INDUSTRIAL A N D ENGIh'EERING CHEMISTRY
September, 1925
98 1
Synthetic Manufacture of Methanol
I
T IYILL undoubtedly be some time before literature other than
the patent literature will be available on the subject of the synthetic manufacture of methanol. Reliable costs cannot be stated until a year or two of large-scale operation, and even then those best informed may not be disposed to disclose their information. The same is true with respect to certain technicalities. In the belief that the information may be welcome to many of our readers, we reprint British Patent 229,715, for which application was made August 23, 1923, and which was issued on February 23, 1925. Of course, we do not guarantee that the procedures given in the examples are those actually followed in the Badische plant, nor that a faithful following of these examples will necessarily produce methanol. From what has been printed in this and in other patents, as well as in scientific articles, it would appear that a t least the following is essential t o the commercial manufacture of synthetic methanol:
1-A gaseous mixture of carbon monoxide and hydrogen in which there are a t least two volumes of hydrogen to one of carbon monoxide. 2-A catalyst, of which a number are available, with the probability that the catalyst actually used consists chiefly of oxide of zinc with a probable admixture of oxide of chromium and metallic copper or copper oxide. 3-Absence of alkali in the catalyst, which would cause the decomposition of the methanol produced and the production of higher alcohols, water, and oily and tarry bodies therefrom. -&-Proper apparatus made of alloy steel and lined with copper, aluminium, or zinc, capable of withstanding very high pressures, a t least 250 atmospheres, and containing a heating element so that the incoming gases will come in contact with the catalyst a t a temperature around 250' to 300' C., without coming in contact with iron, nickel, or cobalt. %Condensation of the methanol produced and the recirculation of the residual gases brought again to the proper concentration by the addition of hydrogen and carbon monoxide.
Patent Specification The Synthetic Manufacture of Methanol I , J A M E S YATEJOHNSON, a British subject, of 4 i , Lincoln's Inn Fields, in the County of London, Gentleman, do hereby declare the nature of this i n r e n tion (which has been communicated to me from abroad by the Badische Aniline 8: Soda Fabrik, of Ludwigshafen-on-Rhine, Germany, a company incorporated according t o German laws), and in what manner the same is t o be performed, t o be particularly described and ascertained in and by the following statement: Hitherto i t has not been possible t o produce methanol successfully by the catalytic reduction of carbon monoxide, though several proposals have been made ior this purpose. M y foreign correspondents have now found t h a t methanol can be produced by the catalytic reduction of carbon oxides with very good yields and a good speed of the reaction so t h a t a n industrial utilization of the process is rendered possible, by employing a t a n elevated temperature and pressure contact masses which contain, besides one or more than one of the following elements: copper, silver, gold, zinc, cadmium, and lead as hydrogenating elements also titanium, vanadium, chromium, manganese and the elements related t o them namely, zirconium, cerium, thorium, niobium, tantalum, molybdenum, tungsten, uranium, or boron or compounds of these elements, or more than one of these elements or compounds thereof. I t is of advantage t o use gas mixtures of carbon monoxide, or dioxide, or both and hydrogen nrith quantities of t h e latter eitceeding by volume the quantities of the oxides of carbon and preferably in the proportions calculated according t o the equations:
+ 2Hn = CHa.OH and + 3Hz = CH3.OH + Hz0
CO CO?
or with even more hydrogen. Such exceeding quantities of hydrogen must be used when contact masses a r e employed consisting of mixtures of the oxides chromium, manganese, molybdenum, titanium, or cerium with zinc. A high excess of hydrogen may be present, for example one and a half of the calculated volume or a multiple of the latter. The gas mixture may also contain hydrocarbons or nitrogen or other inert gases and it may be purified and dried, prior t o the reaction. \Vith the before-mentioned conditions, a very pure methanol is obtained a t comparatively low temperatures. The contact masses may be prepared in any suitable way and the proportions of the components may be varied within wide limits. Inter alia, t h e additional elements mentioned may be compounded, in the form of their higher oxides with a n acid character, with the hydrogenating element t o form a salt, and such salts, for instance vanadates, chromates, manganates, borates, may be subjected t o reduction. Mixtures of such acids with t h e hydrogenating elements may also be used, and the contact mass may be prepared in any other way. Supports may also be employed and a great variety of substances may serve this purpose. I n order t o produce a very pure methanol i t has proved useful t o employ catalysts of the aforesaid kind which contain a s little alkali a s possible and accordingly t o purify thoroughly those contact masses which contain any alkali from their preparation prior t o their use for the present process, or to exclude any alkali compounds when preparing the contact masses. When supports are employed such materials should be used as do not give off any alkali. Thereby the formation of oily products is prevented or greatly diminished.
