CA1256903A - Production of c.sub.2 -c.sub.6 aliphatic alcohols - Google Patents
Production of c.sub.2 -c.sub.6 aliphatic alcoholsInfo
- Publication number
- CA1256903A CA1256903A CA000516720A CA516720A CA1256903A CA 1256903 A CA1256903 A CA 1256903A CA 000516720 A CA000516720 A CA 000516720A CA 516720 A CA516720 A CA 516720A CA 1256903 A CA1256903 A CA 1256903A
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- weight percent
- surface area
- aliphatic alcohols
- micromoles
- 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.)
- Expired
Links
Abstract
(D#78,276-F) ABSTRACT
A method is provided for preparing a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms by reacting a mixture of carbon monoxide and hydrogen under suitable conditions of temperature and pressure in the presence of a catalyst comprising molybdenum, a metal from the group consisting of cobalt, iron and nickel, and copper, said catalyst being modified by the addition of a promoter from the class consisting of potassium, cesium and rubidium, said promoter being employed at a concentration ranging from about 1.8 to 13.0 micromoles of said alkali per square meter of surface area of said catalyst.
A method is provided for preparing a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms by reacting a mixture of carbon monoxide and hydrogen under suitable conditions of temperature and pressure in the presence of a catalyst comprising molybdenum, a metal from the group consisting of cobalt, iron and nickel, and copper, said catalyst being modified by the addition of a promoter from the class consisting of potassium, cesium and rubidium, said promoter being employed at a concentration ranging from about 1.8 to 13.0 micromoles of said alkali per square meter of surface area of said catalyst.
Description
~L~5~
PROD~C'rION OF C2-C6 ALIPHATIC ALCOHOLS
(D-~78,276-F) BACKGROUND OF TEIE INVENTION
Field of the Invention This invention relates to a process for preparing lower aliphatic alcohols. More particularly, this invention relates to the production of a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of alcohols having from 2 to 6 carbon atoms.
Lower aliphatic alcohols have been proposed as fuel extenders or as replacements for gasoline for fueling internal combustion engines. Certain mixtures of lower aliphatic alcohols have the EPA approval for use and are currently being marketed in the United States. The lower aliphatic alcohols can be produced from domestically available non-petroleum sources, and their use in fuels would serve to lessen the dependence o the nation on imported petroleum and petroleum products.
Elydrogen and carbon monoxide, or a synthesis gas mixture of hydrogen and carbon monoxide, can be react~d to orm lower aliphatic alcohols. The synthesis gas feed stream can be produced rom non-petroleum sources, such as coal, biomass or other hydrocarbonaceous materials. The synthesis gas mixture itsel is produced in a partial oxidation reaction of the hydrocarbonaceous material in co~mercially available processes such as coal gasification.
Numerous catalytic processes have heen studied in attempts to provide a viable process for the production of aliphatic alcohols from synthesis yas or from a mixture o hydrogen and carbon monoxide. Hexetofore, the emphasis has been primarily directed to the production of methanol. In contrast~ the present process is directed to a method for producing an alcohol mixture containing a substantial amount of aliphatic alcohols having from 2 to 6 carbon atoms. Under :
~a~
69(~
60~ 2772 selected reaction condltions, this process is effective for pro-ducing a ~raction of higher aliphatic alcohols, i.e. an alcohol fraction consisting of C2 to C6 alcohols, which represents the major or predominant alcohol production in this process.
_isclosure Statement U.S. 1,201,850 discloses a method for the production of hydrocarbons and oxygenated compouncls oE hydrocarbons by passiny an oxide of carbon and hydrogen over a heated ca-talytic agent under a pressure exceeding 5 atmospheres. ~ number oE catalytic materials are disclosed as well as the fact that a basic compound, such as an alkaline metal hydroxide, can be used with the pre-scribed catalytic agents.
U.S. 1,625,929 discloses a process for producing methanol in which the catalyst contains copper, cobalt and a metallic halide.
U.S. 3,345,427 discloses a dehydrogenation catalyst and process in which the catalys-t consists of nickel, molybdenum and alkali metal oxides on an alumina support.
U.S. 4,096,164 discloses a process for reacting hydrogen and carbon monoxide in the presence oE a solid catalyst comprising rhodium with molybdenum or tungsten to produce two carbon atom oxygenated hydrocarbons in which e-thanol is the major component.
U.S. 4,199,522 discloses a Fischer-Tropsch process for producing oleEins.
U.S. 4,235,801 and 4,246,186 disclose the produc-tion of alcohols from a mixture of carbon monoxide and hydrogen in the presence of a rhenium catalyst.
~i~56~C~3 U.S. 4,380,589 discloses a Fischer-Tropsch process :Eor producing nydrocarbons with irnproved selectivity to C2-C4 ole~ins by contacting hydrogen and carbon monoxide in the presence of a catalyst. The catalyst disclosed comprises molybdenum, a promoter cornprising alkali or alkaline earth - 2a -., 6 9 C)~
metal, and a binder comprising an iron-containing calcium aluminate cement.
South A~rican Patent No. 8,401,982 discloses a process for producing alcohols from synthesis gas using a catalyst containing molybdenum with tungsten, rhenium and an alkali metal.
United Stat~s Patent 4,492,772 discloses a similar process in ~hich the catalyst contains rhenium, molybdenum and potassium.
United States Patent 4,661,525 is directed to a process for producing lower aliphatic alcohols from a mixture of carbon monoxide and hydrogen.
Previous catalytic processes have been notably effective for converting carbon monoxide and hydrogen feedstocks into hydro-carbons or methanol, but none have been particularly effective for providing high yields of a lower aliphatic alcohol mixture charac~erized by having a substantial or greater weight amount of alcohols having from 2 to 6 carbon atoms as compared to the co-produced methanol.
