CN106928002B

CN106928002B - Method for removing alkyne by hydrogenation after carbon dioxide

Info

Publication number: CN106928002B
Application number: CN201511032200.6A
Authority: CN
Inventors: 苟尕莲; 张峰; 景喜林; 谷丽芬; 车春霞; 何崇慧; 钱颖; 梁玉龙; 韩伟; 常晓昕; 刘俊涛; 黄德华; 刘敏
Original assignee: China Petroleum and Natural Gas Co Ltd
Current assignee: China Petroleum and Natural Gas Co Ltd
Priority date: 2015-12-31
Filing date: 2015-12-31
Publication date: 2019-12-06
Anticipated expiration: 2035-12-31
Also published as: CN106928002A

Abstract

a method for removing acetylene by hydrogenation after carbon two, the top effluent from deethanizer in hydrogenation after carbon two is sent to adiabatic reactor for selective hydrogenation to remove acetylene. The hydrogenation catalyst is a Fe selective hydrogenation catalyst, the carrier is a high-temperature-resistant inorganic oxide, and the hydrogenation raw material mainly comprises the following components: 0.98-2.2% of acetylene, 11.2-30.3% of ethane and 65.0-85.0% of ethylene. The reaction conditions are as follows: the inlet temperature of the adiabatic bed reactor is 40-100 ℃, the reaction pressure is 1.5-2.5 MPa, and the gas volume space velocity is 2000-10000 h < -1 >. By adopting the alkyne-removing method, the catalyst has moderate reaction activity, good operation elasticity, good ethylene selectivity and far lower green oil generation amount than that of the noble metal catalyst.

Description

Method for removing alkyne by hydrogenation after carbon dioxide

Technical Field

The invention relates to a method for removing acetylene by hydrogenation after carbon dioxide, in particular to a method for converting acetylene contained in an ethylene material into ethylene by hydrogenation by using a Fe-based catalyst.

background

Polymer grade ethylene production is the tap of the petrochemical industry, and polymer grade ethylene and propylene are the most basic raw materials for downstream polymerization plants. The selective hydrogenation of acetylene has very important influence on the ethylene processing industry, the selectivity of the catalyst is excellent except ensuring that the content of the acetylene at the outlet of a hydrogenation reactor reaches the standard, the ethylene can be generated into ethane as little as possible, and the catalyst has important significance for improving the ethylene yield of the whole process and the economic benefit of a device.

The cracked carbon-dioxide fraction contains acetylene with a mole fraction of 0.5-2.5%, and a small amount of acetylene in ethylene reduces the activity of a polymerization catalyst and deteriorates the physical properties of a polymer when polyethylene is produced, so that the acetylene content in ethylene must be reduced to a certain limit to be used as a monomer for synthesizing a high polymer. Acetylene separation and conversion is therefore one of the important processes in the ethylene plant scheme.

The catalytic selective hydrogenation in the ethylene device comprises front hydrogenation and back hydrogenation, wherein the front hydrogenation and the back hydrogenation of acetylene refer to that the hydrogenation reactor is positioned in front of the demethanizer and is front hydrogenation, and the hydrogenation reactor is positioned behind the demethanizer and is back hydrogenation relative to the position of the demethanizer. The post hydrogenation is a sequential separation process, and the process has the advantages of multiple control means in the hydrogenation process, difficult temperature runaway and convenient operation, but has the defects of easy coking of the catalyst and frequent regeneration of the catalyst. The reason for this is that, in the hydrogenation process, since the amount of hydrogen added is small, the hydrodimerization reaction of acetylene easily occurs to produce 1, 3-butadiene, and further to produce an oligomer having a relatively wide molecular weight, commonly referred to as "green oil". The green oil is adsorbed on the surface of the catalyst and further forms coke to block the pore channels of the catalyst, so that the activity and the selectivity of the catalyst are reduced.

At present, the hydrogenation after the carbon dioxide is mainly carried out by adopting a two-section or three-section reactor series connection process, and a device with lower volume space velocity or low alkyne content can adopt a two-section reactor series connection. At present, the industrial device mainly adopts a three-section reactor series connection process.

The post-hydrogenation feed generally consists of: 1.0-2.2% (v) acetylene, 65-85% ethylene and the balance ethane, and hydrogen is added after metering.

The reaction is exothermic, but the temperature rise is relatively low, and the maximum temperature rise of a single reactor is different from 30-60 ℃ according to the volume airspeed, so that an adiabatic reactor is basically adopted.

For two-stage reactors, the first stage reactor is required to convert more than 70% of acetylene, and the second stage reactor converts the residual acetylene to a content of less than 1 μ L/L.

For the device with higher volume space velocity or higher acetylene content, a three-section reactor process is generally adopted, the first section converts about 50 percent, the other two sections convert the residual acetylene, and the acetylene content at the outlet of the three-section reactor is less than 1 mu L/L.

the amount of hydrogen is related to the acetylene content and the process adopted. For the three-stage reactor process, the hydrogen/acetylene ratio of the first stage reactor is generally 0.8-1.2, the hydrogen/acetylene ratio of the second stage reactor is generally 1-1.5, and the hydrogen/acetylene ratio of the third stage reactor is generally 1.5-3.

