CN108728153A

CN108728153A - The production method and a kind of low-carbon alkene production system of a kind of low-carbon alkene

Info

Publication number: CN108728153A
Application number: CN201710256685.XA
Authority: CN
Inventors: 晋超; 吴玉; 张荣俊; 侯朝鹏; 孙霞; 阎振楠; 夏国富; 李明丰
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-04-19
Filing date: 2017-04-19
Publication date: 2018-11-02
Anticipated expiration: 2037-04-19
Also published as: CN108728153B

Abstract

The invention discloses a kind of production method of low-carbon alkene and production system, the preparation method is included under the conditions of steam reforming reaction, and methane is contacted with water, obtains steam reforming synthesis gas；Under dry reforming reaction condition, by methane and carbon dioxide exposure, dry reforming synthesis gas is obtained；Steam reforming synthesis gas and dry reforming synthesis gas are mixed, Fischer-Tropsch synthesis charging is obtained to prepare, Fischer-Tropsch synthesis charging is contacted at a temperature of producing low-carbon alkene with fischer-tropsch synthetic catalyst, obtain Fischer-Tropsch synthetic logistics, isolate the methane and carbon dioxide in Fischer-Tropsch synthetic logistics, methane is sent into steam reforming step and/or dry reforming step, carbon dioxide is sent into dry reforming step.The production method of low-carbon alkene according to the present invention can be effectively reduced the discharge capacity of system energy consumption and greenhouse gases (such as carbon dioxide).

Description

The production method and a kind of low-carbon alkene production system of a kind of low-carbon alkene

Technical field

The present invention relates to a kind of production methods of low-carbon alkene, and the invention further relates to a kind of low-carbon alkene production systems.

Background technology

Alkene is important basic chemical industry raw material in chemical industry production, and weighs a national oil chemical industry hair Open up horizontal mark.The method of preparing low-carbon olefins can be divided into three categories by raw material at present：Petroleum path, natural gas route With coal route.Using the method for light oil cracking, i.e. petroleum path carrys out the method for preparing low-carbon olefins for most of states in the world Family is used, and accounts for about 65% of olefin yield or so.Using natural gas as raw material, low-carbon alkene is taken by oxidative coupling or Benson legal system Hydrocarbon technology, in product mainly based on ethylene, the yield of propylene is relatively low.With research of the coal based synthetic gas through methanol-to-olefins Rapid development is achieved, has built more set process units at home.

China's energy is in the resource distribution situation of rich coal, more natural gases, oil starvation, will be between coal or natural gas by F- T synthesis Switch through that turn to clean, highly effective liquid fuel be the importance for rationally utilizing resource, alleviates the main of China's oil imbalance between supply and demand Technological approaches.Coal chemical technology coal in China's emerges rapidly through methanol-to-olefins in recent years, and coal is through synthesis gas alkene directly processed (FTO techniques) is another coal-to-olefin technique.The technique converts coal or natural gas to synthesis gas (carbon monoxide and hydrogen first Gas), the process of low-carbon alkene of the carbon atom number less than or equal to 4 is directly made using F- T synthesis.

Currently used FTO techniques olefin process flow is as shown in Figure 1, include sequentially connected water-coal-slurry preparation unit I, coal gasification unit II, WGS unit III, purified synthesis gas unit IV, F- T synthesis unit V and low-carbon alkene separation Unit VI, detailed process are that water-coal-slurry C is made in water-coal-slurry preparation unit I in fine coal A and water B, and water-coal-slurry C is delivered into Coal gasification unit II reacts with oxygen D and generates coal gasification crude synthesis gas E, and coal gasification crude synthesis gas E is through WGS unit III adjusts hydrogen and the molar ratio of carbon monoxide becomes crude synthesis gas F after the transformation for meeting Fischer-Tropsch synthesis requirement, then Through synthesis gas clean unit IV removing sour gas and sulfide M, it is purified synthesis gas J, obtained decontaminating syngas J is defeated It is sent into F- T synthesis unit V and carries out Fischer-Tropsch synthesis, generate the fischer-tropsch reaction product N of olefin-containing, fischer-tropsch reaction product N is through low Carbon olefin separative element VI isolates low-carbon alkene K, and the carbon dioxide H and methane G that F- T synthesis unit V is generated are then outer to be arranged, and one The unreacted synthesis gas Y in part is recycled back to F- T synthesis unit V, and the unreacted synthesis gas of another part is discharged as periodic off-gases Z System.It is by the main problem of the technique producing light olefins：1, high energy consumption, carbon atom utilization rate are low；2, CO2 emission Amount is 5-6 times of conventional petroleum route；3, since Fischer-Tropsch synthetic is distributed by Anderson-Schulz-Flory rule (chains Increase the molar distribution according to exponential decrease) limitation, and be limited by a large amount of methane caused by the strongly exothermic property of reaction, carbon dioxide life At the technique entirety efficiency is relatively low, seriously affects the process of industrialization of fischer-tropsch synthesis process.Coal gasifying process is largely cooling to be used Water and externally discharged waste water keep water consume high.

Therefore, there is still a need for optimization fischer-tropsch synthesis process, reduces the discharge capacity of system energy consumption and greenhouse gases.

Invention content

The purpose of the present invention is to provide a kind of production method of low-carbon alkene, this method can be effectively reduced system energy consumption And the discharge capacity of greenhouse gases.

According to the first aspect of the invention, the present invention provides a kind of production method of low-carbon alkene, this method includes Following steps：

S11, under the conditions of steam reforming reaction, methane is contacted with vapor, obtains steam reforming synthesis gas；

S21, under dry reforming reaction condition, by methane and carbon dioxide exposure, obtain dry reforming synthesis gas；

S31, will at least partly steam reforming synthesis gas and at least partly dry reforming synthesis gas mix, with prepare obtain expense Hold in the palm synthetic reaction charging, by the Fischer-Tropsch synthesis charging production low-carbon alkene reaction temperature under with fischer-tropsch synthetic catalyst Contact, obtains Fischer-Tropsch synthetic logistics；

S41, low-carbon alkene, methane and carbon dioxide are isolated from the Fischer-Tropsch synthetic logistics, by what is isolated Methane be sent into one of S11 and S21, or both in, will the carbon dioxide that isolated be sent into S21 in.

According to the second aspect of the invention, the present invention provides a kind of low-carbon alkene production system, which includes water Steam reforming reaction unit, dry reforming reaction member, synthesis gas mixed cell, Fischer-Tropsch synthesis unit, Fischer-Tropsch synthesis Product separative element and cycling element,

The steam reforming reaction unit carries out steam reforming reaction, obtains for contacting methane with vapor Steam reforming synthesis gas；

The dry reforming reaction member is used to, by methane and carbon dioxide exposure, carry out dry reforming reaction, obtain dry reforming Synthesis gas；

The synthesis gas mixed cell is matched for mixing the steam reforming synthesis gas with the dry reforming synthesis gas It is made for Fischer-Tropsch synthesis charging, and the Fischer-Tropsch synthesis is fed in the Fischer-Tropsch synthesis unit；

The Fischer-Tropsch synthesis unit is provided with Fischer-Tropsch synthesis device, for by the Fischer-Tropsch synthesis charging with Fischer-tropsch synthetic catalyst contacts, and obtains the Fischer-Tropsch synthetic logistics containing low-carbon alkene；

The Fischer-Tropsch synthesis product separative element obtains first for detaching the Fischer-Tropsch synthetic logistics Alkane, carbon dioxide, low-carbon alkene, optional hydrogen and optional carbon monoxide；

The methane cycle that the cycling element is used to isolate Fischer-Tropsch synthesis product separative element is sent into vapor One of reforming reaction unit and dry reforming reaction member, or both in, by Fischer-Tropsch synthesis product separative element detach The carbon dioxide recycle gone out is sent into dry reforming reaction member, the hydrogen that Fischer-Tropsch synthesis product separative element is isolated And/or carbon monoxide cycle is sent into Fischer-Tropsch synthesis unit.

Low-carbon alkene production method and system according to the present invention, can be effectively reduced system energy consumption and greenhouse gases The discharge capacity of (such as carbon dioxide).

Description of the drawings

Fig. 1 is for illustrating that existing coal directly prepares the typical process flow of low-carbon alkene (FTO techniques) through synthesis gas.

Fig. 2 is for illustrating low carbon olefin preparation method according to the present invention and system.

Fig. 3 is θ-Al prepared by preparation example 1₂O₃X-ray diffraction spectrogram.

Fig. 1 reference signs

I：Water-coal-slurry preparation unit II：Coal gasification unit III：WGS unit

IV：Purified synthesis gas unit V：F- T synthesis unit VI：Low-carbon alkene separative element

A：Fine coal B：Water C：Water-coal-slurry

D：Oxygen E：Coal gasification crude synthesis gas F：Crude synthesis gas after transformation

G：Methane H：Carbon dioxide K：Low-carbon alkene

M：Sour gas and sulfide N：Fischer-tropsch reaction product Y：Unreacted synthesis gas

Z：Periodic off-gases

Fig. 2 reference signs

I：Unstripped gas separative element II：Steam reforming reaction unit III：Dry reforming reaction member

IV：Fischer-Tropsch synthesis unit V：Fischer-Tropsch synthetic separative element A：Unstripped gas

B：Methane C：Vapor D：Carbon dioxide

E：Steam reforming synthesis gas F：Dry reforming synthesis gas G：Fischer-Tropsch synthesis is fed

H：Fischer-Tropsch synthetic logistics L：Hydrogen and carbon monoxide K for cycle：Low-carbon alkene

M：Methane N：Carbon dioxide Z：Periodic off-gases

Specific implementation mode

The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.

In the present invention, term " low-carbon alkene " refers to the alkene that carbon atom number is less than or equal to 4.

In step S11, the molar ratio of methane and vapor can be 1：0.5-4, preferably 1：1-3.Can by methane with Vapor is contacted at a temperature of 700-950 DEG C, preferably 800-900 DEG C.The reactor that methane is contacted with vapor Interior pressure can be 0.1-5MPa, and preferably 1-3MPa, the pressure is gauge pressure.The steam reforming reaction can be normal It is carried out in the reactor seen.Preferably, the steam reforming reaction carries out in fixed bed reactors.With methane and vapor Total amount meter, volume space velocity can be 10000-100000 hours when the gas of charging^-1, preferably 50000-100000 hours^-1。

In step S11, the various steam reformings suitable for steam reforming reaction commonly used in the art may be used and urge Agent.As an example, the steam reforming catalyst contains the active component of carrier and load on the carrier. The carrier can be the combination of one or more of aluminium oxide, silica, zirconium oxide and silicon carbide.Preferably, institute It is aluminium oxide to state carrier, is specifically as follows γ-Al₂O₃、θ-Al₂O₃、δ-Al₂O₃With α-Al₂O₃One or more of.Institute It can be group VIII metallic element, preferably group VIII non-noble metal j element to state active component, such as one in Fe, Co and Ni Kind is two or more.It is highly preferred that the active component is Ni.Load capacity of the active component on carrier can be conventional Selection.Usually, on the basis of the total amount of catalyst, based on the element, the content of the active component can be 1-30 weight %, Preferably 5-25 weight %, more preferably 10-15 weight %.

In step S21, the molar ratio of methane and carbon dioxide can be 1：0.5-5, preferably 1：0.8-3, more preferably 1：1-2.Methane can be contacted with carbon dioxide at a temperature of 600-800 DEG C, preferably 650-750 DEG C.Methane and dioxy The pressure changed in the reactor that carbon is contacted can be 0.1-5MPa, and preferably 1-3MPa, the pressure is in terms of gauge pressure.It is described Dry reforming reaction can carry out in common reactor.Preferably, the dry reforming reaction carries out in fixed bed reactors. In terms of the total amount of methane and carbon dioxide, volume space velocity can be 10000-100000 hours when the gas of charging^-1, preferably 50000-100000 hours^-1。

In step S21, the various dry reforming catalyst suitable for dry reforming reaction commonly used in the art may be used.As One example, the dry reforming catalyst contain the active component of carrier and load on the carrier.The carrier can be with For the combination of one or more of aluminium oxide, silica, zirconium oxide and silicon carbide.Preferably, the carrier is oxidation Aluminium is specifically as follows γ-Al₂O₃、θ-Al₂O₃、δ-Al₂O₃With α-Al₂O₃One or more of.The active component can Think group VIII metallic element, preferably group VIII non-noble metal j element, as one or both of Fe, Co and Ni with On.It is highly preferred that the active component is Ni.Load capacity of the active component on carrier can be conventional selection.Generally Ground, on the basis of the total amount of catalyst, based on the element, the content of the active component can be 1-30 weight %, preferably 5- 25 weight %, more preferably 10-15 weight %.

The production method of low-carbon alkene according to the present invention, as methane vapor reforming and the raw material of methane dry reforming it One methane can be the methane in various sources, the methane preferably isolated from the unstripped gas rich in methane.At this point, root According to the production method of the low-carbon alkene of the present invention, further includes step S10, in S10, isolated from the unstripped gas containing methane Methane.The unstripped gas can be the common mixture rich in methane.Specifically, the unstripped gas can be selected from shale One or more of gas, coal bed gas, natural gas, refinery gas and oven gas.

Conventional method may be used and isolate methane from the unstripped gas, such as use pressure swing adsorption method from the unstripped gas In isolate methane.As an example, methane is isolated from unstripped gas by condensation at low temperature.The condensation at low temperature is The method for isolating and purifying methane using boiling-point difference according to the boiling point determination of each component in unstripped gas is obtained from gas phase Methane, or methane is obtained from liquid phase.