SUMMARY OF THE INVE~TION
It has been discovered that a mixture of carbon monoxide and hydrogen can be reacted to form a mixture of lower aliphatic alcohols containing a substantial amount of aliphatic alcohols having from 2 to 6 carbon atoms. This reaction is conductecl by contacting a ieed mixture such as synthesis gas with a novel catalyst composition which exhibits good selectivity for the production of C2-C6 aliphatic alcohols under suitable conditions of temperature and pressure. The effective catalyst composition comprises a mixture of molybdenuYD, a metal from the group ~ "r~ , .,,, .~
~5~9~
consisting of cobal~, iron and nickel, and copper. This metal catalyst composition is modified by the addition of a critical amount of an alkali metal promoter from khe class consisting of potassium, cesium and rubiclium in an amount ranging from about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst thereby forming a promoted or modified catalyst.
DETAIL~D EHBODIMENTS OF THE I~VE~TION
In accordance with this invention, a mixture of carbon monoxide and hydrogen a~, for example, a synthesis gas mixture of said reactants, is reacted over a catalyst comprising molybdenum, a metal from the group consisting of cobalt, iron and nickel, and copper, which has been modified by ~he addition of a promoter from the group consisting of potassium, cesium and rubidium, said promoter being employed at a concentration ranging ~rom about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst. The nature and the concentration of the promoter on the catalyst are critical. Concentrations of promoter outside of the prescribed range result in a sharp reduction in the effective-ness of this process.
According to one aspect of the present invention there ls provided a method for preparing lower aliphatic alcohols characterized by producing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 240 to about 400C, a pressure from about 500 to about 3000 psl and a gas hourly space velocity of at least 1000, said catalyst comprising from about 5 to about 50 weight .~.
~5~9~)~
S028~-2772 percent of molybdenum calculated as MoO3, rom about 0.3 to about 15 weiyht pe~cent of a metal selected from ~he group consisting of cobal-t, iron and nickel, calculated as CoO, Fe203 or NiO, respectively, and from about 1.5 to 8 weight percent of copper, calculated as CuO, and the balance a support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubidlum in an amount ranging from about 1.8 to 13.0 micromoles of said alkali metal per square of catalyst surface area.
According to a further aspect of the present invention there is provided a method for preparing lower aliphatic alcohols in which ~he weight ratio of the C2-C6 alcohols to methanol is greater than 1 which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 270 to 360C, a pressure from about 750 to 2500 psi ancl a gas hourly space velocity in the range from about 10,000 to 30,000, said catalyst comprising from about 7 to 30 weight percent of molybdenum calculated as MoO3, from about 0.5 to 10 weight percent of a metal or mixture of metals selected from the group consisting of cobalt, iron and nickel calculated as CoO, Fe203 or NiO
respectively, and from about 2 to 6 waight percent of copper calculated as CuO, and the balance an alumina support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubiclium in an amount ranging from about 2.2 to 10.0 micromoles of said alkali metal per square meter of catalyst surface area.
Table I (set forth hereinafter) gives results obtained ~L~S~3;:~
fro~ this process at differ~nt concen~rations of the copper component in the ca-talyst. The Table gives the values for C
alcohol produc-tivlty in terms of grams of alcohol per gram of catalyst per hour. The Table fuxther expresses the concentration of the novel component copper as copper oxide (CuO) in the catalyst. Data in the Table show that a process which employs a copper-containing potassium-promoted cobalt molybdenum catalyst conducted at 343C is effective for the production of substantial amounts of C2-C6 lower aliphatic alcohols. The selectivity of the catalyst for C2-C6 alcohol production is surprisingly improved when the copper concentration in the catalyst is about 1.5 weight percent or more calculated as CuO.
In United States Patent No. 4,661,525, it has been shown that the critical concentration range for the alkali promoter is an amount from about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst. A preferred alkali promoter concentration is from 2.2 to 10.0 micromoles of alkali per square meter of catalyst surface area with the most preferred alkali promoter concentration being from about 2.5 to about 9.0 micromoles of alkali per square meter of catalyst surface area.
Preferably the support is from about 60 to 80 wei~ht percent of the catalyst. The metal components of the catalyst may be in the free or comhined form.
The catalyst can be prepared in a number of ways known in the art. In general, the use of a catalyst support or carrier comprising a relatively refractory, porous, adsorptive and high surface area material is preferred. Conventional carriers or - 5a -;6~3 60~88-2772 supports, such as alumina, sllica, titan1a, maynesia, silica-alumina and boron phosphates, are suitable support materials for preparing the catalyst for this process. The disclosl1re in United Sta~es 4,098,683 is illustrative.
A preferred method for preparlng the catalyst is to impregnate a carrier, such as alumlna, with a source of molybdenum generally in the form of a soluble salt, then with a metal from the class of cobalt, nickel and iron, generally also in the iorm of a soluble salt and finally with copper in the form of a soluble salt. The impregnation of the carrler wlth the catalyst metals can be done simultaneously or step-wise. The impregnated carrier is dried and then calcined according to known procedures.
It is essential that the catalyst be modified, i.e.
~reated or impregnated, with an alkali metal promoter from the group of potassium, cesium or rubidium generally in the form o~ a salt. The treated or modified catalyst is then subjected to reduction with hydrogen gas generally by heating the promoted catalyst at a temperature between about 300 and 500C for an extended period, usually 2 to 8 hours.
The catalyst comprises from about 5 to 50 weight percent of molybdenum calculated as molybdenum trioxide, from about 0.3 to 15 weight percent of a metal from the group consisting of cobalt, nickel and iron calculated as the respective oxide CoO, NiO or Fe203 or mixtures thereof, and - 5b -~ .
