US1735407A - Process for vaporizing formamid - Google Patents

Description

Patented Nov. 12, 1929 UNITED STATES PATENT 'QFFI'CE I EDUARD Ml 'NCH, OF LUDWIGSHAFEhI-ON-THE-RHINE, GERMANY, 'ASSIGNOR TO I. G.

FARBENINDUSTRJIE AKTIENGESELLSCHAFT, OF FRANKFORT-ON-THE-MAIN, GER- MAN Y, A CORPORATION OF GERMANY PROCESS FOR VAPORIZING FOBMAMID No Drawing. Application filed January 17, 1928,,Seria1 rio. 247,461, and in Germany January 27, 1927.

fact that, at high temperatures, formamid attacks nearly all metals, so that it is prac tically impossible to produce suitable heating apparatus for this purpose.

As a result, formamid cannot be success I fully vaporized on an industrial scale in the I 20 usual manner from stills or similar vaporizing appliances in which the heating surfaces are always covered with the liquid. Even if. the apparatus were able to resist the action of the formamid consi erable losses of the latter would be incurred by the prolonged heating.

I have found that the decomposition of formamid into carbon monoxid and ammonia, in spite of the fact that this decomposition increases as the temperatures rises, can bealmost entirely prevented if the f ormamid be vaporizedv on surfaces, heated to a temperature above theboiling point of formamid, which is 215 C. at ordinary pressure, in such a manner that vaporization occurs immediately on contact therewith and that no formamid can accumulate in the liquid form. in the vaporizer. The formamid is preferably introduced in a finely distributed condition, for examp'leby injection through a nozzle.

, The vaporization may be efi'ected at ordinary pressure, but it is preferably conducted at diminished pressure, and it may be facilitated by the aid of a current of as. The

formamid vapor should be remove from thevaporizerdirectly it has been-formed, and at once led away for the purpose in view, such, for ezaample, as the productionof. hydrogen icyani Q Notwithstandingthe high temperature, the

formamid does not attack theheatingsurfaoes to more than a slight, extent, if at all, under these conditions, since, a parently, a corrod- ,in'g action is exerted by ormamidonly when Ewample The formamid is injected through a nozzle, and at a velocity corresponding to from 50 to 70 kilograms per hour, into a vessel with a capacity of about 40 litres,vheated to about "450 C. by means of powerful gas flames and evacuated to a reduced pressure ,of about 40 millimetres, mercury gauge, the injection being efi'ected in such a manner that the formamid is uniformly distributed over the heating surfaces and that no accumulation of liquid formamid can take place in the bottom of the vessel. The formamid vapor is carried off at once, for further treatment. The loss of formamid through decomposition into carbon monoxid and ammonia is only about 1 per cent of the original quantity.

If the vaporizer be constructed for example of iron, the resulting formamid vapor maybe found to contain hydrogen cyanid which is of advantage when the va or is to be employed for the production of hydrogen cyani WhatIc1a'imis:-

1. A process for vaporizin formamid which com rises contacting liqu d formamid' with a sur ace, heated to a temperature considerably above 215 C.,- while avoiding ac 95 to I together with a current of inert gas with a surface, heatedto a temperature considerably above 215 0., hile avoidingaceumulation of liquid formamid.

4. A process for vaporizing formamid which comprises contacting liquid formamid at reduced pressure with a surface, heated to a temperature considerably above 215 0., while avoiding accumulation of liquid formamid.

5. A process for vaporizing formamid which comprises injecting liquid formamid onto the inner surface of a closed vessel heat-- ed to 450 C. and evacuated to a pressure of 40 millimetres, mercury gauge, While avoid ing accumulation of liquid formamid.

In testimony whereof I havehereunto set my hand EDUARD MUNCH.

DISCLAIMER 1,735,407.-'Eduard Munch, Ludwigshafen-on-the-Rhine, Germany. PRocEss FOR VAPORIZING FORMAMID. Patent dated November 12, 1929. Disclaimer v filed dulyv5, 1934, by the assignee, I. G. Farbenmdustm'e Alctiengesellschafi.

Enters th1s disclaimer to certain of the claims of the above identified patent namely, claims 1, 2, and 3.

[Oflim'al Gazette August 7, 1934.

y DISCLAIMER .Eduard Munch, Ludwigshafen-on-the-Rbine, Germany. Pnocnss FOR VAPORIZING FORMAMID. Patent dated November 12, 1929. Disclaimer filed July 5, 1934:, by the assignee, I. G. Farbfi'mdustrie fiftiengesellschaft.

Enters this disclaimer to certain of the claims of the above identified patent,

namely, claims 1, 2, and 3.

[Ofiicial Gazette August 7, 1984.]