Classifications

• • 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
  • F23G5/008—Incineration of waste; Incinerator constructions; Details, accessories or control therefor adapted for burning two or more kinds, e.g. liquid and solid, of waste being fed through separate inlets
• • 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
  • F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
  • F23G5/08—Incineration of waste; Incinerator constructions; Details, accessories or control therefor having supplementary heating
  • F23G5/14—Incineration of waste; Incinerator constructions; Details, accessories or control therefor having supplementary heating including secondary combustion
  • F23G5/16—Incineration of waste; Incinerator constructions; Details, accessories or control therefor having supplementary heating including secondary combustion in a separate combustion chamber
• • 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
  • F23G5/50—Control or safety arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
  • F23G7/05—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste oils
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
  • F23G7/10—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of field or garden waste or biomasses
  • F23G7/105—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of field or garden waste or biomasses of wood waste
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
  • F23G7/12—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of plastics, e.g. rubber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
  • F23G2207/00—Control
  • F23G2207/40—Supplementary heat supply
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2241/00—Applications
  • F23N2241/18—Incinerating apparatus

Definitions

• the invention relates to a method of energy recovery of waste, of the kind of those which include a waste incineration step in a furnace for the production of thermal energy, a method according to which a waste gasification is carried out at high PCI. to produce gas, and this gas is injected into the furnace combustion chamber.
• Furnaces for the implementation of these processes are designed according to the average lower heating value (average ICP) of the waste to be incinerated and according to the average flow, generally expressed in tons per hour (t / h) of waste to be treated.
• average ICP average lower heating value
• t / h average flow
• a maximum flow is determined, as well as a maximum power of the oven. When operating the machine, it must be avoided that these maximum values are exceeded, which could degrade the performance of the oven.
• the pit manager performs an empirical mix of incoming wastes to provide an "adequate mix" to the combustion furnace.
• This "adequate mix” depends on the know-how of the manager, and can be a source of errors in some cases leading to an inadequate "mix” locating the flow / power pair of the oven outside the operating zone considered normal.
• the operator will seek to operate the furnace by avoiding exceeding the maximum power expected in the construction. For this, if the waste has a relatively high PCI compared to what was taken into account during the design of the furnace, the regulation will limit the mass flow of waste introduced into the oven so as not to risk exceeding the power maximum; this way of operating reduces the capacity of the recovery unit which will not operate at its maximum flow so that the treatment time of a given quantity of waste will be greater.
• the control underestimates the ICP of the waste and makes the oven work at its maximum mass flow, the maximum power of the oven may be exceeded.
• the main purpose of the invention is to optimize the operation of an existing waste energy recovery unit by making it operate, in a controlled manner, in the vicinity of the intersection of the maximum waste stream and the maximum power of the waste. oven.
• the invention also aims to efficiently treat the separately collected high PCI waste.
• a method of energy recovery of waste is characterized in that:
• the waste incinerated in the kiln is urban and / or industrial waste
• high-level waste consists of biomass and / or wood waste, particularly wood B, and the gasification of this waste is carried out in a gasifier to produce syngas, the injection of which into the combustion chamber makes it possible to achieve a higher oven power without increasing the mass flow of waste introduced.
• the gasifier is of the co-current type with the introduction of waste with high PCI in the upper part of the gasifier, introduction of oxidizing gasification agents, in particular air and / or oxygen (O 2 ) substantially at i-height, the output of the product gas being located in part bottom of the gasifier and being connected by at least one pipe to the furnace combustion chamber.
• oxidizing gasification agents in particular air and / or oxygen (O 2 ) substantially at i-height
• a gasification of waste with a PCI greater than 12 MJ / kg Preferably, a gasification of waste with a PCI greater than 12 MJ / kg.
• the furnace is operated at maximum flow and the power of the furnace is controlled by the syngas flow so as to maintain it equal to or close to the maximum power.
• the syngas is advantageously used as fuel. in a burner installed on a pipe of the combustion gases of the furnace, upstream of a reactor for a catalytic denitrification of the combustion gases.