The production method of low-carbon alkene according to the present invention, the methane as one of steam reforming and the raw material of dry reforming In, the mass content of element sulphur be generally 20ppm hereinafter, preferably 10ppm hereinafter, more preferably 5ppm hereinafter, further it is excellent It is selected as 1ppm or less.

The production method of low-carbon alkene according to the present invention according to the reaction property of steam reforming and dry reforming and is taken The requirement of synthetic reaction charging is held in the palm, the amount for the methane that can be sent into step S11 and step S21 by control further increases basis The raw material availability of the method for the present invention.Preferably, the weight of the methane used in step S11 and the methane used in step S21 Amount is than being 1：0.5-2.5.

In step S31, will at least partly steam reforming synthesis gas and at least partly dry reforming synthesis gas mix, to match The Fischer-Tropsch synthesis charging for meeting F- T synthesis charging hydrogen-carbon ratio (that is, molar ratio of hydrogen and carbon monoxide) is made.From The angle for improving selectivity of light olefin is set out, and in Fischer-Tropsch synthesis charging, the molar ratio of hydrogen and carbon monoxide is preferably 0.4-3：1, more preferably 0.6-2.5：1, further preferably 0.8-2.2：1, it is still more preferably 1.5-2.2：1.

The production method of low-carbon alkene according to the present invention, in step S31, by Fischer-Tropsch synthesis charging and F- T synthesis Catalyst contacts, and carries out Fischer-Tropsch synthesis, obtains Fischer-Tropsch synthetic logistics.

The fischer-tropsch synthetic catalyst can be conventional to catalyst of the Fischer-Tropsch synthesis with catalytic action.One In kind preferred embodiment, the fischer-tropsch synthetic catalyst contains the group VIII gold of carrier and load on the carrier Belong to element.

According to the fischer-tropsch synthetic catalyst of the preferred embodiment, the carrier is aluminium oxide, and specific example can be with Including but not limited to：γ-Al₂O₃、θ-Al₂O₃、δ-Al₂O₃With α-Al₂O₃One or more of.It can be according to aluminium oxide Concrete type the parameters such as its specific surface area, average pore size and particle diameter distribution are optimized, to further increase catalyst Catalytic performance.As an example, for γ-Al₂O₃, Kong Rongke is with for 0.6-1mL/g, preferably 0.65-0.9mL/g is more excellent It is selected as 0.65-0.85mL/g；Average pore size can be 8-35nm, preferably 12-30nm, more preferably 15-20nm；Grain size exists The content of particle in 70-150 μ ms can be 80 volume % or more, preferably 85 volume % or more, more preferably 90 bodies Product % or more；Specific surface area can be 100-300m²/ g, preferably 120-250m²/ g, more preferably 150-200m²/g.As Another example, for θ-Al₂O₃, Kong Rongke is with for 0.3-0.8mL/g, preferably 0.35-0.7mL/g, more preferably 0.4- 0.6mL/g；Average pore size can be 12-40nm, preferably 15-35nm, more preferably 18-25nm；Grain size is in 70-150 μm of model The content of particle in enclosing can be 80 volume % or more, preferably 85 volume % or more, more preferably 90 volume % or more；Than Surface area can be 50-200m²/ g, preferably 60-150m²/ g, more preferably 65-100m²/g.In the present invention, specific surface area, Hole holds and average pore size is measured according to nitrogen adsorption methods, specifically, using N₂Adsorption isotherm is measured under 77K constant temperature Then line presses BET formula and calculates specific surface area and Kong Rong, and calculates average pore size distribution by BJH methods；Particle diameter distribution is using sharp Light particle size analyzer determination.

Preferably, the carrier contains θ-Al₂O₃.By introducing θ-Al in the carrier₂O₃So that fischer-tropsch synthetic catalyst Higher catalytic activity and catalytic stability can be obtained, shows higher CO conversion ratios and selectivity of light olefin, simultaneously also With more excellent activity stability.Usually, on the basis of the total amount of aluminium oxide in catalyst, the content of θ-aluminium oxide can Think 10 weight % or more, preferably 20 weight % or more, more preferably 30 weight % or more, further preferably 40 weight % More than, it is still more preferably 50 weight % or more.It is particularly preferred that the carrier is θ-aluminium oxide.

θ-the Al₂O₃It is commercially available, it can also be by by γ-Al₂O₃It is roasted and is obtained.It specifically, can be with By γ-Al₂O₃It is roasted at a temperature of 700-1050 DEG C, preferably 780-1050 DEG C.The duration of the roasting can root It is selected according to the temperature of roasting, to be enough γ-Al₂O₃It is converted into θ-Al₂O₃Subject to.Usually, the roasting it is lasting when Between can be 0.5-5 hours, preferably 1-4 hours.The roasting carries out in air atmosphere.

According to the fischer-tropsch synthetic catalyst of the preferred embodiment, the group VIII metallic element is as catalyst Active component can be group VIII noble metals element, or group VIII non-noble metal j element can also be Section VIII The combination of race's precious metal element and group VIII non-noble metal j element.In a preferred embodiment, the group VIII Metallic element is group VIII non-noble metal j element, specific example can include but is not limited to one kind in Fe, Co and Ni or It is two or more.It is highly preferred that the group VIII metallic element is Fe.

Valence state according to the fischer-tropsch synthetic catalyst of the preferred embodiment, at least partly group VIII metallic element is Less than the highest oxidation valence state of the metallic element.Usually, on the basis of the total amount of group VIII metallic element in the catalyst, Based on the element, it can be 30 weight % or more that valence state, which is the content of the group VIII metallic element less than its highest oxidation valence state, Preferably 40 weight % or more, more preferably 45 weight % or more, further preferably 50 weight % or more (such as 55 weight % with On), it is still more preferably 60 weight % or more, particularly preferably 75 weight % or more.With in the fischer-tropsch synthetic catalyst On the basis of the total amount of group VIII metallic element, valence state is the highest of the group VIII metallic element less than its highest oxidation valence state Content can be 100 weight %, or be less than 100 weight %, such as 99 weight %, 96 weight %, 93 weight %, 90 weights Measure %, 87 weight %.According to the preferred embodiment, the fischer-tropsch synthetic catalyst is used directly for catalysis reaction, and Without carrying out additional reduction activation.In the present invention, when term " highest oxidation valence state " refers to that the metallic element is fully oxidized Chemical valence, by taking Fe as an example, highest oxidation valence state refers to iron oxide (Fe₂O₃) in ferro element chemical valence, for+trivalent.The present invention In, group VIII metallic element and its content with different valence state are measured using X-ray photoelectron spectroscopy.

According to the fischer-tropsch synthetic catalyst of the preferred embodiment, in a particularly preferred example, described Group VIII metal element is Fe, in the x-ray photoelectron spectroscopy spectrogram of the fischer-tropsch synthetic catalyst, is existed corresponding to FeO's Spectral peak (typically occurring at 711.9eV and 724.4eV) and correspond to Fe₅C₂Spectral peak (typically occurring at 717.9eV). There is more excellent catalytic performance and activity stability according to the fischer-tropsch synthetic catalyst of the particularly preferred example.In the spy In not preferred example, based on the element, by the content of Fe that is determined corresponding to the spectral peak of FeO with by corresponding to Fe₅C₂Spectral peak it is true The ratio of the content of fixed Fe can be 8-25：1.From the angle for the catalytic activity and catalytic stability for further increasing catalyst Degree sets out, by the Fe that is determined corresponding to the spectral peak of FeO with by corresponding to Fe₅C₂The ratio of Fe that determines of spectral peak be preferably 9-20： 1, more preferably 9.5-15：1, further preferably 10-12：1.From the angle for further increasing catalytic activity and catalytic stability It sets out, based on the element, on the basis of the total amount of the Fe determined by x-ray photoelectron spectroscopy, by the spectral peak and correspondence corresponding to FeO In Fe₅C₂The content of Fe that determines of spectral peak can be 30% or more (such as 30-99%), preferably not lower than 40% (such as 40- 96%), more preferably it is not less than 45% (such as 45-93%), is further preferably not less than 50% (such as 55% or more), more into one Step is preferably not lower than 60% (such as 60-90%), is particularly preferably not less than 75% (such as 75-87%).

In the present invention, x-ray photoelectron spectroscopy is in Thermo Scientific companies equipped with Thermo It is tested on the ESCALab250 type x-ray photoelectron spectroscopies of Avantage V5.926 softwares, excitaton source is monochromatization Al K α X-rays, energy 1486.6eV, power 150W, penetrating used in narrow scan can be 30eV, base vacuum when analysis test It is 6.5 × 10^-10Mbar, the peaks C1s (284.6eV) correction of electron binding energy simple substance carbon, in Thermo Avantage softwares Upper carry out data processing carries out quantitative analysis in analysis module using sensitivity factor method.

According to the fischer-tropsch synthetic catalyst of the preferred embodiment, the content of the group VIII metallic element can be Conventional selection.Usually, on the basis of the total amount of fischer-tropsch synthetic catalyst, based on the element, the group VIII metallic element Content can be 3-30 weight %, preferably 5-25 weight %, more preferably 8-20 weight %, further preferably 10-15 weights Measure %.In the present invention, the type and content of each metallic element are used according to RIPP 132-92 in catalyst and catalyst precarsor (《Petrochemical analysis method (RIPP experimental methods)》, Yang Cui is surely equal to be compiled, Science Press, nineteen ninety September the 1st edition, 371- Page 379) specified in X-ray fluorescence spectra analysis method measure.

According to the fischer-tropsch synthetic catalyst of the preferred embodiment, containing carrier and load on the carrier While group VIII metallic element, the second metallic element and/or the third metal loaded on the carrier can also be contained Element preferably comprises third metallic element and optional second metallic element loaded on the carrier.Contain described The catalyst of two metallic elements and/or third metallic element shows more excellent catalytic activity and catalytic stability.This hair In bright, it is " optional " indicate with or without.

Second metallic element is one in alkali metal element, alkali earth metal and group ivb metallic element Kind is two or more.The specific example of second metallic element can include but is not limited to：Li, Na, K, Mg, Ca, Zr and Ti One or more of.Preferably, second metallic element is one or more of Li, Zr, Mg and K.With On the basis of the total amount of fischer-tropsch synthetic catalyst, based on the element, the content of second metallic element can be 0.1-15 weight %, Preferably 1-12 weight %, more preferably 2-11 weight %, further preferably 5-7 weight %.

From the angle for the catalytic activity and activity stability for further increasing catalyst, second metallic element is excellent Choosing is containing group ivb metallic element (preferably Zr and/or Mg) and alkali metal element (preferably K and/or Li), with catalyst On the basis of total amount, based on the element, the content of group ivb metallic element (preferably Zr and/or Mg) is preferably 0.5-8 weight %, The content of more preferably 1-4 weight %, further preferably 2-3 weight %, alkali metal element (preferably K and/or Li) are preferred For 1-8 weight %, more preferably 2-6 weight %, further preferably 3-4 weight %.

The third metallic element is selected from one or more of thulium, and specific example can wrap Include but be not limited to one or more of lanthanum, cerium (Ce), praseodymium and neodymium.Preferably, the third metallic element is Ce.To take On the basis of the total amount of Tropsch synthesis catalyst, based on the element, the content of the third metallic element can be 0.1-10 weight %, excellent It is selected as 0.5-6 weight %, more preferably 0.8-3 weight %, further preferably 1.2-2 weight %.

From the angle for the catalytic activity and catalytic stability for further increasing catalyst, according to the preferred embodiment party The fischer-tropsch synthetic catalyst of formula preferably comprises the second metallic element and the third metallic element loaded on the carrier.Described When catalyst contains the second metallic element and third metallic element simultaneously, second metallic element is more preferably group ivb gold Belong to element and/or alkali metal element, further preferably group ivb metallic element and alkali metal element, still more preferably for Zr and K, the third metallic element are more preferably Ce, can obtain more excellent catalytic activity and catalytic stability in this way.

CO₂- TPD is (that is, temperature programmed desorption CO₂) it can be used for characterizing desorption performance of the catalyst for hydrocarbon molecules, CO₂In-TPD spectrograms, the temperature for desorption peaks occur is higher, illustrates that catalyst is conducive to the desorption of hydrocarbon molecules, for same There are multiple catalyst of desorption peaks in position, and the bigger catalyst of peak area is stronger to the desorption ability of hydrocarbon molecules.According to this The fischer-tropsch synthetic catalyst of preferred embodiment shows unique CO₂- TPD be desorbed spectrogram, 300-600 DEG C, preferably 320-500 DEG C, there are desorption peaks (which herein, to be known as CO in more preferable 350-480 DEG C of temperature range₂High temperature Desorption peaks).The CO₂The peak area at elevated temperature desorption peak is generally 0.3-2.5a.u. (arbitrary unit), preferably 0.5-2a.u. (arbitrary unit).According to the CO of the fischer-tropsch synthetic catalyst of the preferred embodiment₂- TPD is desorbed in spectrogram, in 100-200 DEG C, there is also another desorption peaks (which herein, to be known as CO in preferably 150-190 DEG C of temperature range₂Low temperature is desorbed Peak).The CO₂The peak area of low temperature desorption peaks is generally 0.5-3.5a.u. (arbitrary unit), and preferably 1-3.2a.u. is (arbitrary Unit), more preferably 2-3a.u. (arbitrary unit).

