed catalyst system has low catalytic activity, harsh reaction conditions, poor product distribution and difficult post-separation. It restricts the commercialization of mixed alcohol synthesis. Usually, the mixed alcohol synthesis reaction is carried out on a catalyst having hydrogenation, which causes C-0 bond cleavage and CO insertion. The design of process engineering is also important for the effective removal of heat of reaction and the improvement of the yield of alcohol. Therefore, for the catalytic process of synthesizing mixed alcohols, the current focus is on catalyst development and reactor innovation.

The usual mixed alcohol process is as follows: First, coal gasification, purification and desulfurization to obtain a suitable synthesis gas, and then catalytic synthesis at a medium pressure into a mixed alcohol and a part of water. Recent studies on two-stage and slurry-bed reactors have shown that they can overcome the deficiencies of fixed-bed reactors to some extent and improve the synthesis performance. The two-stage reactor provides suitable conversion and selectivity through proper bed combination, providing assurance that further high-value added chemicals are obtained by further separation. The slurry bed reactor has a high heat transfer rate, a dry temperature control and prevention of sintering and deactivation of the catalyst.

Because of the advantages of the supergravity reactor - enhanced 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 action of the supergravity, the reaction exotherm is rapidly taken out of the reaction zone, so that the reaction temperature is easily controlled, and it is suitable for synthesizing the mixed alcohol reaction.

The catalyst for synthesizing a mixed alcohol generally includes the following three types of components; a main metal, a carrier or a structural auxiliary, and various other auxiliary agents and additives. The catalyst usually contains one or more of cerium, molybdenum, cobalt, nickel, iron, copper, and potassium.

The process conditions of the method for the mixed alcohol synthesis using the supergravity reactor of the present invention are as follows: the synthesis reaction is carried out in a supergravity reactor, the supergravity level of the supergravity reactor is 20-400 g _{; and the} temperature is 200 ° C - 500 Ό , pressure is 10-120 atm, syngas volume airspeed is 100-】00000 hf ^3⁄4 . The reaction material is coal-based syngas, natural gas-based syngas, coal-bed gas-based syngas or biomass-based syngas, and the composition thereof has a CO ratio of 20% to 80%. The catalyst is in the form of an integral structure of a honeycomb or plate structure, or in the form of a particle packing, which is fixed to the rotor of the supergravity reactor.

The supergravity reactor described in the method of the present invention refers to various types of supergravity reactors in which the acceleration of the simulated supergravity environment is greater than the gravitational acceleration of the earth (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 achieve supergravity on Earth is to generate centrifugal acceleration The environment is simulated and implemented. 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 the super-gravity science and the 3⁄4 supergravity 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 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 synthetic mixed alcohol reaction through a high-speed rotating catalyst bed. The resulting product is a mixed alcohol mainly composed of Ci-C6 alcohol, and rapidly leaves the catalyst bed under the action of supergravity. , discharged from the outlet of the supergravity reactor and determined by gas chromatography; the supergravity reactor has a supergravity level of 20-400 g _{; the} temperature is 200 Ό-500 Ό, the pressure is 10-120 atm, and the volume velocity of the synthesis gas is 100-iOOOOOtf ¹ . The reaction materials are coal-based syngas, natural gas-based syngas, coalbed methane-based syngas or biomass-based syngas, and the composition thereof has a CO ratio of 20% to 80%.

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 uses the reaction to separate the 3⁄4ί, and adjusts the residence time of the reaction product in the reaction field, thereby controlling or suppressing the second Secondary reactions occur, increasing the selectivity of a particular target product and increasing catalyst life.

In addition, the excessive residence of the product and the intermediate product on the catalyst is also the cause of the carbon deposition of the catalyst. The carbon deposition is one of the important reasons for the deactivation of the synthetic mixed alcohol catalyst. Therefore, the present invention can effectively suppress the surface area carbon generation of the catalyst and improve the lifetime of the catalyst.

Therefore, the present invention utilizes a supergravity reactor for a mixed alcohol synthesis reaction to selectively synthesize a specific target product, a C1-C6 alcohol-based mixed alcohol.

