i Patented‘ Aug. 11,‘ 1936 V 2.050.442 _ UNITED STATES‘. PATENT OFFICE ‘ 2,050,442 _ monomer. or ETHYL Anconor. Floyd 1. Metsger, New York, N. Y., assignor to Air Reduction Company, Inc., New York, N. ‘2., REISSUED ‘ a corporation of New York No Drawing. Application June 21,1931, Serial No; 547,452 14 Claims. (01. 260-158) This invention relates‘ to the production of or into contact with the acid catalyst at a high ethyl alcohol from ethylene. temperature, condensing the alcohol and excess It is known that ethyl alcohol can be manu steam while maintaining the high pressure, and factured from ethylene by absorbing the ethylene 7 recycling the ethylene with suitable further ad ~ 5 in strong sulfuric acid to form ethyl hydrogen ditions of ethylene and steam in the further car- 5 sulfate or diethyl sulfate, diluting with water to rying out of the process. , . hydrolyze the ethyl sulfate, distilling the resulting The catalyst which I have found particularly ethyl alcohol from the diluted mixture and re valuable is a sulfuric acid catalyst which is a much concentrating the dilute acid for further use in weaker sulfuric acid than the strong acid here 10 the process. This process involves a series of tofore commercially used in the manufacture of ill separate and successive operations carried out in ethyl alcohol. The sulfuric acid employed may diii'erentapparatus. The reconcentration of the have a strength, for example, of from 15 to 70% dilute acid is a major expense of the process. The of sulfuric acid. Apparently the ethylene com formation of ethyl alcohol in this way is usually blnes to a considerable extent with the acid to 15 accompanied by the‘ formation of a considerable form ethyl sulfate, so that the catalyst is a mix- 15 amount of ether with corresponding reduction in ture of sulfuric acid and an ethyl sulfate. The the amount of alcohol produced. strength of the acid catalyst is maintained sub The present invention provides an improved stantially constant at the high temperatures and method for the manufacture of ethyl alcohol, pressures employed by using regulated propor 20 which enables the objections above mentioned to tions of ethylene and steam in the gaseous mix- 24;) be largely overcome and minimized, which elim ture passed through or into intimate contact with inates the necessity of using strong sulfuric acid the acid catalyst. and of reconcentrating dilute acid, which enables The temperatures employed in the present the production of the alcohol to be accomplished process will vary with the strength of the acid N :1 without any considerable formation of ether,‘ catalyst, the pressure and the ratio of steam to as which can be carried out in a continuous manner, ethylene employed, but in general the tempera and which has other advantages, such as those tures are much higher than it is possible to em- ' hereinafter set forth. ' ploy with the same strength of acid at atmos~ According to the process of the present inven pheric pressure. By passing the mixture of 30 tion the alcohol is produced continuously by pass steam and ethylene in contact with the sulfuric so ing the ethylene, in admixture with suitable acid catalyst under a high pressure it is possible proportions of steam, into intimate contact with to use a'much higher temperature without in an acid catalyst, and particularly a sulfuric acid creasing the concentration of the acid and even catalyst, while maintaining the catalyst at a high with a much more dilute acid as compared with. 35 temperature and maintaining the gases under a operations at atmospheric pressure. Using a sul- 35 high pressure, with resulting conversion of the furic acid catalyst, without promoters, and with ethylene into alcohol, which is subsequently con mixtures'of steam and ethylene, the temperatures dcnsed along with the excess steam from the es are in general in excess of about 170° C. and for caping gases; - best results I have found a temperature consid 40 I have found that'ethyl alcohol can readily be erably in excess of 200° to be advantageous, e. g., to produced in a continuous manner by passing a around 235 to 250° C. The temperature, however, mixture of ethylene and steam, in suitable pro cannot be varied independently of the other portions, into intimate contact, with a relatively conditions because the temperature, pressure, dilute sulfuric acid catalyst at a regulated high acid strength and ratio of steam and ethylene '45 temperature and pressure, with resulting forma are interdependent. With the same acid strength 45 tion of a gaseous mixture containing the alco and the same ratio of steam and ethylene the hcl together with the excess of ethylene and temperature can be very considerably increased steam, from which the alcohol and steam can be by carrying out the process under a high pres readily condensed. sure, and the increased temperature seems to 