CO-TPD (that is, temperature programmed desorption CO) can be used for characterizing catalyst for the dissociation capability of CO, and it is de- CO occur The temperature at attached peak is higher, shows that the activity of catalyst is higher.For in same position, there are multiple catalyst of desorption peaks, peak faces The bigger catalyst of product is more conducive to CO dissociation.According to the fischer-tropsch synthetic catalyst of the preferred embodiment, in 300-700 DEG C, preferably 400-650 DEG C, there are desorption peaks (herein, which to be known as in more preferable 450-600 DEG C of temperature range CO elevated temperature desorptions peak).The peak area at CO elevated temperature desorptions peak is generally 0.5-7a.u. (arbitrary unit), preferably 1-6a.u. (arbitrary unit), more preferably 2-5.5a.u. (arbitrary unit).According to the fischer-tropsch synthetic catalyst of the preferred embodiment CO-TPD is desorbed in spectrogram, and there is also another desorption peaks in 100-200 DEG C, preferably 150-190 DEG C of temperature range (herein In, which is known as CO low temperature desorption peaks).It is (arbitrary single that the peak area of the CO low temperature desorption peaks is generally 0.5-2a.u. Position), preferably 0.8-1.6a.u. (arbitrary unit).

In the present invention, CO₂- TPD and CO-TPD is all made of Mike's chemical adsorption instrument, using OMistar mass spectrographs as detection Device on-line checking measures, wherein CO₂The signal that-TPD is 44 by mass spectrograph record nucleocytoplasmic ratio, CO-TPD record core by mass spectrograph Matter is than the signal for 28.In the present invention, the position of desorption peaks refers to the location of summit of desorption peaks.

The fischer-tropsch synthetic catalyst can be obtained by fischer-tropsch synthetic catalyst precursor is carried out reduction activation, described Reduction activation includes the following steps：

(1) fischer-tropsch synthetic catalyst precursor in first gas is subjected to prereduction, obtains catalyst pre-reduction；

(2) catalyst pre-reduction in second gas is subjected to reduction activation, obtains reduction activation catalyst.

The fischer-tropsch synthetic catalyst precursor contains the group VIII metallic element of carrier and load on the carrier.

In the fischer-tropsch synthetic catalyst precursor, the group VIII metallic element is supported on described in the form of the oxide The valence state of group VIII metallic element on carrier, and in the oxide is highest oxidation valence state (this paper of the metallic element In, the valence state of the metallic element in metal oxide is also referred to as full oxide for the oxide of highest oxidation valence state).It is described to take The representative instance of Tropsch synthesis catalyst precursor is that dry and roasting is undergone in preparation process (that is, carrying out heat in oxygen atmosphere Processing) and the catalyst precarsor of reduction treatment is not carried out.Group VIII metallic element existing in the form of full oxide needs Reduction activation is carried out, just there is the catalytic performance for meeting requirement.The type and content of the group VIII metallic element The description of fischer-tropsch synthetic catalyst part above is may refer to, and will not be described here in detail.

The first gas be hydrogen or be hydrogen and inert gas gaseous mixture.The inert gas can be choosing From one or more of nitrogen and group 0 element gas, the group 0 element gas for example can be argon gas.Preferably, The inert gas is nitrogen and/or argon gas.When the first gas is the gaseous mixture of hydrogen and inert gas, the inertia The molar ratio of gas and the hydrogen can be 1-30：1.

Institute's F- T synthesis states catalyst precarsor with the Contact Temperature of the first gas can make fischer-tropsch synthetic catalyst The group VIII metallic element that highest oxidation valence state is at least partially in precursor is reduced subject to (that is, valence state reduction).

Specifically, the fischer-tropsch synthetic catalyst precursor can be at 200-600 DEG C, preferably 300- with the first gas 550 DEG C, it is 350-500 DEG C more preferable at a temperature of contacted.The volume space velocity of the first gas (in terms of hydrogen) can be 5000-30000 hours^-1, preferably 10000-20000 hours^-1.In terms of gauge pressure, the pressure in reactor can be 0- 2.5MPa, preferably 0.1-2MPa.The duration of the prereduction can be selected according to the temperature of prereduction.Generally The duration on ground, the prereduction can be 1-20 hours, preferably 2-10 hours, more preferably 5-8 hours.

The second gas is to be gaseous hydrocarbon at a temperature of reduction activation or is gaseous at a temperature of reduction activation The gaseous mixture of hydrocarbon and inert gas.Described is that gaseous hydrocarbon can be for selected from a temperature of reduction activation at a temperature of reduction activation It is one or more of gaseous alkene for gaseous alkane and at a temperature of reduction activation, such as can is choosing From C₁-C₄Alkane and C₂-C₄One or more of alkene.Described is the specific of gaseous hydrocarbon at a temperature of reduction activation Example can include but is not limited to one or more of methane, ethane, ethylene, propylene, propane, butane and butylene.From The angle of the catalytic activity and catalytic stability that further increase the catalyst finally prepared is set out, described in reduction activation temperature It is one or more of gaseous alkane to be preferably selected from a temperature of reduction activation for gaseous hydrocarbon down, more preferably Selected from C₁-C₄One or more of alkane, further preferably ethane.The inert gas can be selected from nitrogen and One or more of group 0 element gas, the group 0 element gas for example can be argon gas.Preferably, the inertia Gas is nitrogen and/or argon gas.It is the mixed of gaseous hydrocarbon and inert gas at a temperature of the second gas is in reduction activation When closing gas, the inert gas with it is described be the molar ratio of gaseous hydrocarbon at a temperature of reduction activation can be 1-200：1, preferably For 1-100：1, more preferably 10-50：1, further preferably 15-30：1.

The reduction activation can 150-500 DEG C, preferably 180-450 DEG C, it is 200-400 DEG C more preferable at a temperature of into Row.The volume space velocity of the second gas (to be in terms of gaseous hydrocarbon at a temperature of reduction activation) can be that 5000-30000 is small When^-1, preferably 10000-20000 hours^-1.During carrying out reduction activation, in terms of gauge pressure, the pressure in reactor can Think 0-2.5MPa, preferably 0.1-2MPa.The duration of the reduction activation can according to the temperature of reduction activation and The pressure of second gas is selected.Usually, the duration of the reduction activation can be 1-20 hours, preferably 2-15 Hour, more preferably 4-12 hours.

Method comprising the following steps preparation may be used in the fischer-tropsch synthetic catalyst precursor：Group VIII metal will be contained The compound of element and compound loaded on carrier optionally containing auxiliary element, the carrier is roasted, is obtained Catalyst precarsor, the carrier are aluminium oxide.

The aluminium oxide can not load additional modifying element and be directly used as carrier (that is, pure aluminium oxide is made For carrier), it is used as carrier after can also being modified.In a preferred embodiment, at least partly carrier be containing The aluminium oxide of modifying element.Usually, on the basis of the total amount of carrier, the content of the aluminium oxide containing modifying element can be 10 Weight % or more, preferably 30 weight % or more, more preferably 50 weight % or more, further preferably 70 weight % or more, Still more preferably it is 90 weight % or more.It is particularly preferred that the carrier is the aluminium oxide containing modifying element.

The modifying element be one kind in alkali metal element, alkali earth metal and group ivb metallic element or It is two or more.The specific example of the modifying element can include but is not limited to one kind in Li, Na, K, Mg, Ca, Zr and Ti or It is two or more.It is furthermore preferred that the modifying element is one or more of K, Mg and Zr.

From the angle for the catalytic activity and activity stability for further increasing the catalyst finally prepared, with carrier On the basis of total amount, based on the element, the content of the modifying element can be 0.1-15 weight %, preferably 0.5-12 weight %, More preferably 1-10 weight %, further preferably 1.5-8 weight %.The modifying element is preferably prior to group VIII gold Belong to element and optional auxiliary element is supported on alumina.

Conventional method may be used and obtain the aluminium oxide containing modifying element.For example, can be in the process for preparing aluminium oxide In, on alumina by modifying element load, such as by co-precipitation, while preparing aluminium oxide, modifying element is supported on On aluminium oxide.

In a preferred example, there is the aluminium oxide of the compound containing modifying element to roast load, to To the aluminium oxide containing modifying element.The roasting can carry out under normal conditions, and usually, the roasting can be in 300- It being carried out at a temperature of 900 DEG C, preferably 400-800 DEG C, the duration of the roasting can be selected according to the temperature of roasting, Typically 0.5-8 hours, preferably 1-6 hours.The roasting carries out in air atmosphere.

It, can will be compound loaded in aluminium oxide containing modifying element by way of dipping in the preferred example On.Specifically, the maceration extract oxide impregnation aluminium containing the compound containing modifying element can be used, the oxidation of maceration extract will be adsorbed with Aluminium is dried and roasts successively, to obtain the aluminium oxide containing modifying element.

In the preferred example, the compound containing modifying element can be water soluble salt containing modifying element and/ Or water-soluble alkali, specific example can include but is not limited to：Nitrate, oxalates, acetate, chloride, hydroxide, carbon One or more of hydrochlorate, bicarbonate and phosphate.In the preferred example, routine may be used in the dipping Dipping method, such as saturation dipping or excessive dipping.The dipping can carry out at ambient temperature.

In the preferred example, it can be enough to remove the volatile materials (master being adsorbed in the aluminium oxide of maceration extract To be the solvent in maceration extract) under conditions of, it is dried.Specifically, the drying can be at 50-300 DEG C, preferably 80-300 DEG C, it is 120-300 DEG C more preferable at a temperature of carry out, the drying can carry out under normal pressure (that is, 1 standard atmospheric pressure, similarly hereinafter), It can also be carried out under conditions of reducing pressure.The duration of the drying can be according to dry temperature and dry pressure It is selected, generally can be 1-12 hours, preferably 2-6 hours.The drying can carry out in air atmosphere.

Oxidation of the conventional method by the oxide of group VIII metallic element and/or group VIII metallic element may be used The precursor of object is supported on carrier.For example, the method that co-precipitation may be used, is preparing aluminium oxide (alternatively, containing modified member The aluminium oxide of element) during, by the oxide carried on carrier of group VIII metallic element.

In a kind of more preferably embodiment, with oxide and/or Section VIII containing group VIII metallic element The maceration extract impregnated carrier of the precursor of the oxide of race's metallic element, and the carrier for being adsorbed with the maceration extract is done It is dry, there are the oxide and/or the carrier of the precursor to obtain load.

The type of the precursor of the oxide of the group VIII metallic element can be selected according to the solvent of maceration extract Select so that subject to the precursor of the oxide of group VIII metallic element can be dissolved in the solvent, such as can be selected from The oxalates of group VIII metallic element, the nitrate of group VIII metallic element, the sulfate of group VIII metallic element, The acetate of group VIII metal element, the chloride of group VIII metallic element, the carbonate of group VIII metallic element, The phosphoric acid of the subcarbonate of group VIII metal element, the hydroxide of group VIII metallic element, group VIII metallic element The water of salt, the molybdate of group VIII metallic element, the tungstates of group VIII metallic element and group VIII metallic element One or more of dissolubility compound.The specific example of the precursor of the oxide of the group VIII metallic element can To include but not limited to：Ferric nitrate, ferric sulfate, ferric acetate, nickel nitrate, nickel sulfate, nickel acetate, basic nickel carbonate, cobalt nitrate, sulphur One or more of sour cobalt, cobalt acetate, basic cobaltous carbonate, cobalt chloride, nickel chloride and ferric citrate.

The carrier for being adsorbed with the maceration extract can be dried under normal conditions, it is molten in maceration extract to remove Agent has the oxide and/or the carrier of precursor to obtain load.Usually, the drying can 50-300 DEG C, it is excellent Select 80-280 DEG C, it is 120-280 DEG C more preferable at a temperature of carry out, the drying can carry out under normal pressure, can also reduce It is carried out under conditions of pressure.The duration of the drying can be selected according to dry temperature and dry pressure, and one As can be 1-12 hours, preferably 2-6 hours.The drying can carry out in air atmosphere.

Can there are the oxide and/or the carrier of the precursor to roast under normal conditions load, to Obtain fischer-tropsch synthetic catalyst precursor.In the fischer-tropsch synthetic catalyst precursor, group VIII metallic element is substantially at it most High oxidation valence state.Usually, the roasting can be in 300-900 DEG C, preferably 350-800 DEG C, more preferable 400-600 DEG C of temperature The duration of lower progress, the roasting can be selected according to the temperature of roasting, typically 1-10 hours, preferably 2-6 hours.The roasting carries out in air atmosphere.

From the angle for the catalytic activity and activity stability for further increasing the catalyst finally prepared, preferably also wrap Include in supported on carriers auxiliary element, the auxiliary element be selected from alkali metal element and thulium (lanthanum, cerium, praseodymium and One or more of one or more of neodymium).The specific example of the auxiliary element may include but unlimited In：One or more of Li, Na, K and Ce.Preferably, the auxiliary element is one or both of Li, K and Ce More than.It is highly preferred that the auxiliary element is K and/or Ce.It is further preferred that the auxiliary element is Ce.It needs to illustrate It is, although auxiliary element is identical as the type possibility of modifying element of modified aluminas, in auxiliary element and modification When element is identical, even if carrier is using the carrier containing modifying element, it is still desirable in the carrier containing modifying element Upper extra load auxiliary element, vice versa.

The auxiliary element is on the basis of the load capacity on carrier makes by the total amount of catalyst precarsor, based on the element, institute The content for stating auxiliary element can be 0.1-10 weight %, preferably 1-8 weight %, more preferably 2-6 weight %.

