CN108101871B - Process method for preparing maleic anhydride by oxidizing n-butane - Google Patents
Process method for preparing maleic anhydride by oxidizing n-butane Download PDFInfo
- Publication number
- CN108101871B CN108101871B CN201611045756.3A CN201611045756A CN108101871B CN 108101871 B CN108101871 B CN 108101871B CN 201611045756 A CN201611045756 A CN 201611045756A CN 108101871 B CN108101871 B CN 108101871B
- Authority
- CN
- China
- Prior art keywords
- catalyst
- reaction
- butane
- molar ratio
- vanadium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D307/56—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D307/60—Two oxygen atoms, e.g. succinic anhydride
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Furan Compounds (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a process method for preparing maleic anhydride by oxidizing n-butane. N-butane, air and circulating tail gas are mixed, the obtained mixed reaction gas flows in parallel and sequentially passes through more than two reaction zones connected in series, and the mixed reaction gas is contacted with a vanadium-phosphorus oxide catalyst to react under the condition of oxidation reaction; each of said reaction zones, except the most downstream reaction zone, comprises more than two catalyst beds; wherein the molar ratio of P/V of the catalyst in the downstream reaction zone is lower than the molar ratio of P/V of the catalyst in the upstream reaction zone in the order of contact with the mixed reaction gas; and, in each of said reaction zones except the most downstream reaction zone, the P/V molar ratio in the downstream catalyst bed is higher than the P/V molar ratio in the upstream catalyst bed. The method can give full play to the activity of the catalyst, particularly in a tail gas recycling process, can make up for the influence of the reduction of the conversion rate caused by the reduction of the oxygen content in the raw materials, reduce reaction hot spots and improve the selectivity of products.
Description
Technical Field
The invention relates to a process method for preparing maleic anhydride by oxidizing n-butane, which can be used for a reaction process for preparing maleic anhydride by oxidizing n-butane by adopting a fixed bed process.
Background
Maleic anhydride is called maleic anhydride for short, and maleic anhydride is an important organic chemical raw material, is second only to phthalic anhydride and acetic anhydride, is the third largest organic anhydride in the world, and is widely used in the industries of petrochemical industry, food processing, medicines, building materials and the like. Specific applications include the manufacture of unsaturated polyester resins, alkyd resins, maleic acid (maleic acid), fumaric acid (fumaric acid), as well as pesticides, coatings, glass fiber reinforced plastics, lubricating oil additives, papermaking chemical additives, surfactants, and the like. The process for producing 1, 4-butanediol by esterification and low-pressure hydrogenation of maleic anhydride by a new method is disclosed, so that the 1, 4-butanediol, tetrahydrofuran and gamma-butyrolactone which are fine chemical intermediates with high added values are important raw materials, and the application field is rapidly expanded.
Benzene oxidation method and n-butane oxidation method are two main production methods for producing maleic anhydride, wherein benzene oxidation method is the earliest applied process, the reactor and catalyst technology are mature, but because the price of raw material benzene is relatively expensive, the generated environmental pollution is relatively serious, and the defects are gradually shown. The process for preparing maleic anhydride by the n-butane oxidation method of Monsanto company is industrialized for the first time in 1974, and the process has the advantages of low cost of raw materials, small environmental pollution and low manufacturing cost of maleic anhydride, and is a main route for global maleic anhydride production at present. The preparation of the maleic anhydride by the selective oxidation of n-butane can be divided into production processes such as a fixed bed, a fluidized bed, a moving bed and the like.
At present, in the production of maleic anhydride by oxidizing n-butane, the fixed bed process has become a main method for producing maleic anhydride due to high utilization rate of butane raw materials, stable product quality and simple and convenient operation. However, in the production process in a fixed bed mode, due to the characteristic of strong heat release of oxidation reaction, the reaction heat of the main reaction for generating maleic anhydride is 1236kJ/mol, and the side reaction for generating CO2The CO reaction heat is 2656kJ/mol and 1521kJ/mol respectively, so that the reaction heat is removed by adopting molten salt which is circulated in a jacket of a reactor from the outside in the industrial production, but hot spots still exist on the local part of the catalyst and are difficult to optimize and control, and the performance of the catalyst is adversely affected by the existence of the reaction hot spots, so that the stabilization of the hot spots in the reaction process becomes the key for controlling the reaction process, and further, the conversion rate of butane, the selectivity of maleic anhydride and the yield of the maleic anhydride product are directly affected by the height of the hot spots of a catalyst bed layerAnd stability of the catalyst.
On the other hand, in the process, n-butane and air are mixed and then enter a fixed bed reactor to react under the action of a VPO catalyst to generate a main product, namely maleic anhydride, wherein the n-butane conversion rate is 85 percent. The reaction product enters an absorption tower after being cooled, is absorbed and separated by solvent dibutyl phthalate, and is sent to an incinerator from the top of the tower for direct incineration, and the tail gas contains 15% of unreacted n-butane, so that the waste of the n-butane is caused. In order to recycle unreacted raw materials in tail gas and reduce environmental pollution, a plurality of production devices develop the improvement of tail gas recycling, Wuzheng is the recycling [ J ] petrochemical technology and application of the tail gas in the production process of maleic anhydride by n-butane oxidation method, 1 month in 2014, No. 32, No. 1 reports that the petroleum and natural gas chemical plant of China oil Tuoha oil field company carries out the improvement of the tail gas recycling technology on the production device of maleic anhydride by n-butane oxidation method of 2 ten thousand tons per year. The calculation result shows that the tail gas limit circulation rate of the device is 45.2%, the first technical transformation only realizes 15.0% of recycling, and the potential is still large. The gas phase composition of the feedstock in the off-gas recycle process will vary, in particular the volume fraction of oxygen will gradually decrease with increasing recycle ratio, and in the same case the n-butane conversion will decrease, which will therefore place greater demands on the catalyst performance, as shown below in the table for the equilibrium content of the reactor feed components in the off-gas recycle process.
TABLE 1 equilibrium content of reactor feed components in the Tail gas recycle Process
| Tail gas circulation ratio | Fresh air feed ratio | n-C4H10/v% | O2/v% | CO2/v% | CO/v% | N2/v% |
| 0.6 | 0.47 | 1.8 | 12.1 | 1.3 | 1.8 | 83.0 |
| 0.5 | 0.57 | 1.8 | 14.8 | 0.9 | 1.2 | 81.3 |
| 0.4 | 0.67 | 1.8 | 16.6 | 0.7 | 0.8 | 80.1 |
| 0.3 | 0.77 | 1.8 | 17.9 | 0.5 | 0.5 | 79.3 |
| 0.2 | 0.85 | 1.8 | 18.8 | 0.4 | 0.3 | 78.7 |
| 0.1 | 0.93 | 1.8 | 19.6 | 0.3 | 0.1 | 78.2 |
| 0 | 1.00 | 1.8 | 20.2 | 0.2 | 0 | 77.8 |
Note: the fresh air feeding ratio refers to the ratio of the fresh air feeding amount under the tail gas circulation process to the air feeding amount under the tail gas-free circulation process.
The vanadium phosphorus oxygen catalyst is considered to be the best industrial catalyst in the process of preparing maleic anhydride by oxidizing n-butane, the selective oxidation reaction of n-butane by the vanadium phosphorus oxygen catalyst is a typical representative of a large class of hydrocarbon selective oxidation reaction carried out according to a redox (Re-dox) mechanism, the process of chemical reaction relates to the transfer of 14 electrons, wherein the electron removal on 8 hydrogen atoms and the electron insertion on 3 oxygen atoms are included, the exploration of the reaction mechanism is always the hotspot of the research of the vanadium phosphorus oxygen catalyst, the vanadium phosphorus oxygen catalyst is a complex catalyst system, the physical property and the structure of the vanadium phosphorus oxygen catalyst have great relation with the preparation method, the physical property and the structure of the vanadium phosphorus oxygen catalyst have great influence on the catalytic performance, in 1985, Hodnet in CATAL. REV. -SCI.ENG,27(3) 373-424(1985) summarizes the preparation method of various precursors of the vanadium phosphorus oxygen catalyst for preparing maleic anhydride by oxidizing n-butane, and becomes the classic basis for the research of the vanadium phosphorus oxide catalyst.
Hodnett summarizes that the P/V ratio of the catalyst, the addition of the auxiliary agent, the activation method of the catalyst, and the like all have obvious effects on the performance of the catalyst.
B.K HODNETT conducted extensive studies on the effect of the P/V ratio in a vanadium phosphorus oxide catalyst on the properties and composition of the catalyst and the catalytic performance in applied Catalysis, 6 (1983)231-244, and the results showed that the P/V ratio of the catalyst had a significant effect on the estimated valence of vanadium in the catalyst, with the P/V ratio increasing from 0.94 to 1.07 and the average valence of vanadium in the catalyst decreasing from 4.97 to 4.04.
USP4,632,915 provides a method for preparing and activating a vanadium-phosphorus-oxygen catalyst, which comprises the steps of adding isobutanol, phosphoric acid (100%), vanadium pentoxide, lithium chloride and iron powder into a stirring reaction kettle with a reflux cooler under cooling, introducing hydrogen chloride gas, refluxing for more than 2.5 hours at 102 ℃ to obtain a catalyst precursor, drying, roasting and forming, wherein the activation process comprises the steps of firstly increasing the activation temperature of the catalyst from 230 ℃ to 280 ℃ in an air atmosphere containing 1.8% of water at a heating rate of 3 ℃/min, then adding n-butane with the molar content of 0.6% into the air atmosphere, continuously increasing the activation temperature to 400 ℃ at a heating rate of 1 ℃/min and keeping the temperature for 1 hour, then keeping the temperature for 5 hours in a nitrogen atmosphere, and finishing the activation. The performance of the activated catalyst is evaluated, and the reaction result is as follows: the conversion rate of butane is more than 78.1 percent, and the molar yield of the maleic anhydride is 54.5 percent.
USP4,855,459 provides a preparation method for preparing maleic anhydride by n-butane oxidation, which is carried out by adopting a method of diluting and filling inert silicon-aluminum balls and a catalyst, and the purposes of reducing the reaction hot spot temperature, improving the selectivity of the maleic anhydride and improving the yield of the maleic anhydride are achieved by diluting and filling the hot spot generating part of a reaction tube, and meanwhile, the stabilization period of the catalyst is prolonged, but the adverse factor is the addition of inert materials, so that the effective volume of a reactor is reduced, and the production efficiency is also reduced.
In the existing technology for preparing maleic anhydride by oxidizing n-butane through a fixed bed, catalysts with different activities are respectively filled in a reactor along the direction of reactant flow, so that the catalytic activity is changed along the feeding direction according to the reaction requirement when the catalysts are filled, the control of the oxidation reaction is realized, the cyclic utilization of reaction tail gas is realized, and the method for increasing the product yield is not reported so far.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a process method for preparing maleic anhydride by n-butane oxidation by a fixed bed method.
The invention relates to a process method for preparing maleic anhydride by oxidizing n-butane, which comprises the following steps:
n-butane, air and circulating tail gas are mixed, the obtained mixed reaction gas flows in parallel and sequentially passes through more than two reaction zones connected in series, and the mixed reaction gas is contacted with a vanadium-phosphorus oxide catalyst to react under the condition of oxidation reaction; each of said reaction zones, except the most downstream reaction zone, comprises more than two catalyst beds; wherein the molar ratio of P/V of the catalyst in the downstream reaction zone is lower than the molar ratio of P/V of the catalyst in the upstream reaction zone in the order of contact with the mixed reaction gas; and, in each of said reaction zones except the most downstream reaction zone, the P/V molar ratio in the downstream catalyst bed is higher than the P/V molar ratio in the upstream catalyst bed.
The process according to the invention, wherein in two adjacent reaction zones, the P/V molar ratio of the catalyst in the downstream reaction zone is generally between 0.01 and 0.15 units, preferably between 0.02 and 0.12 units, most preferably between 0.03 and 0.05 units lower than the P/V molar ratio of the catalyst in the upstream reaction zone.
In other reaction zones except the most downstream reaction zone, in two adjacent vanadium-phosphorus-oxygen catalyst bed layers, the P/V molar ratio of the downstream catalyst bed layer is generally higher than that of the upstream catalyst bed layer by 0.01-0.15 unit, preferably 0.02-0.12 unit, and most preferably 0.03-0.05 unit.
In the method of the present invention, the P/V molar ratio of the vanadium phosphorus oxide catalyst is generally 0.95 to 1.35, preferably 0.97 to 1.25.
In the process of the present invention, the mixed reaction gas of n-butane, air and recycled tail gas is preferably passed through 3 to 5 reaction zones, each reaction zone preferably comprising 2 to 3 beds of vanadium phosphorus oxide catalyst except the most downstream reaction zone. When three reaction zones are selected, two beds of vanadium phosphorus oxide catalyst are typically included in the first reaction zone and in the second reaction zone. According to the sequence of contact with the mixed reaction gas, in the first reaction zone, the P/V molar ratio of an upstream catalyst bed layer is 1.05-1.15, and the P/V molar ratio of a downstream catalyst bed layer is 1.15-1.25; in the second reaction zone, the P/V molar ratio of the upstream catalyst bed layer is 0.97-1.0, and the P/V molar ratio of the downstream catalyst bed layer is 1.0-1.05; the P/V molar ratio of the catalyst in the third reaction zone is 0.95-1.0. The packing technique of the vanadium phosphorus oxide catalyst in each reaction zone is a conventional operation method in the field.
In the method, the vanadium element in the catalyst is quantitatively analyzed by a fluorescence method, the phosphorus element is quantitatively analyzed by a colorimetric method, and the average valence state of the vanadium in the vanadium-phosphorus-oxygen catalyst is usually determined by an ammonium ferrous sulfate titration method, such as an ammonium ferrous sulfate titration method adopted by Qiaoshine (analysis laboratory, volume 17, supplement, 2008, 5 months, P222-P223) and the like. The average valence of vanadium was also determined in the study of the catalyst for preparing maleic anhydride VPO by butane oxidation by ferrous ammonium sulfate titration (Hirschhorn university report, volume 14, 2 nd, 1999, month 5, P34-38).
The vanadium phosphorus oxide catalysts having different P/V molar ratios may be prepared according to conventional techniques in the art. In the process of the present invention, it is recommended to prepare vanadium phosphorus oxide catalysts having different P/V molar ratios in accordance with the requirements by the following method.
The preparation method of the vanadium phosphorus oxide catalyst provided by the invention comprises the following steps:
(1) preparing a vanadium phosphorus oxide serving as a precursor of the VPO catalyst by adopting a conventional technical means in the technical field;
(2) drying and roasting the catalyst precursor obtained in the step (1) and forming Raschig ring-shaped or cylindrical catalyst particles;
(3) and (3) keeping the catalyst formed in the step (2) at a certain temperature, and activating in a nitrogen or inert gas atmosphere or a normal butane/empty mixed gas atmosphere to obtain the activated vanadium-phosphorus-oxygen catalyst.
Wherein, in the step (1), the vanadium phosphorus oxide as a precursor of the vanadium phosphorus oxide catalyst can be prepared by the methods known in the art or conventional techniques, such as the methods disclosed in chinese patent CN103769181A or U.S. patent USP4,632,915. The preparation method of the catalyst precursor, namely the vanadium phosphorus oxide, is common knowledge in the field.
In the step (2), the forming mode can be a forming method which is conventional in the field, such as strip extrusion, sheet beating or balling.
Wherein in the step (3), the activation can be carried out under the atmosphere of one or a combination of a nitrogen/air mixed gas, a water vapor/air mixed gas or a normal butane/air mixed gas. In the present invention, it is preferable to carry out the activation treatment for the prepared catalysts having different P/V molar ratios using the same activation conditions.
In the preparation of the catalyst precursor, catalyst precursors with different P/V molar ratios can be prepared by controlling the mass ratio of the vanadium pentoxide and the phosphoric acid added as raw materials, and the P/V ratio of the vanadium phosphorus oxygen catalyst precursor is a key factor for determining the performance of the final VPO catalyst. This is mainly because: 1. the P/V ratio affects the redox ability, and excess phosphorus largely prevents the movement of lattice oxygen, reducing the oxidation ability of the catalyst. 2. Influence on the composition of the crystalline phase of the catalyst, 4 when the phosphorus added to the catalyst is close to or exceeds (i.e. 1: 1)+The vanadium can be kept stable when being calcined at high temperature in the air to generate a large amount of (VO)2P2O7Phase, only a small fraction of VOPO4GeneratingThe P/V ratio therefore in fact influences the average valence of the vanadium of the catalyst, as a result of which catalysts of different P/V ratios possess different average valence of vanadium, oxidation capacity and product selectivity.
In the process of the present invention, when three graded reaction zones are selected, the first reaction zone and the second reaction zone typically comprise two beds of vanadium phosphorus oxide catalyst, respectively. The volume of all vanadium phosphorus oxygen catalysts is used for metering, according to the sequence of contact with mixed reaction gas, in a first reaction zone, the P/V molar ratio of an upstream catalyst bed layer is 1.05-1.15, and the filling proportion is 5% -20%; the P/V molar ratio of a downstream catalyst bed layer is 1.15-1.25, and the filling proportion is 5% -20%; in the second reaction zone, the P/V molar ratio of the upstream catalyst is 0.97-1.0, the filling proportion is 10-30%, the P/V molar ratio of the downstream catalyst bed layer is 1.0-1.05, and the filling proportion is 10-40%; the P/V molar ratio of the catalyst in the third reaction zone is 0.95-1.0, and the filling proportion is 10-40%. The packing technique of the vanadium phosphorus oxide catalyst in each reaction zone is a conventional operation method in the field.
In the method, the volume fraction of n-butane is generally 1.0-1.8% and the volume fraction of oxygen is generally 15-20% in the mixed reaction gas obtained by n-butane, air and circulating tail gas. The oxidation reaction conditions are as follows: the reaction pressure is normal pressure to 0.5MPa, the reaction temperature is 380 to 450 ℃, and the volume space velocity of the mixed reaction gas is 1000 to 3500h-1。
The inventors of the present application, when studying the process for the preparation of maleic anhydride by oxidation of n-butane, have surprisingly found that the use of several VPO catalysts with different P/V molar ratios, the active phases (VO) of these catalysts2P2O7Phase, VOPO4The catalyst has different vanadium average valence states due to different contents of phases, the catalyst has obvious difference in activity, the VPO catalyst with different P/V molar ratios is adopted for grading filling, the regulation and control of the catalyst performance can be realized, the reaction hot point can be effectively controlled, the product yield is improved, meanwhile, the grading method can ensure that the activity of the catalyst is uniformly distributed according to the reaction requirement, the activity of the catalyst is fully exerted, and particularly, the tail gas is recycled for preparing the catalyst by normal butane oxidationIn the anhydride reaction, the influence of the reduction of the normal butane conversion rate caused by the reduction of the oxygen volume fraction of the reaction raw material can be compensated. And the method and results are novel and unexpected.
Therefore, compared with the prior art, the method for preparing maleic anhydride by n-butane oxidation provided by the invention has the following beneficial effects:
1. aiming at the characteristic of strong heat release of n-butane oxidation reaction, catalysts with different P/V molar ratios and different activities are adopted, and filling is carried out in a mode of uniformly modulating the activity of the catalysts according to the sequence that the P/V molar ratio of the catalysts is matched according to the height along the direction of reactant flow and the total trend is gradually reduced from the height. The oxidation reaction carried out by adopting the catalyst filling mode has the advantages that the average reaction temperature of a catalyst bed layer is high, the reaction hot point is low, the characteristic of catalyst activity complementation can be fully exerted, the influence of reduction of butane conversion rate caused by reduction of oxygen concentration due to tail gas circulation is made up, and the reaction for preparing maleic anhydride by oxidizing n-butane in the scheme of the invention has high conversion rate, good selectivity and high yield of maleic anhydride.
2. In the method, in the reaction of preparing maleic anhydride by oxidizing n-butane, in the feeding direction of a fixed bed, the raw material mixed with the circulating tail gas meets a catalyst with higher activity at the inlet end, the reaction temperature is raised to a higher level, the oxidation reaction is violent at the temperature, and the defect of temperature reduction caused by the reduction of oxygen concentration in the prior art can be overcome; the catalyst with lower activity is arranged in the next catalyst filling section, and the reaction heat release is smaller on the catalyst bed layer, so that the violent rise of a reaction hot point can be effectively restrained; by analogy, the relative activity of the graded catalyst system is in an ascending trend along with the reduction of the butane concentration in the reaction process, so that the stability of the reaction activity is ensured, and the reaction for preparing maleic anhydride by the n-butane oxidation recycled by tail gas is smoothly carried out.
3. The method for quantitatively adjusting the P/V molar ratio in the catalyst is realized by controlling the raw material ratio, namely the adding amount of vanadium pentoxide and phosphoric acid, in the preparation process of the catalyst precursor, the adjusting and controlling method is simple, the result is reliable, and the reaction activity of the catalyst is conveniently adjusted and controlled by controlling the P/V molar ratio.
4. The VPO catalyst has a life of about 5 years in the commercial process of maleic anhydride and the catalyst deactivation during operation is due to the loss of phosphorus from the catalyst. The oxidation process of the n-butane is a strong exothermic reaction, hot spot temperature exists in the reaction, and the rapid loss of phosphorus in the catalyst can be promoted due to the fact that the hot spot temperature is too high, so that the high hot spot temperature in the reaction is a key factor influencing the activity stability of the catalyst.
5. It is generally desirable in the art to have a vanadium phosphorus oxide catalyst with better activity, i.e. a higher P/V molar ratio in the vanadium phosphorus oxide catalyst. In the invention, the research on the n-butane oxidation process finds that the effect is not ideal when only one catalyst is used for catalysts with different P/V molar ratios; however, the catalysts with different P/V molar ratios can obtain good technical effects after being graded according to a certain sequence. Therefore, the invention provides a new process route for n-butane oxidation.
Drawings
FIG. 1 is a schematic view of the structure of a synthesis tank used in the present invention.
Fig. 2 is a XRD spectrum of the catalyst precursor. Wherein: -VOHPO4·0.5H2O。
FIG. 3 is an XRD spectrum of the catalyst product obtained after activation in examples 1-4.
Detailed Description
The vanadium phosphorus oxide catalysts of the present invention, having different P/V molar ratios, can be prepared by the following recommended method.
(1) Synthesis of vanadium phosphorus oxide as catalyst precursor
Adding isobutanol, vanadium pentoxide and an auxiliary agent into a reaction kettle with a stirring device and a reflux condensing device through a feeding port, starting the stirring device, simultaneously heating and keeping the reaction temperature at 95-120 ℃, carrying out reflux reaction for 2-12 hours, adding concentrated phosphoric acid (with the concentration of 85% -100%), wherein the molar ratio of phosphorus to vanadium is 0.95-1.35, continuously keeping the reflux reaction for 4-8 hours, and discharging the reaction product through a reaction material outlet after the reaction is finished. The reaction mixture was cooled to room temperature and then filtered. And leaching the filter cake with a small amount of isobutanol for three times, naturally drying the filter cake for 12-24 hours at room temperature, then drying the filter cake for 8-12 hours in an oven, and finally roasting the filter cake for 4-8 hours in a muffle furnace at 200-285 ℃ to obtain a dark brown catalyst precursor, namely the nano vanadium-phosphorus oxide.
(2) Preparation of vanadium phosphorus oxide catalyst
The vanadium phosphorus oxide obtained in the step (1) is firstly molded, the prepared vanadium phosphorus oxide catalyst can be in the shapes of tablets, spheres, extruded strips and the like, and the phase of the precursor of the catalyst is (VOHPO)4·0.5H2O）。
(3) Activation treatment of vanadium phosphorus oxide catalyst
And (3) activating the catalyst precursor formed in the step (2) in a nitrogen or inert gas atmosphere or a n-butane/air mixed gas atmosphere to obtain the activated vanadium-phosphorus-oxygen catalyst.
In the step (3), the activation temperature is generally 350-450 ℃, preferably 375-425 ℃; the activation time is generally 5 to 40 hours, preferably 12 to 20 hours. The volume space velocity of the nitrogen, inert gas or n-butane/air mixed atmosphere is generally 100-2000 h-1Preferably 500 to 1000 hours-1。
In the present invention, it is preferable to carry out the activation treatment for the prepared catalysts having different P/V molar ratios using the same activation conditions. For example, the shaped catalyst is placed in a tubular reactor under an n-butane/air atmosphere having an n-butane content of 0.6% (v) and a n-butane/air volume space velocity is maintained for 500h-1Heating rate is 2 ℃/min, the activation temperature is increased from room temperature to 400 ℃ for roasting treatment, the roasting treatment is carried out at 400 ℃ for 40 hours, the activation process is finished, the green vanadium-phosphorus-oxygen catalyst is obtained, and the phase of the obtained catalyst is (VO)2P2O7Phase, and a minor portion of VOPO4And (4) phase(s).
The vanadium phosphorus oxide catalyst after activation canThe performance evaluation was carried out as follows: the prepared vanadium phosphorus oxide catalyst is loaded into a fixed bed reactor, n-butane air mixed gas is introduced, and the composition of a reaction product is analyzed by gas chromatography. The reaction conditions were evaluated as follows: the reaction temperature is 380-450 ℃, the pressure is normal pressure-0.5 MPa, and the space velocity of the n-butane mixed gas is 1000-3500 h-1And the concentration of the n-butane is 1.0 to 1.8 percent (volume percentage), and the activity evaluation test of the catalyst is carried out.
The present invention is further described in detail with reference to the following examples, which are not intended to limit the scope of the present invention, and those skilled in the art can appropriately extend the scope of the present invention in combination with the description and the entirety of the present invention.
In the examples, the detection of the crystal phase was carried out by using a D/max-2500X-ray diffractometer from RIGAKU, Japan, and the specific surface area was measured by using an AUTONORB 3B model full-automatic specific surface area and pore size analyzer from Quantachrome, USA. The vanadium element in the catalyst is quantitatively analyzed by a fluorescence method, the phosphorus element is quantitatively analyzed by a colorimetric method, and the average valence state of the vanadium in the catalyst is determined by an ammonium ferrous sulfate titration method.
Example 1
442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added into a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 47.50kg of phosphoric acid with the concentration of 85 percent is added, the molar ratio of phosphorus to vanadium is 1.27, the reflux is continuously carried out for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, naturally drying the filter cake in an enamel tray at room temperature, drying the filter cake in a drying oven at 100 ℃ for 8 hours, and finally roasting the filter cake in a muffle furnace at 250 ℃ for 5 hours to obtain a black brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating rate is 2 ℃/min, heating activation temperature from room temperature to 400 ℃ for roasting treatment, keeping at 400 ℃ for 40 hours, and ending the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 21m2Per g, pore volume of 0.11cm3(ii) in terms of/g. The catalyst was analyzed by colorimetry to find the phosphorus content was 22.92%, the catalyst was analyzed by fluorometry to find the vanadium content was 30.17%, the P/V molar ratio of the catalyst was 1.25, and the average valence of the vanadium in the catalyst was + 4.01.
Example 2
442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added into a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 44.13kg of phosphoric acid with the concentration of 85 percent is added, the molar ratio of phosphorus to vanadium is 1.18, the reflux is continuously carried out for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, and finishing the reaction. And (3) naturally drying the filter cake in an enamel plate at room temperature, drying in a drying oven at 100 ℃ for 8 hours, and finally roasting in a muffle furnace at 250 ℃ for 5 hours to obtain a black-brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating at 2 deg.C/min, calcining at 400 deg.C and maintaining at 400 deg.C for 40 deg.CAnd h, finishing the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 27m2Per g, pore volume of 0.12cm3(ii) in terms of/g. The catalyst has a phosphorus content of 21.12% by colorimetric analysis, the catalyst has a vanadium content of 30.21% by fluorescent analysis, the P/V molar ratio of the catalyst is 1.15, and the average valence of vanadium in the catalyst is + 4.05.
Example 3
In a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, 442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 34.33kg of phosphoric acid with the concentration of 100 percent is added, the molar ratio of phosphorus to vanadium is 1.08, the reflux is continued for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, and finishing the reaction. And (3) naturally drying the filter cake in an enamel plate at room temperature, drying in a drying oven at 100 ℃ for 8 hours, and finally roasting in a muffle furnace at 250 ℃ for 5 hours to obtain a black-brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating rate is 2 ℃/min, heating activation temperature from room temperature to 400 ℃ for roasting treatment, keeping at 400 ℃ for 40 hours, and ending the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 35m2Per g, pore volume of 0.15cm3(ii) in terms of/g. The catalyst was analyzed by colorimetry to determine a phosphorus content of 19.32%, the catalyst was analyzed by fluorometry to determine a vanadium content of 30.27%, the P/V molar ratio of the catalyst was 1.05, and the average valence of the vanadium in the catalyst was + 4.10.