, ~56~
from about 1.5 to 8 weigh~ percent of copper as copper oxid~
(CuO), with the balance being the support. A preferred catalyst composition comprises from about 7 to 30 weight percen~ of molybdenum trioxide, from about 0.5 to 10 weight percent of cobalt, nickel, or iron oxide or a combination thereof and from about 2 to 6 weight percent of copper. Still more preferred is a catalyst comprising from about 7 to 12 weight percent molybdenum, from about 1.5 to 5 weight percent of a me~al from the group consisting of cobalt, iron and nickel or a mixture thereof and from about 2.5 to 5 weight percent of copper, all calculated as hereinabove described.
The catalyst should have a surface area of 125 m2/gm (square meters per gram of catalyst) or more. A more effective catalyst will have a surface area from about 150 to 350 m2/gm and the most preferred will have a surface area from about 160 to 300 m /gm.
Alternatively, a commercially available catalyst comprising molybdenum, one or more of the metals from the class consisting of sobalt, nickel and iron, and copper meeting the foregoing specifications can be impregnated or modified by treatment with the prescribed alkali metal and then reduced under hydrogen and treated as noted above.
The carbon monoxide and hydrogen employed to form the lower aliphatic alcohols in this process can be provided from any available source. One particularly useful source is synthesis gas produced in the gasification of hydrocarbonaceous materials, such as coals and biomassO An effective gasifica-tion process is described in U.S. 3,54~,291 wherein a hydro-carbonaceous fuel is partially oxidized with a free oxygen-containing gas in a gas generator. In general, the mole ratio of hydrogen to carbon monoxide employed in this process should range from about 0.1 to 50 moles of hydrogen per mole of carbon monoxide with the preferred ratio being from about 0.5 to 20 moles of hydrogen per mole of carbon monoxide.
The reaction conditions for effecting the conversion of the carbon monoxide-hydrogen feed into lower aliphatic alcohols employing the prescribed catalyst of t~e invention include a reaction temperature ranging from about 2~0 to about 400C with a preferred temperature range being from about 270 to 360C and the most preferred temperature being from about 290 to about 350C. The effective pressure range for this process is from about 3.4 X 106 Pa (500 psi) to about 2.4 X
107 Pa (3500 psi). The preferred pressure range is from about 5.1 X 106 Pa (750 psi) to about 1.7 X 107 Pa (2500 psi~.
The space velocity employed to effect the conversion of carbon monoxide and hydrogen over the prescribed catalyst to the aliphatic alcohols is a vital feature of this process. In general, the space velocity, that is the volume of gas passed through a given volume of catalyst per hour expressed as GHSV(hr 1), must be at least 1000. A preferred range is from about 5000 to about 50,000. A highly effective process is realized when the space velocity employed ranges from about 10,000 to about 30/000. Under preferred conditions the ratio of weight percent of C2-C6 alcohols to weight percent methanol can exceed 1, and more preferably can be from 1.25 to 2.
The present invention is more fully described in the following Examples. The reactor used for this work was a 1"
I.D. type 316 stainless steel tube. lOcc of the catalyst was diluted with 90cc of alpha alumina and packed into the reactor.
The catalyst was reduced for 4 hours, at 400C, at a pressure 25 of 1500 psig with a flow of hydrogen gas at 2.5 liters per minute. The catalyst was then cooled to reaction temperature and subjected to a mixture of hydrogen and carbon monoxide in a ratio of 2:1, at a pressure o 1500 psig and a GHSV of 28,000 hr 1.
The product emerging from the reactor was sent through a condensor which liquefied the alcohols and water products. The resulting liquid was analyzed by gas chroma-tography. The non-condensable gas was also analyzed by gas chromatography.
The selectivity to hydrocarbons, methanol, and alcohols containing 2 to 6 carbon atoms is set forth in the table. The alcohol production in grams of alcohol per gram o~
catalyst per hour is also set forth in the table~ Selectivity is defined as the percentage of carbon atoms converted from carbon monoxide to a specified compound or compounds.
~XAMPLE 1 A promoted catalyst was prepared by impregnating a commercially available catalyst comprising cobalt and molybdenum on an alumina carrier first with a solution of copper nitrate, and after calcination with a solution of potassium carbonate. The commercial catalyst was made by Armak catalyst division, Pasadena, Texas and sold under the name Ketjen KF 124 LD~ The copper nitrate solution was made by dissolving 1.2 grams of copper nitrate in 50cc of distilled water which was then added to 98.8 grams of the catalyst. The impregnated catalyst was then dried and calcined at 450C for several hours. After calcination a solution of 5.9 grams of potassium carbonate, in distilled water, was added to 33.0 grams of the calcined catalyst. This was then dried in a nitrogen purged vacuum oven at 135C for several hours. The chemical analysis of the catalyst is set forth in the table under Example 1.
A second promoted catalyst was made as in example 1, however, the ca~alyst was impregnated with a solution made by dissolving 4.8 grams of copper nitrate in 50cc of distilled water, which was added to 95.2 grams of the catalyst. After drying and calcination a solution of 5.6 grams of potassium carbonate, dissolved in distilled water, was added to 32 grams of the calcined catalyst. This was then dried in a vacuum oven for several hours. The chemical analysis of the catalyst is set forth in the table under example 2.
A promoted catalyst was made as in example 1 r however, the catalyst was impregnated with a solution made by dissolving 9.5 grams of copper nitrate in 50cc of distilled ~r~ k -8-9i~
water, ~hich ~as added to 90.5 grams of the catalyst. After drying and calcination a solution of 5.1 grams of potassium carbonate, dissolved in distilled water, was added to 29.0 grams of the calcined catalyst. The catalyst was then dried in a vacuum oven at 135C for s~veral hours. The chemical analysis of this catalyst is set forth in the table under example 3.