For the two-stage reactor process, the hydrogen/acetylene ratio in the first stage reactor is generally 1-1.5, and the hydrogen/acetylene ratio in the second stage reactor is generally 2-4.

the reaction mechanism is as follows:

The main reaction C2H2+ H2 → C2H 4. delta. H-175.7 kJ/mol (1)

side reactions

CH+H→CH ΔH＝-138.1kJ/mol (2)

CH+2H→CH (3)

2CH+H→CH (4)

CH+nCH+H→CH (5)

In these applications, reaction (1) is the hydrogenation of acetylene and reactions (2) and (3) are the hydrogenation of ethylene. Reaction (4) is a hydrodimerization of acetylene, which contributes significantly to the production of green oil, and reaction (5) is a general reaction formula for producing green oil.

Among these reactions, only the reaction (1) is a desired reaction, and the others are undesired reactions.

US5856262 reports a process for the preparation of a low acid palladium catalyst with potassium hydroxide (or hydroxide of barium, strontium, rubidium etc.) modified silica as support, with an outlet acetylene mole fraction of less than 0.1 μ L/L and an ethylene selectivity of 56% at a volume space velocity of 3000h-1, an inlet temperature of 35 ℃, an inlet acetylene mole fraction of 0.71%, and a hydrogen acetylene mole ratio of 1.43. In the patent US4404124, alumina is used as a carrier, and a promoter silver is added to react with palladium, so that the carbon dioxide hydrogenation catalyst with excellent performance is prepared. The catalyst has the characteristics of reducing the ethane generation amount, inhibiting acetylene adsorbed on the surface of the catalyst from carrying out partial hydrodimerization reaction, inhibiting the generation of 1, 3-butadiene, reducing the generation of green oil, improving the ethylene selectivity and reducing the generation amount of oxygen-containing compounds, and is widely applied to the ethylene industry. However, the above catalysts are prepared by impregnation method, and are limited by the preparation method, the metal dispersion degree is only about 30%, and the catalyst performance has many defects, and further improvement is still needed.

The traditional Pd-Ag bimetallic selective hydrogenation catalyst is prepared by adopting an aqueous solution impregnation method. When the sub-leaching method is adopted, one component is more enriched on the surface of the carrier, the other component is enriched on the outer surface, and only part of metal atoms are mutually permeated to form an alloy structure. Meanwhile, by adopting a co-immersion method, due to different interaction between precursors of two metal ions and a carrier and surface tension and solvation, uniform loading of the two components is difficult to form, and only an alloy structure can be partially formed. When the catalyst is applied to selective hydrogenation of carbon dioxide fraction, the selectivity is good at the initial stage of reaction, the selectivity is continuously reduced along with the extension of the operation time, regeneration is needed after the catalyst is generally operated for 3-6 months, and the economic loss is large.

CN201110086174.0 forms a polymer coating layer on the surface of the carrier in a certain thickness by adsorbing a specific polymer compound on the carrier, and the compound with a functional group reacts with the polymer to enable the polymer to have the functional group capable of complexing with the active component, and the active component is ensured to be orderly and highly dispersed by the complexing reaction of the active component on the functional group on the surface of the carrier. By adopting the method, the carrier adsorbs specific high molecular compounds, and the high molecular compounds are chemically adsorbed with the high molecular compounds through the hydroxyl groups of the alumina, and the amount of the high molecular compounds adsorbed by the carrier is limited by the number of the hydroxyl groups of the alumina; the functional polymer and Pd have weak complexing effect, sometimes the loading capacity of the active component can not meet the requirement, and part of the active component remains in the impregnation liquid, so that the cost of the catalyst is increased; the method for preparing the carbon dioxide hydrogenation catalyst also has the defect of complicated process flow.

CN2005800220708.2 discloses a selective hydrogenation catalyst for acetylene and diolefin in light olefin raw material, which is composed of a first component selected from copper, gold and silver and a second component selected from nickel, platinum, palladium, iron, cobalt, ruthenium and rhodium, and in addition, the catalyst also includes at least one inorganic salt and oxide selected from zirconium, lanthanide and alkaline earth metal mixture. The catalyst forms a fluorite structure after being calcined, used or regenerated. The total content of the catalyst oxide is 0.01-50%, and the preferred roasting temperature is 700-850 ℃. The addition of a third oxide, modified alumina or silica support, helps to increase catalyst selectivity and activity, selectivity after regeneration. The technology still takes copper, gold, silver, palladium and the like as active components and takes nickel, platinum, palladium, iron, cobalt, ruthenium, rhodium and the like as auxiliary components, and the regeneration performance of the catalyst is improved by modifying the oxide of the carrier.

CN102218323A discloses a hydrogenation catalyst for unsaturated hydrocarbons, the active component is a mixture of 5-15% of nickel oxide and 1-10% of other metal oxides, the other metal oxides can be one or more of molybdenum oxide, cobalt oxide and iron oxide, and in addition, 1-10% of an auxiliary agent is also included. The technology is mainly used for hydrogenating and converting ethylene, propylene, butylene and the like in the tail gas of the coal-to-liquid industry into saturated hydrocarbon, and has good deep hydrogenation capacity. The technology is mainly used for the total hydrogenation of ethylene, propylene, butylene and the like in various industrial tail gases rich in CO and hydrogen, and is not suitable for the selective hydrogenation of alkyne and dialkene.

