US 4,153,426 A · Synthetic gas production

Abstract

Disclosed is a method and apparatus for producing synthetic gas by using a blast furnace as a gasifier. The furnace is charged in a conventional manner with particles of solid carbonaceous material such as normal, low grade or undersized coke together with slag-producing material, such as limestone, silica and/or basic oxygen furnace and/or open hearth furnace slag. Fluent fuel such as pulverized coal mixed with oxygen-containing gas and with lime if desired is injected into pre-ignition chambers near the hearth line of the furnace. The fluent fuel is ignited and partially gasified in the pre-ignition chambers, creating a hot reducing gas that enters the furnace raceway and passes upwardly into and through the body of charge material in the furnace stack. At the resulting high temperatures ash from the fluent fuel liguifies within the system to provide a liquid slag. Under a controlled high temperature reducing atmosphere, the liquid lime removes essentially all sulfur from the product gas. To reduce the high gas temperature, steam is injected above the pre-ignition chambers. The steam reacts with the hot solid carbonaceous material in the stack to disassociate and enrich the product gas with additional hydrogen and carbon monoxide. Liquid carbonaceous material such as oil, tar, or the like is injected into the furnace stack above the location at which steam is injected and is cracked by the sensible heat of the gas passing through the body of charge material in the furnace, thus further cooling the gas and enriching its calorific value. The resulting product gas can be used in place of natural gas for heating purposes in steel making operations, as a gas in the production of chemicals, as a reducing gas for the metals industries, for general heating purposes, as well as for other purposes.

Claims41

Dependent claims

A method of manufacturing synthetic gas having a substantial calorific content, in a large volume slag type shaft furnace such as a blast furnace having a hearth in the lower portion thereof and a shaft above the hearth, which method comprises charging through the top of said furnace charge material comprising particulate solid carbonaceous material and slag-producing flux material in a size range of particles of material normally charged into a blast furnace in conventional blast furnace practice, to form a body of said charge material in the shaft of said furnace, introducing finely divided solid carbonaceous material and oxygen-containing gas into pre-ignition gasification chamber means that discharges into said furnace above said hearth while pre-igniting and commencing gasification of said finely divided carbonaceous material in said oxygen-containing gas in said pre-ignition chamber means so as to discharge into said furnace from said pre-ignition chamber means hot products of gasification and unburned finely divided carbonaceous material at a temperature high enough to enable substantially all carbon in said finely divided carbonaceous material to combine with available oxygen in said furnace to produce hot gas of substantial calorific content that moves upwardly through said body of charge material;

discharging steam into said body of charge material at a location in the furnace where the furnace temperature is sufficient to cause reaction between said steam and carbon in said carbonaceous material in said body of charge material to produce hydrogen and carbon monoxide which are added to said gas;
discharging liquid carbonaceous material into said shaft of said furnace at a location whereat the gas in said furnace is at a temperature high enough to crack said liquid carbonaceous material and lower the temperature of said gas;
and thereafter withdrawing the resulting synthetic gas from the top of said furnace.

A method of manufacturing synthetic gas having a substantial calorific content, in a large volume slag type shaft furnace such as a blast furnace having a hearth in the lower portion thereof and a shaft above the hearth, which method comprises charging through the top of said furnace charge material comprising particulate solid carbonaceous material and lime-containing slag-producing flux material to form a body of said charge material in the shaft of said furnace, introducing finely divided solid carbonaceous material and oxygen-containing gas into pre-ignition gasification chamber means that opens into said furnace above said hearth while pre-igniting and commencing gasification of said finely divided carbonaceous material in said oxygen-containing gas in said pre-ignition chamber means so as to discharge into said furnace from said pre-ignition chamber means hot products of gasification and unburned finely divided carbonaceous material at a temperature between about 3000.degree. F. and about 3600.degree. F. high enough to enable substantially all carbon in said carbonaceous material to combine with available oxygen in said furnace, to produce hot gas of substantial calorific content that moves upwardly through said body of charge material;