Conventional method may be used auxiliary element is supported on carrier, such as infusion process.It can be by auxiliary element and Group VIII metal element is supported on carrier simultaneously, auxiliary element and group VIII metallic element may not be synchronize be supported On carrier.Preferably, auxiliary element and group VIII metallic element are supported on carrier simultaneously, at this point it is possible to using containing There is the precursor of the oxide of group VIII metallic element and/or the oxide of group VIII metallic element and contains auxiliary agent The maceration extract impregnated carrier of the compound of element, and the carrier for being adsorbed with maceration extract is dried and is roasted successively, to To catalyst precarsor.

The compound containing auxiliary element can be the common substance being dispersed in maceration extract that can dissolve, such as Can be nitrate, chloride, sulfate, acetate, oxalates, carbonate, bicarbonate and hydroxide in one kind or It is two or more.The specific example of the compound containing auxiliary element can include but is not limited to：Sodium nitrate, sodium chloride, sulphur Sour sodium, sodium acetate, sodium oxalate, sodium carbonate, sodium bicarbonate, lithium carbonate, lithium nitrate, lithium chloride, potassium nitrate, potassium chloride, potassium sulfate, One or more of potassium acetate, potassium oxalate, potassium carbonate, saleratus, manganese nitrate and manganese chloride.

When group VIII metallic element and optional auxiliary element are supported on carrier by the way of dipping, institute The number for stating dipping can be primary, or more than twice.It lives from the catalysis for further increasing the catalyst finally prepared Property and the angle of activity stability are set out, and are preferably impregnated more than twice.When being impregnated more than twice, it is impregnated every time Afterwards, preferably the carrier for being adsorbed with maceration extract is dried and is roasted successively.

The production method of low-carbon alkene according to the present invention in step S31, can carry out F- T synthesis under normal conditions Reaction.Preferably, Fischer-Tropsch synthesis charging can be in 200-400 DEG C, preferably 300-380 DEG C of item with fischer-tropsch synthetic catalyst It is contacted under part.The pressure that Fischer-Tropsch synthesis charging is contacted with fischer-tropsch synthetic catalyst can be 0.5-3MPa, excellent It is selected as 1-2.5MPa, the pressure is in terms of gauge pressure.

The production method of low-carbon alkene according to the present invention, Fischer-Tropsch synthesis can be connect in fixed bed reactors It touches, can also be contacted in a fluidized bed reactor, it can also be in the combination of fixed bed reactors and fluidized-bed reactor It is contacted.Preferably, hydrogen and carbon monoxide are contacted in a fluidized bed reactor with fischer-tropsch synthetic catalyst.

The production method of low-carbon alkene according to the present invention, in the F- T synthesis using previously described preferred embodiment When catalyst, even if at a high space velocity, hydrogen and carbon monoxide are contacted with catalyst, it is anti-also to obtain good catalysis Answer effect.Specifically, the volume space velocity of Fischer-Tropsch synthesis charging can be 5000-50000 hours¹, preferably 10000- 30000 hours^-1。

Conventional method may be used from F- T synthesis in step S41 in the production method of low-carbon alkene according to the present invention Low-carbon alkene, methane and carbon dioxide are isolated in product stream.As an example, condensation at low temperature may be used, to taking Support synthetic product logistics is detached, to respectively obtain low-carbon alkene, methane and carbon dioxide.

The methane isolated from Fischer-Tropsch synthetic logistics is sent by the production method of low-carbon alkene according to the present invention In step S11 and/or step S21, as steam reforming reaction and/or the charging of dry reforming reaction.It will be produced from F- T synthesis The carbon dioxide isolated in object logistics is made to be sent into step S21, the charging as dry reforming reaction.Low-carbon according to the present invention The production method of alkene by the way that steam reforming and dry reforming to be applied in combination, and will be detached from Fischer-Tropsch synthetic logistics The methane and carbon dioxide gone out recycles, and is effectively improved raw material availability, and significantly reduce greenhouse gases dioxy Change the discharge capacity of carbon.

The production method of low-carbon alkene according to the present invention, from the angle for further increasing raw material availability, preferably Further include unreacted hydrogen and/or carbon monoxide are isolated from Fischer-Tropsch synthetic logistics, and will at least partly hydrogen and/ Or at least partly carbon monoxide is sent into step S31, for preparing Fischer-Tropsch synthesis charging.It preferably, will be from F- T synthesis The hydrogen partial and/or part carbon monoxide cycle isolated in product stream are sent into step S31, for preparing F- T synthesis Reaction feed, and using remainder hydrogen and/or remainder carbon monoxide as periodic off-gases, outer discharge system.Usually, with On the basis of the total amount of the hydrogen and carbon monoxide isolated in Fischer-Tropsch synthetic logistics, for the hydrogen of cycle and an oxidation The amount of carbon can be 10-98%, preferably 15-98%.

According to the second aspect of the invention, the present invention provides a kind of low-carbon alkene production system, which includes water Steam reforming reaction unit, dry reforming reaction member, synthesis gas mixed cell, Fischer-Tropsch synthesis unit, Fischer-Tropsch synthesis Product separative element and cycling element.

Steam reforming reaction unit carries out steam reforming reaction, obtains water steaming for contacting methane with vapor Gas reformed syngas.The steam reforming reaction unit can be arranged conventional steam reforming reaction device and accordingly into Expect component, outlet member and control unit, so that methane can carry out reforming reaction with vapor, obtains with hydrogen and an oxygen Change carbon and makees steam reforming synthesis gas as main component.

Dry reforming reaction member is used to, by methane and carbon dioxide exposure, carry out dry reforming reaction, obtain dry weight and be integrated into Gas.The dry reforming reaction member can be arranged conventional dry reforming reactor and corresponding feed pieces, outlet member and Control unit so that methane and carbon dioxide can carry out reforming reaction, obtain using hydrogen and carbon monoxide as mainly at The dry reforming synthesis gas divided.

Synthesis gas mixed cell respectively with the steam reforming synthesis gas output port and dry weight of steam reforming unit The dry reforming synthesis gas output port of whole reaction member is connected to, for integrating the steam reforming synthesis gas and the dry weight It is mixed at gas, preparing, which becomes Fischer-Tropsch synthesis, feeds, and it is anti-that the Fischer-Tropsch synthesis fed to the F- T synthesis It answers in unit.The synthesis gas mixed cell can be arranged to be integrated into for accommodating and mixing steam reforming synthesis gas and dry weight The container of gas in a reservoir mixes steam reforming synthesis gas with dry reforming synthesis gas, to obtain F- T synthesis charging.Institute Pipe-line mixer can also be used by stating synthesis gas mixed cell, and vapor is directly lived again synthesis gas and dry reforming synthesis gas defeated It send in pipeline and is mixed, to obtain Fischer-Tropsch synthesis charging.The synthesis gas mixed cell can be arranged common each Kind control device, the mixed proportion for controlling steam reforming synthesis gas and dry reforming synthesis gas, to obtain meeting Fischer-Tropsch The Fischer-Tropsch synthesis of synthetic reaction hydrogen-carbon ratio is fed.

Fischer-Tropsch synthesis unit is provided with Fischer-Tropsch synthesis device, with the Fischer-Tropsch synthesis of synthesis gas mixed cell into Expect outlet, contacting, obtaining containing low-carbon alkene with fischer-tropsch synthetic catalyst for feeding the Fischer-Tropsch synthesis Fischer-Tropsch synthetic logistics.The Fischer-Tropsch synthesis device can be common various reactor types, specifically, the Fischer-Tropsch Synthesis reactor can be fixed bed reactors, or fluidized-bed reactor can also be fixed bed reactors and fluidisation The combination of bed reactor, preferably fluidized-bed reactor.

The Fischer-Tropsch synthesis unit is preferably additionally provided with reduction activation subelement, and the reduction activation subelement is used for Fischer-tropsch synthetic catalyst precursor is subjected to reduction activation, fischer-tropsch synthetic catalyst precursor is transformed into catalytic activity Fischer-tropsch synthetic catalyst.The reduction activation subelement can be by connecing fischer-tropsch synthetic catalyst precursor with reducibility gas It touches, to which fischer-tropsch synthetic catalyst precursor reduction activation is become fischer-tropsch synthetic catalyst.

In a preferred embodiment, the reduction activation subelement includes first gas storing and conveying device, Two gas storing and conveying devices, reducing gas control device and reduction activation reactor.

The first gas storing and conveying device is sent into reduction activation reaction for storing first gas, and by first gas In device.The first gas is the gaseous mixture of hydrogen or hydrogen and inert gas.The first gas storing and conveying device quilt It is set as being enough to store and conveys first gas.It can instruct according to prior art first gas storage conveying dress is arranged It sets, can store and convey first gas.The second gas storing and conveying device is for storing second gas, and by the Two gases are sent into reduction activation reactor, the second gas be gaseous hydrocarbon or in reduction temperature under reduction temperature The lower gaseous mixture for gaseous hydrocarbon and inert gas of degree.The composition of the first gas and the second gas above into Detailed description is gone, and will not be described here in detail.

The reducing gas control device is used to control the feeding of the gas type and gas of being sent into reduction activation reactor Amount.Specifically, when the reduction activation subelement is run, the reducing gas control device is arranged to first anti-to reduction activation It answers and inputs first gas in device, so that fischer-tropsch synthetic catalyst precursor is contacted with hydrogen carries out prereduction reaction, obtain prereduction Then catalyst inputs second gas into reduction activation reactor, so that the catalyst pre-reduction is contacted with second gas, Carry out reduction activation reaction.Conventional control element, such as various control valves may be used in the reducing gas control device, control System is sent into the gas type of reduction activation reactor and the feeding amount of gas.

The reduction activation reactor for accommodating fischer-tropsch synthetic catalyst precursor, and with first gas storing and conveying device It is connected to second gas storing and conveying device, so that fischer-tropsch synthetic catalyst precursor connects with first gas and second gas successively It touches, carries out reduction activation, obtain the fischer-tropsch synthetic catalyst with F- T synthesis catalytic activity.

The reduction activation reactor can be same reactor with Fischer-Tropsch synthesis device, i.e., in Fischer-Tropsch synthesis device The interior reduction activation for carrying out fischer-tropsch synthetic catalyst precursor.

The reduction activation reactor may not be same reactor, i.e. Fischer-Tropsch synthesis with Fischer-Tropsch synthesis device Device and reduction activation reactor are respective self-existent reactor.At this point, the reduction activation of the reduction activation reactor is urged Agent output port is set as being connected to the catalyst input port of the Fischer-Tropsch synthesis device, by reduction activation reactor The reduction activation catalyst of output is sent into the Fischer-Tropsch synthesis device.The reduction activation of reduction activation reactor can be urged Agent output port is connected to the catalyst input port of the Fischer-Tropsch synthesis device using transfer pipeline, and in transfer pipeline Upper setting control valve, when reduction activation reactor exports reduction activation catalyst, opening controlling valve, by reduction activation reactor Reduction activation catalyst output port be connected to the catalyst input port of Fischer-Tropsch synthesis device, by reduction activation catalyst It is sent into Fischer-Tropsch synthesis device.

Low-carbon alkene production system according to the present invention, the cycling element are used to detach Fischer-Tropsch synthesis product single Methane cycle that member is isolated be sent into one of steam reforming reaction unit and dry reforming reaction member, or both in, will The carbon dioxide recycle that Fischer-Tropsch synthesis product separative element is isolated is sent into dry reforming reaction member, optionally by Fischer-Tropsch The hydrogen and/or carbon monoxide cycle that synthetic reaction product separative element is isolated are sent into Fischer-Tropsch synthesis unit.

The cycling element, which can be arranged, is respectively used to connection Fischer-Tropsch synthesis product separative element and vapor weight The methane transfer pipeline of whole reaction member and dry reforming reaction member and the control valve being arranged on the methane transfer pipeline, It is respectively fed to steam reforming reaction unit with the methane for isolating Fischer-Tropsch synthesis product separative element and dry reforming is anti- It answers in unit.The cycling element can be arranged single for being connected to Fischer-Tropsch synthesis product separative element and dry reforming reaction The carbon dioxide transfer pipeline of member and the control valve being arranged on the carbon dioxide transfer pipeline, by Fischer-Tropsch synthesis The carbon dioxide of product separative element output is sent into dry reforming reaction member.

When Fischer-Tropsch synthesis product separative element also isolates hydrogen and carbon monoxide, the cycling element is preferably set It sets the transfer pipeline for being connected to Fischer-Tropsch synthesis product separative element and Fischer-Tropsch synthesis unit and is arranged in institute The control valve on transfer pipeline is stated, the hydrogen and/or carbon monoxide that Fischer-Tropsch synthesis product separative element is isolated It is sent into Fischer-Tropsch synthesis unit.Hydrogen and carbon monoxide can be sent into Fischer-Tropsch synthesis list by same transfer pipeline In member, hydrogen and carbon monoxide can also be respectively fed to by different transfer pipelines in Fischer-Tropsch synthesis unit, at this time Can be respectively set hydrogen delivery tube road and corresponding control valve and with carbon monoxide transfer pipeline and corresponding control valve Door.

Low-carbon alkene production system according to the present invention preferably further includes unstripped gas separative element, the unstripped gas separation Unit for isolating methane from the unstripped gas containing methane, the methane output port of the unstripped gas separative element respectively with institute State the methane feed input port of steam reforming reaction unit and the methane feed input terminal of the dry reforming reaction member Mouth connection, the methane isolated is respectively fed in steam reforming reaction unit and the dry reforming reaction member.

The unstripped gas separative element may be used conventional separation method and isolate methane from unstripped gas.In a kind of reality It applies in mode, the unstripped gas separative element isolates methane using pressure swing adsorption method from unstripped gas.It is more highly preferred in one kind Embodiment in, the unstripped gas separative element isolates methane using condensation at low temperature from unstripped gas.It is more excellent at this In the embodiment of choosing, can low-temperature condenser be set in unstripped gas separative element, unstripped gas is condensed, to isolate Methane in the unstripped gas.The low-temperature condenser can be conventional condenser, be not particularly limited.