The method of the invention has the characteristics of high conversion rate of reaction materials, oriented production of CI-C6 alcohol-based mixed alcohol products, good mass transfer, good heat transfer performance and long catalyst life.

^Illustration

Figure is a schematic representation 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 mixed alcohol synthesis catalyst is installed in the rotor of the supergravity reactor, and the catalyst bed is always in a rotating state during the reaction. Syngas is introduced from the inlet of the supergravity reactor through a high speed rotating catalyst bed. The resulting supergravity reactor outlet was discharged and determined by gas chromatography analysis.

Example

A synthesis gas is used to prepare a mixed alcohol reaction using a supergravity reactor. The synthesis gas is a mixture of CO + H ₂ , and the CO/H ₂ = l/2 K-Co-Mo/C 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: 50011, reaction temperature: 300 reaction pressure: 5MPa

Catalyst bed supergravity level: 20g

The results of the reaction of the super-gravity reactor in the synthesis gas mixture:

Implementing feed 2

Synthetic pneumothorax mixed alcohol reaction was carried out using a supergravity reactor. The synthesis gas is a mixture of CCHH ₂ and the CO/H2-1/2 Cu-Zn-Cr catalyst is placed in a mesh support and fixed to the rotor of the supergravity reactor.

The reaction conditions are as follows - synthesis gas space velocity: 15001^, reaction temperature: 400 ° C, reaction pressure: 12 MPa

Catalyst bed supergravity level: 400g

Super-gravity reactor for synthesis gas mixed alcohol reaction results -

Example 3

The synthesis gas is mixed with a synthesis gas using a supergravity reactor. The synthesis gas is a mixture of CO + H ₂ , and the CO/H ₂ = l/2 Co-Mo/C 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: 3000h Reaction temperature: 500 TJ _? Reaction pressure: 2.5MPa

Catalyst bed supergravity level: 210g

Super-gravity reactor for synthesis gas mixed alcohol reaction results -

Contrast feed 1

Synthetic pneumothorax mixed alcohol reaction was carried out using a fixed bed reactor. The synthesis gas is a mixture of CCHH ₂ and the CO/H2-1/2 Κ-CoMo/C catalyst is packed in a fixed bed reactor.

The reaction conditions are as follows - synthesis gas space velocity; 500i ³ , reaction temperature: 320 Ό , reaction pressure: 5 MPa

Using a fixed bed reactor to synthesize a gas to produce a mixed alcohol reaction result:

CO conversion rate (%) Me()H/C ₂ ^÷ ()H (%) total alcohol selectivity (%)

18,4% 0.25 41

Claims

Claim

A method for synthesizing mixed alcohols by syngas, characterized in that the syngas is synthesized in a supergravity reactor, the reaction temperature is 200 Ό 500 ° C, the pressure is 10-120 atm, and the synthesis gas volume Airspeed of 100-iOOOOOl directed synthesis of mixed alcohol under the action of supergravity environment and catalyst

2 . The method for synthesizing mixed alcohol in syngas 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. The reaction environment of 8m/s ² is in the super-gravity environment.

3 . The method for synthesizing mixed alcohol in syngas according to claim 1 , wherein the reaction material is coal-based syngas, natural gas-based syngas, coalbed methane-based syngas or biomass-based syngas, and the composition thereof The molar ratio of CO is 20% - 80%.

4 . The method for synthesizing mixed alcohol in syngas according to claim 1 , wherein the catalyst is prepared by various methods, containing various structures including bismuth, molybdenum, cobalt, nickel, iron, copper, One or several catalysts of potassium.

5 . The method for synthesizing mixed alcohol in syngas 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 super-gravity in the form of particles. On the reactor rotor.

6. A method of synthesizing a mixed alcohol from a syngas according to claim 1, wherein the catalyst bed of the method is always in a rotating state during the reaction, and the supergravity level is 20-400 g.

7. The method for synthesizing mixed alcohol of syngas according to claim 1, wherein the reaction temperature is 200 Ό-500 Ό, the pressure is 10-120 atm, and the volume velocity of the synthesis gas is 100 iOOOOl.