ZL201080011940.0 discloses an ordered cobalt-aluminum and iron-aluminum intermetallic compound as acetylene hydrogenation catalyst, the intermetallic compound is selected from the group consisting of CoAl, CoAl3, Co2Al5, Co2Al9, o-Co4Al13, h-Co4Al13, m-Co4Al13, FeAl2, Fe3Al, Fe2Al5 and Fe4Al 13. Among them, Fe4Al13 and o-Co4Al13 are preferable. The intermetallic compound is prepared by a hot melting method in solid chemistry. The catalyst hydrogenation performance test is carried out in a quartz tube furnace, the reaction temperature is 473K, after the stable reaction is carried out for 20 hours, the acetylene conversion rate of the o-Co4Al13 catalyst reaches 62%, the ethylene selectivity reaches 71%, the acetylene conversion rate on the Fe4Al13 catalyst reaches 40%, and the ethylene selectivity reaches 75%. The technology is used for preparing intermetallic compounds under the condition of high temperature, is used for selective hydrogenation of acetylene, has low acetylene conversion rate and high reaction temperature, and is not beneficial to industrial application. And the catalyst is prepared by a hot melting method, and the conditions are harsh.

In summary, the selective hydrogenation of low carbon alkynes and dienes mainly adopts noble metal catalysts, and a great deal of work is carried out on the research and development of non-noble metal catalysts, but the selective hydrogenation is far away from the industrial application. In order to solve the problem, the invention provides a novel Fe-based hydrogenation catalyst and a preparation method thereof.

Disclosure of Invention

the invention aims to provide a method for removing alkyne by hydrogenation after carbon dioxide. In particular to a Fe system selective hydrogenation catalyst which can selectively hydrogenate acetylene contained in the tower top effluent from a deethanizer and completely convert the acetylene into ethylene without loss of the ethylene.

the invention provides a method for removing acetylene by hydrogenation after carbon dioxide, which comprises the steps of enabling an effluent at the top of a deethanizer to enter an adiabatic bed reactor for selective hydrogenation to remove trace acetylene, wherein a Fe selective hydrogenation catalyst is filled in the adiabatic bed reactor, a carrier is a high-temperature-resistant inorganic oxide, and the catalyst contains 2-12% of Fe, preferably 4-10% of Fe and 0-1.6% of X by 100% of the mass of the catalyst, wherein the X is selected from one or more of K, La and Ce, and the preferably 0.5-1.0% of X; the specific surface area of the catalyst is 10-200 m2/g, preferably 30-100 m2/g, and the pore volume is 0.2-0.63 ml/g, preferably 0.35-0.49 ml/g; wherein Fe is loaded on a carrier by a dipping mode, is roasted at 300-700 ℃, is reduced by atmosphere containing hydrogen at 250-500 ℃, and Fe element in the catalyst mainly exists in a form of alpha-Fe 2O 3. Selecting the hydrogenation reaction conditions: the inlet temperature of the adiabatic bed reactor is 40-100 ℃, the reaction pressure is 1.5-2.5 MPa, the gas volume space velocity is 2000-10000H < -1 >, and the volume ratio of H2/C2H2 is 1-20. Preferred hydrogenation conditions are: the inlet temperature of the adiabatic bed reactor is 45-55 ℃, the reaction pressure is 1.8-2.2 MPa, the gas volume space velocity is 5000-8000H < -1 >, and the volume ratio of H2/C2H2 is 1.2-5.

The acetylene removing method adopts the hydrogenation catalyst, the carrier is a high-temperature-resistant inorganic oxide, and the technical key point of the method is that the catalyst contains Fe, and the catalyst is roasted and reduced, so that the carrier has no special requirement, such as one or more of alumina, silica, zirconia, magnesia and the like. However, alumina or alumina-based carriers, which are composite carriers of alumina and other oxides, in which alumina accounts for 50% or more of the mass of the carrier, are also preferred, and for example, alumina and oxides such as silica, zirconia, magnesia, etc., and alumina-zirconia composite carriers, in which the alumina content is 60% or more, are also preferred. The alumina can be theta, alpha, gamma or a mixture of a plurality of crystal forms, and is preferably alpha-Al 2O3 or mixed crystal form alumina containing alpha-Al 2O 3.

The preparation process of the Fe catalyst adopted by the alkyne removing method comprises the following steps:

The catalyst is obtained by preparing Fe precursor aqueous solution and X precursor aqueous solution, respectively impregnating the carrier, respectively aging, drying and roasting, or impregnating the carrier with mixed solution thereof, then aging, drying, roasting and finally reducing.

The preferred conditions in the preparation process of the catalyst used in the present invention are:

The dipping temperature is 30-60 ℃, the dipping time is 10-60 min, the pH value of the dipping solution is 1.5-5.0, the aging temperature is 30-60 ℃, the aging time is 30-120 min, the roasting temperature is 300-700 ℃, and the roasting time is 180-300 min.

In the present invention, the drying is preferably temperature-programmed drying, and the drying temperature program is set as follows:

In the present invention, the calcination, i.e. the activation process, is preferably temperature programmed calcination, and the calcination temperature program is set as follows:

The catalyst can be prepared by adopting any one impregnation mode of isometric impregnation, excessive impregnation, surface spray impregnation, vacuum impregnation and multiple impregnation.

