Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B47/00—Destructive distillation of solid carbonaceous materials with indirect heating, e.g. by external combustion
  • C10B47/28—Other processes
  • C10B47/32—Other processes in ovens with mechanical conveying means
  • C10B47/44—Other processes in ovens with mechanical conveying means with conveyor-screws
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B53/00—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
  • C10B53/02—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form of cellulose-containing material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
  • C10B57/04—Other carbonising or coking processes; Features of destructive distillation processes in general using charges of special composition
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
  • F23G5/02—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment
  • F23G5/027—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment pyrolising or gasifying stage
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G2201/00—Pretreatment
  • F23G2201/30—Pyrolysing
  • F23G2201/303—Burning pyrogases
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G2203/00—Furnace arrangements
  • F23G2203/80—Furnaces with other means for moving the waste through the combustion zone
  • F23G2203/801—Furnaces with other means for moving the waste through the combustion zone using conveyors
  • F23G2203/8013—Screw conveyors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/10—Biofuels, e.g. bio-diesel

Definitions

• the invention relates to a method for thermal treatment of organic matter of a low calorific value, in which method the matter to be processed is brought by a feed arrangement to a conveyor arrangement connected to a process space that is substantially of a Thompson Converter type.
• the matter to be processed is made to move in the process space in the longitudinal direction thereof by means of a conveyor arrangement closed in relation to the space.
• Pyrolysis gas formed by heat transfer from the process space into the matter to be processed contained in the conveyor system is conveyed into a combustion space provided in the process space for combustion of the gas, flue gas thereby formed being discharged from the process space by means of a discharge arrangement, and thermally treated matter is discharged from the conveyor arrangement for further processing.
• the pyroly- sis gas created inside the screw conveyors is conventionally carried within the matter to be processed in the travel direction thereof from the discharge end of the screw conveyors to a collection chamber and further on a connecting conduit to a combustion furnace below the screw conveyor space, where it is burned.
• Fuel gas leaves the combustion furnace to enter a screw conveyor space, where the heat contained in the fuel gas is transferred by convective heat transfer into the screw conveyors before being discharged from the process space through a discharge assembly.
• an essential disadvantage is that the preheating of the furnace space requires using either solid fuel for a relatively long period of time or a continuous use of an auxiliary flame produced by separate fuel to allow pyrolysis gas to be burned.
• current technology does not enable organic matter of a low calorific value to be made use of by thermal processing at reasonable investment and operating costs in particular.
• An object of the invention is to provide a decisive improvement to the above problems and thereby significantly raise the level of the art prevailing in the field.
• the method of the invention is primarily characterized in that for improving the calorific value of the matter to be processed, matter of a low calorific value is fed into the process space through the conveyor arrangement together with at least one organic matter of a better calorific value.
• the method of the invention enables to implement thermal treatment of organic matter of a low calorific value in a technically extremely simple and efficient manner by using, firstly, a continuous conveyor arrangement provided with a feed and discharge member substantially gas tight in relation to the environment.
• the large inner volume enables, firstly, fuel gases to be burned at a temperature exceeding 850 0 C for a delay of two seconds, as required by the EU waste incineration directive.
• an SNCR nitrogen reduction Selective Non-catalytic Reduction
• a temperature of 800 to 1100 0 C and an oxidizing atmosphere prevail at the rear part of the combustion space.
• the volume efficiency of the apparatus implemented according to the invention is optimal when heat transfer to the conveyor arrangement takes place in the process space by direct radiation heat from the flame of the gas burner/burners and the walls of the combustion space (the radiation heat transfer being proportional to the fourth order of the temperature), thus speeding up the initiation of the carbon separation process because direct radiation from the gas flame increases the surface temperatures of the conveyor system significantly more rapidly than convective heat transfer.
• the method of the invention thus enables to assemble an apparatus which is compact and signifi- cantly smaller than corresponding, currently available apparatuses and naturally also significantly more affordable in terms of investment, service and maintenance costs than prior art solutions.
• Figure 1 shows, by way of an example, a perspective view of an apparatus whose operation is based on the method of the invention
• Figure 2 shows a longitudinal section illustrating the operating prin- ciple of a similar apparatus
• Figures 3a and 3b show examples of two alternative Pl diagrams of an apparatus in which the method of the invention is applied.
• the invention relates to a method for separating carbon by thermal treatment, in which method matter to be processed x is brought by a feed arrangement 1 to a conveyor arrangement 3 connected to a process space 2 that is substantially of a Thompson Converter type.
