CN1086604C

CN1086604C - Process for preparing molybdenum contg. component catalyst for direct gas phase carbonylation of methyl (ethyl) alcohol

Info

Publication number: CN1086604C
Application number: CN99116132A
Authority: CN
Inventors: 彭峰
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 1999-04-06
Filing date: 1999-04-06
Publication date: 2002-06-26
Anticipated expiration: 2019-04-06
Also published as: CN1231942A

Abstract

The present invention relates to a method for preparing a molybdenum comprising component catalyst for the direct gas phase carbonylation of methyl (ethyl) alcohol, which comprises the following steps: ammonium molybdate tetrahydrate is dissolved in water, active carbon is immersed in the ammonium molybdate tetrahydrate dissolved in the water, the content of molybdenum is from 10 to 20%, and the active carbon adsorbing the ammonium molybdate tetrahydrate stands for certain time and stirs for a plurality of times; after a high-temperature drying process for certain time in a constant temperature cabinet, a liquid phase sulfiding process is carried out by ammonium sulphide solution with a certain sulfur content, and the molar ratio of the sulfur to the molybdenum is from 2 to 6; after a standing process for certain time and a high temperature drying process for certain time, reduction activation is carried out by pure hydrogen flow at certain temperature. The method prepares the molybdenum comprising component catalyst for the direct gas phase carbonylation of methyl (ethyl) alcohol, and the molybdenum comprising component catalyst has the advantages of high activity, high selectivity and high stability.

Description

What be used for the pure DIRECT VAPOR-PHASE CARBONYLATION of first (second) contains the molybdenum component method for preparing catalyst

The present invention be used for the pure DIRECT VAPOR-PHASE CARBONYLATION of first (second) contain molybdenum component method for preparing catalyst, metal catalyst preparing technical field.

Carbonylation of methanol system acetic acid is the most important technology path of acetic acid industry in the world at present, the seventies U.S. Meng Shan is Noble Metal Rhodium (Rh)---promoter iodine (I) catalyst system and catalyzing of (Monsanto) company exploitation, makes methyl alcohol liquid-phase carbonylation system acetic acid technology heavy industrialization.But this technology need be used the rhodium of resource scarcity, and needs the circulation of well-designed catalyst to reclaim; In addition, a large amount of iodide make equipment corrosion serious as promoter, and equipment needs expensive Hastelloy steel to make; And product and catalyst separation complex process, iodide reclaim difficulty.Adopting the normal pressure vapor phase method is unusual active research direction both at home and abroad in recent years, and the Ni/C catalyst of load is at present being obtained better experimental result aspect the ordinary-pressure gas-phase carbonylation.But system still need add a large amount of iodide does promoter, otherwise activity is very low.Carbonylation of methanol is still indirect carbonylation process in fact, iodomethane and carbon monoxide carbonylation before this, and then with the methyl alcohol effect, generate methyl acetate, methyl alcohol generates iodomethane with the hydrogen iodide effect that preceding reaction generates again, and reaction cycle is gone down.This is not fundamentally solving equipment corrosion, and iodide reclaim problem.Challenge and solve the problem that existing methyl alcohol liquid phase carbonylation process exists, must develop a kind of DIRECT VAPOR-PHASE CARBONYLATION OF METHANOL new technology, be methyl alcohol direct and the synthetic methyl acetate of carbon monoxide carbonylation or acetic acid under no any promoter, its key is the raw catelyst of the non-halogen of a kind of non-rhodium of exploitation.About the research of this DIRECT VAPOR-PHASE CARBONYLATION OF METHANOL catalyst, the abbreviated message report was once arranged in 1994 abroad, the loaded by heteropoly acid that adopts rhodium (Rh) exchange is at SiO ₂On make catalyst, carry out DIRECT VAPOR-PHASE CARBONYLATION OF METHANOL, though the methyl acetate optimal yield can reach 40%, system still adopts Noble Metal Rhodium and expensive heteropoly acid, and this catalyst just lost activity under 250 ℃ of temperature in 6 hours.In addition, selectivity of product is less than 50%, and half is arranged is the accessory substance dimethyl ether; Also has the CoMo/C catalyst of the sulfuration adopted in addition as the methanol vapor phase carbonylating catalyst, but the Mo/C of sulfuration does not have the carbonylation activity, Co plays the carbonylation active function, its reaction conversion ratio only 20%, product selection rate 50%, space-time yield is extremely low, only is 0.15mol/kgCat.h, does not have further research report at present.