Example 4
In a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, 442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 31.97kg of phosphoric acid with the concentration of 100 percent is added, the molar ratio of phosphorus to vanadium is 1.0, the reflux is continued for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, and finishing the reaction. And (3) naturally drying the filter cake in an enamel plate at room temperature, drying in a drying oven at 100 ℃ for 8 hours, and finally roasting in a muffle furnace at 250 ℃ for 5 hours to obtain a black-brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating rate is 2 ℃/min, heating activation temperature from room temperature to 400 ℃ for roasting treatment, keeping at 400 ℃ for 40 hours, and ending the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 35m2Per g, pore volume of 0.15cm3(ii) in terms of/g. The catalyst was analyzed by colorimetry to show a phosphorus content of 17.89%, the catalyst was analyzed by fluorimetry to show a vanadium content of 30.34%, the P/V molar ratio of the catalyst was 0.97, and the average valence of vanadium in the catalyst was + 4.25.
Example 5
In a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, 442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 32.74kg of phosphoric acid with the concentration of 100 percent is added, the molar ratio of phosphorus to vanadium is 1.03, the reflux is continued for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, and finishing the reaction. And (3) naturally drying the filter cake in an enamel plate at room temperature, drying in a drying oven at 100 ℃ for 8 hours, and finally roasting in a muffle furnace at 250 ℃ for 5 hours to obtain a black-brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating rate is 2 ℃/min, heating activation temperature from room temperature to 400 ℃ for roasting treatment, keeping at 400 ℃ for 40 hours, and ending the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 31m2Per g, pore volume of 0.12cm3(ii) in terms of/g. The catalyst was analyzed by colorimetry to show a phosphorus content of 18.42%, the catalyst was analyzed by fluorimetry to show a vanadium content of 30.31%, the P/V molar ratio of the catalyst was 1.0, and the average valence of vanadium in the catalyst was + 4.15.
Example 6
In a reaction kettle with a stirring device and a reflux condensing device shown in figure 1, 442.95kg of isobutanol, 29.53kg of vanadium pentoxide, 0.3kg of auxiliary agent ferric nitrate hexahydrate and 0.5kg of auxiliary agent zirconium nitrate are added, stirring is started, the reaction temperature is raised and maintained at 100 +/-2 ℃, reflux reaction is carried out, the reflux time is maintained for 4 hours, 35.91kg of phosphoric acid with the concentration of 85 percent is added, the molar ratio of phosphorus to vanadium is 1.0, the reflux is continued for 8 hours, and the reaction is finished. And cooling the reaction liquid to room temperature, carrying out vacuum filtration, leaching the filter cake with a small amount of isobutanol for three times, and finishing the reaction. And (3) naturally drying the filter cake in an enamel plate at room temperature, drying in a drying oven at 100 ℃ for 8 hours, and finally roasting in a muffle furnace at 250 ℃ for 5 hours to obtain a black-brown catalyst precursor.
Adding graphite powder with the mass fraction of 4% into the prepared catalyst precursor, fully mixing, and extruding into a Raschig annular catalyst finished product by adopting a rotary tablet press and properly adjusting the impact force.
150g of the Raschig ring catalyst is put into a tubular reactor, and the n-butane/air volume space velocity is maintained for 500h under the n-butane/air atmosphere with the n-butane content of 0.6 percent (v)-1Heating rate is 2 ℃/min, heating activation temperature from room temperature to 400 ℃ for roasting treatment, keeping at 400 ℃ for 40 hours, and ending the activation process to obtain the green vanadium-phosphorus-oxygen catalyst.
The obtained catalyst has a crystalline phase (VO) detected by XRD2P2O7And beta-VOPO4Mixture of phases, specific surface area 29m2Per g, pore volume of 0.10cm3(ii) in terms of/g. The catalyst was analyzed by colorimetry to show a phosphorus content of 17.54%, the catalyst was analyzed by fluorimetry to show a vanadium content of 30.37%, the P/V molar ratio of the catalyst was 0.95, and the average valence of vanadium in the catalyst was + 4.30.
Example 7
On a 200mL test device for preparing maleic anhydride by small n-butane oxidation of a fixed bed, a stainless steel reaction tube with the inner diameter of 18mm is adopted as the reaction tube, three sections (namely three reaction zones) are graded and filled from bottom to top along the material flow direction, the catalyst grading scheme takes the weight of all catalysts as a reference, the upper part of the first section adopts a catalyst with the P/V molar ratio of 1.05, the filling amount is 10%, the lower part of the first section adopts a catalyst with the P/V molar ratio of 1.25, the filling amount is 15%, the upper part of the second section adopts a catalyst with the P/V molar ratio of 1.0, the filling amount is 30%, the lower part of the second section adopts a catalyst with the P/V molar ratio of 1.05, the filling amount is 20%, the third section adopts a catalyst with the P/V molar ratio of 0.97, the filling amount is 25%, and the rest parts are filled with inert magnetic rings. In the reactionThe salt bath temperature of the reactor is 420 ℃, the reaction pressure is 0.25MPa, the volume concentration of the reaction raw material gas is 1.8 percent of n-butane, the tail gas circulation ratio is 20 percent, the volume fraction of oxygen content is 18.8 percent of n-butane/air mixed gas, and the gas space velocity is 1560h-1The reaction of preparing maleic anhydride from n-butane is carried out under the reaction condition. As a result of the test, the n-butane conversion was 82.8 mol% and the maleic anhydride yield was 61.3 mol%.
Example 8
On a 200mL test device for preparing maleic anhydride by small n-butane oxidation of a fixed bed, a stainless steel reaction tube with the inner diameter of 18mm is adopted as the reaction tube, three sections (three reaction zones) are graded and filled from bottom to top along the material flow direction, the catalyst grading scheme takes the weight of all catalysts as a reference, a catalyst with the P/V molar ratio of 1.05 is adopted at the upper part of the first section, the filling amount is 15%, a catalyst with the P/V molar ratio of 1.15 is adopted at the lower part of the first section, the filling amount is 15%, a catalyst with the P/V molar ratio of 0.97 is adopted at the upper part of the second section, the filling amount is 25%, a catalyst with the P/V molar ratio of 1.0 is adopted at the lower part of the second section, the filling amount is 25%, a catalyst with the P/V molar ratio of 0.95 is adopted at the third section, the filling amount is 20%, and the rest parts are filled with inert magnetic rings. Under the conditions that the salt bath temperature of a reactor is 420 ℃, the reaction pressure is 0.25MPa, the volume concentration of reaction raw material gas is 1.8 percent of n-butane, the tail gas circulation ratio is 30 percent, the volume fraction of oxygen content is 17.9 percent of n-butane/air mixed gas, and the gas space velocity is 1560h-1Under the reaction condition of (3), the reaction of preparing maleic anhydride from n-butane is carried out. The test results showed that the n-butane conversion was 84.2% (mol) and the maleic anhydride yield was 60.5% (mol).
Comparative example 1
On a 200mL test device for preparing maleic anhydride by n-butane oxidation in a fixed bed, a reaction tube is a stainless steel reaction tube with the inner diameter of 18mm, 100mL of the catalyst prepared by the method provided by USP4,632,915 is filled, and the rest part is filled with an inert magnetic ring. At the reaction temperature of 430 ℃, the reaction pressure of 0.25MPa, the reaction gas is n-butane/air mixed gas with butane volume concentration of 1.8 percent, and the gas space velocity is 1560h-1Under the reaction condition of (3), the reaction of preparing maleic anhydride from n-butane is carried out. The test results showed that the conversion of butane was 78.1% and the molar yield of maleic anhydride was 54.5%. The test results and catalyst bed hot spots are shown in Table 1, respectively.
Comparative example 2
On a 200mL test device for preparing maleic anhydride by n-butane oxidation in a fixed bed, a stainless steel reaction tube with the inner diameter of 18mm is filled with a catalyst with the P/V molar ratio of 0.97, the filling amount is 50mL, and the rest part is filled with an inert magnetic ring. At the reactor salt bath temperature of 420 ℃, the reaction pressure of 0.25MPa, the volume concentration of the reaction raw material gas of n-butane of 1.8 percent, the recycle ratio of the tail gas of 30 percent, the volume fraction of the oxygen content of 17.9 percent and the gas space velocity of 1560h-1Under the reaction condition of (3), the reaction of preparing maleic anhydride from n-butane is carried out. The test results showed that the conversion of n-butane was 95.5 mol% and the yield of maleic anhydride was 49.3 mol%. The test results and the catalyst bed hot spots are shown in Table 1, respectively.
Comparative example 3
On a 200mL test device for preparing maleic anhydride by n-butane oxidation in a fixed bed, a stainless steel reaction tube with the inner diameter of 18mm is filled with a catalyst with the P/V molar ratio of 1.25, the filling amount is 50mL, and the rest part is filled with an inert magnetic ring. Under the conditions that the salt bath temperature of a reactor is 420 ℃, the reaction pressure is 0.25MPa, the volume concentration of reaction raw material gas is 1.8 percent of n-butane, the tail gas circulation ratio is 20 percent, the volume fraction of oxygen content is 18.8 percent of n-butane/air mixed gas, and the gas space velocity is 1560h-1Under the reaction condition of (3), the reaction of preparing maleic anhydride from n-butane is carried out. As a result of the test, the n-butane conversion was 66.1 mol% and the yield of maleic anhydride was 47.7 mol%. The test results and the catalyst bed hot spots are shown in Table 1, respectively.
TABLE 1 Experimental results of examples and comparative examples
| N-butane conversion, mol% | Yield of maleic anhydride, mol% | Bed layerHotspot/. degree.C | |
| Example 7 | 82.8 | 61.3 | 433 |
| Example 8 | 84.2 | 60.5 | 439 |
| Comparative example 1 | 78.1 | 54.5 | 457 |
| Comparative example 2 | 95.5 | 49.3 | 466 |
| Comparative example 3 | 66.1 | 47.7 | 428 |
Claims (3)
1. A process method for preparing maleic anhydride by n-butane oxidation comprises the following steps:
n-butane, air and circulating tail gas are mixed, the obtained mixed reaction gas flows in parallel and sequentially passes through three reaction zones connected in series, and the mixed reaction gas is contacted with a vanadium-phosphorus oxide catalyst to react under the condition of oxidation reaction; except for the most downstream reaction zone, the first reaction zone and the second reaction zone respectively comprise two vanadium-phosphorus-oxygen catalyst beds;
according to the sequence of contact with the mixed reaction gas, in the first reaction zone, the P/V molar ratio of an upstream catalyst bed layer is 1.05-1.15, and the P/V molar ratio of a downstream catalyst bed layer is 1.15-1.25; in the second reaction zone, the P/V molar ratio of the upstream catalyst bed layer is 0.97-1.0, and the P/V molar ratio of the downstream catalyst bed layer is 1.0-1.05; the P/V molar ratio of the catalyst in the third reaction zone is 0.95-1.0;
in the first reaction zone, the filling proportion of an upstream catalyst bed layer is 5-20 percent and the filling proportion of a downstream catalyst bed layer is 5-20 percent by volume of all vanadium-phosphorus-oxygen catalysts; in the second reaction zone, the filling proportion of the upstream catalyst is 10-30%, and the filling proportion of the downstream catalyst bed layer is 10-40%; the filling proportion of the catalyst in the third reaction zone is 10-40%.