The method comprises the following specific steps:

(1) And measuring the water absorption of the carrier and then weighing the carrier.

(2) accurately weighing a certain amount of Fe precursor (recommending soluble nitrate, chloride or sulfate) according to the load, preparing an impregnation solution according to the water absorption rate of the carrier and an impregnation method, adjusting the pH value of the impregnation solution to 1.5-5.0 according to requirements, and heating the solution to 30-60 ℃ for later use.

(3) When an isometric immersion or spray immersion method is adopted, the weighed carrier can be placed into a rotary drum, the rotating speed of the rotary drum is adjusted to be 25-30 r/min, the carrier is completely turned over, the prepared immersion liquid at the temperature of 30-60 ℃ is poured or sprayed onto the carrier at a certain speed, and the carrier is loaded for 5-10 min.

When an excessive impregnation method is adopted, the weighed carrier is placed in a container, then the prepared impregnation solution with the temperature of 30-60 ℃ is added, the container is quickly shaken, so that heat emitted in the adsorption process is quickly released, the active component is uniformly loaded on the carrier, and standing is carried out for 5-10 min so that the surface active component and the active component in the solution compete for adsorption balance.

When a vacuum impregnation method is adopted, the weighed carrier is placed in a cyclone evaporator, the vacuum is pumped, impregnation liquid with the temperature of 30-60 ℃ is added for impregnation for 5-10 min, and the carrier is heated in a water bath until the surface of the carrier is completely dried.

(4) Transferring the impregnated catalyst into a container, and aging the catalyst for 30-120 min at 25-60 ℃.

(5) filtering out excessive solution after impregnation, and then drying in an oven by adopting a temperature programming method, wherein the drying temperature programming is as follows:

(6) Roasting the dried catalyst by adopting a temperature programming method, wherein the roasting temperature programming comprises the following steps:

The catalyst X component is loaded by adopting the same steps, the roasting temperature is 300-700 ℃, preferably 400-500 ℃, the two components can also be prepared into a mixed solution, and the mixed solution is dipped on the surface of the carrier at one time according to the steps.

The active component of the catalyst is mainly Fe, and the catalyst can be a non-noble metal catalyst, even can not contain cobalt, nickel, molybdenum and tungsten, so that the cost is greatly reduced, and the cost of the catalyst is far lower than that of a noble metal Pd catalyst.

in the hydrogenation method, the Fe element in the adopted hydrogenation catalyst can exist in forms of Fe, Fe2O3, Fe3O4 and FeO, but the content of the Fe in the form of alpha-Fe 2O3 is higher than that in other forms, and preferably accounts for more than 50% of the total mass of the Fe. In the invention, one or more of K, La and Ce is recommended to be added into the active composition containing iron, which is beneficial to the formation and dispersion of the active phase of the catalyst, the stability of the active phase and the improvement of the selectivity and the coking resistance of the catalyst.

The activation temperature of the catalyst is related to the active composition, content and carrier of the catalyst, and the alpha-Fe 2O 3-form Fe is formed after the activation process, so that the catalyst is stable and the activation temperature cannot be too high; on the other hand, the activation degree determines the reduction condition of the catalyst, and the excessive reduction of the catalyst provided by the invention, which still takes the Fe in the form of alpha-Fe 2O3 as the main component, can influence the effect of the catalyst, influence the selectivity and is easy to coke.

The catalyst needs to be reduced by hydrogen-containing gas, the content of H2 is preferably 10-50%, the reduction temperature is 250-500 ℃, the volume space velocity is 100-500H < -1 >, and the reduction pressure is 0.1-0.8 MPa; the recommended conditions are that mixed gas of N2 and H2 is used for reduction at the temperature of 300-400 ℃ under the micro-positive pressure condition, the reduction time is preferably 240-360 min, the volume space velocity is preferably 200-400H-1, and the reduction pressure is preferably 0.1-0.5 MPa. The process is usually carried out before the selective hydrogenation reaction, and is preferably carried out outside the reactor, i.e., outside the selective hydrogenation reaction apparatus.

The invention relates to a method for removing acetylene by hydrogenation after carbon dioxide, which is characterized in that acetylene contained in a material flowing out of the top of a deethanizer is selectively hydrogenated and converted into ethylene in a two-section or three-section series adiabatic reactor.

According to the method for removing acetylene by hydrogenation after carbon dioxide, when the adiabatic bed reactor is connected in series in three sections, the inlet temperature of the first section reactor is 40-50 ℃, the volume ratio of hydrogen to acetylene is 0.8-1.2, the inlet temperature of the second section reactor is 45-55 ℃, the volume ratio of hydrogen to acetylene is 1-1.5, the inlet temperature of the third section reactor is 50-60 ℃, and the volume ratio of hydrogen to acetylene is 1.5-3.0.

According to the method for removing acetylene by hydrogenation after carbon dioxide, when the adiabatic bed reactor is reversely connected in series by two sections, the inlet temperature of the first section reactor is 40-50 ℃, the volume ratio of hydrogen to acetylene is 1-1.5, the inlet temperature of the second section reactor is 50-60 ℃, and the volume ratio of hydrogen to acetylene is 2-4.