Fig. 2 shows a kind of preferred embodiment of low-carbon alkene production system according to the present invention, below in conjunction with Fig. 2 into Row is described in detail.As shown in Fig. 2, the low-carbon alkene production system includes unstripped gas separative element I, steam reforming reaction list First II, dry reforming reaction member III, Fischer-Tropsch synthesis unit IV, Fischer-Tropsch synthetic separative element V and cycling element.

Unstripped gas A, which enters in unstripped gas separative element I, to be detached, and methane B is obtained.Methane B is respectively fed to vapor In reforming reaction unit II and dry reforming reaction member III, while vapor C is sent into steam reforming reaction unit II, So that methane carries out reforming reaction with vapor, steam reforming synthesis gas E is obtained.It is sent into dry reforming reaction member III Enter carbon dioxide D, so that methane carries out reforming reaction with carbon dioxide, obtains dry reforming synthesis gas F.Steam reforming is closed At gas E and dry reforming synthesis gas F mixing (preferably using pipe-line mixer), prepare as Fischer-Tropsch synthesis hydrogen-carbon ratio is met Fischer-Tropsch synthesis feeds G.Fischer-Tropsch synthesis charging G enters in Fischer-Tropsch synthesis unit IV, with fischer-tropsch synthetic catalyst Contact carries out Fischer-Tropsch synthesis.Fischer-Tropsch synthesis device in Fischer-Tropsch synthesis unit IV is in the temperature for producing low-carbon alkene Lower operation.The Fischer-Tropsch synthetic logistics H of Fischer-Tropsch synthesis unit IV output enter in Fischer-Tropsch synthetic separative element V into Row separation, obtains low-carbon alkene K, unreacted hydrogen and carbon monoxide, methane M and carbon dioxide N.Wherein, low-carbon alkene K is sent Go out system.

The hydrogen and carbon monoxide isolated can be recycled for preparing Fischer-Tropsch synthesis charging, can also be discharged outside and are System can also be part cycle for preparing Fischer-Tropsch synthesis charging, the outer discharge system of remainder.Preferably, such as Fig. 2 Shown, hydrogen and carbon monoxide L for cycle are mixed with steam reforming synthesis gas E and dry reforming synthesis gas F, for preparing Fischer-Tropsch synthesis feeds G；Remainder hydrogen and carbon monoxide are as the outer discharge systems of periodic off-gases Z.

The carbon dioxide N isolated is sent into dry reforming reaction member III, one of raw material as dry reforming reaction cycle It uses.The methane M isolated is respectively fed in steam reforming reaction unit II and dry reforming reaction member III anti-as reforming One of raw material answered recycles.

The present invention will be described in detail with reference to embodiments, but the range being not intended to limit the present invention.

In following embodiment, preparation example and comparative example, if not otherwise specified, pressure is gauge pressure.

In following embodiment, preparation example and comparative example, CO conversion ratios (X_CO)、CH₄SelectivityAnd C₂-C₄Hydro carbons Selectivity is (wherein,Indicate C₂-C₄Olefine selective,Indicate C₂-C₄Paraffin selectivity) pass through following public affairs respectively Formula is calculated：

Wherein, V₁、V₂Be illustrated respectively under the status of criterion, enter in certain period the unstripped gas of reaction system volume and Flow out the exhaust gas volumes of reaction system；

C_1,CO、C_2,COMole containing for CO in the unstripped gas of reaction system and the tail gas of outflow reaction system is indicated entry into respectively Amount；

n_conTo participate in the molal quantity of the CO reacted；

For the CH of generation₄Molal quantity；

For the C of generation₂-C₄The molal quantity of hydro carbons.

Preparation example 1-24 is used to prepare fischer-tropsch synthetic catalyst and evaluates its performance.

In following preparation example, specific surface area, hole hold and average pore size is measured according to nitrogen adsorption methods, specifically Ground, using N₂Adsorption isotherm is measured under 77K constant temperature, is then pressed BET formula and is calculated specific surface area and Kong Rong, and presses the side BJH Method calculates average pore size distribution；Particle diameter distribution is measured using laser particle analyzer.

In following preparation example, the content of each metallic element is used according to RIPP 132-92 in catalyst and catalyst precarsor (《Petrochemical analysis method (RIPP experimental methods)》, Yang Cui is surely equal to be compiled, Science Press, nineteen ninety September the 1st edition, 371- Page 379) specified in X-ray fluorescence spectra analysis method measure.When catalyst is measured, catalyst sample is stored in argon In gas atmosphere.

In following preparation example, CO₂- TPD and CO-TPD is all made of Mike's chemical adsorption instrument, using OMistar mass spectrographs as Detector on-line checking measures, wherein CO₂The signal that-TPD is 44 by mass spectrograph record nucleocytoplasmic ratio, CO-TPD are remembered by mass spectrograph Record the signal that nucleocytoplasmic ratio is 28.

In following preparation example, X-ray photoelectron spectroscopic analysis is in Thermo Scientific companies equipped with Thermo It is tested on the ESCALab250 type x-ray photoelectron spectroscopies of Avantage V5.926 softwares, excitaton source is monochromatization Al K α X-rays, energy 1486.6eV, power 150W, penetrating used in narrow scan can be 30eV, base vacuum when analysis test It is 6.5 × 10^-10Mbar, the peaks C1s (284.6eV) correction of electron binding energy simple substance carbon, in Thermo Avantage softwares Upper carry out data processing carries out quantitative analysis in analysis module using sensitivity factor method.

Preparation example 1

(1) preparation of carrier

Take γ-Al₂O₃(Sasol products, specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1) 200g, It is roasted 2 hours in 980 DEG C of air atmospheres, product of roasting is subjected to X-ray diffraction analysis (as shown in Figure 1), what determination obtained It is θ-Al₂O₃, specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1.

Five water zirconium nitrates are dissolved in 43g deionized waters, modified zirconium solution is made, 100.0g systems are added to modified zirconium solution Standby obtained θ-Al₂O₃, impregnated 2 hours in 25 DEG C of saturations.Then, the mixture that dipping obtains is placed in baking oven, in 120 DEG C And it is 5 hours dry in air atmosphere under normal pressure (1 standard atmospheric pressure, similarly hereinafter).By the substance being dried to obtain in 400 DEG C of air atmospheres Middle roasting 3 hours, obtains carrier.The carrier of preparation is subjected to X-ray fluorescence spectra analysis, is determined using the total amount of carrier as base Standard, based on the element, the content of Zr is 3 weight %.

(2) preparation of catalyst precarsor

Ferric citrate, potassium carbonate, cerium nitrate hexahydrate are added in 12mL deionized waters, heats and stirs in 50 DEG C of water-baths It mixes uniformly mixed, obtains maceration extract.The maceration extract for taking 50 volume %, into maceration extract add 15g carriers, in environment temperature (for 25 DEG C) it is saturated dipping 1 hour.Then, the mixture that dipping obtains is placed in baking oven, the air atmosphere under 120 DEG C and normal pressure Middle drying 5 hours.Substance will be dried to obtain to roast 3 hours in 400 DEG C of air atmospheres, obtain a leaching rear catalyst.

One leaching rear catalyst is added in remaining maceration extract, is impregnated 1 hour in environment temperature (for 25 DEG C) saturation.So Afterwards, the mixture that dipping obtains is placed in baking oven, it is 5 hours dry in air atmosphere under 120 DEG C and normal pressure.It will be dried to obtain Substance roasts 3 hours in 400 DEG C of air atmospheres, obtains catalyst precarsor.

(3) reduction activation of catalyst precarsor

Catalyst precarsor is fitted into fluidized-bed reactor, H is passed through into reactor₂, adjusting reactor pressure is The volume space velocity of 0.1MPa, hydrogen are 20000 hours^-1, the temperature of reactor is increased to 400 DEG C by 25 DEG C, and in the temperature Lower constant temperature 8 hours.Then, reactor is cooled to 200 DEG C, hydrogen is switched to ethane, and the volume space velocity of ethane is 15000 Hour^-1, after maintaining 12 hours, fischer-tropsch synthetic catalyst is obtained, the composition of the catalyst is shown in table 2 and table 4, CO₂-TPD It is listed in table 3 with CO-TPD test results.

(4) preparation of low-carbon alkene

After reduction activation, it is passed through synthesis gas into reactor, and the temperature of reactor is warming up to 340 DEG C, carries out Fischer-Tropsch synthesis, wherein the volume space velocity of synthesis gas is 30000 hours^-1, pressure is 1.5MPa (in terms of gauge pressure), synthesis gas For the gaseous mixture of hydrogen and carbon monoxide, consisting of H₂：CO=50：50 (molar ratios).In reaction process, online gas phase is utilized Chromatograph analyzes the composition for the reaction mixture gas that reactor exports, and reacts 50 hours and 200 hours results measured point It is not listed in table 5 and table 6.

Preparation example 2

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (1), γ-Al₂O₃It without roasting, but is directly impregnated with modified zirconium solution, to prepare carrier, wherein using the total amount of carrier as base Standard, based on the element, the content of Zr is 3 weight %.

Preparation example 3

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (1), θ- Al₂O₃It is not contacted with modified zirconium solution, but is directly used in step (2) and prepares catalyst precarsor.

Preparation example 4

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (2), Cerium nitrate hexahydrate is not used when preparing maceration extract.

Preparation example 5

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (2), leaching Stain is single-steeping, and dipping, dry and roasting condition are identical as preparation example 1, that is, use 6mL maceration extracts to be saturated impregnated carrier, And the mixture that dipping obtains is dried and is roasted successively, to obtain catalyst precarsor.

Preparation example 6

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (3), second Alkane is replaced with isometric ethylene.

Preparation example 7

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (1), with Modified zirconium solution contact is by γ-Al₂O₃With θ-Al₂O₃According to weight ratio 1：1 mixture being mixed to get.

Preparation example 8

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (1), change Become the dosage of five water zirconium nitrates, in the carrier of preparation, on the basis of the total amount of carrier, based on the element, the content of Zr is 1.5 weights Measure %.

Preparation example 9

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (1), change Become the dosage of five water zirconium nitrates, in the carrier of preparation, on the basis of the total amount of carrier, based on the element, the content of Zr is 8 weights Measure %.

Preparation example 10

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (3), lead to After hydrogen, do not continue to be passed through ethane, but directly carry out step (4), i.e., reduction activation is only with hydrogen, without using ethane.

Preparation example 11

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (3), second Alkane is replaced with isometric CO.

Preparation example 12

Catalyst is prepared using method identical with preparation example 1 and prepares low-carbon alkene, unlike, in step (3), no The operation of logical hydrogen is carried out, but leads to ethane directly into reactor, i.e., reduction activation is only with ethane, without using hydrogen.

Preparation example 13

Catalyst is prepared using method identical with preparation example 2 and prepares low-carbon alkene, unlike, in step (3), lead to After hydrogen, do not continue to be passed through ethane, but directly carry out step (4), i.e., reduction activation is only with hydrogen, without using ethane.

Preparation example 14

Catalyst is prepared using method identical with preparation example 2 and prepares low-carbon alkene, unlike, in step (3), second Alkane is replaced with isometric CO.

Preparation example 15

Catalyst is prepared using method identical with preparation example 3 and prepares low-carbon alkene, unlike, in step (3), lead to After hydrogen, do not continue to be passed through ethane, but directly carry out step (4), i.e., reduction activation is only with hydrogen, without using ethane.

Preparation example 16

Catalyst is prepared using method identical with preparation example 3 and prepares low-carbon alkene, unlike, in step (3), second Alkane is replaced with isometric CO.

Preparation example 17

(1) preparation of carrier

Take γ-Al₂O₃(Sasol products, specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1) 200g, It is roasted 1 hour in 1050 DEG C of air atmospheres, product of roasting is subjected to X-ray diffraction analysis, that determination obtains is θ-Al₂O₃, Specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1.

Magnesium nitrate is dissolved in 41g deionized waters, modified magnesium solution is made, 100.0g, which is added, to modified magnesium solution is prepared into θ-the Al arrived₂O₃, impregnated 2 hours in 25 DEG C of saturations.Then, the mixture that dipping obtains is placed in baking oven, in 200 DEG C and often It depresses 3 hours dry in air atmosphere.The substance being dried to obtain is roasted 1 hour in 800 DEG C of air atmospheres, obtains carrier. The carrier of preparation is subjected to X-ray fluorescence spectra analysis, is determined on the basis of the total amount of carrier, based on the element, the content of Mg is 6 Weight %.

(2) preparation of catalyst precarsor

Ferric nitrate, lithium carbonate, cerium nitrate hexahydrate are added in 12mL deionized waters, heating stirring is mixed in 50 DEG C of water-baths It closes uniformly, obtains maceration extract.The maceration extract for taking 50 volume % adds 15g carriers into maceration extract, in environment temperature (for 25 DEG C) Saturation dipping 1 hour.Then, the mixture that dipping obtains is placed in baking oven, it is dry in air atmosphere under 200 DEG C and normal pressure 3 hours.Substance will be dried to obtain to roast 2 hours in 600 DEG C of air atmospheres, obtain a leaching rear catalyst.

One leaching rear catalyst is added in remaining maceration extract, is impregnated 1 hour in environment temperature (for 25 DEG C) saturation.So Afterwards, the mixture that dipping obtains is placed in baking oven, it is 3 hours dry in air atmosphere under 200 DEG C and normal pressure.It will be dried to obtain Substance roasts 2 hours in 600 DEG C of air atmospheres, obtains catalyst precarsor.