50 I have further found that this conversion of have the effect of greatly increasing the activity 50 ethylene into-‘ethyl alcohol can advantageously be of the acid catalyst and promoting the formation carried out in a cyclic manner by maintaining a of alcohol. I circulating stream of ethylene under a high'pres The pressures employed in the present process' sure, admixing therewith‘ steam in suitable pro- are in general in excess of 100 pounds, and much 55 portions, passing the resulting mixture through higher pressures are more advantageous, such as 55 0 2 ’ 9,050,442 pressures above 200 pounds, and more particularly of steam and ethylene ‘can also be prepared by pressures around 600 pounds or higher. with passing the ethylene through a body of water the higher pressures, for example, around 600 maintained at a sufl‘iciently high temperature and pounds, or even much higher pressures, there under the same pressure employed in the con 6 should be a proper correlation of the strength of verter. In this case the recirculating ethylene can 5 the acid catalyst, the temperature and the pro be passed through such a boiler containing water portion of steam and ethylene. With such high . and the temperature of the boiler maintained to pressures it is possible to use temperatures much I give the proper proportion of steam and higher than it is possible to use at atmospheric ethylene in the gases passing therefrom to the l0 pressure with a sulfuric acid'catalyst and at the - converter. 10 same time to maintain a much lower strength of Instead of carrying out the process in a cyclic acid catalyst. The combined use of a high tem manner, by passing the mixture of steam and perature and pressure with a relatively dilute acid ethylene through a single converter, then through catalyst makes it possible to produce ethyl alcohol a condenser, and then recirculating the ethylene 15 in commercial quantities without the objection with admixture of steam under the same high 15 able decomposition which would take place at the pressure to the same converter, two or more con higher temperatures and with stronger acids at verters can be employed in series with or without atmospheric pressure. condensation of the alcohol and steam from the The proportions of steam and ethylene can be gases escaping from the first converter, then 20 varied but in general for the production of alco-. admixing additional steam or ethylene or both 20 hol free or relatively free from ether I have found if desired, and passing the gases through the sec it advantageous to use an excess of steam over ond converter, etc., and in such case the con that theoretically required for combining with densers as well as the‘ converters are advan the ethylene for example, the ratio of one and tageously maintained under a high pressure so 25 one-half parts of steam to one of ethylene or of that condensation as well as conversion may take 25 two of steam to one of ethylene or even a higher place under such pressure. ratio of steam to ethylene, e. g., four or more The use of a series of converters makes possible parts of steam to one of ethylene. the maintenance of di?erent strengths of acid I have also found it possible to produce ether catalyst and of diiferent temperature and pres 30 as well as alcohol, where that is desired, by using sure conditions in the different converters, there- 30 a lower ratio of steam to ethylene or a stronger by making it possible for example to produce acid or a lower pressure; but in general the ethyl alcohol free or relatively free from ether strength of the acid catalyst will depend upon the in one converter and a mixture of alcohol and ratio of steam to ethylene and the conditions of vether in another converter where this is desired. 35 temperature and pressure employed. When a Instead of using a sulfuric acid catalyst, other 35 ., .aconstant mixture of steam and ethylene is passed acid catalysts can be employed, for example, a through or in intimate contact with the acid phosphoric acid catalyst, or a mixture of phos catalyst under a high temperature and pressure, phoric and sulfuric acids. In referring to the the strength of the acid catalyst will reach an acid catalyst I use the term to include the acid 40 equilibrium and will thereafter remain at the catalyst with whatever other constituents such 40 equilibrium strength as long as the conditions of as alkyl sulfates it may contain during the cata the process, 1. e., the temperature, pressure and lytic conversion. Provision should be made for ratio of steam to ethylene remain constant; but insuring intimate contact of the gases with the the equilibrium reached will represent a much acid catalyst, such as the dissemination or dis 45 more dilute acid than that which would represent tribution of the gases throughout the acid cata- 45 the equilibrium at the same temperature and at lyst.