The temperatures of the reaction may be raised to above 500' C., but in general they need not exceed 300° C., and in many cases considerably lower temperatures are sufficient which are in favor of the formation of pure methanol. The pressure may be raised t o any degree. Less active contact masses require very high pressures and rather high temperatures in order to give ample yields. I n all cases it is important t h a t iron, nickel and cobalt a r e not present or only in comparatively small amounts and only together with one or more of the aforesaid hydrogenating elements, a s otherwise methane or other hydrocarbons may be formed. The following examples will serve t o further illustrate how the invention may be carried into effect but i t is to be understood t h a t the invention is in no way restricted t o these examples. The parts are by weight where no other statement is made.
EXAMPLE 1 Prepare a catalyst by introducing 50 parts of asbestos wool into a solution of 86 parts of copper nitrate and from 8 t o 10 parts of chromium acetate, heat t o boiling, precipitate with sodium carbonate, filter, wash well and dry. Then loosen the asbestos wool and reduce it a t between a temperature of 190" t o ZOOo C. by means of hydrogen a t ordinary or increased pressure. Over the contact mass thus prepared a gas mixture containing 20 parts, by volume, of hydrogen, for each one part of carbon monoxide is passed a t a temperature of from 220° t o 250" C. and a t a pressure of about 100 atmospheres. The speed of the gas mixture may he between 2 and 10 cubic meters (calculated on ordinary conditions as t o temperature and pressure) per hour for each kilogram of contact mass, Between about 20 and 5 per cent of the carbon monoxide (depending on the speed of passing over) are converted into methanol and small amounts of oily matter, insoluble in water, and a little methane, may sometimes be formed. Mixtures of carbon dioxide and hydrogen may also be employed which may contain carbon monoxide, hydrocarbons and nitrogen or other inert gases.
EXAMPLE 2 Introduce 50 p a r t s of asbestos into a dilute solution of 56 parts of potassium dichromate, then add 70 parts of copper nitrate whereby copper chromate is precipitated on the asbestos fiber. Then wash, d r y , loosen t h e asbestos a n d reduce in a n atmosphere of hydrogen a t a temperature of about 200' C. Over the contact mass thus prepared a gas mixture containing S t o 10 parts by volume of hydrogen for each p a r t of carbon monoxide is passed a t a temperature of about 230' C. a n d a t a pressure of about 150 atmospheres and a t the r a t e of between about 3 and 100 cubic meters (calculated on ordinary conditions), per hour for each kilogram of contact mass. About from a half t o a quarter of carbon monoxide in the gas mixture is converted into methanol. Very good yields are also obtained with the chromates or silver, or of silver a n d copper, or with the molybdates or tungstates of silver, or copper, or a n y other of the aforesaid hydrogenating metals, or with salts or mixtures of salts of such met& derived from any other of the aforesaid associated elements including salts or mixtures containing more than one hydrogenating element or additional element.
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ISDCSTRIAL ,450 E,VGI.VEERI-VG CHEMISTRY EXAXPI.E 3
Dissolve in water 25 parts of neutral copper acetate and 21.3 parts of silver nitrate, then a d d 50 parts of asbestos wool, heat t o boiling. a d d 25 parts of chromic acid, evaporate while mixing a t intervals, d r y , loosen the mass and reduce in a current of hydrogen a t a temperature of about 400' C. and a t a pressure of 25 atmospheres. When a mixture of carbon monoxide and hydrogen (with about 1 volume of the former t o each 6 volumes of the latter) is passed over this contact mass at about 230' C. and 120 atmospheres, and with a speed corresponding t o between 2 and 200 cubic meters (calculated on atmospheric pressure) per hour a n d kilogram of contact mass, 10 per cent and less of t h e carbon monoxide, depending on the speed of the current, are reduced t o methanol. A contact mass prepared by decomposing potassium chromate with copper acetate and lead nitrate in t h e presence of asbestos wool can be employed in a similar manner.