• the matter to be processed x is made to move in the process space 2 in a longitudinal direction s thereof by means of a conveyor arrangement 3 closed in relation to the space, whereby pyrolysis gas y formed by heat transfer from the process space into the matter to be processed x contained in the conveyor system is conveyed into a combustion space 4 provided in the process space for combustion of the gas.
• Flue gas y' thereby formed is discharged from the process space by means of a discharge arrangement 5 and thermally treated matter x' is discharged from the conveyor arrangement for further processing.
• the matter of a low calorific value x is fed into the process space 2 through the conveyor arrangement 3 together with at least one organic matter w of a better calorific value.
• pyrolysis gas y is conveyed within the conveyor arrangement 3 by countercur- rent towards feed end I of the conveyor arrangement for transferring heat contained in the pyrolysis gas into the matter to be processed x that is moving to the opposite direction s and for feeding cooled pyrolysis gas y directly to the gas burner arrangement 7 for further processing, as shown for example in the exemplary Pl diagram of Figure 3a, or to a heat exchanger 13 and/or small separation arrangement 6, as shown in Figure 3b, for separating the tar contained therein before the combustion of the pyrolysis gas.
• the pyrolysis gas y is conveyed to the conveyor arrangement 3 for further processing through a flow arrangement 8 connected to the outside of the process space 1.
• the conveyor system 3 is heated immediately after its introduction into the process space 2 by one or more gas burners 7; 7a arranged to the entry wall 2a of the process space parallel with the conveyor arrangement.
• the matter to be processed x, w is handled in connection with the process space 2 by a continuous conveyor arrangement 3 provided with feed and discharge members 1 a, 1 b that are substantially gas tight in relation to the environment, the arrangement being implemented by means of one or more screw conveyors 3a or the like that are driven by an electric motor o and steplessly regulated by means of a frequency converter, for example.
• the matter to be processed may be fed to the conveyor system 3 by using the method and feed arrangement of Finnish Patent 119125, for example, particularly for implementing overfeed of the matter to be processed, firstly, in a continuous manner and, secondly, according to the principle of the Pl diagrams of Figure 3a and 3b, for example, in such a way that proc- ess gases are prevented from escaping from the conveyor arrangement or the process space into the environment in an uncontrolled manner.
• drier matter w is preferably mixed therein in the longitudinal direction of the conveyor arrangement by two successive feeders 1 ; 1 a , for example as shown in the accompanying drawings 1 and 2, the matter fed by which then becomes mixed as the screw conveyor 3a pushes them towards the process space.
• the wet and dry matter x, w being mixed in a separate mixing space and conveyed by one con- veyor to the conveyor arrangement 3.
• the calorific value of the matter to be processed is improved by adding to the wet matter x drier matter and/or matter of a better calorific value, the matter being substantially fluid, such as grease waste, glycerol and/or the like.
• air supply to the gas burner arrangement 7, such as one or more parallel gas burners 7a, is implemented by a separate combustion air blower 9.
• an ejector blower 10 is applied, also in a preferred manner, in connection with one or more gas burners 7 belonging to the gas burner arrange- ment 3 for sucking pyrolysis gas y through an ejector nozzle 11 into the gas burner.
• the tar p contained in the pyrolysis gas y is separated according to a preferred embodiment by an electrostatic precipitator (ESP).
• ESP electrostatic precipitator
• thermally treated carbonized matter x', w' is removed from the proc- ess space 2 and then ground in step A by mixing therein tar p obtained from the small separation arrangement 6.
• the ground, carbonized matter x', w' and the tar p mixed together are compressed into briquettes in step B by one or more briquette pressers.
• a nitrogen reduction is carried out in the process space by feeding ammonia-containing medium, such as urea mist, ammonia- water solution or the like, into the combustion space 4 by an additional nozzle arrangement z.
• ammonia-containing medium such as urea mist, ammonia- water solution or the like
• the medium sprayed through the nozzle arrangement evaporates, whereby the remaining ammonia becomes mixed and has enough time to work on the flue gases so that a significant nitrogen reduction is achieved.
• the method of the invention also preferably ensures by means of a Lambda sensor, for example, that con- tinuous excess air is maintained in the combustion.
• the pyrolysis gas y is cooled to about 30 0 C before being fed to the small separation arrangement 6.
• thermally treated carbonized matter x' is removed from the process space 2 preferably at a temperature of 450°.
• the transfer power of the conveyor arrangement 3, such as one or more screw conveyors 3a is changed in the longitudinal direction s of the processing space so as to particularly reduce the layer thickness of the matter to be processed x from the feed end I of the conveyor arrangement 3 towards its discharge end II.
• the conveyor arrangement 3 is preferably implemented by a screw conveyor 3a provided with one or more lower pitches at the front end thereof and one or more higher pitches at the rear end thereof.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Gasification And Melting Of Waste (AREA)
• Processing Of Solid Wastes (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Cited By (2)

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Citations (6)

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• 2009
  • 2009-07-08 FI FI20095781A patent/FI20095781A0/fi not_active Application Discontinuation
  • 2009-09-25 CN CN200910174239XA patent/CN101943411A/zh active Pending
• 2010
  • 2010-07-07 CA CA2767629A patent/CA2767629A1/en not_active Abandoned
  • 2010-07-07 EP EP10796780A patent/EP2451898A1/en not_active Withdrawn
  • 2010-07-07 WO PCT/FI2010/050586 patent/WO2011004075A1/en active Application Filing

Patent Citations (6)

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