Patent GB-155776-A (GB)
Title: Process for effecting chemical reaction in the interior of compressors
IPC: C10G9/42
Filed: 1920-12-22
Abstract: In carrying out chemical reactions, other than the combustion of hydrocarbon and like fuels, in the interior of a compressor, the reacting-substances are first brought to a suitable pressure and temperature condition for the reaction by compression, expansion or other means, and the reaction is then carried out while maintaining the pressure and temperature as constant as possible; in any case, the conditions must be such that in endothermic reactions the temperature does not fall, in exothermic reactions the temperature does not rise, in reactions with an increasing number of molecules the pressure must not rise, and in reactions with a decreasing number of molecules the pressure must not fall.  The constancy of the temperature and pressure is attained by suitably selecting the point of the cycle at which the reaction is started, by the gradual introduction of one or more of the reacting-substances, and by the addition or subtraction of heat while the reaction is in progress; to control the temperature heating or cooling liquids or vapours may be injected into the compression space or a liquid may be circulated through the jacket of the cylinder or through spiral tubes arranged in the compression space, or there may be provided in the latter electric heating bodies or flaming arcs-the necessary catalysts may be placed in the compression space, adjacent to these cooling tubes or electrically-heated bodies.  The reaction may also be started by electric arcs, sparks or other discharges, or ultra-violet light. The following reactions are carried out during the expansion stroke:-exothermic reactions with an increasing or constant number of molecules, and endothermic reactions with an increasing number of molecules; the following during the compression stroke : exothermic reactions with a decreasing number of molecules, and endothermic reactions with a decreasing number of molecules.  The following manufactures are described:-The synthesis of ammonia.-A mixture of nitrogen and hydrogen in the necessary proportions is introduced into the cylinder, and compressed; at about the middle of the compression stroke, when the pressure reaches 50 atmospheres and the temperature 500 DEG  C., the reaction is started, and thereafter, for the remainder of the stroke; constancy of temperature and pressure is maintained by injecting a mixture of nitrogen and hydrogen in the form of highly compressed gas or liquid, or any other gas, or even water; the catalysts are placed in the compression space.  Cracking of mineral oils and coal tar.-A charge of superheated steam &c. is introduced into the cylinder, and compressed; at the end of the compression stroke, when a pressure of 50 atmospheres and a temperature of 550 DEG  C. are attained, the oil &c. to be cracked is injected in a finely divided state; if the reaction is endothermic heat must be supplied to the mixture by means of heated glowing surfaces. Hydrogenation.-A charge of hydrogen is compressed, for example to 12 atmospheres and 180 DEG  C., and during the compression stroke the oil is introduced in finely divided form; constancy of temperature and pressure is obtained by introducing with the fatty acid highly compressed hydrogen; the catalyst, if required, may be mixed with the oil, and it may be retained in the compression space. The Specification as open to inspection under Sect. 91 (3) (a) includes also the following manufactures:-Acetaldehyde from acetylene and water vapour-these are brought to reaction during the compression stroke, and the temperature and pressure is maintained constant by injecting water; formaldehyde, by a similar process in which air is added; acetic acid, by a similar process but substituting hydrogen peroxide for water vapour; production of ozone-oxygen is compressed and during the remaining part of the compression stroke is subjected to "induction sparks," silent discharges, or ultra-violet light, the gases being released at the end of the compression stroke in order to prevent decomposition of the ozone; the ozone so obtained, may be employed in situ for effecting the oxidation of methane, illuminating gas, acetylene, alcohol, &c., to alcohol, acetaldehyde, acids, &c., of isoeugenol to vanillin, and of steam to hydrogen peroxide; nitrogen oxide, by exposing air rich in oxygen during the compression stroke to ultra-violet light or electric arcs, and at the end of the stroke exhausting the gases through a suitably cooled valve, to prvent decomposition of the nitrogen oxide; sulphur trioxide by the contact process-air alone, or mixed with sulphur dioxide, is compressed to the necessary temperature, and during the remainder of the stroke rise of temperature is obviated by the introduction of sulphur dioxide or of air, suitably cooled.  This subject-matter does not appear in the Specification as accepted.ALSO:The Specification as open to inspection under Sect. 91 (3) (a) describes certain chemical processes in which the reactions are carried out in the interior of a compressor under such conditions that the reacting-substances are first brought to a suitable temperature and pressure either by compression, expansion or other means, and are then brought to reaction while maintaining the temperature and pressure substantially constant.  This latter condition is attained by starting the reaction at a selected point of the cycle, that is at a point on the inward or outward stroke of the piston; by the gradual introduction of one or more of the reacting substances; and by the addition or abstraction of heat while the reaction is taking place.  In general, the selection will depend on whether the reaction is endothermic or exothermic, and whether it is accompanied by an increase or decrease in the number of molecules or whether the number of molecules remains the same.  For the addition or abstraction of heat, heating or cooling liquids may be directly injected into the cylinder or may be circulated through its jacket or through spiral tubes passing through the end compression space; or flame arcs or other electric heating-means may be employed.  For catalytic reactions, the necessary catalysts may be placed in the end compression space or may be attached to the piston, and they may be heated by the electric heating-means.  Other reactions may be effected by electric sparks or discharges, or ultra-violet light.  The reaction products under pressure may be allowed to escape, or the energy in them may be recovered by allowing them to expand in the cylinder.  The following are manufactures to which the invention is applicable:-Acetaldehyde from acetylene and water vapour-these are brought to reaction during the compression stroke, and the temperature and pressure is maintained constant by injecting water; formaldehyde, by a similar process in which air is added; acetic acid, by a similar process but substituting hydrogen peroxide for water vapour; pyridine and pyrrol, by a similar process useing acetylene and ammonia, except that to start the reaction glowing surfaces are used in the place of "induction sparks"; formaldehyde, by the combination of hydrogen with carbon monoxide and dioxide under pressure and in the presence of heated platinum wires, increase in temperature and pressure being obviated by injecting water; sodium acetate, by injecting into compressed carbon monoxide "liquid caustic soda" containing sufficient water to obviate an increase of temperature; acetic acid, by combining steam and carbon monoxide at very high temperatures; the polymerization of acetylene, by compressing the latter in the presence of suitable protective gases or vapours, and in this condition subjecting it to the action of suitable catalysts or other physical agencies; the production of ozone-oxygen is compressed and during the remaining part of the compression stroke is subjected to "induction sparks," silent discharges, or ultra-violet light, the gases being released at the end of the compression stroke in order to prevent decomposition of the ozone; the ozone so obtained may be employed in situ for effecting the oxidation of methane, illuminating gas, acetylene, alcohol, &c., to alcohol, acetaldehyde, acids, &c., and of isaeugenol to vanillin.  This subject-matter does not appear in the Specification as accepted.ALSO:The hydrogenation of fatty acids is carried out in the cylinder of a compressor; the reaction is started during the compression stroke and is continued while maintaining the temperature and pressure as constant as possible; the conditions must be such that during the reaction, which is exothermic, the temperature does not rise and the pressure does not fall.  Control of the temperature and pressure is assisted by the gradual introduction of the material to be treated, by the removal of heat while the hydrogenation is in progress, for instance, cooling liquids may be injected into the compression space or a liquid may be circulated through the jacket of the cylinder or through spiral tubes arranged within the latter.  In an example, a charge of hydrogen is compressed to 12 atmospheres and 180 DEG  C., and during the compression stroke the fatty acid is sprayed in; constancy of pressure and temperature is attained by introducing with the fatty acid highly compressed hydrogen.  The Specification as open to inspection under Sect. 91 (3) (a) refers also to the carrying-out of "saponifications" in a similar manner.  These are effected during the compression or expansion strokes according as the reaction is endothermic or exothermic.  This subject-matter does not appear in the Specification as accepted.ALSO:Chemical reactions are carried out in the interior of a compressor under such conditions that the reacting-substances are first brought to a suitable temperature and pressure either by compression, expansion or other means, and are then brought to reaction while maintaining the te