EXAMPLE 4 Eighty-four p a r t s of copper nitrate and 10 p a r t s of uranium nitrate are dissolved in water a n d 50 p a r t s of asbestos wool a r e introduced. The mixture is then heated t o boiling precipitated with caustic potash lye, filtered thoroughly, washed, dried a n d loosened. When a mixture of carbon monoxide and hydrogen in the proportion of about 1 t o 8 is passed over this catalyst a t a temperature of 220' C. and a pressure of 80 atmospheres, methanol is produced with very good yield and a t great speed. The gas mixture is passed over a t t h e r a t e of from 1 t o 150 cubic meters (calculated on atmospheric pressure) per hour for each kilogram of contact mass, and 30 per cent or less of the carbon monoxide will be converted into methanol.
EXAMPLE 5 A mixture of carbon monoxide and hydrogen, in the proportions of about
1 t o 10, is passed a t a temperature of about 260' C. and a pressure of 100 atmospheres over a contact mass containing 63.6 p a r t s of copper, 11.4 p a r t s
of uranium a n d 3.9 p a r t s of manganese deposited a s hydroxides or carbonates on a carrier. Between 0.5 and 50 cubic meters of gas (calculated on ordinary pressure) may be employed per hour a n d kilogram of contact mass and 30 per cent or less of the carbon monoxide a r e converted into methanol. On cooling t h e reaction gases methanol condenses with a n excellent yield. The percentage of either uranium or manganese or both may also be higher. With such contact masses or with higher pressure, the yield may rise t o 50 per cent or more.
EXAMPLE 6 Pass a mixture of 10 parts, by volume, of carbon monoxide and 90 parts, by volume, of hydrogen, a t a temperature of about 220' C. and a pressure of 100 atmospheres over a catalyst consisting of asbestos with a n intimate mixture of 50 p a r t s of manganese dioxide, 30 p a r t s of copper oxide, 15 p a r t s of cobalt oxide, a n d 5 p a r t s of silver oxide precipitated thereon which has been reduced beforehand a t a temperature of about 200' C. in a current of hydrogen a t ordinary or increased pressure. The reaction gas leaving the catalyst will deposit, on cooling, n liquid chiefly consisting of methanol. Very good results are also obtained when employing salts of the acid high oxides of t h e associated elements together with hydrogenating elements. For example t h e reduction products of copper or silver vanadate, copper or silver manganate, or t h e like may be used. When a speed of gas current corresponding t o between 5 and 250 cubic meters (calculated on ordinary con. ditions) per hour and kilogram of contact mass is employed, 5 per cent or less of t h e carbon monoxide will enter reaction.
T'ol. 17, S o . 9
kilogram of contact mass. The higher the pressure the higher the yield. With 90 atmospheres gas pressure, about 20 per cent of the carbon monoxide enter reaction. By increasing the speed of the gas the percentage of carbon monoxide undergoing hydrogenation is reduced. Other organic compounds, especia!ly oily substances, are either not a t all obtained or only in very small amounts. If instead of a mixture of hydrogen and carbon monoxide a mixture of hydrogen and carbqn dioxide, for example in the proportions of 5 to 1, is passed over the said catalyst a t a temperature of about 220° C. aod a pressure of about 100 atmospheres, the reaction gases, on cooling, give a liquid which is composed of water and chiefly methanol, and in quantity corresponds t o about 10 per cent or less of the carbon dioxide passed over, when the speed of the gas current was between 1 and 100 cubic meters (calculated on atmospheric pressure) per hour and kilogram of contact mass.