EXAMPI,E 4 -A promoted catalyst was made as in example 1, however, the catalyst was impregnated with a solution made by dissolving 18.2 grams of copper nitrate in 60cc of distilled water, which was added to 81.0 grams of the catalyst. Aftex drying and calcination a solution of 13.1 grams of potassium carbonate, dissolved in distilled water, was added to the calcined catalyst. The cat,alyst was then dried at 125~C for several hours, The chemical analysis of this catalyst is set forth in the table under example 4.
This catalys~ was tested in a 0.5 liter stainless steel Berty~ type recirculating gradientless reactor from,, Autoclave Engineers. 20cc of catalyst was used~ The conditions for the test were the same as ~hose previously described except that the hydxogen flow during reduction was 5 liters per minute instead of 2.5 liters per minute~
A promoted catalyst was made as in example 1, however, no copper nitrate was added. 30 grams of potassium carbonate, dissolved in 90cc of distilled water was added to 170 grams of the base catalyst (KF 124 LD). This was then dried at 135C for several hours. The chemical analysis of this catalyst is set forth in the table under example 4.
~ ~r~ ~a r k _g_ o~
TABLE I
~Comp.) Cataly~t Composition Wt%
3 9-9 9-5 9.5 8.7 9.7 CoO 3.4 3.4 3.4 3.0 3.1 10 CuO 0.4 1.7 3.4 6.2 -~-A123 78.3 77.9 75.7 73.1 78.3 K2O 8.0 7.5 8.0 9.0 8.9 H2/CO Ratio 2.0 2.0 2.0 2.0 2.0 15 Temperature C 343 343 343 3~3 343 GHSV(HR ) 28,00028,00028,00028,00028,000 Pressure Pa lx107 lx107 lx107 lx107 lx107 -Mole K = 6.2 5.8 6.2 6.9 6.9 M
Selectivity 1%) To 25 C1-C6 Hydrocarbons 20 21 21 32 31 MeOH 12 10 14 7 7 C2-C6 Alcvhols 19 17 22 13 17 Alcohol Production 0.240.35 0.50 0.42 0.27 IG/G-hr) C2-C6 Alcohols Wt% _ 1.6 1.7 1.6 1.8 2.4 MeOH Liquids Wt%
C2+Alc.Prod. (G/G-hr3 0.150.22 0.30 0.27 0.19 The foregoing examples demonstrate that a process for the production of lower aliphatic alcohols from a mixture of carbon monoxide and hydrogen within the critical parameters for the prescribed catalyst modified or promoted with the specified alkali metal is effective for produc.ing a high yield of C2-C6 aliphatic alcohols in relation to the production of methanolO
PROD~C'rION OF C2-C6 ALIPHATIC ALCOHOLS
(D-~78,276-F) BACKGROUND OF TEIE INVENTION
Field of the Invention This invention relates to a process for preparing lower aliphatic alcohols. More particularly, this invention relates to the production of a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of alcohols having from 2 to 6 carbon atoms.
Lower aliphatic alcohols have been proposed as fuel extenders or as replacements for gasoline for fueling internal combustion engines. Certain mixtures of lower aliphatic alcohols have the EPA approval for use and are currently being marketed in the United States. The lower aliphatic alcohols can be produced from domestically available non-petroleum sources, and their use in fuels would serve to lessen the dependence o the nation on imported petroleum and petroleum products.
Elydrogen and carbon monoxide, or a synthesis gas mixture of hydrogen and carbon monoxide, can be react~d to orm lower aliphatic alcohols. The synthesis gas feed stream can be produced rom non-petroleum sources, such as coal, biomass or other hydrocarbonaceous materials. The synthesis gas mixture itsel is produced in a partial oxidation reaction of the hydrocarbonaceous material in co~mercially available processes such as coal gasification.
Numerous catalytic processes have heen studied in attempts to provide a viable process for the production of aliphatic alcohols from synthesis yas or from a mixture o hydrogen and carbon monoxide. Hexetofore, the emphasis has been primarily directed to the production of methanol. In contrast~ the present process is directed to a method for producing an alcohol mixture containing a substantial amount of aliphatic alcohols having from 2 to 6 carbon atoms. Under :
~a~
69(~
60~ 2772 selected reaction condltions, this process is effective for pro-ducing a ~raction of higher aliphatic alcohols, i.e. an alcohol fraction consisting of C2 to C6 alcohols, which represents the major or predominant alcohol production in this process.
_isclosure Statement U.S. 1,201,850 discloses a method for the production of hydrocarbons and oxygenated compouncls oE hydrocarbons by passiny an oxide of carbon and hydrogen over a heated ca-talytic agent under a pressure exceeding 5 atmospheres. ~ number oE catalytic materials are disclosed as well as the fact that a basic compound, such as an alkaline metal hydroxide, can be used with the pre-scribed catalytic agents.
U.S. 1,625,929 discloses a process for producing methanol in which the catalyst contains copper, cobalt and a metallic halide.
U.S. 3,345,427 discloses a dehydrogenation catalyst and process in which the catalys-t consists of nickel, molybdenum and alkali metal oxides on an alumina support.
U.S. 4,096,164 discloses a process for reacting hydrogen and carbon monoxide in the presence oE a solid catalyst comprising rhodium with molybdenum or tungsten to produce two carbon atom oxygenated hydrocarbons in which e-thanol is the major component.
U.S. 4,199,522 discloses a Fischer-Tropsch process for producing oleEins.