Purpose of the present invention is exactly in order to overcome and to solve that to have the DIRECT VAPOR-PHASE CARBONYLATION OF METHANOL catalyst activity now little, selectivity is low, stability (life-span is short) is poor, and still adopt the shortcoming and the problem of Noble Metal Rhodium and expensive heteropoly acid etc., a kind of high activity of research invention, high selectivity, high stability can realize the industrialized molybdenum component method for preparing catalyst that contains of the pure DIRECT VAPOR-PHASE CARBONYLATION new technology of first (second).

The present invention is achieved through the following technical solutions: originally be used for the Mo/C catalyst that the molybdenum component catalyst is called the reduction of sulfuration back that contains of the pure DIRECT VAPOR-PHASE CARBONYLATION of first (second), it is list (two or many) component composite oxides---the amorphous state structure of sulfide that loads on the containing metal molybdenum (Mo) on the absorbent charcoal carrier; It is to adopt saturated infusion process, be dissolved in the deionized water earlier with chemical pure ammonium molybdate reagent, do carrier impregnation absorption with the high surface active carbon, dissolving ammonium molybdate institute amount of water is a bit larger tham the active carbon saturated water adsorptive value, the water consumption of 10 gram active carbons can be 15～20ml, the consumption of ammonium molybdate is that molybdenum weight content in catalyst is 10～20% in the catalyst, active carbon behind the absorption ammonium molybdate, left standstill 2～5 hours under 20～35 ℃ of the room temperatures, stir therebetween and make it even for 2～3 times, in insulating box dry 5～10 hours then, 100～120 ℃ of temperature made pre-catalyst; Liquid phase sulfuration method is adopted in the sulfuration of pre-catalyst, its vulcanizing agent employing sulfur content is 8～12% ammonium sulfide solution, ammonium sulfide solution slowly joins in the pre-catalyst and constantly and stirs, making itself and ammonium molybdate reaction generate sediment is adsorbed on the active carbon surfaces externally and internally, the ammonium sulfide consumption is that sulphur and molybdenum mol ratio are 2～6, pre-catalyst after the sulfuration left standstill 3～5 hours, stir therebetween 2～3 times, in thermostatic drying chamber slowly dry 10～20 hours, 105～115 ℃ of temperature make the Mo/C catalyst of sulfuration of the present invention; Catalyst after the sulfuration directly carries out the reaction of the pure vapor phase carbonylation of first (second), and is active very low with selectivity, even 400 ℃ of heat treatment several hours in nitrogen stream, catalyst selectivity is still very low.The present invention also adopts the flow of pure hydrogen reduction activation, reduction 1 gram catalyst hydrogen flow rate is 30～60ml/min, reduction temperature is 400～500 ℃, recovery time is 1～3 hour, this just be prepared into a kind of high activity, high selectivity, high stability be used for the pure DIRECT VAPOR-PHASE CARBONYLATION of first (second) contain the molybdenum component catalyst---i.e. the Mo/C catalyst of sulfuration back reduction.

The catalyst that adopts the present invention to make carries out the pure DIRECT VAPOR-PHASE CARBONYLATION reaction of first (second), its reaction process condition is: 260～300 ℃ of reaction temperatures, reaction velocity GHSV can change at 3000～10000L/kgCat.h, carbon monoxide and methanol feeding mol ratio can change between 2～12, and catalyst of the present invention can obtain high carbonylation activity in the gas-solid phase reaction bed in these scopes.

The present invention compared with prior art, following advantage and beneficial effect are arranged: (1) with the catalyst activity height of the present invention preparation, and selectivity height, good stability, life-span are long, are used for gas-solid phase continuous process, its life-span has been investigated 48 hours, and its active nothing obviously descends; (2) the inventive method can make the Mo/C catalyst of the monometallic component of no carbonylation activity have high activity, high selectivity; (3) the present invention has proved that the pure DIRECT VAPOR-PHASE CARBONYLATION activity of such catalysts of first (second) is amorphous state mutually, and by the preparation method of this optimization, active component becomes the individual layer decentralized photo to form amorphous state on carrier active carbon, has high carbonylation activity; (4) catalyst that makes of the inventive method, not only adapt to and be used for the acetic acid synthesized methyl esters of DIRECT VAPOR-PHASE CARBONYLATION OF METHANOL, therefore the same propionic acid synthesized ethyl ester of ethanol DIRECT VAPOR-PHASE CARBONYLATION that is suitable for, can progressively realize the industrialization of the pure DIRECT VAPOR-PHASE CARBONYLATION new technology of first (second).React under 260 ℃ of temperature, carbonylation product selection rate can reach 86.2%, and the product space-time yield can reach more than the 16mol/kgCat.h, has increased more than 100 times than literature value.Particularly bimetallic component CoMo is become monometallic component Mo, the sulfuration Mo/C catalyst of the no carbonylation activity of original report has been created the new Mo/C catalyst that reduces after the sulfuration that becomes to have premium properties by preparation method of the present invention, had breakthrough.The present invention brings up to level near suitability for industrialized production to the methyl acetate space-time yield, for realizing that first (second) alcohol direct and carbon monoxide gas phase carbonylation system methyl acetate new technology in the presence of no any promoter provides catalyst of new generation, has substantial economics.

Enforcement ratio of the present invention is easier to, as long as operate enforcement by the described preparation method of top specification, just can implement the present invention preferably.The inventor has various successful embodiment through long term studies, only enumerates several embodiment below, and tabulation as shown in Table 1.

Table one

Continuous table

Claims

1, a kind of be used for methyl alcohol or ethanol DIRECT VAPOR-PHASE CARBONYLATION contain the molybdenum component method for preparing catalyst, it is characterized in that: it be load on containing metal molybdenum Mo on the absorbent charcoal carrier the two or multi-component composite oxides of list---the amorphous state structure of sulfide: it adopts saturated infusion process, be dissolved in chemical pure ammonium molybdate reagent in the deionized water earlier, do carrier impregnation absorption with the high surface active carbon, dissolving ammonium molybdate institute amount of water is a bit larger tham the active carbon saturated water adsorptive value, the water consumption of 10 gram active carbons can be 15～20ml, the consumption of ammonium molybdate is that molybdenum weight content in catalyst is 10～20% in the catalyst, active carbon behind the absorption ammonium molybdate, left standstill 2～5 hours under 20～35 ℃ of the room temperatures, stir therebetween and make it even for 2～3 times, in insulating box dry 5～10 hours then, 100～120 ℃ of temperature make pre-catalyst; Liquid phase sulfuration method is adopted in the sulfuration of pre-catalyst, its vulcanizing agent employing sulfur content is 8～12% ammonium sulfide solution, very long the joining in the pre-catalyst and constantly of ammonium sulfide solution stirred, making itself and ammonium molybdate reaction generate sediment is adsorbed on the active carbon surfaces externally and internally, the ammonium sulfide consumption is that sulphur and molybdenum mol ratio are 2～6, pre-catalyst after the sulfuration left standstill 3～5 hours, stir therebetween 2～3 times, in thermostatic drying chamber slowly dry 10～20 hours, 105～115 ℃ of temperature make the Mo/C catalyst of sulfuration of the present invention; Adopt the flow of pure hydrogen reduction activation again, reduction 1 gram catalyst, hydrogen flow rate is 30～60ml/min, reduction temperature is 400～500 ℃, recovery time is 1～3 hour, this just is prepared into a kind of high activity, high selects, high stability be used for methyl alcohol or ethanol DIRECT VAPOR-PHASE CARBONYLATION contain the molybdenum component catalyst.