• the invention also relates to a waste energy recovery unit, for the production of thermal energy, comprising an oven for the combustion of waste, and a waste gasification with high PCI, characterized in that:
• the oven is a furnace for the combustion of waste with relatively low PCI, in particular less than 8 MJ / kg,
• High PCI in particular greater than 12 MJ / kg, consisting of biomass and / or wood waste, particularly wood B, to produce syngas,
• the or each connecting line for the syngas is connected to a secondary air inlet of the furnace combustion chamber.
• a unit in which the combustion furnace is provided to operate between a maximum power and a minimum power, with a waste stream comprised between a maximum flow and a minimum flow, the waste PCI being between a higher value and a lower value , is characterized in that a regulation is provided to adjust the flow of syngas injected into the oven and to operate the oven at its maximum power.
• a solenoid valve can be installed on the connecting line and be controlled by the control for adjusting the flow of syngas injected into the furnace.
• the gas generator is co-current, downflow, with feed at the top for waste high PCI, power lateral for an oxidizing gasification agent, the output of the produced syngas being located in the lower portion of the gasifier.
• the combustor may be a grid or roller oven.
• a unit, as defined above, comprising a catalytic denitrification installation of the furnace combustion gases, with a burner installed on a flue gas discharge pipe, upstream of a denitrification unit, is characterized in that a syngas feed line of the burner is provided between the output of the gasifier and the burner, to supply the latter in syngas when the solids treated in the gasogene can generate a syngas own.
• Fig. 1 is a combustion diagram illustrating the operation of an oven for the combustion of waste.
• Fig. 2 is a diagram of an energy recovery unit of waste according to the invention.
• Fig. 3 is a schematic of a selective catalytic denitrification plant with a burner.
• Fig. 1 of the drawings we can see a combustion diagram that defines the operating range of an oven for the combustion of urban and / or industrial waste.
• the furnace power expressed in MW (megawatts) is plotted on the ordinate, while the mass flow of waste introduced into the furnace is plotted on the abscissa and is expressed in tons / hour (t / h).
• the iso-PCI curves are therefore straight lines originating from the origin 0 and whose slope is proportional to the PCI.
• the straight line D1 corresponds to the iso-PCI mini curve while the straight line D2 corresponds to the iso-PCI max curve, these two PCI having been taken into consideration at the time of furnace design.
• the maximum permissible flow corresponds to a vertical line E2.
• the maximum allowable power corresponds to a horizontal line P2.
• the construction of the combustion diagram is made from the data on the deposit of waste to be burned, taking into account the annual capacity and the lower heating value PCI, the number of furnaces or of furnace lines, and the power of the (or) boiler (s).
• PCI the annual capacity and the lower heating value
• PCI the number of furnaces or of furnace lines
• PCI the power of the (or) boiler
• a flux m in im um E1 is a percentage of the maximum flux, in particular 50 to 60% of the maximum flux.
• a mass overload zone Zm corresponds to a vertical band comprised between the straight line E2 of the maximum continuous permissible flow and a vertical line E3 corresponding to 1 10% of the maximum flux. Operation in this zone Zm remains acceptable but temporarily.
• a thermal overheating zone Zt corresponds to a horizontal band between the line P2 of maximum power and a line P3 corresponding to 1 1 0% of the maximum power. Operation in this zone Zt remains acceptable, but it is preferable to avoid it.
• the optimal operation corresponds to the point B located at the intersection of the straight line P2 of maximum power and the vertical E2 of maximum flow.
• the PCI waste does not exceed that defined by the line D4 iso-PCI from the origin 0 and which passes by point B.
• the operator will therefore endeavor to prepare waste mixtures corresponding to an iso-PCI line such as D5 located below D4 so as to be able to process the maximum mass flow of waste, without exceeding the power maximum permissible.
• This straight line D5 cuts the vertical E2 at the operating point B1 which corresponds to a power lower than the maximum power.
• the energy recovery unit comprises a gasifier 1 (FIG 2) in which high-level wastes are gasified, in particular greater than 12 MJ / kg and up to 15 MJ / kg or more, constituting a solid with high calorific value.
• a gasifier 1 (FIG 2) in which high-level wastes are gasified, in particular greater than 12 MJ / kg and up to 15 MJ / kg or more, constituting a solid with high calorific value.
• High-level waste consists mainly of biomass, wood waste, especially wood B, which can result from the shredding of discarded furniture.
• the gasifier 1 can be of any type.
• the gasifier is of the co-current type with waste introduction to
• oxidizing gasification agents in particular air and / or oxygen (O2) is performed laterally, as symbolized by the arrow 3, substantially to halfway up.
• agents such as carbon dioxide (CO2) and / or water (H 2 0) is also possible.