EXAMPLB 9 A contact mass is prepared from 21.8 parts of copper in form of the nitrate, 10 parts of uranyl nitrate, 5 parts of cerium nitrate and 50 parts of asbestos wool, substantially a s described in t h e foregoing example, and a mixture of one volume of carbon monoxide and 10 parts of hydrogen i s passed over thia mass a t a pressure of about 50 t o 150 atmospheres and a t a temperature of about 220' C. Methanol is recovered from the reaction gases by cooling. The pressure and proportions of carbon monoxide or dioxide t o hydrogen may be varied within a wide range, b u t the hydrogen should preferably be present in an exceeding quantity in all cases. The greater the pressure, t h e greater the yield and the quantity of gases undergoing reaction, the yield corresponding t o about 30 per cent or less of the carbon monoxide passed over the catalyst, depending on the velocity of the gas current which may vary between say 1 and 230 cubic meters (calculated on ordinary conditions) per hour for each kilogram of contact mass. Having now particularly described and ascertained the nature of my said invention and in what manner the same is t o be performed, I declare t h a t what I claim is: 1-The process of synthetically manufacturing methanol or products substantially consisting of methanol by catalytically reducing carbon monoxide or dioxide at elevated temperature and pressure which is characterized b y t h e use of contact masses containing besides one or more of the following elements, copper, silver, gold, zinc, cadmium and lead, also titanium, vanadium, chromium, manganese and other cognate elements related t o them namely, zirconium, cerium, thorium, niobium, tantalum, molybdenum, tungsten, uranium, or boron, or more than one of these elements, or compounds thereof and preferably also using such gas mixtures as contain more bydrogeo, by volume, than carbon oxides, which gas mixtures should be used in any case when mixtures of zinc, with oxides of chromium, manganese, molybdenum, titanium, or cerium are used as catalysts. 2-In the process of manufacturing methanol, according t o Claim 1, t h e use of catalysts of the kind described which are free from alkali compounds and from iron and nickel. 3-The process of manufacturing methanol, substantially as described in the foregoing examples. 4-As an article of manufacture methanol, either pure or mixed n i t k oily substances when prepared according t o the foregoing clauses. Dated this 23rd day of August, 1923. . JOHNSONS & WILLCOX 47, Lincoln's Inn Fields, London, 1%'. C. 2, a g e n t s Reference has been directed in pursuance of Section 7, Sub-section 4, 01 the Patents and Designs Acts, 1907 and 1919, to Specification No. 20,488 to 1913.
EXAWPIS7 Dissolve so much of copper nitrate as corresponds t o 21.8 parts of copper, and 10 parts of thorium nitrate in water, add 50 parts of asbestos, heat t o boiling, precipitate with a n excess of caustic potash lye, filter off, wash thoroughly, dry, loosen t h e asbestos and reduce in a current of hydropeu a t ordinary or increased pressure at a temperature of about 200' C. When a d r y mixture of carbon monoxide and hydrogen in the proportions of about 1 t o 7 is passed over this mass a t a temperature of about 220' C. and a pressure of 100 atmospheres, methanol is produced with good yield. The speed of t h e gases may amount t o from 3 t o 50 cubic meters (calculated on ordinary conditions) per hour and kilogram of contact mass, the yield redching 10 per cent or less of the carbon monoxide.
E X A M P8L ~ Dissolve so mucn of copper nitrate as corresponds t o 21.8 parts of copper, 10 parts of uranyl nitrate and 5 p a r t s of tnorium nitrate in water, add 50 p a r t s of asbestos wool, heat t o boiling, precipitate with a n excess of caustic potash lye, filter off, wash thoroughly, d r y , loosen and reduce a t a temperat u r e of about ZOOo C. in a current of hydrogen at ordinary or increased pressure. When a dried mixture of carbon monoxide and hydrogen in the proportions of about 1 t o 5 is passed over this catalyst a t a temperature of about 220° C., reaction takes place a t about 35 atmospheres and a liquid is obtained with good yields chiefly consisting of methanol. About 5 per cent of the carbon monoxide are converted into methanol when 3 cubic meters of gas mixt u r e (calculated on atmospherr pressure) per hour are employed for each
Calendar of Meetings American Society of Bakery Engineers-Buffalo, N. Y., September 16 and 16, 1926. American Electrochemical Society-Fall Meeting, Signal klountain Hotel, Chattanooga, Tenn., September 24 t o 26, 1925. National Exposition of Chemical Industries-Grand Central Palace, New York, N. Y., September 28 to October 3, 1925. Army Ordnance Association-7th Annual Meeting, Aberdeen Proving Ground, Aberdeen, Md., October 2, 1925. The Franklin Institute, the National Aeronautical Association, and National Machine Tool Builders' Association will participate. Institute of American Meat Packers-Annual Meeting, Chicago, Ill., October 16 to 21, 1925. American Chemical Society-7lst Meeting, Tulsa, Okla., -4pril 5 to 9, 1926. Association of Chemical Equipment Manufacturers-2nd Chemical Equipment Exposition, Cleveland, Ohio, May 10 to 15, 1926.