2. The process according to claim 1, wherein the volume fraction of n-butane in the mixed reaction gas is 1.0% to 1.8%, and the volume fraction of oxygen is 17.9% to 19.6%.
3. The process of claim 2 wherein said oxidation reaction conditions are: the reaction pressure is normal pressure to 0.5MPa, the reaction temperature is 380 to 450 ℃, and the volume space velocity of the mixed reaction gas is 1000 to 3500h-1。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611045756.3A CN108101871B (en) | 2016-11-24 | 2016-11-24 | Process method for preparing maleic anhydride by oxidizing n-butane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611045756.3A CN108101871B (en) | 2016-11-24 | 2016-11-24 | Process method for preparing maleic anhydride by oxidizing n-butane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108101871A CN108101871A (en) | 2018-06-01 |
| CN108101871B true CN108101871B (en) | 2022-01-04 |
Family
ID=62203916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611045756.3A Active CN108101871B (en) | 2016-11-24 | 2016-11-24 | Process method for preparing maleic anhydride by oxidizing n-butane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108101871B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115463618B (en) * | 2022-08-08 | 2023-11-10 | 北京鑫缘化工有限公司 | Reactor for preparing maleic anhydride by oxidizing n-butane |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1068324A (en) * | 1991-07-08 | 1993-01-27 | 孟山都公司 | Produce the method for maleic anhydride with high yield |
| JP2006104204A (en) * | 1994-12-22 | 2006-04-20 | Mitsubishi Chemicals Corp | Method for producing maleic anhydride |
| CN102337145A (en) * | 2010-07-22 | 2012-02-01 | 中国石油化工股份有限公司 | Fixed bed Fischer-Tropsch method for preparing liquid hydrocarbon |
| CN102850308A (en) * | 2011-06-30 | 2013-01-02 | 中国石油化工股份有限公司 | Production method of maleic anhydride |
-
2016
- 2016-11-24 CN CN201611045756.3A patent/CN108101871B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1068324A (en) * | 1991-07-08 | 1993-01-27 | 孟山都公司 | Produce the method for maleic anhydride with high yield |
| JP2006104204A (en) * | 1994-12-22 | 2006-04-20 | Mitsubishi Chemicals Corp | Method for producing maleic anhydride |
| CN102337145A (en) * | 2010-07-22 | 2012-02-01 | 中国石油化工股份有限公司 | Fixed bed Fischer-Tropsch method for preparing liquid hydrocarbon |
| CN102850308A (en) * | 2011-06-30 | 2013-01-02 | 中国石油化工股份有限公司 | Production method of maleic anhydride |
Non-Patent Citations (3)
| Title |
|---|
| The design of a new ZrO2-supported V/P/O catalyst for n-butane oxidation to maleic anhydride: The build-up of the active phase during thermal treatment;A. Caldarelli等;《Catalysis Today》;20100317;第157卷;第204-210页 * |
| 丁烷氧化制顺酐VPO 催化剂前躯体的研究进展;谭乃迪等;《天津化工》;20120131;第26卷(第1期);第4-7页 * |
| 不同P 与V 比的Mo /VPO 催化剂物相组成及其催化性能;曾炜等;《工业催化》;20140831;第22卷(第8期);第597页左栏最后一段及表1、右栏第1段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108101871A (en) | 2018-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8877966B2 (en) | Process for preparing acrylic acid from methanol and acetic acid | |
| US8507721B2 (en) | Process for preparing acrylic acid from ethanol and formaldehyde | |
| US7132384B2 (en) | Process for producing composite oxide catalyst | |
| JP6527499B2 (en) | Process for producing unsaturated aldehyde and / or unsaturated carboxylic acid | |
| CN101370763B (en) | Process for the long-term operation of a heterogeneously catalyzed partial gas phase oxidation of an organic starting compound | |
| CN107866241B (en) | Catalyst for preparing pyromellitic anhydride by oxidizing durene | |
| US7115776B2 (en) | Heterogeneously catalyzed gas-phase partial oxidation of at least one organic compound | |
| WO2012049246A2 (en) | Method for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to obtain acrolein | |
| US8106220B2 (en) | Preparation of phthalic anhydride by gas phase oxidation of O-xylene in a main reactor and postreactor | |
| US6982347B2 (en) | Heterogeneously catalyzed partial gas phase oxidation of acrolein to acrylic acid | |
| CN107866257B (en) | Catalyst for preparing pyromellitic anhydride from durene | |
| US6960684B2 (en) | Production process for unsaturated aldehyde | |
| CN108101872B (en) | Catalyst grading method for producing maleic anhydride by oxidizing n-butane | |
| KR101558941B1 (en) | Process For Producing Methacrolein And/Or Methacrylic Acid | |
| CN108101871B (en) | Process method for preparing maleic anhydride by oxidizing n-butane | |
| US7019176B2 (en) | Heterogeneously catalyzed partial gas phase oxidation of propene to acrolein | |
| US20050261520A1 (en) | Process for producing catalyst for production of unsaturated carboxylic acid | |
| JP4950986B2 (en) | Method for producing methacrolein and / or methacrylic acid | |
| CN107866228B (en) | Catalyst for synthesizing homoanhydride | |
| US9120743B2 (en) | Integrated process for the production of acrylic acids and acrylates | |
| CN109071393B (en) | Process for producing unsaturated aldehyde and unsaturated carboxylic acid | |
| CN108101873A (en) | A kind of method that n butane oxidation prepares cis-butenedioic anhydride | |
| CN111468136B (en) | Catalyst for preparing acrylic acid by oxidizing propane and preparation method thereof | |
| CN101279264B (en) | High load fluidized bed catalyst for preparing acrylonitrile | |
| US20080269522A1 (en) | Process for operating an exothermic heterogeneously catalyzed partial gas phase oxidation of an organic starting compound to an organic target compound |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |