Patent GB-400297-A (GB)
Title: Improvements in or relating to the partial oxidation of unsaturated hydrocarbons
IPC: C07D301/08
Filed: 1932-04-28
Abstract: In the oxidation by means of oxygen of gaseous unsaturated hydrocarbons for the production of olefine oxides, glycols, and the like, the process is effected at 250-600 DEG  C. in a reaction vessel having a ratio of surface to volume not exceeding about 4 : 1, the units being square and cubic inches.  In the apparatus shown, ethylene and oxygen or air are fed into the system, at an inlet 1 by means of a pump 2 which circulates the gas through the apparatus. The gas passes first through a pre-heater 3 packed preferably with pieces of glass, porcelain, clay, or siliceous material, the pre-heating being to a temperature above the reaction temperature, e.g. 300-600 DEG  C., but no <PICT:0400297/III/1> reaction occurs owing to the large surface of the packing.  The gas then passes to the reaction vessel 4 maintained at a suitable temperature.  The reaction gases then pass through a heat-exchanger 8 surrounding the pre-heater 3, thence to a cooler 9 to separate the products, uncondensed gas together with fresh gas being again circulated by the pump 2.  Examples describe the oxidation of ethylene to ethylene oxide, formaldehyde and formic acid, and the oxidation of propylene to propylene oxide, propylene glycol, propionaldehyde, propionic acid, and acetic and formic acids and aldehydes.  The time of contact in the reaction vessel may be from 100 seconds to a fraction of a second, and the olefine is preferably in excess, a high proportion of hydrocarbon favouring the speed of reaction.  Tables are given showing the relation between temperatures, reaction times, composition of reaction mixtures, and nature of products, and particulars of the influence of the volume of the reaction vessel in relation to its surface are also given.  Preferably the interior surface of the reaction vessel is of a siliceous material such as glass, porcelain or clay.  The process may be effected at, above, or below atmospheric pressure.  Specification 138,113, [Class 1 (i), Chemical processes &c.], is referred to.  The Specification as open to inspection under Sect. 91 states that the reaction vessel may have alkali or alkaline earth metals or their compounds applied to the interior walls.  This subject-matter does not appear in the Specification as accepted.ALSO:<PICT:0400297/IV/1> In the oxidation by means of oxygen of gaseous unsaturated hydrocarbons for the production of olefine oxides, glycols and the like, the process is effected at 250-600 DEG  C. in a reaction vessel having a ratio of surface to volume not exceeding about 4 : 1, the units being square and cubic inches.  In the apparatus shown, ethylene and oxygen or air are fed into the system at an inlet 1 by means of a pump 2 which circulates the gas through the apparatus.  The gas passes first through a preheater 3 packed preferably with pieces of glass, porcelain, clay or siliceous material, the preheating being to a temperature above the reaction temperature, e.g. 300-600 DEG  C., but no reaction occurs owing to the large surface of the packing.  The gas then passes to the reaction vessel 4 maintained at a suitable temperature.  The reaction gases then pass through a heat-exchanger 8 surrounding the preheater 3, thence to a cooler 9 to separate the products, uncondensed gas together with fresh gas being again circulated by the pump 2.  Examples describe the oxidation of ethylene to ethylene oxide, formaldehyde and formic acid, and the oxidation of propylene to propylene oxide, propylene glycol, propionaldehyde, propionic acid, and acetic and formic acids and aldehydes.  The time of contact in the reaction vessel may be from 100 seconds to a fraction of a second, and the olefine is preferably in excess, a high proportion of hydrocarbon favouring the speed of reaction. Tables are given showing the relation between temperatures, reaction times, composition of reaction mixtures, and nature of products, and particulars of the influence of the volume of the reaction vessel in relation to its surface are also given. Preferably the interior surface of the reaction vessel is of a siliceous material such as glass, porcelain or clay.  The process may be effected at, above, or below atmospheric pressure. Specification 138,113, [Class 2 (iii), Dyes &c.], is referred to.  The Specification as open to inspection under Sect. 91 states that the reaction vessel may have alkali or alkaline-earth metals or their compounds, applied to the interior walls.  This subject-matter does not appear in the Specification as accepted.