Patent GB-709035-A (GB)
Title: Improvements relating to the production of pyrogenic chemical reactions
Inventor: II JAMES WHEDBEE MULLEN
IPC: C07C2/76
Filed: 1952-02-06
Abstract: In a method of carrying out pyrogenic chemical reactions by continuously burning a mixture of fuel and oxidant under pressure in an elongated chamber to produce a flowing stream of high temperature gaseous combustion products, and then introducing a reactant into the flowing stream and rapidly cooling the reaction products, such pressures are used that a substantial portion of the stream is flowing with at least sonic velocity when reaction is taking place and while the cooling is effected.  Sonic velocity may be attained by gases issuing through a nozzle from a burner operating above atmospheric pressure.  The reactant may be mixed with the hot combustion gases before or after they have attained sonic velocity, or may be introduced with the fuel and oxidant; the fuel and reactant may be the same material.  Cooling may result from the expansion of the gases to sonic velocity, or may be effected by spraying a liquid, e.g. water, into the gases either before or after expansion; other methods of cooling are to lead the gases into a body of liquid or to expand them in a heat engine e.g. a turbine.  The reactant may be used as the cooling agent, and in this case the gases are recycled after separating the reaction products.  Reaction time may be controlled by varying the length of the reaction chamber, and reaction temperature by varying the mass flow of the gases.  Air and oxygen are suitable oxidants and fuels referred to are natural gas, liquid hydrocarbons, water gas, producer gas, blast furnace gas, hydrogen, coal, carbon disulphide, and phosphorus.  The fuel-oxidant ratio may be varied to produce either an oxidizing or reducing atmosphere, and to control the temperature.  A cooling agent may be mixed with the combustion gases before contact with the reactant. Reference is made to the preheating of the reactant, fuel, and oxidant, and to the use of catalysts. Examples describe the formation of ethylene from ethane; acetylene, formaldehyde, hydrogen, and carbon black from natural gas; aromatic hydrocarbons, including benzene, from lower paraffins; and biphenyl and terphenyls from benzene.  Thermal cracking of hydrocarbons and partial ozidation of hydrocarbons to aldehydes, ketones, acids, and hydroxy compounds are also referred to.  The apparatus may be made of steel and surrounded by a water jacket; various arrangements of suitable apparatus are shown diagrammatically.ALSO:In a method of carrying out pyrogenic chemical reactions by continuously burning a mixture of fuel and oxidant under pressure in an elongated chamber to produce a flowing stream of high temperature gaseous combustion products, and then introducing a reactant into the flowing stream and rapidly cooling the reaction products, such pressures are used that a substantial portion of the stream is flowing with at least sonic velocity when reaction is taking place and while the cooling is effected.  Sonic velocity may be attained by gases issuing through a nozzle from a burner operating above atmospheric pressure.  The reactant may be mixed with the hot combustion gases before or after they have attained sonic velocity, or may be introduced with the fuel and oxidant; the fuel and reactant may be the same material.  Cooling may result from the expansion of the gases to sonic velocity, or may be effected by spraying a liquid, e.g. water, into the gases either before or after expansion; other methods of cooling are to lead the gases into a body of liquid or to expand them in a heat engine, e.g. a turbine.  The reactant may be used as the cooling agent, and in this case the gases are recycled after separating the reaction products.  Reaction time may be controlled by varying the length of the reaction chamber, and reaction temperature by varying the mass flow of the gases.  Air and oxygen are suitable oxidants, and fuels referred to are natural gas, liquid hydrocarbons, water gas, producer gas, blast furnace gas, hydrogen, coal, carbon disulphide, and phosphorus.  The fuel-oxidant ratio may be varied to produce either an oxidizing or reducing atmosphere, and to control the temperature. A cooling agent may be mixed with the combustion gases before contact with the reactant.  Reference is made to preheating the reactant, fuel, and oxidant, and to the use of catalysts.  Examples describe the formation of ethylene from ethane; acetylene, formaldehyde, hydrogen, and carbon black from natural gas; aromatic hydrocarbons, including benzene, from lower paraffins; and biphenyl and terphenyls from benzene.  Thermal cracking of hydrocarbons and partial oxidation of hydrocarbons to aldehydes, ketones acids, and hydroxy compounds are also referred to.  The apparatus may be made of steel and surrounded by a water jacket; various arrangements of suitable apparatus are shown diagrammatically.