• the outlet 4 of the gas produced by the gasifier, called syngas, is located in the lower part of the gasifier and is connected by at least one pipe 5 to the combustion chamber 6 of an oven H to incinerate urban waste W and / or industrial.
• the gasifier 1 is generally constituted by a cylindrical metal tower having, in the lower part, triggering means 7 for starting the combustion in the gasifier.
• the means 7 may be electrical tripping means.
• the pipe 5 is equipped with a solenoid valve 8 controlled by a regulation R which makes it possible to adjust the flow of syngas to ensure the optimum conditions of combustion in the furnace H, which can be of any type.
• the furnace H is a grated oven on the 9th inclined; waste W to burn are introduced in the upper part of this grid, and burn down on the grid. The ashes are removed at the bottom.
• the primary combustion air is supplied by a fan 1 1 below the grid 9.
• the combustion chamber 6 extends upwardly above the grid 9 and has inputs 12 for the secondary air.
• the pipe 5 is connected to at least one secondary air inlet so that the syngas is injected at the level of this secondary air into the chamber 6, above the littering bed.
• Natural gas or oil burners are provided in the furnace H to start the combustion to a given temperature of the gases in the chamber 6, this temperature being generally set at 850 ° C for the flue gases, also called fumes.
• the desired temperature in particular 850 ° C
• the gas burners were actuated to maintain this temperature.
• the injection of syngas into the combustion chamber 6, in particular at the level of the secondary air injection makes it possible to obtain and maintain the desired combustion temperature, without it is necessary to operate burners, in the case where the ICP waste is insufficient.
• the operating point of the furnace for a waste PCI corresponding to the line D5 iso-PCI would be at point B2 at the intersection of E3 and D5.
• the injection of syngas would then make it possible to pass the operating point from B2 to B3 located on vertical E3 and on line P2 of maximum power of the furnace.
• the invention ensures the transformation of a solid with high power fuel gas by gasification, ie thermochemical oxidation under conditions below the stoichiometric relationship, which is coupled to an energy recovery unit.
• the mixture of fuels must not be made within the combustion grate or in the unloading pit, in order not to degrade the combustion diagram of the furnace envisaged during its construction, the gasification of solid waste with high PCI.
• the gasification of solid waste with high PCI allows to feed the combustion furnace in syngas within the combustion chamber, preferably at the level of the secondary air line by using arrivals already installed on the furnaces. In this way, it is possible to add any type of solid, including other waste, in the gasifier 1, in order to comply with the standards imposed, including fumes in the combustion furnace heated to a temperature of 850 ° C for at least two seconds.
• Fig. 3 is a schematic of a selective catalytic denitrification unit which may be provided in an energy recovery unit.
• the combustion gases from the furnace circulate in a pipe 13 to be introduced into a catalytic reactor 14 operating at a temperature of about 230 ° C.
• Ammonia from a reservoir 15 is injected into line 13 upstream of reactor 14 for catalytic removal of nitrogen oxides.
• the gases exit the reactor 14 through a pipe 16 connected to the suction of a fan 17 which discharges into a discharge chimney 17a.
• the nitrogen oxide content of the gases leaving the reactor 14 is measured by a probe 18.
• a regulation is provided to control a valve 19 regulating the ammonia injection flow rate as a function of the NOx nitrogen oxide content. provided by the probe 18.
• a burner 20 is installed on the pipe 13, upstream of the ammonia injection.
• the burner 20 is provided to allow the combustion gases to be heated up to 320 ° C. before entering the reactor 14. According to the state of the art, the burner 20 is supplied with natural gas .
• this syngas when the gasifier 1 is fed into a solid fuel capable of providing a clean syngas, that is to say not creating a risk for compliance with the thresholds imposed on gas discharges of energy recovery units, this syngas can be used as fuel by the burner 20, in order to reduce the consumption of natural gas during catalytic denitrification.
• a pipe 21 provided with a valve 22 provides a connection between the syngas outlet of the gasifier and the fuel inlet of the burner 20. This connection is put into operation, by opening the valve 22, when the solid fuel supplied to the gasifier allows to obtain syngas clean.
• composition of the syngas obtained as well as its PCI expressed in kWh / Nm 3 are given below.
• the invention allows the coupling of the gasification of biomass / wood (wood waste, clean wood, biomass wood) on energy recovery units of waste:

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Processing Of Solid Wastes (AREA)
• Gasification And Melting Of Waste (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=49713338

Family Applications (1)

Country Status (3)

Family Cites Families (4)

• 2013
  • 2013-10-17 FR FR1360108A patent/FR3012053B1/fr active Active
• 2014
  • 2014-10-16 EP EP14799004.8A patent/EP3058278B1/de active Active
  • 2014-10-16 WO PCT/IB2014/065371 patent/WO2015056214A1/fr active Application Filing

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events