discharging steam into said body of charge material at a location above said pre-ignition chamber means where the furnace temperature is between about 2600.degree. F. and about 2800.degree. F. to cause reaction between said steam and carbon in said carbonaceous material to produce hydrogen and carbon monoxide which are added to said gas;
discharging liquid carbonaceous material into said shaft of said furnace at a location substantially above the location at which said steam is injected into said furnace and whereat the temperature is between about 1000.degree. F. and about 1800.degree. F., to crack said liquid carbonaceous material and lower the temperature of said gas;
and thereafter withdrawing the resulting product gas from the top of said furnace, the quantity of said slag-producing flux material and the temperature in said furnace being controlled to cause the formation in said furnace of slag that collects in a molten pool in the hearth of the furnace.

A shaft furnace of the type in which charge material including carbonaceous material is charged into the upper portion of the furnace and oxygen containing gas is introduced into the lower portion of the furnace, said furnace comprising a hearth in the lower portion of the furnace, a shaft above the hearth, charging means at the upper portion of said shaft by which charge material essentially comprising particulate solid carbonaceous material and slag-producing flux material is introduced into said furnace to produce in said furnace a body of charge material essentially comprising only said particulate solid carbonaceous material and said flux material;

pre-ignition gasification chamber means opening into said furnace above said hearth and associated with means for introducing into said pre-ignition chamber means finely divided solid carbonaceous material and oxygen-containing gas, said pre-ignition chamber means being adapted to operate to ignite, heat, burn, and gasify said finely divided carbonaceous material introduced into said pre-ignition chamber means at a temperature between about 3000.degree. F. and 3600.degree. F., and to discharge into said furnace hot reducing gases along with unburned finely divided carbonaceous material from said pre-ignition chamber means at a temperature high enough to enable substantially all carbon in the carbonaceous material in said furnace in the vicinity of the location of discharge into said furnace from said pre-ignition chamber means to combine with available oxygen in said furnace in said vicinity to produce in said furnace hot gas of substantial calorific content that passes upwardly through said body of charge material in said furnace, said pre-ignition chamber means being adapted to discharge said unburned finely divided carbonaceous material into said furnace at a temperature at least approximating the temperature of the carbonaceous material in the body of charge material in the furnace in the vicinity of the location of discharge into the furnace from said pre-ignition chamber means;
means for discharging steam into said furnace above said hearth portion and above and separate from the location at which said pre-ignition chamber means discharges into said furnace;
and means at the upper portion of said furnace for withdrawing gas so produced in said furnace.

introducing finely divided solid carbonaceous material and oxygen-containing gas into preignition gasification chamber means that discharges into said furnace above said hearth while igniting, burning, heating and gasifying said finely divided carbonaceous material in said oxygen-containing gas in said pre-ignition chamber means to gasify said finely divided carbonaceous material to produce hot reducing gases that are discharged into said furnace from said pre-ignition chamber means along with unburned finely divided carbonaceous material at a temperature between about 3000.degree. F. and about 3600.degree. F. and high enough to enable substantially all carbon in the carbonaceous material in said furnace in the vicinity of the location of discharge from said pre-ignition chamber means to combine with available oxygen in said furnace in said vicinity to produce hot gas of substantial calorific content that moves upwardly through said body of charge material in said furnace, said unburned finely divided carbonaceous material being discharged into said furnace along with said hot gases from said pre-ignition chamber means at a temperature at least approximating the temperature of the carbonaceous material in the body of charge material in the furnace in said vicinity of the location of discharge of said heated finely divided carbonaceous material into said furnace from said preignition chamber means;
and withdrawing from the upper portion of said furnace the gas so produced.

Dependencies are inferred from the claim text.

Synthetic gas production

Life of this patent

Synthetic gas production

Life of this patent

Abstract

Claims41