(3) reduction activation of catalyst precarsor

Catalyst precarsor is fitted into fluidized-bed reactor, H is passed through into reactor₂With gaseous mixture (wherein, the argon of argon gas Gas is 10 in the molar ratio of hydrogen：1), adjustment reactor pressure is 0.1MPa, and the volume space velocity of hydrogen is 15000 hours^-1, will The temperature of reactor is increased to 350 DEG C, and constant temperature 8 hours at such a temperature by 25 DEG C.Then, reactor is cooled to 250 DEG C, Hydrogen is switched to ethane, and the volume space velocity of ethane is 10000 hours^-1, after maintaining 4 hours, fischer-tropsch synthetic catalyst, this is urged The composition of agent shows in table 2 and table 4, CO₂- TPD and CO-TPD test results are listed in table 3.

(4) preparation of low-carbon alkene

After reduction activation, it is passed through synthesis gas into reactor, the temperature of reactor is warming up to 340 DEG C, carries out expense Hold in the palm synthetic reaction, wherein the volume space velocity of synthesis gas is 30000 hours^-1, pressure is 5MPa (in terms of gauge pressure), and synthesis gas is hydrogen The gaseous mixture of gas and carbon monoxide, consisting of H₂：CO=50：50 (molar ratios).In reaction process, online gas-chromatography is utilized Instrument analyzes the composition for the reaction mixture gas that reactor exports, and reacts 50 hours and 200 hours results measured exist respectively It is listed in table 5 and table 6.

Preparation example 18

Catalyst is prepared using method identical with preparation example 17 and prepares low-carbon alkene, unlike, in step (1), γ-Al₂O₃It without roasting, but is directly impregnated with modified magnesium solution, to prepare carrier, wherein using the total amount of carrier as base Standard, based on the element, the content of Mg is 6 weight %.

Preparation example 19

(1) preparation of carrier

Take γ-Al₂O₃(Sasol products, specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1) 200g, It is roasted 4 hours in 780 DEG C of air atmospheres, product of roasting is subjected to X-ray diffraction analysis, that determination obtains is θ-Al₂O₃, Specific surface area, Kong Rong, average pore size and particle diameter distribution are as shown in table 1.

Potassium nitrate is dissolved in 53g deionized waters, modified potassium solution is made, 100.0g, which is added, to modified potassium solution is prepared into θ-the Al arrived₂O₃, impregnated 2 hours in 25 DEG C of saturations.Then, the mixture that dipping obtains is placed in baking oven, in 300 DEG C and often It presses 2 hours dry in air atmosphere under (1 standard atmospheric pressure, similarly hereinafter).The substance being dried to obtain is roasted in 500 DEG C of air atmospheres It burns 6 hours, obtains carrier.The carrier of preparation is subjected to X-ray fluorescence spectra analysis, is determined on the basis of the total amount of carrier, with The content of element meter, potassium is 2.5 weight %.

(2) preparation of catalyst precarsor

Ferric nitrate, potassium carbonate, cerium nitrate hexahydrate are added in 15mL deionized waters, heating stirring is mixed in 50 DEG C of water-baths It closes uniformly, obtains maceration extract.The maceration extract for taking 50 volume % adds 15g carriers into maceration extract, in environment temperature (for 25 DEG C) Saturation dipping 1 hour.Then, the mixture that dipping obtains is placed in baking oven, it is dry in air atmosphere under 280 DEG C and normal pressure 2 hours.Substance will be dried to obtain to roast 6 hours in 500 DEG C of air atmospheres, obtain a leaching rear catalyst.

One leaching rear catalyst is added in remaining maceration extract, is impregnated 1 hour in environment temperature (for 25 DEG C) saturation.So Afterwards, the mixture that dipping obtains is placed in baking oven, it is 2 hours dry in air atmosphere under 280 DEG C and normal pressure.It will be dried to obtain Substance roasts 6 hours in 500 DEG C of air atmospheres, obtains catalyst precarsor.

(3) reduction activation of catalyst precarsor

Catalyst precarsor is fitted into fluidized-bed reactor, H is passed through into reactor₂, adjusting reactor pressure is The volume space velocity of 0.15MPa, hydrogen are 10000 hours^-1, the temperature of reactor is increased to 500 DEG C by 25 DEG C, and in the temperature Lower constant temperature 6 hours.

Then, reactor is cooled to 350 DEG C, hydrogen is switched to gaseous mixture (wherein, ethane and the argon of ethane and argon gas The molar ratio of gas is 1：20), and the volume space velocity of ethane is 20000 hours^-1, after maintaining 4 hours, obtain F- T synthesis catalysis The composition of agent, the catalyst shows in table 2 and table 4, CO₂- TPD and CO-TPD test results are listed in table 3.

(4) preparation of low-carbon alkene

After reduction activation, it is passed through synthesis gas into reactor, and the temperature of reactor is warming up to 340 DEG C, carries out Fischer-Tropsch synthesis, wherein the volume space velocity of synthesis gas is 30000 hours^-1, pressure is 1MPa (in terms of gauge pressure), and synthesis gas is The gaseous mixture of hydrogen and carbon monoxide, consisting of H₂：CO=60：40 (molar ratios).In reaction process, online gas phase color is utilized Spectrometer analyzes the composition for the reaction mixture gas that reactor exports, the result difference reacted 50 hours and measured for 200 hours It is listed in table 5 and table 6.

Preparation example 20

Catalyst is prepared using method identical with preparation example 19 and prepares low-carbon alkene, unlike, nitre in step (2) Sour iron is replaced with cobalt nitrate.

Preparation example 21

Catalyst is prepared using method identical with preparation example 19 and prepares low-carbon alkene, unlike, nitre in step (2) Sour iron is replaced with nickel nitrate.

Preparation example 22

Catalyst is prepared using method identical with preparation example 19 and prepares low-carbon alkene, unlike, in step (3), With the gaseous mixture of isometric CO and argon gas, (wherein, the molar ratio of CO and argon gas is 1 to ethane：20) it replaces.

Preparation example 23

Catalyst is prepared using method identical with preparation example 19 and prepares low-carbon alkene, unlike, in step (2), When preparing maceration extract, potassium carbonate is not used, but accordingly improves the dosage of cerium nitrate hexahydrate.

Preparation example 24

Catalyst is prepared using method identical with preparation example 19 and prepares low-carbon alkene, unlike, in step (2), When preparing maceration extract, flowing water cerous nitrate is not used, but accordingly improves the dosage of potassium carbonate.

Table 1

Table 2 (on the basis of the total amount of catalyst)

Table 3

Table 4

¹：Fe is not detected₅C₂ ²：FeO and Fe is not detected₅C₂

Table 5

*：O/P is C₂-C₄Olefine selective (S_C2 ⁼ _-C4 ⁼) and C₂-C₄Paraffin selectivity (S_C2°_-C4°) ratio.

Table 6

*：On the basis of 50 hours corresponding datas

By preparation example 1 and preparation example 10-12, preparation example 2 and preparation example 13 and 14, preparation example 3 and preparation example 15 and 16, with And after preparation example 19 is compared with preparation example 22 as can be seen that catalyst precarsor is carried out prereduction with hydrogen, then used in also It is that gaseous hydrocarbon carries out reduction activation under former activation temperature, the catalysis that can significantly improve finally formed reduction activation catalyst is lived Property, it can especially significantly improve the selectivity for low-carbon alkene.By preparation example 1 and preparation example 2, preparation example 17 and preparation example 18 It is compared as can be seen that using θ-Al₂O₃The catalytic activity of fischer-tropsch synthetic catalyst can be significantly improved.

Embodiment 1-6 is used to illustrate the low-carbon alkene production method and production system of the present invention.

Embodiment 1

The present embodiment use Fig. 2 shows low-carbon alkene production system, including unstripped gas separative element I, steam reforming It reaction member II, dry reforming reaction member III, Fischer-Tropsch synthesis unit IV, Fischer-Tropsch synthetic separative element V and follows Ring element.Concrete technology flow process is as follows.

(1) it is 220kmol/h using flow and shale gas that pressure is 2.0MPa is sent into unstripped gas separation as unstripped gas A Cryogenic condensation separation, removing sulphur, carbon and other impurity are carried out in unit I, the mass content for obtaining sulphur is less than 1ppm methane B.

Methane B is divided into two strands through current divider, is respectively fed to steam reforming reaction unit II and dry reforming reaction member In III.

(2) by first strand of methane and flow is 120kmol/h, temperature is 370 DEG C and pressure is 3MPa middle pressure vapor C After mixing, it is 600 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of steam reforming reaction unit II In, reforming reaction is carried out, steam reforming synthesis gas E is obtained.Wherein, the molar ratio of methane and vapor is 1：3, in reactor The catalyst of filling is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 10 weight %, Al₂O₃ For α-Al₂O₃), the temperature in catalyst bed is 900 DEG C, and the pressure in reactor is 3MPa, with the total amount of methane and vapor Meter, volume space velocity is 50000h when gas^-1。

(3) second strand of methane is mixed with flow is 100kmol/h, temperature is 370 DEG C and pressure is 2MPa carbon dioxide D After conjunction, it is 600 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of dry reforming reaction member III, is carried out Reforming reaction obtains dry reforming synthesis gas F.Wherein, the molar ratio of methane and carbon dioxide is 1：1, that loads in reactor urges Agent is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 10 weight %, Al₂O₃For α- Al₂O₃), the temperature in catalyst bed is 750 DEG C, and the pressure in reactor is 2MPa, in terms of the total amount of methane and vapor, Volume space velocity is 80000h when gas^-1。

(4) steam reforming synthesis gas E and dry reforming synthesis gas F are mixed, it is 2.1 that preparing, which becomes hydrogen-carbon ratio,：1 Fischer-Tropsch Synthetic reaction feeds G.Fischer-Tropsch synthesis charging G is sent into the Fischer-Tropsch synthesis device of Fischer-Tropsch synthesis unit IV (for stream Fluidized bed reactor) in, it is contacted with fischer-tropsch synthetic catalyst (fischer-tropsch synthetic catalyst prepared for preparation example 1), carries out Fischer-Tropsch conjunction At reaction.Wherein, the temperature in reactor is 340 DEG C, and the pressure in reactor is 1MPa, on the basis of the total amount of synthesis gas, Volume space velocity is 30000h when gas^-1。

(5) the Fischer-Tropsch synthetic logistics H of Fischer-Tropsch synthesis unit IV outputs is sent into Fischer-Tropsch synthetic separation list It is detached in first V.The flow of separation is：Gas-liquid separation is carried out first, obtains low-carbon alkene K and gaseous product；Then, make gas Body product is by cryogenic separation, to remove carbon dioxide therein；Then, the gaseous product for having isolated carbon dioxide is carried out Cryogenic separation obtains methane and unreacted hydrogen and carbon monoxide.

By discharge system outside low-carbon alkene K；The carbon dioxide N cycles isolated are sent into dry reforming reaction member III； The methane M isolated is respectively fed in steam reforming reaction unit II and dry reforming reaction member III；The hydrogen that will be isolated A part of L of gas and carbon monoxide cycles are sent into Fischer-Tropsch synthesis unit IV, and remainder is discharged outside as periodic off-gases Z is System, wherein on the basis of the total amount of the hydrogen and carbon monoxide isolated, the hydrogen of cycle and the amount of carbon monoxide L are 98%. In reaction process, using on-line gas chromatography to the group of the gas-phase product logistics of the reactor discharge of Fischer-Tropsch synthesis unit At being analyzed, 50 hours results measured of reaction are listed in table 7.System totality water consume, CO2 emissions and energy Amount efficiency is listed in table 8.

Comparative example 1

The fischer-tropsch synthetic catalyst that this comparative example uses is identical as the fischer-tropsch synthetic catalyst that embodiment 1 uses.

This comparative example use system shown in FIG. 1, including sequentially connected water-coal-slurry preparation unit I, coal gasification unit II, WGS unit III, purified synthesis gas unit IV, F- T synthesis unit V and low-carbon alkene separative element VI.Concrete technology Flow is as follows.

By fine coal A (for by solid material coal (Inner Mongol production lignite), through fine coal obtained from crushing and screening, (grain size is Water-coal-slurry C 10mm)) is made in water-coal-slurry preparation unit I for the water B of 360t/h with the flow of 360t/h and flow, by water coal Slurry C delivers into coal gasification unit II, under conditions of temperature is 1300 DEG C and pressure is 3MPa, is reacted with oxygen D and generates coal Gasify crude synthesis gas E.Molar ratios of the coal gasification crude synthesis gas E through WGS unit III adjustment hydrogen and carbon monoxide be 2：1, then through synthesis gas clean unit IV removing sour gas and sulfide M, it is purified synthesis gas, wherein hydrogen and an oxygen The molar ratio for changing carbon is 2.1：1.By obtained decontaminating syngas be conveyed into F- T synthesis unit V in fluidized-bed reactor into Row Fischer-Tropsch synthesis generates the fischer-tropsch reaction product N of olefin-containing (Fischer-Tropsch synthesis condition is with embodiment 1).Fischer-tropsch reaction Product N isolates low-carbon alkene K through low-carbon alkene separative element VI, the carbon dioxide H and methane G that F- T synthesis unit V is generated Then outer row, a part of unreacted synthesis gas are recycled back to expense (on the basis of the total amount for the synthesis gas isolated, content 98%) Synthesis unit V is held in the palm, the unreacted synthesis gas of another part is as periodic off-gases Z discharge systems.