U.S. 4,235,801 and 4,246,186 disclose the produc-tion of alcohols from a mixture of carbon monoxide and hydrogen in the presence of a rhenium catalyst.
~i~56~C~3 U.S. 4,380,589 discloses a Fischer-Tropsch process :Eor producing nydrocarbons with irnproved selectivity to C2-C4 ole~ins by contacting hydrogen and carbon monoxide in the presence of a catalyst. The catalyst disclosed comprises molybdenum, a promoter cornprising alkali or alkaline earth - 2a -., 6 9 C)~
metal, and a binder comprising an iron-containing calcium aluminate cement.
South A~rican Patent No. 8,401,982 discloses a process for producing alcohols from synthesis gas using a catalyst containing molybdenum with tungsten, rhenium and an alkali metal.
United Stat~s Patent 4,492,772 discloses a similar process in ~hich the catalyst contains rhenium, molybdenum and potassium.
United States Patent 4,661,525 is directed to a process for producing lower aliphatic alcohols from a mixture of carbon monoxide and hydrogen.
Previous catalytic processes have been notably effective for converting carbon monoxide and hydrogen feedstocks into hydro-carbons or methanol, but none have been particularly effective for providing high yields of a lower aliphatic alcohol mixture charac~erized by having a substantial or greater weight amount of alcohols having from 2 to 6 carbon atoms as compared to the co-produced methanol.
SUMMARY OF THE INVE~TION
It has been discovered that a mixture of carbon monoxide and hydrogen can be reacted to form a mixture of lower aliphatic alcohols containing a substantial amount of aliphatic alcohols having from 2 to 6 carbon atoms. This reaction is conductecl by contacting a ieed mixture such as synthesis gas with a novel catalyst composition which exhibits good selectivity for the production of C2-C6 aliphatic alcohols under suitable conditions of temperature and pressure. The effective catalyst composition comprises a mixture of molybdenuYD, a metal from the group ~ "r~ , .,,, .~
~5~9~
consisting of cobal~, iron and nickel, and copper. This metal catalyst composition is modified by the addition of a critical amount of an alkali metal promoter from khe class consisting of potassium, cesium and rubiclium in an amount ranging from about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst thereby forming a promoted or modified catalyst.
DETAIL~D EHBODIMENTS OF THE I~VE~TION
In accordance with this invention, a mixture of carbon monoxide and hydrogen a~, for example, a synthesis gas mixture of said reactants, is reacted over a catalyst comprising molybdenum, a metal from the group consisting of cobalt, iron and nickel, and copper, which has been modified by ~he addition of a promoter from the group consisting of potassium, cesium and rubidium, said promoter being employed at a concentration ranging ~rom about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst. The nature and the concentration of the promoter on the catalyst are critical. Concentrations of promoter outside of the prescribed range result in a sharp reduction in the effective-ness of this process.
According to one aspect of the present invention there ls provided a method for preparing lower aliphatic alcohols characterized by producing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 240 to about 400C, a pressure from about 500 to about 3000 psl and a gas hourly space velocity of at least 1000, said catalyst comprising from about 5 to about 50 weight .~.
~5~9~)~
S028~-2772 percent of molybdenum calculated as MoO3, rom about 0.3 to about 15 weiyht pe~cent of a metal selected from ~he group consisting of cobal-t, iron and nickel, calculated as CoO, Fe203 or NiO, respectively, and from about 1.5 to 8 weight percent of copper, calculated as CuO, and the balance a support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubidlum in an amount ranging from about 1.8 to 13.0 micromoles of said alkali metal per square of catalyst surface area.
According to a further aspect of the present invention there is provided a method for preparing lower aliphatic alcohols in which ~he weight ratio of the C2-C6 alcohols to methanol is greater than 1 which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 270 to 360C, a pressure from about 750 to 2500 psi ancl a gas hourly space velocity in the range from about 10,000 to 30,000, said catalyst comprising from about 7 to 30 weight percent of molybdenum calculated as MoO3, from about 0.5 to 10 weight percent of a metal or mixture of metals selected from the group consisting of cobalt, iron and nickel calculated as CoO, Fe203 or NiO
respectively, and from about 2 to 6 waight percent of copper calculated as CuO, and the balance an alumina support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubiclium in an amount ranging from about 2.2 to 10.0 micromoles of said alkali metal per square meter of catalyst surface area.
Table I (set forth hereinafter) gives results obtained ~L~S~3;:~
fro~ this process at differ~nt concen~rations of the copper component in the ca-talyst. The Table gives the values for C
alcohol produc-tivlty in terms of grams of alcohol per gram of catalyst per hour. The Table fuxther expresses the concentration of the novel component copper as copper oxide (CuO) in the catalyst. Data in the Table show that a process which employs a copper-containing potassium-promoted cobalt molybdenum catalyst conducted at 343C is effective for the production of substantial amounts of C2-C6 lower aliphatic alcohols. The selectivity of the catalyst for C2-C6 alcohol production is surprisingly improved when the copper concentration in the catalyst is about 1.5 weight percent or more calculated as CuO.
In United States Patent No. 4,661,525, it has been shown that the critical concentration range for the alkali promoter is an amount from about 1.8 to 13.0 micromoles of alkali per square meter of surface area of the catalyst. A preferred alkali promoter concentration is from 2.2 to 10.0 micromoles of alkali per square meter of catalyst surface area with the most preferred alkali promoter concentration being from about 2.5 to about 9.0 micromoles of alkali per square meter of catalyst surface area.
Preferably the support is from about 60 to 80 wei~ht percent of the catalyst. The metal components of the catalyst may be in the free or comhined form.