The invention relates to a method for removing alkyne by hydrogenation after carbon dioxide, wherein a hydrogenation material is a distillate at the top of a deethanizer, and the method mainly comprises the following raw materials: 0.98-2.2% of acetylene, 11.2-30.3% of ethane and 65.0-85.0% of ethylene.

by adopting the alkyne-removing method, the catalyst has moderate reaction activity, good operation elasticity and good ethylene selectivity, and the green oil generation amount is far lower than that of a noble metal catalyst.

drawings

FIG. 1 is a flow diagram of a carbon dioxide selective hydrogenation process employing a sequential separation scheme. An oil washing tower; 2-water washing tower; 3-alkaline washing tower; 4-a dryer; 5-a demethanizer; 6-deethanizer; 7-a carbon dioxide hydrogenation adiabatic bed reactor; 8-heat exchanger.

FIG. 2 shows the XRD spectrum (with the carrier background removed) of the catalyst of example 3 in which the invention is applied.

figure 3 is the XRD spectrum of the catalyst of comparative example 2 (minus the background of the support).

Figure 4 is the XRD spectrum of the catalyst of comparative example 5 (with the carrier background subtracted).

XRD measurement conditions:

German Bruker D8ADVANCE X-ray diffractometer

Tube voltage: 40kV current 40mA

scanning: step size of 0.02 degree, frequency of 0.5s, scanning range of 4-120 degree, temperature of 25 degree C

Cu Ka 1 wavelength, diffraction angle 2 theta on abscissa and diffraction intensity on ordinate

The symbols in fig. 2 illustrate:

● is alpha-Fe 2O3, tangle-solidup is Fe3O4, and diamond-solid is CeO.

The symbols in fig. 3 illustrate:

● is alpha-Fe 2O3, tangle-solidup is Fe3O4, ■ is LaFeO 3.

symbolic illustration in fig. 4:

Tangle-solidup is Fe3O4, t is Ce, and ^ alpha-Fe.

In FIG. 2, Fe in the catalyst appears mainly in the form of α -Fe2O3 with a relative content of 7.6%.

In FIG. 3, the second component La in the catalyst is mainly combined with the iron oxide to form LaFeO3, the co-component is sintered with the active component, the distribution and the structure of the active component are damaged, and the activity of the catalyst is reduced.

in FIG. 4, the alpha-Fe 2O3 phase is not contained, Fe mainly appears in the form of simple substance alpha-Fe, the relative content is 8.92%, and the third component appears in the form of simple substance Ce.

Detailed Description

The analysis and test method comprises the following steps:

Specific surface area: GB/T-5816

Pore volume: GB/T-5816

Content of Fe oxide in different crystal forms: XRD

The content of active components of the catalyst is as follows: GB/T1537-94

Acetylene conversion (C)

Selectivity (S) for hydrogenation to ethylene

Example 1

Weighing cloverleaf type alpha-alumina carrier with phi of 4.5 multiplied by 4.5 mm. Taking ferric nitrate, heating and dissolving in 60ml of deionized water, adjusting the pH value to be 2.5, keeping the temperature of an impregnation liquid at 50 ℃, impregnating the surface of a carrier in an equal volume, rapidly turning over the carrier for impregnation for 6min, standing for 30min until adsorption is balanced, aging at 60 ℃ for 30min, and then placing in an oven according to the following procedures: drying the catalyst, and then activating the catalyst by adopting a programmed heating method, wherein the activating program comprises the following steps: weighing lanthanum nitrate, and impregnating according to the preparation steps.

Before the catalyst is used, reducing the catalyst in a reducing furnace by using 40 percent of hydrogen and 60 percent of nitrogen at the reducing temperature of 300 ℃ and under the pressure of 0.5MPa for 4 hours. The catalyst is packed in an adiabatic bed reactor.

The post-hydrogenation process is adopted, the process flow diagram is shown as the attached figure 1, and the raw materials comprise:

CH：1.6％(Φ)，CH 75.3％(Φ)，CH23.1％(Φ)。

Reaction conditions are as follows: two sections of adiabatic bed reactors are connected in series for reaction, namely, the material at the outlet of the first section of reactor enters the second section of reactor. Each reactor section is provided with an independent gas distribution system.

Material gas volume space velocity: 2000h-1, operating pressure: 2.5 MPa. First stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 3: 1 (molar ratio), the catalyst properties are shown in table 1, and the reaction results are shown in table 2.

Example 2

Stirring and mixing the NaAlO2 solution and the ZrCl4 solution at 50 ℃, then neutralizing with a nitric acid solution, stirring for 10 hours, and coprecipitating to generate uniform Al-Zr particles. And filtering the resultant, washing Na + and Cl-ions in the resultant by deionized water, adding a proper amount of polyvinyl alcohol with the mass concentration of 15% as a pore-forming agent, and kneading and forming. Drying at 130 ℃ for 2h, and roasting at 650 ℃ for 4h to obtain the Zr-Al composite carrier. The mass ratio of alumina to zirconia in the carrier was 4: 1.