Comparative example 2

Low-carbon alkene is prepared using method same as Example 1, unlike, it is not provided with dry reforming reaction member III, Methane (including fresh methane and cycle methane), which fully enters in steam reforming reaction unit II, carries out reforming reaction.

Comparative example 3

Low-carbon alkene is prepared using method same as Example 1, unlike, it is not provided with steam reforming reaction unit II, methane (including fresh methane and cycle methane), which fully enters in dry reforming reaction member III, carries out reforming reaction.

Embodiment 2

Low-carbon alkene is prepared using method same as Example 1, unlike, the fischer-tropsch synthetic catalyst used is system Fischer-tropsch synthetic catalyst prepared by standby example 2.

Embodiment 3

Low-carbon alkene is prepared using method same as Example 1, unlike, the fischer-tropsch synthetic catalyst used is system Fischer-tropsch synthetic catalyst prepared by standby example 10.

Embodiment 4

Low-carbon alkene is prepared using method same as Example 1, unlike, the fischer-tropsch synthetic catalyst used is system Fischer-tropsch synthetic catalyst prepared by standby example 11.

Embodiment 5

The present embodiment uses reaction system shown in Fig. 2, the expense that the fischer-tropsch synthetic catalyst used is prepared for preparation example 17 Tropsch synthesis catalyst.Concrete technology flow process is as follows.

(1) it is 500kmol/h using flow and oven gas gas that pressure is 3.0MPa is sent into raw material qi leel as unstripped gas A From cryogenic condensation separation, removing sulphur, carbon and other impurity is carried out in unit I, the mass content for obtaining sulphur is less than 1ppm methane B.

(2) by first strand of methane and flow is 240kmol/h, temperature is 370 DEG C and pressure is 3MPa middle pressure vapor C After mixing, it is 700 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of steam reforming reaction unit II In, reforming reaction is carried out, steam reforming synthesis gas E is obtained.Wherein, the molar ratio of methane and vapor is 1：2, in reactor The catalyst of filling is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 10 weight %, Al₂O₃ For α-Al₂O₃), the temperature in catalyst bed is 900 DEG C, and the pressure in reactor is 3MPa, with the total amount of methane and vapor Meter, volume space velocity is 50000h when gas^-1。

(3) second strand of methane is mixed with flow is 200kmol/h, temperature is 370 DEG C and pressure is 2MPa carbon dioxide D After conjunction, it is 600 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of dry reforming reaction member III, is carried out Reforming reaction obtains dry reforming synthesis gas F.Wherein, the molar ratio of methane and carbon dioxide is 1：1.5, it loads in reactor Catalyst is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 10 weight %, Al₂O₃For α- Al₂O₃), the temperature in catalyst bed is 750 DEG C, and the pressure in reactor is 2MPa, in terms of the total amount of methane and vapor, Volume space velocity is 100000h when gas^-1。

(4) steam reforming synthesis gas E and dry reforming synthesis gas F are mixed, it is 2.2 to prepare as hydrogen-carbon ratio is met：1 Fischer-Tropsch synthesis feeds G.Fischer-Tropsch synthesis charging G is sent into the Fischer-Tropsch synthesis device of Fischer-Tropsch synthesis unit IV It in (for fluidized-bed reactor), is contacted with fischer-tropsch synthetic catalyst, carries out Fischer-Tropsch synthesis.Wherein, the temperature in reactor It it is 340 DEG C, the pressure in reactor is 1.5MPa, and on the basis of the total amount of synthesis gas, volume space velocity is 30000h when gas^-1。

By discharge system outside low-carbon alkene K；The carbon dioxide N cycles isolated are sent into dry reforming reaction member III； The methane M isolated is respectively fed in steam reforming reaction unit II and dry reforming reaction member III；The hydrogen that will be isolated A part of L of gas and carbon monoxide cycles are sent into Fischer-Tropsch synthesis unit IV, and remainder is discharged outside as periodic off-gases Z is System, wherein on the basis of the total amount of the hydrogen and carbon monoxide isolated, the hydrogen of cycle and the amount of carbon monoxide L are 20%. In reaction process, tail gas composition is analyzed using on-line gas chromatography, 50 hours results measured of reaction arrange in table 7 Go out.Device totality water consume, CO2 emissions and energy efficiency are listed in table 8.

Embodiment 6

The present embodiment uses reaction system shown in Fig. 2, the expense that the fischer-tropsch synthetic catalyst used is prepared for preparation example 19 Tropsch synthesis catalyst.Concrete technology flow process is as follows.

(1) it is 150kmol/h using flow and oven gas gas that pressure is 1MPa is sent into unstripped gas separation as unstripped gas A Cryogenic condensation separation, removing sulphur, carbon and other impurity are carried out in unit I, the mass content for obtaining sulphur is less than 1ppm methane B.

(2) by first strand of methane and flow is 300kmol/h, temperature is 450 DEG C and pressure is 3MPa middle pressure vapor C After mixing, it is 700 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of steam reforming reaction unit II In, reforming reaction is carried out, steam reforming synthesis gas E is obtained.Wherein, the molar ratio of methane and vapor is 1：1, in reactor The catalyst of filling is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 15 weight %, Al₂O₃ For α-Al₂O₃), the temperature in catalyst bed is 900 DEG C, and the pressure in reactor is 1MPa, with the total amount of methane and vapor Meter, volume space velocity is 100000h when gas^-1。

(3) second strand of methane is mixed with flow is 150kmol/h, temperature is 450 DEG C and pressure is 3MPa carbon dioxide D After conjunction, it is 700 DEG C that the temperature of mixture, which is increased, subsequently into the fixed bed reactors of dry reforming reaction member III, is carried out Reforming reaction obtains dry reforming synthesis gas F.Wherein, the molar ratio of methane and carbon dioxide is 1：1, that loads in reactor urges Agent is Ni/Al₂O₃(on the basis of the total amount of catalyst, based on the element, the content of Ni is 12 weight %, Al₂O₃For α- Al₂O₃), the temperature in catalyst bed is 750 DEG C, and the pressure in reactor is 2MPa, in terms of the total amount of methane and vapor, Volume space velocity is 80000h when gas^-1。

(4) steam reforming synthesis gas E and dry reforming synthesis gas F are mixed, it is 1.5 to prepare as hydrogen-carbon ratio is met：1 Fischer-Tropsch synthesis feeds G.Fischer-Tropsch synthesis charging G is sent into the Fischer-Tropsch synthesis device of Fischer-Tropsch synthesis unit IV It in (for fluidized-bed reactor), is contacted with fischer-tropsch synthetic catalyst, carries out Fischer-Tropsch synthesis.Wherein, the temperature in reactor It it is 360 DEG C, the pressure in reactor is 2.5MPa, and on the basis of the total amount of synthesis gas, volume space velocity is 20000h when gas^-1。

By discharge system outside low-carbon alkene K；The carbon dioxide N cycles isolated are sent into dry reforming reaction member III； The methane M isolated is respectively fed in steam reforming reaction unit II and dry reforming reaction member III；The hydrogen that will be isolated A part of L of gas and carbon monoxide cycles are sent into Fischer-Tropsch synthesis unit IV, and remainder is discharged outside as periodic off-gases Z is System, wherein on the basis of the total amount of the hydrogen and carbon monoxide isolated, the hydrogen of cycle and the amount of carbon monoxide L are 15%. In reaction process, tail gas composition is analyzed using on-line gas chromatography, 50 hours results measured of reaction arrange in table 7 Go out.Device totality water consume, CO2 emissions and energy efficiency are listed in table 8.

Table 7

Table 8

	Water consume (ton/ton_{Low-carbon alkene})	CO2 emission (ton/ton_{Low-carbon alkene})	Energy efficiency (%)
				Embodiment 1	15	0.5	56
Comparative example 1	20	6.2	36
				Comparative example 2	21	4.2	41
Comparative example 3	19	0.6	46
				Embodiment 5	19	1.2	48
Embodiment 6	17	1.8	47

Note：The calorific value of the low-carbon alkene of energy efficiency=finally go out device/into the coal electricity vapor catalyst solvent of device The comprehensive energy consumption of the sum of the calorific value of equal raw materials, the i.e. calorific value of gained low-carbon alkene/produce needed for these low-carbon alkenes.Wherein, comprehensive It includes raw material calorific value and public work energy consumption to close energy consumption, includes mainly：Bunker coal and feed coal calorific value, device technique motor Pump institute's consuming electric power, the indirect energy consumptions such as recirculated cooling water, boiler feedwater, plant air, instrument air, fresh water.

Table 8 the result shows that, the present invention is by combining methane vapor reforming technique and methane dry reforming technique, to dioxy Change carbon and methane both greenhouse gases are used simultaneously, is allowed to be changed into the product with high added value, reduces greenhouse Gas discharges, and significantly improves resource, the energy utilization rate of integrated artistic.

The preferred embodiment of the present invention has been described above in detail, and still, the present invention is not limited thereto.In the skill of the present invention In art conception range, technical scheme of the present invention can be carried out a variety of simple variants, including each technical characteristic with it is any its Its suitable method is combined, and it should also be regarded as the disclosure of the present invention for these simple variants and combination, belongs to Protection scope of the present invention.

Claims

1. a kind of production method of low-carbon alkene, this approach includes the following steps：

S31, will at least partly steam reforming synthesis gas and at least partly dry reforming synthesis gas mix, with prepare obtain Fischer-Tropsch close At reaction feed, Fischer-Tropsch synthesis charging is connect under the reaction temperature of production low-carbon alkene with fischer-tropsch synthetic catalyst It touches, obtains Fischer-Tropsch synthetic logistics；

S41, low-carbon alkene, methane and carbon dioxide are isolated from the Fischer-Tropsch synthetic logistics, the methane that will be isolated Be sent into one of S11 and S21, or both in, will the carbon dioxide that isolated be sent into S21 in.

2. according to the method described in claim 1, wherein, in S11, the molar ratio of methane and vapor is 1：0.5-4；

Preferably, methane is contacted with vapor under conditions of temperature is 700-950 DEG C and pressure is 0.1-5MPa, institute Pressure is stated in terms of gauge pressure；

It is highly preferred that the steam reforming reaction carries out in fixed bed reactors, in terms of the total amount of methane and vapor, into Volume space velocity is preferably 10000-100000 hours when the gas of material^-1。

3. according to the method described in claim 1, wherein, in S21, the molar ratio of methane and carbon dioxide is 1：0.5-5；

Preferably, methane is contacted with carbon dioxide under conditions of temperature is 600-800 DEG C and pressure is 0.1-5MPa, The pressure is in terms of gauge pressure；

It is highly preferred that the dry reforming reaction carries out in fixed bed reactors, and in terms of the total amount of methane and carbon dioxide, charging Gas when volume space velocity be preferably 10000-100000 hours^-1。

4. according to the method described in claim 1, wherein, in S31, the reaction temperature for producing low-carbon alkene is 200-400 DEG C, pressure Preferably 0.5-3MPa, the pressure is in terms of gauge pressure；

Preferably, in the Fischer-Tropsch synthesis charging, the molar ratio of hydrogen and carbon monoxide is 0.4-3：1, preferably 1.5- 2.2：1；

Preferably, the contact carries out in a fluidized bed reactor, and the volume space velocity of Fischer-Tropsch synthesis charging is preferably 5000- 50000 hours¹。

5. method according to claim 1 or 4, wherein the fischer-tropsch synthetic catalyst contains carrier and is supported on institute The group VIII metallic element on carrier is stated, the carrier is aluminium oxide, and the valence state of at least partly group VIII metallic element is Less than the highest oxidation valence state of the metallic element, the group VIII metallic element is preferably one kind or two in Fe, Co and Ni Kind or more, more preferably Fe.

6. according to the method described in claim 5, wherein, the group VIII metallic element is Fe, the F- T synthesis is catalyzed In the x-ray photoelectron spectroscopy spectrogram of agent, there is the spectral peak corresponding to FeO and correspond to Fe₅C₂Spectral peak；

Preferably, based on the element, by the content of Fe that is determined corresponding to the spectral peak of FeO with by corresponding to Fe₅C₂Spectral peak determination Fe content ratio be 8-25：1, preferably 10-12：1；

Preferably, based on the element, on the basis of the total amount of the Fe determined by x-ray photoelectron spectroscopy, by the spectral peak corresponding to FeO With corresponding to Fe₅C₂Spectral peak determine Fe content be 30-99%, preferably not lower than 50%, be more preferably not less than 75%.

7. method according to claim 5 or 6, wherein the CO of the fischer-tropsch synthetic catalyst₂- TPD is desorbed in figure, 300-600 DEG C, preferably 320-500 DEG C, there are CO in more preferable 350-480 DEG C of temperature range₂Elevated temperature desorption peak；

Preferably, the CO of the fischer-tropsch synthetic catalyst₂- TPD is desorbed in figure, in 100-200 DEG C, preferably 150-190 DEG C of temperature There is also CO in section₂Low temperature desorption peaks；

Preferably, in the CO-TPD desorption figures of the fischer-tropsch synthetic catalyst, there are CO high in 300-700 DEG C of temperature range Warm desorption peaks；

It is highly preferred that in the CO-TPD desorption spectrograms of the fischer-tropsch synthetic catalyst, also deposited in 100-200 DEG C of temperature range In CO low temperature desorption peaks.

8. according to the method described in any one of claim 5-7, wherein with group VIII metal in fischer-tropsch synthetic catalyst On the basis of the total amount of element, based on the element, valence state is that the content of the group VIII metallic element less than its highest oxidation valence state is 30 weight % or more, preferably 50 weight % or more, more preferably 55 weight % or more, further preferably 60 weight % with On.