The catalyst can be prepared in a number of ways known in the art. In general, the use of a catalyst support or carrier comprising a relatively refractory, porous, adsorptive and high surface area material is preferred. Conventional carriers or - 5a -;6~3 60~88-2772 supports, such as alumina, sllica, titan1a, maynesia, silica-alumina and boron phosphates, are suitable support materials for preparing the catalyst for this process. The disclosl1re in United Sta~es 4,098,683 is illustrative.
A preferred method for preparlng the catalyst is to impregnate a carrier, such as alumlna, with a source of molybdenum generally in the form of a soluble salt, then with a metal from the class of cobalt, nickel and iron, generally also in the iorm of a soluble salt and finally with copper in the form of a soluble salt. The impregnation of the carrler wlth the catalyst metals can be done simultaneously or step-wise. The impregnated carrier is dried and then calcined according to known procedures.
It is essential that the catalyst be modified, i.e.
~reated or impregnated, with an alkali metal promoter from the group of potassium, cesium or rubidium generally in the form o~ a salt. The treated or modified catalyst is then subjected to reduction with hydrogen gas generally by heating the promoted catalyst at a temperature between about 300 and 500C for an extended period, usually 2 to 8 hours.
The catalyst comprises from about 5 to 50 weight percent of molybdenum calculated as molybdenum trioxide, from about 0.3 to 15 weight percent of a metal from the group consisting of cobalt, nickel and iron calculated as the respective oxide CoO, NiO or Fe203 or mixtures thereof, and - 5b -~ .
, ~56~
from about 1.5 to 8 weigh~ percent of copper as copper oxid~
(CuO), with the balance being the support. A preferred catalyst composition comprises from about 7 to 30 weight percen~ of molybdenum trioxide, from about 0.5 to 10 weight percent of cobalt, nickel, or iron oxide or a combination thereof and from about 2 to 6 weight percent of copper. Still more preferred is a catalyst comprising from about 7 to 12 weight percent molybdenum, from about 1.5 to 5 weight percent of a me~al from the group consisting of cobalt, iron and nickel or a mixture thereof and from about 2.5 to 5 weight percent of copper, all calculated as hereinabove described.
The catalyst should have a surface area of 125 m2/gm (square meters per gram of catalyst) or more. A more effective catalyst will have a surface area from about 150 to 350 m2/gm and the most preferred will have a surface area from about 160 to 300 m /gm.
Alternatively, a commercially available catalyst comprising molybdenum, one or more of the metals from the class consisting of sobalt, nickel and iron, and copper meeting the foregoing specifications can be impregnated or modified by treatment with the prescribed alkali metal and then reduced under hydrogen and treated as noted above.
The carbon monoxide and hydrogen employed to form the lower aliphatic alcohols in this process can be provided from any available source. One particularly useful source is synthesis gas produced in the gasification of hydrocarbonaceous materials, such as coals and biomassO An effective gasifica-tion process is described in U.S. 3,54~,291 wherein a hydro-carbonaceous fuel is partially oxidized with a free oxygen-containing gas in a gas generator. In general, the mole ratio of hydrogen to carbon monoxide employed in this process should range from about 0.1 to 50 moles of hydrogen per mole of carbon monoxide with the preferred ratio being from about 0.5 to 20 moles of hydrogen per mole of carbon monoxide.
The reaction conditions for effecting the conversion of the carbon monoxide-hydrogen feed into lower aliphatic alcohols employing the prescribed catalyst of t~e invention include a reaction temperature ranging from about 2~0 to about 400C with a preferred temperature range being from about 270 to 360C and the most preferred temperature being from about 290 to about 350C. The effective pressure range for this process is from about 3.4 X 106 Pa (500 psi) to about 2.4 X
107 Pa (3500 psi). The preferred pressure range is from about 5.1 X 106 Pa (750 psi) to about 1.7 X 107 Pa (2500 psi~.
The space velocity employed to effect the conversion of carbon monoxide and hydrogen over the prescribed catalyst to the aliphatic alcohols is a vital feature of this process. In general, the space velocity, that is the volume of gas passed through a given volume of catalyst per hour expressed as GHSV(hr 1), must be at least 1000. A preferred range is from about 5000 to about 50,000. A highly effective process is realized when the space velocity employed ranges from about 10,000 to about 30/000. Under preferred conditions the ratio of weight percent of C2-C6 alcohols to weight percent methanol can exceed 1, and more preferably can be from 1.25 to 2.
The present invention is more fully described in the following Examples. The reactor used for this work was a 1"
I.D. type 316 stainless steel tube. lOcc of the catalyst was diluted with 90cc of alpha alumina and packed into the reactor.
The catalyst was reduced for 4 hours, at 400C, at a pressure 25 of 1500 psig with a flow of hydrogen gas at 2.5 liters per minute. The catalyst was then cooled to reaction temperature and subjected to a mixture of hydrogen and carbon monoxide in a ratio of 2:1, at a pressure o 1500 psig and a GHSV of 28,000 hr 1.
The product emerging from the reactor was sent through a condensor which liquefied the alcohols and water products. The resulting liquid was analyzed by gas chroma-tography. The non-condensable gas was also analyzed by gas chromatography.
The selectivity to hydrocarbons, methanol, and alcohols containing 2 to 6 carbon atoms is set forth in the table. The alcohol production in grams of alcohol per gram o~
catalyst per hour is also set forth in the table~ Selectivity is defined as the percentage of carbon atoms converted from carbon monoxide to a specified compound or compounds.
