CN101733137A - Catalyst for preparing propylene oxide from propylene by gas-phase one-step oxidation and preparation method thereof - Google Patents

Abstract

The invention discloses a catalyst for preparing propylene oxide from propylene by gas-phase oxidation and a preparation method thereof. The catalyst of the invention is a low-content Ag-Cu bimetallic catalyst supported on a calcium carbonate, barium carbonate or barium sulphate carrier, and is used for the process of preparing the propylene oxide from the propylene by gas-phase one-step oxidation by taking molecular oxygen as an oxidant. The catalyst of the invention is low in loading of active components, namely Ag and Cu, low in production cost, simple and feasible in the preparation method for the catalyst, and favorable for industrialized production; and simultaneously, because no any inhibitor needs to be added into feed gas and the propylene oxide is high in selectivity, the catalyst of the invention is a high-efficiency and low-cost propylene epoxidated catalyst,.

Description

The Catalysts and its preparation method that is used for preparing propylene oxide from propylene by gas-phase one-step oxidation

Technical field

The present invention relates to a kind of Catalysts and its preparation method that is used for PROPENE IN GAS PHASE OXIDATION system expoxy propane, specifically, be a kind of Ag-Cu bimetallic catalyst that loads on the low content on calcium carbonate, brium carbonate or the barium sulfate carrier, being used for the molecular oxygen is the preparing propylene oxide from propylene by gas-phase one-step oxidation process of oxidant.

Background technology

Expoxy propane (PO) is a kind of important basic Organic Chemicals, is the third-largest organic chemical industry's product that output is only second to polypropylene and acrylonitrile in the acryloyl derivative.Its maximum purposes is to produce PPG, and then produces polyurethane; Also can produce broad-spectrum propane diols and nonionic surface active agent, oil field demulsifier, farm chemical emulgent, fire retardant, plasticizer and wetting agent etc.

The production technology of PO mainly contains chlorohydrination and indirect oxidation (Halcon) method at present, and up to now, the production capacity of these two kinds of technologies accounts for more than 99% of whole world total productive capacity.Chlorohydrination is to use propylene, the reaction of chlorine G﹠W generates chloropropyl alcohol, generate expoxy propane with the white lime saponification again, early be applied to industrial production, maturation possesses skills, flow process is simple, operational load elasticity is bigger, purity requirement to raw material propylene is not high, selectivity is good, the yield height, advantages such as capital expenditure is few, but need to consume a large amount of chlorine (will have chlor-alkali plant supporting), can produce a large amount of chloride sewage and waste residue (1 ton of PO of every production will discharge 40～80 tons of chlorine-contained wastewaters and 2 tons of calcium chloride waste residues) in the production process, equipment corrosion is serious, serious three wastes, environmental protection treatment expense height.The Halcon method mainly comprises iso-butane method and ethylbenzene method, iso-butane or ethylbenzene generate iso-butane peroxide or ethylbenzene peroxide through peroxidization, generate PO with the propylene reaction again, simultaneously the coproduction tert-butyl alcohol or Alpha-Methyl benzyl carbinol (can further be processed into styrene).This technology does not have corrosion substantially, three waste discharge is few, but complex process, long flow path, high to the equipment requirement, investment is big, simultaneously because joint product many (1 ton of PO of every production wants 2～3 tons of co-product of output), be subjected to market factor restriction serious, this class device should be built near the large-scale petroleum chemical plant installations, should not build the device of middle and small scale.

Expoxy propane is as a kind of important basic Organic Chemicals, and annual requirement increases year by year, and therefore, chlorohydrination and indirect oxidation method will be the main technique route of producing expoxy propane in one period from now on.Along with the increasingly stringent of national requirements for environmental protection, it is trend of the times that with serious pollution chlorohydrination is eliminated.The future of indirect oxidation method depends on the sales situation of supply of raw material and joint product on the market.One step of propylene epoxidation technique is Synthesis of Propylene Oxide development in future direction, wherein TS-1 molecular sieve catalytic H ₂O ₂One step epoxidation propylene technology has bigger competitiveness, but present TS-1 molecular sieve catalyst and H ₂O ₂Too high and the accumulating difficulty of the cost of oxidant etc. remains the subject matter of this technology of puzzlement.The epoxidation reaction of utilizing molecular oxygen directly to carry out propylene is the reaction the most desirable, that Atom economy is the highest, with oxygen (air) directly gas-phase epoxidation production of propylene PO technology have that technology is simple, accessory substance is few, production cost is low and advantages of environment protection, it is a pollution-free green chemical process, it is PO production technology development in future direction, in case study successfully tool industrialization competitiveness.