The catalyst is prepared by alumina-zirconia composite carrier. Heating and dissolving ferric chloride and potassium chloride in deionized water, adjusting the pH value to be 2.0, soaking the carrier in excess at the temperature of 80 ℃, shaking a beaker for soaking for 10min, filtering out excessive soaking liquid, aging the catalyst in a water bath at the temperature of 60 ℃ for 50min, and then drying in an oven according to the following procedures: drying the catalyst, and activating the catalyst by adopting a programmed heating method, wherein the activating program comprises the following steps:

Before the catalyst is used, reducing the catalyst in a reducing furnace by using 30 percent of hydrogen and 60 percent of nitrogen at 320 ℃, under the pressure of 0.5MPa and for 4 hours. The catalyst is packed in an adiabatic bed reactor.

CH：1.4％(Φ)，CH 80.0％(Φ)，CH 18.6％(Φ)。

Material gas volume space velocity: 5000h-1, operating pressure: 2.2 MPa. First stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 4:1 (molar ratio), the catalyst properties are shown in table 1, and the reaction results are shown in table 2.

Example 3

Spherical alumina with phi of 1.5mm is weighed to prepare the catalyst. Dissolving ferric nitrate in deionized water, adjusting the pH value to 3.0, keeping the temperature of the impregnation liquid at 40 ℃, spraying the carrier by a spraying pot, loading for 10min to uniformly load the active components, and then, in an oven, according to the following procedures: drying the catalyst, and activating the catalyst by adopting a programmed heating method, wherein the activating program comprises the following steps: to obtain a leached catalyst.

And (3) dissolving cerium nitrate, spraying and soaking the dissolved cerium nitrate on the surface of the first-soaked catalyst, drying and roasting to obtain the final catalyst by adopting the same method in the first step. And (3) drying procedure: and (3) roasting procedure:

before the catalyst is used, reducing the catalyst in a reducing furnace by using 20 percent hydrogen at the reducing temperature of 340 ℃, under the pressure of 0.5MPa and for 4 hours. XRD analysis of the reduced catalyst is shown in figure 2. The catalyst is packed in an adiabatic bed reactor.

The post-hydrogenation process is adopted, and the reaction raw materials are as follows:

CH：2.2(v％)CH 79.3(v％)，CH 18.5(v％)。

Reaction conditions are as follows: the three-section bed adiabatic bed reactor series process is characterized in that the material at the outlet of the first-section reactor enters a second-section reactor, the material at the outlet of the second-section reactor enters a third-section reactor, and each section of reactor is provided with an independent gas distribution system.

Material gas volume space velocity: 7000h-1, operating pressure: 1.8 MPa. One-stage reactor H2/C2H2 ═ 1: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio); three-stage reactor H2/C2H2 ═ 3: 1 (molar ratio), the catalyst properties are shown in table 1, and the reaction results are shown in table 2.

Example 4

The spherical titanium dioxide carrier with the diameter of 2.0mm is weighed and placed in a vacuum impregnation device. Dissolving ferric nitrate in deionized water, and adjusting the pH value to 3.5 for later use. Opening a vacuum pumping pump of a vacuum impregnation device until the vacuum degree is 0.1mmHg, then slowly adding the prepared impregnation liquid from a feeding port, finishing the addition for 5min, evaporating at 60 ℃ until the flowing moisture on the surface of the catalyst completely disappears, finishing the loading, and putting the loaded catalyst in an oven according to the following procedures: drying in a muffle furnace according to the following steps: and (4) roasting. To obtain a leached catalyst.

And (3) taking cerium nitrate, impregnating according to the same method, drying, and roasting to obtain the final catalyst. And (3) drying procedure: and (3) roasting procedure:

Before the catalyst is used, reducing the catalyst in a reducing furnace by using 15 percent hydrogen at 360 ℃ under 0.5MPa for 4 h. The catalyst is packed in an adiabatic bed reactor.

CH：2.2(v％)CH 79.3(v％)，CH18.5(v％)。

Reaction conditions are as follows: the three-section bed adiabatic reactor series process is characterized in that the material at the outlet of the first-section reactor enters a second-section reactor, the material at the outlet of the second-section reactor enters a three-section reactor, and each section of reactor is provided with an independent gas distribution system.

Material gas volume space velocity: 10000h-1, operating pressure: 1.5 MPa. One-stage reactor H2/C2H2 ═ 1: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio); three-stage reactor H2/C2H2 ═ 3: 1 (molar ratio). The physical properties of the catalyst are shown in Table 1, and the reaction results are shown in Table 2.

Example 5

A catalyst was prepared by weighing 100ml of an α -alumina carrier having a diameter of 4.0mm by the same method as in example 3. The activation temperature was 650 ℃.

Before the catalyst is used, the catalyst is reduced by 25 percent hydrogen in a reducing furnace, the temperature is 380 ℃, the pressure is 0.5MPa, and the reduction time is 4 h. The catalyst is packed in an adiabatic bed reactor.

CH：1.2(v％)CH 80.3(v％)，CH18.5(v％)。

example 6

The method comprises the following steps of mixing commercially available pseudo-boehmite, silica gel, zirconium oxychloride powder and extrusion aid according to the weight ratio of alumina: silicon oxide: uniformly mixing zirconium oxide in a ratio of 8:1:3, extruding the mixture on a strip extruding machine for forming, drying the mixture at 120 ℃, and roasting the mixture in a muffle furnace at 550 ℃ for 3 hours to obtain the Zr-Si-Al composite oxide carrier. The catalyst was prepared by the same method as in example 4.