~XAMPLE 1 A promoted catalyst was prepared by impregnating a commercially available catalyst comprising cobalt and molybdenum on an alumina carrier first with a solution of copper nitrate, and after calcination with a solution of potassium carbonate. The commercial catalyst was made by Armak catalyst division, Pasadena, Texas and sold under the name Ketjen KF 124 LD~ The copper nitrate solution was made by dissolving 1.2 grams of copper nitrate in 50cc of distilled water which was then added to 98.8 grams of the catalyst. The impregnated catalyst was then dried and calcined at 450C for several hours. After calcination a solution of 5.9 grams of potassium carbonate, in distilled water, was added to 33.0 grams of the calcined catalyst. This was then dried in a nitrogen purged vacuum oven at 135C for several hours. The chemical analysis of the catalyst is set forth in the table under Example 1.
A second promoted catalyst was made as in example 1, however, the ca~alyst was impregnated with a solution made by dissolving 4.8 grams of copper nitrate in 50cc of distilled water, which was added to 95.2 grams of the catalyst. After drying and calcination a solution of 5.6 grams of potassium carbonate, dissolved in distilled water, was added to 32 grams of the calcined catalyst. This was then dried in a vacuum oven for several hours. The chemical analysis of the catalyst is set forth in the table under example 2.
A promoted catalyst was made as in example 1 r however, the catalyst was impregnated with a solution made by dissolving 9.5 grams of copper nitrate in 50cc of distilled ~r~ k -8-9i~
water, ~hich ~as added to 90.5 grams of the catalyst. After drying and calcination a solution of 5.1 grams of potassium carbonate, dissolved in distilled water, was added to 29.0 grams of the calcined catalyst. The catalyst was then dried in a vacuum oven at 135C for s~veral hours. The chemical analysis of this catalyst is set forth in the table under example 3.
EXAMPI,E 4 -A promoted catalyst was made as in example 1, however, the catalyst was impregnated with a solution made by dissolving 18.2 grams of copper nitrate in 60cc of distilled water, which was added to 81.0 grams of the catalyst. Aftex drying and calcination a solution of 13.1 grams of potassium carbonate, dissolved in distilled water, was added to the calcined catalyst. The cat,alyst was then dried at 125~C for several hours, The chemical analysis of this catalyst is set forth in the table under example 4.
This catalys~ was tested in a 0.5 liter stainless steel Berty~ type recirculating gradientless reactor from,, Autoclave Engineers. 20cc of catalyst was used~ The conditions for the test were the same as ~hose previously described except that the hydxogen flow during reduction was 5 liters per minute instead of 2.5 liters per minute~
A promoted catalyst was made as in example 1, however, no copper nitrate was added. 30 grams of potassium carbonate, dissolved in 90cc of distilled water was added to 170 grams of the base catalyst (KF 124 LD). This was then dried at 135C for several hours. The chemical analysis of this catalyst is set forth in the table under example 4.
~ ~r~ ~a r k _g_ o~
TABLE I
~Comp.) Cataly~t Composition Wt%
3 9-9 9-5 9.5 8.7 9.7 CoO 3.4 3.4 3.4 3.0 3.1 10 CuO 0.4 1.7 3.4 6.2 -~-A123 78.3 77.9 75.7 73.1 78.3 K2O 8.0 7.5 8.0 9.0 8.9 H2/CO Ratio 2.0 2.0 2.0 2.0 2.0 15 Temperature C 343 343 343 3~3 343 GHSV(HR ) 28,00028,00028,00028,00028,000 Pressure Pa lx107 lx107 lx107 lx107 lx107 -Mole K = 6.2 5.8 6.2 6.9 6.9 M
Selectivity 1%) To 25 C1-C6 Hydrocarbons 20 21 21 32 31 MeOH 12 10 14 7 7 C2-C6 Alcvhols 19 17 22 13 17 Alcohol Production 0.240.35 0.50 0.42 0.27 IG/G-hr) C2-C6 Alcohols Wt% _ 1.6 1.7 1.6 1.8 2.4 MeOH Liquids Wt%
C2+Alc.Prod. (G/G-hr3 0.150.22 0.30 0.27 0.19 The foregoing examples demonstrate that a process for the production of lower aliphatic alcohols from a mixture of carbon monoxide and hydrogen within the critical parameters for the prescribed catalyst modified or promoted with the specified alkali metal is effective for produc.ing a high yield of C2-C6 aliphatic alcohols in relation to the production of methanolO
Claims (23)
1. A method for preparing lower aliphatic alcohols characterized by producing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 240 to about 400°C, a pressure from about 500 to about 3000 psi and a gas hourly space velocity of at least 1000, said catalyst comprising from about 5 to about 50 weight percent of molybdenum calculated as MoO3, from about 0.3 to about 15 weight percent of a metal selected from the group consisting of cobalt, iron and nickel, calculated as CoO, Fe2O3 or NiO,respectively, and from about 1.5 to 8 weight percent of copper, calculated as CuO, and the balance a support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubidium in an amount ranging from about 1.8 to 13.0 micromoles of said alkali metal per square meter of catalyst surface area.
2. A method according to Claim 1 in which said catalyst contains from about 2 to 6 weight percent of said copper determined as CuO.
3. A method according to Claim 1 in which said catalyst contains from about 2.5 to 5 weight percent of said copper determined as CuO.
4. A method according to Claim 1 in which said reaction is conducted at a temperature ranging from about 270 to 360°C.
5. A method according to Claim 1 in which said reaction is conducted at a temperature ranging from about 290 to 350°C.
6. A method according to Claim 1 in which said alkali metal promoter is potassium employed at a concentration ranging from about 2.2 to 10.0 micromoles of potassium per square meter of catalyst surface area.
7. A method according to Claim 6 in which said promoter is employed at a concentration ranging from about 2.5 to 9.0 micromoles.
8. A method according to Claim 1 in which said catalyst is modified by the addition of 2.2 to 10.0 micromoles of cesium per square meter of catalyst surface area.