Be used for oxygen (air) directly the catalyst of gas-phase epoxidation production of propylene PO technology to be mainly Ag catalyst based:

Chinese patent CN1446626A discloses a kind of Ag-MoO ₃/ ZrO ₂Catalyst, the percentage by weight of this catalyst consists of: 10～50%Ag, 0.1～8%MoO ₃, 42～89.9%ZrO ₂In reaction temperature is 400 ℃, and gas space velocity is 7500h ^-1, unstripped gas is formed: 22.7% propylene, and 9.0% oxygen, under the condition of 68.3% nitrogen, propylene conversion is 1.6%, the expoxy propane selectivity is 60.3%.

Chinese patent CN1347760A discloses a kind of non-loading type Ag-CuCl catalyst, and the percentage by weight of this catalyst consists of: 70～75%Ag, 25～30%CuCl.In reaction temperature is 350 ℃, and gas space velocity is 18000h ^-1, unstripped gas is formed: 10% propylene, and 20% oxygen, under the condition of 70% nitrogen, propylene conversion is 1.63%, the expoxy propane selectivity is 30.5%.

U.S. Pat 5625084 and US5686380 disclose a kind of alkaline earth metal carbonate carried silver catalyst, and the percentage by weight of this catalyst consists of: 25～60%Ag, 0.5～3%K, 0.05～2.5%Mo, 34.5～74.45%CaCO ₃In reaction temperature is 245 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 5% oxygen, 200ppm vinyl chloride, 10% carbon dioxide, under the condition of 75% nitrogen, propylene conversion is 2.8%, the expoxy propane selectivity is 58%.

U.S. Pat 5703254 discloses a kind of alkaline earth metal carbonate load Yin-Jin bimetallic catalyst, and the percentage by weight of this catalyst consists of: 5～50%Ag, 1～10%Au, 40～94%CaCO ₃In reaction temperature is 250 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 5% oxygen, under the condition of 85% nitrogen, propylene conversion is 2%, the expoxy propane selectivity is 40%.

U.S. Pat 5770746 discloses a kind of alkaline earth metal carbonate carried silver catalyst, and the percentage by weight of this catalyst consists of: 10～60%Ag, 0.2～2.2%Mo, 37.8～89.8%CaCO ₃Adopting vinyl chloride preliminary treatment 18 hours, is 250 ℃ in reaction temperature, and gas space velocity is 1200h ^-1, unstripped gas is formed: 8.15% propylene, and 6.35% oxygen, 14.8% carbon dioxide, under the condition of 70.7% nitrogen, propylene conversion is 6.5%, the expoxy propane selectivity is 52%.

U.S. Pat 5780657 discloses a kind of alkaline earth metal carbonate carried silver catalyst, and the percentage by weight of this catalyst consists of: 10～60%Ag, 0.05～2%Cl, 0.5～10%K, 28～89.45%CaCO ₃In reaction temperature is 250 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 6% oxygen, under the condition of 84% nitrogen, propylene conversion is 21%, the expoxy propane selectivity is 42%.

U.S. Pat 5861519 discloses a kind of alkaline earth metal carbonate carried silver catalyst, and the percentage by weight of this catalyst consists of: 10～60%Ag, 0.5～5%K, 0.6～7%W, 28～88.9%CaCO ₃In reaction temperature is 260 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 5% oxygen, 200ppmNO, 50ppm vinyl chloride, under the condition of 85% nitrogen, propylene conversion is 8.8%, the expoxy propane selectivity is 53%.