9. according to the method described in any one of claim 5-8, wherein the fischer-tropsch synthetic catalyst, which also contains, to be supported on The second metallic element on the carrier and/or third metallic element, second metallic element are selected from alkali metal element, alkali One or more of earth metal element and group ivb metallic element, preferably one kind in Li, K, Mg and Zr or two Kind or more, the third metallic element is selected from one or more of thulium, preferably Ce；

Preferably, on the basis of the total amount of fischer-tropsch synthetic catalyst, based on the element, the content of second metallic element is 0-15 Weight %, preferably 2-11 weight %, more preferably 5-7 weight %；The content of the third metallic element is 0-10 weight %, The content of preferably 0.5-6 weight %, more preferably 0.8-3 weight %, second metallic element and third metallic element is not It is 0 simultaneously；

It is highly preferred that the fischer-tropsch synthetic catalyst contains the second metallic element and the third metal member loaded on the carrier Element, second metallic element are preferably group ivb metallic element and/or alkali metal element, preferably group ivb metallic element And alkali metal element, more preferably Zr and K, the third metallic element is preferably Ce.

10. according to the method described in any one of claim 5-9, wherein on the basis of the total amount of fischer-tropsch synthetic catalyst, Based on the element, the content of the group VIII metallic element is 3-30 weight %, preferably 8-20 weight %, more preferably 10- 15 weight %.

11. according to the method described in any one of claim 1 and 5-10, wherein the fischer-tropsch synthetic catalyst is to pass through Obtained from catalyst precarsor is carried out reduction activation, the method for the reduction activation includes：

(1) catalyst precarsor is carried out to prereduction in first gas, obtains catalyst pre-reduction, the first gas is hydrogen The gaseous mixture of gas or hydrogen and inert gas, the catalyst precarsor contain carrier and are supported in the form of the oxide The valence state of group VIII metallic element on the carrier, the group VIII metallic element in the oxide is the metallic element Highest oxidation valence state, the carrier is aluminium oxide, the group VIII metallic element be preferably one kind in Fe, Co and Ni or It is two or more, more preferably Fe；

(2) catalyst pre-reduction in second gas is subjected to reduction activation, obtains reduction activation catalyst, described second Gas is to be gaseous hydrocarbon at a temperature of reduction activation or be the mixed of gaseous hydrocarbon and inert gas at a temperature of reduction activation Gas is closed, the reduction activation carries out at a temperature of 150-500 DEG C.

12. according to the method for claim 11, wherein the prereduction carries out at a temperature of 200-600 DEG C, preferably exists It is carried out at a temperature of 300-550 DEG C；

Preferably, in terms of gauge pressure, it is 0-3MPa, preferably 0.1-1MPa to carry out the pressure in the reactor of prereduction；；

It is highly preferred that in terms of hydrogen, the volume space velocity of the first gas is 5000-30000 hours^-1, preferably 10000- 20000 hours^-1；

It is further preferred that the duration of the prereduction is 1-20 hours, preferably 2-10 hours.

13. method according to claim 11 or 12, wherein it is gaseous state that the second gas, which is at a temperature of reduction activation, Hydrocarbon and inert gas gaseous mixture；

Preferably, the inert gas be the molar ratio of gaseous hydrocarbon at a temperature of reduction activation be 1-200：1, preferably 15-30：1.

14. according to the method described in any one of claim 11-13, wherein described is gaseous state at a temperature of reduction activation Hydrocarbon be selected from be at a temperature of reduction activation gaseous alkane and at a temperature of reduction activation be in gaseous alkene one Kind is two or more, is preferably selected from C₁-C₄Alkane and C₂-C₄One or more of alkene, be more preferably selected from One or more of methane, ethane, ethylene, propylene, propane, butane and butylene.

15. according to the method described in any one of claim 11-14, wherein temperature of the reduction activation at 180-450 DEG C Degree is lower to carry out, and is preferably carried out at a temperature of 200-400 DEG C；

Preferably, in terms of gauge pressure, it is 0-2.5MPa, preferably 0.1-2MPa to carry out the pressure in the reactor of reduction activation；

It is highly preferred that be in terms of gaseous hydrocarbon at a temperature of reduction activation, the volume space velocity of the second gas is 5000- 30000 hours^-1, preferably 10000-20000 hours^-1；

It is further preferred that the duration of the reduction activation is 1-20 hours, preferably 4-12 hours.

16. according to the method described in any one of claim 11-15, wherein the first gas and the second gas In inert gas it is identical or different, respectively be selected from one or more of nitrogen and group 0 element gas, preferably respectively From for nitrogen and/or argon gas.

17. according to the method described in any one of claim 11-16, wherein on the basis of the total amount of catalyst precarsor, with The content of element meter, the group VIII metallic element is 3-30 weight %, preferably 8-20 weight %, more preferably 10-15 Weight %.

18. according to the method described in any one of claim 11-17, wherein the catalyst precarsor, which also contains, to be supported on The second metallic element on the carrier and/or third metallic element, second metallic element are selected from alkali metal element, alkali One or more of earth metal element and group ivb metallic element, preferably one kind in Li, K, Mg and Zr or Two or more, the third metallic element is selected from one or more of thulium, preferably Ce；

Preferably, on the basis of the total amount of catalyst precarsor, based on the element, the content of second metallic element is 0-15 weights Measure %, preferably 2-11 weight %, more preferably 5-7 weight %；The content of the third metallic element is 0-10 weight %, excellent It is selected as 0.5-6 weight %, more preferably 0.8-3 weight %, the content of second metallic element and the third metallic element Content difference when be 0；

It is highly preferred that the catalyst precarsor contains the second metallic element and the third metallic element loaded on the carrier, Second metallic element is preferably group ivb metallic element and/or alkali metal element, preferably group ivb metallic element and Alkali metal element, more preferably Zr and K, the third metallic element is preferably Ce.

19. according to the method described in any one of claim 11-18, wherein it includes following that the catalyst precarsor, which uses, It is prepared by the method for step：By the compound of the metallic element containing group VIII and optionally containing the compound loaded of auxiliary element On carrier, the carrier is roasted, obtains catalyst precarsor, the carrier is aluminium oxide, described containing group VIII gold The compound for belonging to element is the predecessor of the oxide of group VIII metallic element and/or the oxide of group VIII metallic element Object, the auxiliary element be selected from one or more of alkali metal element and thulium, preferably Li, K and One or more of Ce, more preferably K and/or Ce；

Preferably, the auxiliary element and the group VIII metallic element are loaded on the carrier simultaneously.

20. according to the method for claim 19, wherein temperature of the roasting at 300-900 DEG C, preferably 400-600 DEG C The duration of lower progress, the roasting is preferably 1-10 hours.

21. the method according to claim 19 or 20, wherein at least partly carrier is the aluminium oxide containing modifying element, The modifying element be selected from one or more of alkali metal element, alkali earth metal and group ivb metallic element, Preferably one or more of K, Mg and Zr；

Preferably, on the basis of the total amount of the carrier, based on the element, the content of the modifying element is 0.1-15 weight %, Preferably 1.5-8 weight %.

22. according to the method for claim 21, wherein the preparation method of the aluminium oxide containing modifying element includes：With containing The aluminium oxide for being adsorbed with maceration extract is dried and is roasted successively by the maceration extract oxide impregnation aluminium for having the compound containing modifying element It burns, obtains the aluminium oxide containing modifying element, the drying preferably carries out at a temperature of 50-300 DEG C, and the drying continues Time is preferably 1-12 hours, and the roasting preferably carries out at a temperature of 300-900 DEG C, and the duration of the roasting is preferred It is 0.5-8 hours.

23. according to the method described in any one of claim 5-22, wherein the aluminium oxide contains θ-aluminium oxide；

Preferably, on the basis of the total amount of aluminium oxide in catalyst, the content of the θ-aluminium oxide is 50 weight % or more；

It is highly preferred that the aluminium oxide is θ-aluminium oxide.

24. according to the method described in any one of claim 5-23, wherein what the aluminium oxide use included the following steps It is prepared by method：By γ-Al₂O₃At a temperature of 700-1050 DEG C, roasted in air atmosphere, the roasting it is lasting when Between preferably 0.5-5 hours.

25. according to the method described in claim 1, wherein, this method further includes being isolated not from Fischer-Tropsch synthetic logistics The hydrogen and/or carbon monoxide of reaction, will at least partly hydrogen and/or at least partly carbon monoxide cycle for prepare Fischer-Tropsch conjunction At reaction feed.

26. according to the method described in claim 1, wherein, this method further includes S10, in S10, from the raw material containing methane The methane isolated in gas, the unstripped gas are preferably selected from shale gas, coal bed gas, natural gas, refinery gas and oven gas It is one or more kinds of；

Preferably, methane is isolated from the unstripped gas using condensation at low temperature.

27. according to the method described in any one of claim 1,25 and 26, wherein adopted in the methane and S21 that are used in S11 The weight ratio of methane is 1：0.8-1.5, preferably 1：0.9-1.3.

28. a kind of low-carbon alkene production system, which includes steam reforming reaction unit, dry reforming reaction member, synthesis Gas mixed cell, Fischer-Tropsch synthesis unit, Fischer-Tropsch synthesis product separative element and cycling element,

The steam reforming reaction unit carries out steam reforming reaction, obtains water steaming for contacting methane with vapor Gas reformed syngas；

The dry reforming reaction member is used to, by methane and carbon dioxide exposure, carry out dry reforming reaction, obtain dry weight and be integrated into Gas；

The synthesis gas mixed cell is configured to for mixing the steam reforming synthesis gas with the dry reforming synthesis gas It is fed for Fischer-Tropsch synthesis, and the Fischer-Tropsch synthesis is fed in the Fischer-Tropsch synthesis unit；

The Fischer-Tropsch synthesis unit is provided with Fischer-Tropsch synthesis device, for feeding and Fischer-Tropsch the Fischer-Tropsch synthesis Synthetic catalyst contacts, and obtains the Fischer-Tropsch synthetic logistics containing low-carbon alkene；

The Fischer-Tropsch synthesis product separative element for the Fischer-Tropsch synthetic logistics to be detached, obtain methane, Carbon dioxide, low-carbon alkene, optional hydrogen and optional carbon monoxide；

The methane cycle that the cycling element is used to isolate Fischer-Tropsch synthesis product separative element is sent into steam reforming One of reaction member and dry reforming reaction member, or both in, Fischer-Tropsch synthesis product separative element is isolated Carbon dioxide recycle is sent into dry reforming reaction member, hydrogen that Fischer-Tropsch synthesis product separative element is isolated and/or Carbon monoxide cycle is sent into Fischer-Tropsch synthesis unit.

29. system according to claim 28, wherein the system further includes unstripped gas separative element, the raw material qi leel From unit for isolating methane from the unstripped gas containing methane, the methane output port of the unstripped gas separative element respectively with The methane feed of the methane feed input port of the steam reforming reaction unit and the dry reforming reaction member inputs Port is connected to, and the methane isolated is respectively fed in steam reforming reaction unit and the dry reforming reaction member；

Preferably, the unstripped gas separative element is provided with low-temperature condenser, for being condensed to the unstripped gas, with separation Go out the methane in the unstripped gas.

30. the system according to claim 28 or 29, wherein the Fischer-Tropsch synthesis unit further includes reduction activation Unit, the reduction activation subelement are used for the fischer-tropsch synthetic catalyst precursor reduction activation.

31. system according to claim 30, wherein the reduction activation subelement includes first gas storage conveying dress It sets, second gas storing and conveying device, reducing gas control device and reduction activation reactor,

The first gas storing and conveying device is sent into reduction activation reactor for storing first gas, and by first gas In, the first gas is hydrogen or is hydrogen and inert gas；

The second gas storing and conveying device is sent into reduction activation reactor for storing second gas, and by second gas In, the second gas is to be gaseous hydrocarbon under reduction temperature or is gaseous hydrocarbon and inert gas under reduction temperature Gaseous mixture,

The reducing gas control device is used to control the feeding amount of the gas type and gas of being sent into reduction activation reactor, When the reduction activation subelement operation, the reducing gas control device is arranged to first input hydrogen into reduction activation reactor Gas obtains catalyst pre-reduction, then to reduction so that fischer-tropsch synthetic catalyst precursor is contacted with hydrogen carries out prereduction reaction Second gas is inputted in activated reactor, so that the catalyst pre-reduction is contacted with second gas, carries out reduction activation reaction.

32. system according to claim 31, wherein it is described be at a temperature of reduction activation gaseous hydrocarbon be selected from also Under former activation temperature it is gaseous alkane and is one or more of gaseous alkene at a temperature of reduction activation, It is preferably selected from C₁-C₄Alkane and C₂-C₄One or more of alkene, be more preferably selected from methane, ethane, second One or more of alkene, propylene, propane, butane and butylene；

Preferably, the inert gas in the first gas and the second gas is identical or different, is preferably respectively and is selected from nitrogen One or more of gas and group 0 element gas, preferably respectively nitrogen and/or argon gas.

33. the system according to claim 31 or 32, wherein the reduction activation reactor is with Fischer-Tropsch synthesis device Same reactor, or

The reduction activation reactor and Fischer-Tropsch synthesis device are not same reactors, the reduction of the reduction activation reactor Activated catalyst output port is connected to the catalyst input port of the Fischer-Tropsch synthesis device, by reduction activation reactor The reduction activation catalyst of output is sent into the Fischer-Tropsch synthesis device.

34. according to the system described in any one of claim 28-33, wherein the Fischer-Tropsch synthesis device is fluid bed Reactor.