Before the catalyst is used, 45% hydrogen and 55% nitrogen are used in a reducing furnace, the temperature is 400 ℃, the pressure is 0.5MPa, and the activation time is 4 h. The catalyst is packed in an adiabatic bed reactor.

CH：2.2(v％)CH 79.3(v％)，CH18.5(v％)。

Example 7

A catalyst was prepared in the same manner as in example 1 using alumina having a particle diameter of 4.0mm as a carrier, and activated at 450 ℃.

Before the catalyst is used, the catalyst is reduced by 30 percent hydrogen in a reducing furnace, the temperature is 270 ℃, the pressure is 0.5MPa, and the activation time is 4 h. The catalyst is packed in an adiabatic bed reactor.

CH：1.2(v％)CH 79.2(v％)，CH19.6(v％)。

Reaction conditions are as follows: the series process of two-stage adiabatic reactor includes feeding the material from the outlet of the first stage reactor into the second stage reactor, and each stage reactor has independent gas distributing system.

Material gas volume space velocity: 12000h-1, operating pressure: 1.6 MPa. One-stage reactor H2/C2H2 ═ 2: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio). The physical properties of the catalyst are shown in Table 1, and the reaction results are shown in Table 2.

Reaction conditions are as follows: the volume space velocity is 18000h-1, and the pressure is 2.5 MPa.

The physical properties of the catalyst are shown in Table 1, and the reaction results are shown in Table 2.

Comparative example 1

The alumina carrier with phi of 4.0mm is taken, the specific surface is 22.3m2/g, and the pore volume is 0.31 ml/g. The method comprises the steps of adopting an isometric impregnation method, impregnating a silver nitrate solution onto a carrier in an isometric manner, aging, drying and roasting to obtain a primary impregnated catalyst, then dissolving palladium chloride, impregnating in an isometric manner, aging, drying and roasting to obtain a final catalyst (a petrochemical research institute LY-C2-02 hydrogenation catalyst). The catalyst contains 0.040% of Pd and 0.12% of Ag.

The catalyst is reduced by hydrogen for 160min at 100 ℃, the pressure is 0.5MPa, and the volume space velocity of the hydrogen is 100h < -1 >. The catalyst is packed in an adiabatic bed reactor.

The same process as in example 1 was used, with the reaction conditions: volume space velocity 6000h-1, operating pressure: 2.0 MPa. The physical properties of the catalyst are shown in Table 1, and the reaction results are shown in Table 2.

Comparative example 2

The catalyst was prepared in the same manner as in example 1 using alumina of Φ 4.0mm as a carrier, and the catalyst activation temperature was 850 ℃.

Before the catalyst is used, the catalyst is reduced by 25 percent hydrogen in a reducing furnace, the temperature is 300 ℃, the pressure is 0.5MPa, and the activation time is 4 h. The catalyst is packed in an adiabatic bed reactor. The XRD diffraction pattern of the reduced catalyst is shown in figure 3.

the same procedure as in example 1 was used. The raw materials comprise:

CH：1.4％(Φ)，CH 80.0％(Φ)，CH 18.6％(Φ)。

Reaction conditions are as follows: volume space velocity 2000h-1, operating pressure: 2.5 MPa.

Comparative example 3

A catalyst was prepared by the same method as in example 1 by using alumina having a particle diameter of 4.0mm as a carrier, and activated at 450 ℃.

Before the catalyst is used, the catalyst is reduced by 45 percent hydrogen in a reducing furnace, the temperature is 300 ℃, the pressure is 0.5MPa, and the activation time is 4 h. The hydrogenation scheme shown in figure 1 was used, and the catalyst was packed in an adiabatic bed reactor.

Material gas volume space velocity: 8000h-1, operating pressure: 1.5 MPa. One-stage reactor H2/C2H2 ═ 1: 1 (molar ratio); two-stage reactor H2/C2H2 ═ 1.5: 1 (molar ratio); three-stage reactor H2/C2H2 ═ 3: 1 (molar ratio).

Comparative example 4

The same catalyst as in example 1 was used, and the catalyst was activated at 450 ℃ and then directly started without reduction with hydrogen. The hydrogenation scheme shown in figure 1 was used, and the catalyst was packed in an adiabatic bed reactor.

The process of three-section series adiabatic reactor is adopted, the raw material composition is the same as that of the example 1, and the reaction conditions are as follows: volume space velocity 3000h-1, operating pressure: 2.0 MPa.

Comparative example 5

The same catalyst as in example 1 was used and activated at 450 ℃.

The catalyst is reduced in a tubular furnace under the atmosphere of 30% hydrogen and 55% nitrogen at 850 ℃, the pressure of 0.5MPa and the activation time of 4 h. The hydrogenation scheme shown in figure 1 was used, and the catalyst was packed in an adiabatic bed reactor. The XRD diffraction pattern of the reduced catalyst is shown in figure 4.

The composition of the hydrogenation raw material is the same as that of the example 7, and two stages of hydrogenation are connected in series, and the reaction conditions are as follows: the volume space velocity is 15000h < -1 > and the pressure is 2.0 MPa.

the catalyst properties are shown in Table 1, and the operating results are shown in Table 2.

TABLE 1 catalyst preparation Using Carrier Properties

TABLE 2 Process conditions and catalyst Properties

Claims

1. A hydrogenation acetylene removal method after carbon two, in the hydrogenation ethylene device after carbon two, enter the adiabatic bed reactor to carry on the selective hydrogenation after the effluent material from the top of the deethanizer mixes hydrogen, in order to remove acetylene among them; the method is characterized in that: a Fe system selective hydrogenation catalyst is filled in the adiabatic bed reactor, a carrier is a high-temperature-resistant inorganic oxide, the catalyst contains 2-12% of Fe and 0-1.6% of X by 100% of the mass of the catalyst, wherein the X is selected from one or more of K, La and Ce; the specific surface area of the catalyst is 10-200 m2/g, and the pore volume is 0.2-0.63 mL/g; wherein Fe is loaded on a carrier in an impregnation mode, is roasted at 300-700 ℃, is reduced by atmosphere containing hydrogen at 250-500 ℃, and Fe element in the catalyst mainly exists in a form of alpha-Fe 2O 3; selecting the hydrogenation reaction conditions: the inlet temperature of the adiabatic bed reactor is 40-100 ℃, the reaction pressure is 1.5-2.5 MPa, the gas volume space velocity is 2000-10000H < -1 >, and the volume ratio of H2/C2H2 is 1-20.

2. The method of claim 1, wherein: the catalyst contains 4-10% of Fe and 0.5-1.0% of X by 100% of the mass of the catalyst; the specific surface of the catalyst is 30-100 m2/g, the pore volume is 0.35-0.49 mL/g, and the hydrogenation conditions are as follows: the inlet temperature of the adiabatic bed reactor is 45-55 ℃, the reaction pressure is 1.8-2.2 MPa, the gas volume space velocity is 5000-8000H < -1 >, and the volume ratio of H2/C2H2 is 1.2-5.

3. The method of claim 1, wherein: in the catalyst, the Fe in the form of alpha-Fe 2O3 accounts for more than 50% of the total weight of the Fe.

4. The method of claim 1, wherein: the carrier of the catalyst is alumina or a composite carrier of alumina and other oxides, the alumina accounts for more than 50% of the mass of the carrier, and the other oxides are silicon oxide, zirconium oxide, magnesium oxide or titanium oxide; the alumina may be of the theta, alpha, gamma type.

5. The method of claim 4, wherein the support of the catalyst is an alumina-zirconia composite support and the alumina is α -Al2O 3.

6. The method according to claim 1, wherein the impregnation is an equal volume impregnation, an excess impregnation, a surface spray impregnation, a vacuum impregnation or a plurality of impregnations.

7. the method of claim 1, wherein: the catalyst is obtained by preparing Fe precursor aqueous solution and X precursor aqueous solution, respectively impregnating the carrier, respectively aging, drying and roasting or impregnating the carrier with mixed solution thereof, and then aging, drying, roasting and reducing.

8. the method of claim 7, wherein: the catalyst is prepared at the dipping temperature of 30-60 ℃, the dipping time of 10-60 min, the pH value of a dipping solution of 1.5-5.0, the aging temperature of 30-60 ℃, the aging time of 30-120 min and the roasting temperature of 300-700 ℃; the roasting time is 180-300 min.

9. the method of claim 8, wherein: the roasting temperature is 400-500 ℃.

10. The method of claim 7, wherein: the drying during the preparation of the catalyst is temperature programmed drying, and the drying temperature program is set as follows:

11. The method according to claim 1 or 7, characterized in that: the roasting is temperature programmed roasting, and the roasting temperature program is set as follows:

12. The method according to claim 1 or 7, characterized in that: the reduction is to reduce the catalyst by using mixed gas of N2 and H2, wherein the volume content of H2 is 10-50%, the reduction temperature is 250-500 ℃, the reduction time is 240-360 min, the volume space velocity is 100-500H < -1 >, and the reduction pressure is 0.1-0.8 MPa.

13. The method of claim 12, wherein: the reduction condition is that the reduction is carried out at 300-400 ℃, the volume airspeed is 200-400 h < -1 >, and the reduction pressure is 0.1-0.5 MPa.

14. The method of claim 1, wherein: the adiabatic bed reactor is connected in series in three sections, the inlet temperature of the first section reactor is 40-50 ℃, the volume ratio of hydrogen to acetylene is 0.8-1.2, the inlet temperature of the second section reactor is 45-55 ℃, the volume ratio of hydrogen to acetylene is 1-1.5, the inlet temperature of the third section reactor is 50-60 ℃, and the volume ratio of hydrogen to acetylene is 1.5-3.0.

15. The method of claim 1, wherein: the adiabatic bed reactor is reversely connected in series by two sections, the inlet temperature of the first section reactor is 40-50 ℃, the volume ratio of hydrogen to acetylene is 1-1.5, the inlet temperature of the second section reactor is 50-60 ℃, and the volume ratio of hydrogen to acetylene is 2-4.

16. the method of claim 1, wherein: the selective hydrogenation raw material comes from the top effluent of the deethanizer in the hydrogenation process after carbon two; the raw materials mainly comprise the following components by volume: 0.98-2.2% of acetylene, 11.2-30.3% of ethane and 65.0-85.0% of ethylene.