U.S. Pat 5864047 discloses a kind of alkaline earth metal carbonate carried silver catalyst, and the percentage by weight of this catalyst consists of: 10～60%Ag, 1～3%K, 0.2～2.5%Re, 34.5～88.8%CaCO ₃In reaction temperature is 250 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 5% oxygen, 200ppmNO, 50ppm vinyl chloride, under the condition of 85% nitrogen, propylene conversion is 10%, the expoxy propane selectivity is 51%.

U.S. Pat 6083870 discloses a kind of CaF ₂Carried silver catalyst, the percentage by weight of this catalyst consists of: 25～60%Ag, 0.5～3%K, 37～74.5%CaF ₂In reaction temperature is 250 ℃, and gas space velocity is 1200h ^-1, unstripped gas is formed: 10% propylene, and 5% oxygen, 200ppm NO, 50ppm vinyl chloride, under the condition of 85% nitrogen, propylene conversion is 7%, the expoxy propane selectivity is 40%.

Though above-mentioned existing patented technology respectively has its characteristics, the part that also comes with some shortcomings, for example: silver-colored load capacity is higher, needs to add inhibitor such as chlorohydrocarbon, nitrogen oxide, carbon dioxide in the unstripped gas to improve the selectivity of expoxy propane.

Summary of the invention

The object of the invention is to provide a kind of and is applicable under the high-speed condition, need not in the unstripped gas to add any inhibitor, and with the molecular oxygen Catalysts and its preparation method of the preparing propylene oxide from propylene by gas-phase one-step oxidation process of oxidant.

Catalyst of the present invention is the Ag-Cu bimetallic catalyst that loads on the low content on calcium carbonate, brium carbonate or the barium sulfate carrier, and catalyst is formed and weight percent content is:

Ag content is 0.5～10%,

Cu content is 0.05～2.5%,

Vector contg is 87.5～99.45%.

Wherein carrier is selected from a kind of carrier in calcium carbonate, brium carbonate or the barium sulfate.

Catalyst of the present invention can adopt any method among following four kinds of preparation methods to prepare:

Said preparation method one comprises the steps:

Silver nitrate, copper nitrate and stabilizing agent (polyvinyl alcohol or polyvinylpyrrolidone) are dissolved in deionized water or the absolute ethyl alcohol, then under intense agitation, slowly drip the reaction of sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution and add catalyst carrier after 4～8 hours, continuation stirring reaction filtration washing after 12～36 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

Said preparation method two comprises the steps:

Silver nitrate, copper nitrate and stabilizing agent (polyvinyl alcohol or polyvinylpyrrolidone) are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and following dry 12～24 hours at 100～120 ℃.Then under intense agitation, slowly drip sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution, continue reaction filtration washing after 4～8 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

Said preparation method three comprises the steps:

Silver nitrate and copper nitrate are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and following dry 12～24 hours at 100～120 ℃.Then under intense agitation, slowly drip sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution, continue reaction filtration washing after 4～8 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

Said preparation method four comprises the steps:

Silver nitrate and copper nitrate are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and 100～120 ℃ dry 12～24 hours down, 200～500 ℃ of following roastings 3～8 hours in hydrogen atmosphere at last.

The process conditions of preparing propylene oxide from propylene by gas-phase one-step oxidation reaction are: fixed bed reactors, reaction temperature are 200～300 ℃, and reaction pressure is 0.1～1.0MPa, and the volume ratio of propylene and oxygen is 1: 4～4: 1, and air speed is 5000～15000h-1.

One of remarkable advantage of catalyst of the present invention is, the load capacity of active component A g and Cu is low in the catalyst, and production cost is low, and method for preparing catalyst is simple, helps suitability for industrialized production.

Two of the remarkable advantage of catalyst of the present invention is, need not to add any inhibitor in the unstripped gas, and expoxy propane selectivity height helps the separation of product, is a kind of oxidation catalyst of cyclopropene of economical and efficient.

The specific embodiment

Embodiment 1

0.15 gram silver nitrate, 0.016 gram copper nitrate and 1g polyvinyl alcohol stabilizing agent are dissolved in the 20 gram absolute ethyl alcohols, then under intense agitation, slowly drip sodium borohydride aqueous solution (5 grams per liter water) and continue to react adding 2 gram brium carbonate carriers after 5 hours, continuation stirring reaction filtration washing after 24 hours, following dry 12 hours at 110 ℃ successively at last, 450 ℃ of following roastings are 4 hours in nitrogen atmosphere, make the 1# catalyst.

The appreciation condition of catalyst performance is: with 0.5 milliliter of particle diameter is that to be packed into internal diameter be in 5 millimeters the stainless steel fixed bed reactors to 20～40 purpose catalyst, reaction temperature is 230 ℃, synthesis under normal pressure, unstripped gas is made up of 20% propylene, 10% oxygen and 70% nitrogen, and air speed is 5000h ^-1Product is carried out on-line analysis with two gas chromatographs.Catalyst performance evaluation result as shown in Table 1.

Embodiment 2

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, other processes are identical with embodiment 1, obtain the 2# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 3

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 20 gram absolute ethyl alcohols change 20 gram water into, and other processes are identical with embodiment 1, obtain the 3# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 4

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 450 ℃ of roastings changed in air atmosphere 450 ℃ of roastings 4 hours in 4 hours in nitrogen atmosphere, and other processes are identical with embodiment 1, obtain the 4# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 5

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 2 gram brium carbonate carriers change 2 gram barium sulfate carriers into, and other processes are identical with embodiment 1, obtain the 5# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 6

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 2 gram brium carbonate carriers change 2 gram calcium carbonate carriers into, and other processes are identical with embodiment 1, obtain the 6# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 7

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, the sodium borohydride aqueous solution reducing agent changes 4 gram ethylene glycol into, and other processes are identical with embodiment 1, obtain the 7# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 8

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.15 gram silver nitrate changes 0.3 gram silver nitrate into, and other processes are identical with embodiment 1, obtain the 8# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 9

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.15 gram silver nitrate changes 0.075 gram silver nitrate into, and other processes are identical with embodiment 1, obtain the 9# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 10

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.15 gram silver nitrate changes 0.015 gram silver nitrate into, and other processes are identical with embodiment 1, obtain the 10# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 11

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.016 gram copper nitrate changes 0.16 gram copper nitrate into, and other processes are identical with embodiment 1, obtain the 11# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 12

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.016 gram copper nitrate changes 0.08 gram copper nitrate into, and other processes are identical with embodiment 1, obtain the 12# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 13

Change 1 gram polyvinyl alcohol among the embodiment 1 into 1 gram polyvinylpyrrolidone, 0.016 gram copper nitrate changes 0.004 gram copper nitrate into, and other processes are identical with embodiment 1, obtain the 13# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 14

0.15 gram silver nitrate, 0.016 gram copper nitrate and 0.1g polyvinylpyrrolidone are dissolved in the 1 gram deionized water, add 2 gram brium carbonate carriers then, successively normal temperature dipping 24 hours and 120 ℃ dry 24 hours down.Under intense agitation, slowly drip sodium borohydride aqueous solution (5 grams per liter water) then, continue reaction filtration washing after 6 hours, at last successively 120 ℃ dry 24 hours down, 450 ℃ of following roastings are 5 hours in nitrogen atmosphere, obtain the 14# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 15

0.15 gram silver nitrate and 0.004 gram copper nitrate are dissolved in the 1 gram deionized water, add 2 gram brium carbonate carriers then, successively normal temperature dipping 24 hours and 110 ℃ dry 12 hours down, 300 ℃ of following roastings 4 hours in hydrogen atmosphere at last obtain the 15# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 16

Change 1 gram water among the embodiment 15 into 0.8 gram absolute ethyl alcohol, other processes are identical with embodiment 10, obtain the 16# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 17

With among the embodiment 15 in hydrogen atmosphere 300 ℃ of roastings changed in nitrogen atmosphere 500 ℃ of roastings 4 hours in 4 hours into, obtain the 17# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 18

0.15 gram silver nitrate and 0.016 gram copper nitrate are dissolved in the 1 gram deionized water, add 2 gram brium carbonate carriers then, successively normal temperature dipping 24 hours and 110 ℃ dry 12 hours down.Under intense agitation, slowly drip sodium borohydride aqueous solution (5 grams per liter water) then, continue reaction filtration washing after 5 hours, at last successively 110 ℃ dry 12 hours down, 450 ℃ of following roastings are 4 hours in nitrogen atmosphere, obtain the 18# catalyst.Catalyst performance evaluation result as shown in Table 1.

Embodiment 19

0.15 gram silver nitrate and 1g polyvinyl-pyrrolidone stabilizer are dissolved in the 20 gram absolute ethyl alcohols, then under intense agitation, slowly drip sodium borohydride aqueous solution (5 grams per liter water) and continue to react adding 2 gram brium carbonate carriers after 5 hours, continuation stirring reaction filtration washing after 24 hours, following dry 12 hours at 110 ℃ successively at last, 450 ℃ of following roastings are 4 hours in nitrogen atmosphere, obtain the 19# catalyst.

Table one catalyst performance evaluation result

Catalyst	Propylene conversion/%	Expoxy propane selectivity/%
			??1#	?0.9	?26
??2#	?1.1	?55

Catalyst	Propylene conversion/%	Expoxy propane selectivity/%
			??3#	?1.3	?35
??4#	?1.5	?19
			??5#	?0.8	?10
??6#	?1.2	?25
			??7#	?4.5	?30
??8#	?3.0	?45
			??9#	?1.1	?52
??10#	?0.7	?40
			??11#	?1.5	?18
??12#	?1.4	?40
			??13#	?1.5	?28
??14#	?3.2	?41
			??15#	?1.4	?28
??16#	?2.5	?30
			??17#	?0.6	?40
??18#	?1.5	?32
			??19#	?7.8	?19

Claims (6)

1. a catalyst that is used for PROPENE IN GAS PHASE OXIDATION system expoxy propane is characterized in that, the composition of described catalyst and weight percent content thereof are:

Ag????0.5～10％，

Cu????0.05～2.5％，

Carrier 87.5～99.45%,

Wherein carrier is selected from a kind of carrier in calcium carbonate, brium carbonate or the barium sulfate.

2. catalyst according to claim 1, it is characterized in that, the catalytic reaction condition of preparing propylene oxide from propylene by gas-phase one-step oxidation is: fixed bed reactors, reaction temperature is 200～300 ℃, reaction pressure is 0.1～1.0MPa, the volume ratio of propylene and oxygen is 1: 4～4: 1, and air speed is 5000～15000h ^-1

3. prepare the method for the described catalyst of claim 1, it is characterized in that, this preparation method comprises the steps:

Silver nitrate, copper nitrate and stabilizing agent (polyvinyl alcohol or polyvinylpyrrolidone) are dissolved in deionized water or the absolute ethyl alcohol, then under intense agitation, slowly drip the reaction of sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution and add catalyst carrier after 4～8 hours, continuation stirring reaction filtration washing after 12～36 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

4. prepare the method for the described catalyst of claim 1, it is characterized in that, this preparation method comprises the steps:

Silver nitrate, copper nitrate and stabilizing agent (polyvinyl alcohol or polyvinylpyrrolidone) are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and following dry 12～24 hours at 100～120 ℃.Then under intense agitation, slowly drip sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution, continue reaction filtration washing after 4～8 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

5. prepare the method for the described catalyst of claim 1, it is characterized in that, this preparation method comprises the steps:

Silver nitrate and copper nitrate are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and following dry 12～24 hours at 100～120 ℃.Then under intense agitation, slowly drip sodium borohydride aqueous solution (3～7 grams per liter water) or ethylene glycol solution, continue reaction filtration washing after 4～8 hours, at last successively 100～120 ℃ dry 12～24 hours down, 300～600 ℃ of following roastings are 3～8 hours in air or nitrogen atmosphere.

6. prepare the method for the described catalyst of claim 1, it is characterized in that, this preparation method comprises the steps:

Silver nitrate and copper nitrate are dissolved in deionized water or the absolute ethyl alcohol, add catalyst carrier then, successively normal temperature dipping 12～36 hours and 100～120 ℃ dry 12～24 hours down, 200～500 ℃ of following roastings 3～8 hours in hydrogen atmosphere at last.