9. A method according to Claim 1 in which said catalyst is modified by the addition of 2.2 to 10.0 micromoles of rubidium per square meter of catalyst surface area.
10. A method according to Claim 1 in which said support is selected from the class consisting of alumina, silica, titania, magnesia, silica-alumina and boron phosphates.
11. A method according to Claim 1 in which said support is alumina and comprises from about 60 to 80 weight percent of said catalyst.
12. A method according to Claim 1 in which said gas hourly space velocity ranges from about 5,000 to 50,000.
13. A method according to Claim 1 in which the gas hourly space velocity ranges from about 10,000 to about 30,000.
14. A method according to Claim 1 in which the molar ratio of hydrogen to carbon monoxide ranges from about 20:1 to 0.5:1.
15. A method according to Claim 1 in which said catalyst has a surface area greater than about 125 m2/gm.
16. A method according to Claim 1 in which said catalyst has a surface area ranging from about 150 to 350 m2/gm.
17. A method according to Claim 1 in which the weight ratio of the aliphatic alcohols having from 2 to 6 carbon atoms to methanol is at least 1.
18. A method according to Claim 1 in which the weight ratio of the C2-C6 alcohols to methanol is in the range of 1.25-2:1.
19. A method according to Claim 1 in which the metal components of a catalyst are in the free or combined form.
20. A method for preparing lower aliphatic alcohols in which the weight ratio of the C2-C6 alcohols to methanol is greater than 1 which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst at a temperature from about 270 to 360°C, a pressure from about 750 to 2500 psi and a gas hourly space velocity in the range from about 10,000 to 30,000, said catalyst comprising from about 7 to 30 weight percent of molybdenum calculated as MoO3, from about 0.5 to 10 weight percent of a metal or mixture of metals selected from the group consisting of cobalt, iron and nickel calculated as CoO, Fe2O3 or NiO respectively, and from about 2 to 6 weight percent of copper calculated as CuO, and the balance an alumina support, said catalyst being modified by the addition of an alkali metal promoter from the class consisting of potassium, cesium and rubidium in an amount ranging from about 2.2 to 10.0 micromoles of said alkali metal per square meter of catalyst surface area.
21. A method according to Claim 20 in which said alumina support comprises from about 60 to 80 weight percent of said catalyst.
22. A method according to Claim 20 in which said catalyst comprises from about 7 to 12 weight percent of molybdenum, from about 1.5 to 5 weight percent of a metal from the class consisting of cobalt, iron and nickel, and from about 2.5 to 5 weight percent of copper.
23. A method according to Claim 20 in which said reaction is conducted at a temperature ranging from about 290 to 350°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000516720A CA1256903A (en) | 1986-08-25 | 1986-08-25 | Production of c.sub.2 -c.sub.6 aliphatic alcohols |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000516720A CA1256903A (en) | 1986-08-25 | 1986-08-25 | Production of c.sub.2 -c.sub.6 aliphatic alcohols |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1256903A true CA1256903A (en) | 1989-07-04 |
Family
ID=4133791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000516720A Expired CA1256903A (en) | 1986-08-25 | 1986-08-25 | Production of c.sub.2 -c.sub.6 aliphatic alcohols |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1256903A (en) |
-
1986
- 1986-08-25 CA CA000516720A patent/CA1256903A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1261883A (en) | Process for producing lower aliphatic alcohols | |
| EP0110449B1 (en) | Process for the preparation of a fischer-tropsch catalyst, a catalyst so prepared and use of this catalyst in the preparation of hydrocarbons | |
| EP0216967B1 (en) | Improved cobalt catalysts, useful for the preparation of hydrocarbons from synthesis gas or methanol, and processes using the catalysts | |
| US4607056A (en) | Mixed aliphatic alcohol production | |
| US4616040A (en) | Production of C2 -C6 aliphatic alcohols | |
| CA1329190C (en) | Catalyst and process for production of hydrocarbon | |
| US4607055A (en) | Aliphatic alcohol production | |
| Inoue et al. | Hydrogenation of carbon dioxide and carbon monoxide over supported rhodium catalysts under 10 bar pressure | |
| EP2305379A2 (en) | Catalyst for synthesizing methanol from synthesis gas and preparation method thereof | |
| US5140049A (en) | Method for producing olefins from H2 and CO2 using an iron carbide based catalyst | |
| US4980380A (en) | Catalyst and method for producing lower aliphatic alcohols | |
| US4579995A (en) | Process for the conversion of methanol to hydrocarbons | |
| CA1150321A (en) | Process for preparing unsaturated hydrocarbons | |
| Hoflund et al. | Higher alcohol synthesis reaction study using K-promoted ZnO catalysts. III | |
| US4605639A (en) | Methods for making a supported iron-copper catalyst | |
| US4556752A (en) | Preparation of liquid hydrocarbons from methanol | |
| US5070058A (en) | Method for making a catalyst composition used in the production of lower aliphatic alcohols | |
| KR101653429B1 (en) | Process for oxidative dehydrogenation of paraffinic lower hydrocarbons | |
| US4565831A (en) | Process for producing aromatic hydrocarbons from carbon monoxide and water | |
| CA1256903A (en) | Production of c.sub.2 -c.sub.6 aliphatic alcohols | |
| US4518714A (en) | Process for the selective production of olefins from synthesis gas | |
| CA1220776A (en) | Iron on titania catalyst and its use for hydrocarbon synthesis | |
| US5013764A (en) | Catalyst and method for producing lower aliphatic alcohols | |
| US4719240A (en) | Cerium promoted fischer-tropsch catalysts | |
| US4168276A (en) | Methanation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |