FR2823555A1 - Incineration system for waste animal products has solid fuel furnace, thermolysis/pyrolysis column, homogeniser and heat exchanger - Google Patents

Abstract

The system consists of a solid fuel furnace (1), fuelled e.g. with wood, fibre and cellyulose material of vegetable biomass origin, having a grate (10) and oxygen injection system, a thermolysis/pyrolysis column (2) with inclined grilles (21, 22, 23) and inlets (25, 26) for the fuel and materials to be incinerated. The furnace incorporates a homogenisation chamber (3) for burned gases and organic vapours, combustion (4) and post-combustion (5) chambers, a heat exchanger (6) to recover energy from gases leaving the post-combustion chamber, and an extractor (7) for the gases after the heat exchanger.

Description

- 1 - 2823555

  "System and method for incinerating organic materials, in particular meal and fat of animal origin" The present invention relates to a system for incinerating organic material, especially meal and fat of animal origin. It also covers an incineration process implemented in this system. The elimination of organic matter, especially from animal production and the food industry, is a major problem for businesses and communities. This is indeed to ensure that all of the pathogenic structures possibly contained in these organic materials are destroyed for reasons

obvious public health concerns.

  Techniques for the incineration of organic materials already exist, but most of the current methods have the disadvantage of discharging into the environment compounds with high toxicity such as dioxin or furans. In addition, these incineration processes consume a lot of energy and have a negative impact on the environment. Document JP11304117A2 effectively discloses an animal carcass incineration system without generation of dioxin, comprising a primary combustion chamber equipped with a burner, a secondary combustion chamber disposed above the primary combustion chamber, a stabilizer for accumulate heat to generate radiant heat and a high temperature air vortex, and a smoke suppressor burner to heat with high temperature flames the interior space of the secondary combustion chamber which is in the continuity of the primary combustion chamber and the stabilizer. The secondary combustion chamber suppresses the generation of dioxin by completely burning the unburned gases leaving the primary combustion chamber. Such a system, however, has the drawback of nocessiting a

  substantial fuel supply for the two burners.

  The aim of the present invention is to remedy these drawbacks by proposing an organic matter incineration system which at the same time guarantees the complete destruction of all organic compounds, in particular proteins and viruses, while being part of a process

  environmentally friendly and energy efficient.

  This objective is achieved with an incinerator system comprising: - a solid fuel oven comprising a grid receiving solid fuel and means for injecting oxygen, - a thermolysis / pyrolysis column comprising grids inclined towards the oven, means for bringing solid fuel to the furnace and means for bringing organic matter to be incinerated above said inclined grids, 1S - a chamber for homogenization of the burnt gases and organic vapors from the thermolysis / pyrolysis column, - a chamber combustion followed by a post-combustion chamber, - heat exchange means for recovering the energy of the exhaust gases from the post-combustion chamber, and - means for extracting combustion gases at the outlet means

heat exchange.

  The solid fuel advantageously consists of densified ligno-fibro-cellulosic plant biomass. This fuel is notably distributed under the name [Bio-D] and is described in the

2 5 document FR2790403.

  In a preferred embodiment, the oxygen injection means comprise primary oxygen injection means under the oven rack, and secondary oxygen injection means at the heart of a bed of embers produced above the oven rack by

solid fuel in combustion.

  - 3 - The in ci nator system according to the invention preferably comprises in addition means for controlling the supply of solid fuel in a way to avoid any entry of parasitic air into the oven, means for controlling the atmosphere at within the thermolysis / pyrolysis column so as to be without residual oxygen, means for controlling the speed of the gases and / or their temperature to allow the thermal acquisition required for the vaporization of the gasifiable organic materials, means for controlling the feeding in

  organic matter so as to avoid any parasitic entry of air.

  In a preferred embodiment of an incinerator system according to the invention, the combustion chamber is cylindrical and has a parabolic bottom open on the gas nozzle, of diameter smaller than that of said combustion chamber, and provided with a central cone directed towards said nozzle. The post-combustion chamber is also cylindrical and has a tube in its axis to support the bottom.

  parabolic of the combustion chamber.

  According to another aspect of the invention, there is provided a method for incinerating organic matter, characterized in that it comprises: - production of thermal energy required for thermolysis and pyrolytic reduction of organic matter within a thermolysis / pyrolysis column, by combustion of a solid fuel under oxygen, - a volatilization of the gasifiable components of said organic materials along the thermolysis / pyrolysis column, - a combustion of the non-gasified organic compounds on a bed of embers from combustion of the solid fuel, - homogenization of the pyrolysis and combustion gases of the solid fuel in a mixing chamber, - injection of oxygen into said pyrolysis and combustion gases to enable them to self-ignite,

- 4 - 2823555

  - an injection of an ignited gas mixture into a combustion chamber, - an expansion of the burnt gases in a controlled afterburner chamber, and - recovery of the thermal energy at the outlet of the burnt gases. As part of a complete ecological operation, the elements from the incinerator system according to the invention are concentrable and recoverable. The elimination of animal meal is therefore carried out without any rejection, the ashes themselves being usable. Carbon dioxide CO2 is a product consumed industrially and its recovery is therefore possible. Cogeneration of energy ensures the profitability of the incineration process according to the invention by providing the heat necessary for the preparation of the preparations and the electricity which can be marketed. In the case where the incineration of organic materials is carried out directly on the site of production of these materials, for example on a rendering site, the energy produced by cogeneration can then be

directly consumed on this site.

  The incineration system according to the invention has the major advantage of using a solid and renewable fuel, solely composed of carbon, as basic energy, for the reduction and incineration of organic matter. This fuel is particularly suitable for combustion under oxygen, which allows an ignition of the solid fuel in hyper-oxidation for a drastic control of combustion and of the temperature, and a pyrolysis / thermolysis, in the gasification column, under control

absence of residual oxygen.

  The use of oxygen as oxidizer makes it possible to rationalize the control and the adjustment of the stages of the incineration process according to the invention. Otherwise; the implementation of this process allows a

- 5 - 2823555

  significant thermal energy production and cogeneration of energy

  enhanced by the regularity of the thermal energy produced.

  In addition, with the incineration process according to the invention, it is impossible to cause the formation of dioxins, furans and other compound molecules, polluting in the absence of elements contributing thereto. The incineration system according to the invention can be used

punctually or continuously.

  Another advantage of the incineration system according to the invention is that it concentrates all of the thermolysis / pyrolysis operations,

  incineration, gas combustion and energy recovery.

  The use of oxygen as an oxidizer allows this concentration by limiting the interior volumes of the system. This results in a reduced footprint for greater operating capacity by

  compared to current incineration processes.

  In addition, the concentration of carbon dioxide by cryogenization contributes to the suppression of carbon dioxide emissions in the atmosphere. The investment of the cryogenization unit can be amortized by the production of oxygen at the place of consumption

  and by industrial recovery of liquid carbon dioxide.

  Other advantages and characteristics of the invention will become apparent from

  examining the detailed description of a method of implementation

  in no way limiting, and appended drawings in which: - Figure 1 is a block diagram of an incineration system according to the invention, and 2 5 - Figure 2 illustrates the essential phases of the incineration process

according to the invention.

  We will now describe, with reference to FIG. 1, an example

  for producing an incineration system according to the invention.

  The incineration system S according to the invention comprises: a furnace 1 for solid fuel with upward flow comprising a grid receiving a solid fuel and oxygen injectors 1 1,

- 6- 2823555

  - a thermolysis / pyrolysis column 2, - a chamber 3 for the homogenization of burnt gases and organic vapors, terminated by a nozzle 30 proportional to the required flow rates, - a cylindrical combustion chamber 4 having a parabolic bottom 30 open on the nozzle of gas 31 and comprising in opposition a parabola 40, of a diameter smaller than the cylinder, with a central cone 41, - a cylindrical post-combustion chamber 5, expanded, comprising in its axis a support tube 50 of the parabola 40, - a heat exchanger 6 recovering the energy of the exhaust gases, connected to an energy cogeneration unit 9, - a combustion gas extractor 7, the system operating under vacuum. The oven 1 has in its lower part the grid 10 under which an ashtray 13 is disposed, and above its upper part,

  a fuel supply chute 25.

  The oxygen injection is carried out in primary under the grid, and in secondary in the heart of the ember bed. We thus obtain a very magma

responsive, easily controllable.

  The oven 1 is made of special steel to allow obtaining

  very high temperatures greater than or equal to 1600 C.

  Under the grate 10, the ashtray 13, airtight, collects the non-combustible residues C, ashes composed mainly of non-combustible minerals contained in organic matter, and of minerals contained in solid fuel for less 1% in quantity. The walls of the oven 1, its grid 10 and the walls of the ashtray 13 are hydraulically cooled. The air-tight fuel supply chute 25 is disposed above the furnace 1, with a supply

  continuously controlled in order to avoid any entry of parasitic air.

  The thermolysis / pyrolysis column 2 comprises:

- 7 - 2823555

  - a parallelepiped 26 of height adapted to the desired thermal acquisition, - tubular grids 21, 22, 23 inclined towards the furnace and composed of perforated tubes, - a supply 25 of densified biomass, at the level of the furnace, - a supply 24 organic matter to be incinerated above the grids. In this column 2, the atmosphere is controlled so as to be without residual oxygen. The speed of the combustion gases and their temperature are controlled to allow thermal acquisition

  required for vaporization of gasifiable organic matter.

  A fraction of the solid fuel is injected 26 into the flow of organic matter to be incinerated, which facilitates their

  permanent flow and unclogging of the grates of column 2.

  The homogenization chamber 3 is configured so as to direct the gases coming from the thermolysis / pyrolysis column towards the combustion chamber 4, through the nozzle 30 at the level of which a

oxygen injector 31.

  In the combustion chamber 4, of cylindrical shape, the cylinder 20 of ignited gases coming from the nozzle 31 is split due to the arrangement of the cone 41 and the flames are put in turbulence by the presence of the parabola 40, the burnt gases then being evacuated through the passage between the periphery of the parabola and the cylindrical wall of the combustion chamber. The support tube 50 of the parabola 40 and of the cone

41 is hydraulically cooled.

  The cylindrical post-combustion chamber 5 has, at its outlet end, exhaust gas turbulence which are hydraulically cooled. The atmosphere of this chamber is controlled in composition, temperature, pressure and speed, so as to have no residual oxygen at the outlet of the exhaust gases. The walls of the

- 8 - 2823555

  cylindrical post-combustion chamber 5 which are in contact with the

  Oxygen ignition gases are made of special steel.

  The exhaust gases recovered in the heat exchanger 6 are mainly composed of carbon dioxide CO2 and water H2O, taking into account the composition of organic matter and

solid fuel.

  We will now describe, with reference to FIG. 2, the incineration process according to the invention, the principle of which is to minimize, by thermal effects, the organic compounds to be eliminated, with a high gasifiable proportion. The main stages of the incineration process according to the invention include: - production (1) of the thermal energy required for thermolysis and pyrolitic reduction (II) of organic matter, by burning solid fuel on a low grate, under oxygen, - volatilization (IV) of the gasifiable components throughout the thermolysis / pyrolysis column without available oxygen, - completion of the combustion (111) of non-carbonated organic compounds on a bed of embers, - homogenization ( V) pyrolysis and combustion gases of solid fuel in a mixing chamber, - an injection (Vl) of oxygen into said pyrolysis and combustion gases, at the outlet of a nozzle, to allow their self-ignition, an injection of the gaseous mixture thus obtained and a combustion (V11) of this mixture in a combustion chamber, in a cylinder of ignited gases, an expansion (V111) of the gases burned in a post c chamber controlled umbustion, and

  - recovery (IX) of the thermal energy at the outlet of the burnt gases.

  With regard to the production of the thermal energy required for thermolysis and pyrolytic reduction, the use of oxygen

9 - 2823555

  as an oxidizer allows high temperatures guaranteeing effective pyrolysis. Parasitic cooling due to nitrogen in the air and the risk of nitrogen oxide production are avoided. In addition, combustion under oxygen is more reliable, both in terms of temperature regulation and for obtaining a perfectly st_chiometric combustion. During the development of gasifiable components, the oxidizing oxygen is completely consumed by the ember bed M of the solid fuel in ignition and the combustible organic materials which are not gasifiable. This combustion control cannot be performed with

insurance only under oxygen.

  In the combustion phase of the gas mixture in the combustion chamber 4, the cylinder of ignited gases is exploded on the cone 41 of the combustion chamber. Reflected by the parabola 40 along the outer walls of the chamber 4, the flames cause

  turbulence conducive to the complete combustion of the mixture.

  The exhaust of the burnt gases takes place through the peripheral space of the

parable 40.

  The expansion of the burnt gases on the rear of the parabola 40 in the controlled post-combustion chamber 5 is carried out so as to have only carbon dioxide CO2 and water H2O at the outlet and to control

the absence of oxygen O2.

  Recovery of thermal energy at the outlet of burnt gases

  can be carried out with existing known recovery systems.

  Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention. The incineration system according to the invention can thus be manufactured with any size, and can be installed in a battery. This system can be integrated into any size of animal organic material processing unit while respecting the environment and with a guarantee of destruction of everything.

harmful element.

- 10 2823555

Claims (20)

  1. System (S) for incinerating organic matter, characterized in that it comprises: - a solid fuel oven (1) comprising a grid (10) receiving a solid fuel and means for injecting oxygen, - a thermolysis / pyrolysis column (2) comprising grids (21, 22, 23) inclined towards the furnace, means (25) for bringing solid fuel to the furnace level and means (26) for bringing organic matter to incinerate above said inclined grids, a homogenization chamber (3) of the burnt gases and organic vapors from the thermolysis / pyrolysis column (2),   - a combustion chamber (4) followed by a post-   combustion (5), - heat exchange means (6) for recovering the energy of the exhaust gases from the post-combustion chamber (5), and - means (7) for extracting combustion gases out of heat exchange means.   2. Incinerator system (S) according to claim 1, characterized in that the solid fuel consists of plant biomass   densified ligno-fibro-cellulosic.   3. System (S) according to one of claims 1 or 2, characterized in   that the oxygen injection means comprise means (12)   of primary oxygen injection under the oven rack.   4. System (S) according to claim 3, characterized in that the oxygen injection means further comprise means (1 1) of secondary oxygen injection at the heart of a bed of embers (M) produced above the grid (10) of the furnace (1) by solid fuel in combustion.   5. System (S) according to any one of the preceding claims,   characterized in that it further comprises an ashtray (13) located under the   oven rack (10) for receiving non-combustible residues.   6. System according to claim 5, characterized in that it further comprises means for hydraulically cooling the walls and the rack of the oven.   7. System according to any one of the preceding claims,   characterized in that it further comprises means for controlling the supply of solid fuel so as to avoid any entry of air parasite in the oven.   8. System according to any one of the preceding claims,   characterized in that the inclined grids within the column of   thermolysis / pyrolysis are composed of perforated tubes.   9. System according to any one of the preceding claims,   characterized in that it further comprises means for controlling the atmosphere within the thermolysis / pyrolysis column so as to be without residual oxygen.   10. System according to any one of the preceding claims,   characterized in that it further comprises means for controlling the speed of the gases and / or their temperature to allow the thermal acquisition required for the vaporization of the gasifiable organic matter.   11. System according to any one of the preceding claims,   3 0 characterized in that it further comprises means for controlling - 1 2 - 2823555   Organic matter supply in order to avoid any entry air parasite.   12. System according to any one of the preceding claims,   characterized in that the homogenization chamber is terminated by a gas nozzle.   13. The system of claim 12, characterized in that the combustion chamber is cylindrical and has a parabolic bottom open on the gas nozzle, of diameter less than that of said chamber   combustion, and provided with a central cone directed towards said nozzle.   14. System according to claim 13, characterized in that the post-combustion chamber is cylindrical and has in its axis a tube   to support the parabolic bottom of the combustion chamber.   15. System according to claim 14, characterized in that it comprises   further means for cooling the support tube.   2 0 1 6. System according to any one of the preceding claims,   characterized in that it further comprises means for controlling   the atmosphere inside the afterburner.   17. A method for incinerating organic matter, characterized in that it comprises: - a production (I) of thermal energy required for thermolysis and a pyrolytic reduction (II) of organic matter within a thermolysis column / pyrolysis, by combustion of a solid fuel under oxygen, a volatilization (IV) of the gasifiable components of said organic materials along the thermolysis / pyrolysis column, - 13 - 2823555   - a combustion (111) of the non-gasified organic compounds on a bed of embers resulting from the combustion of solid fuel, - a homogenization (V) of the pyrolysis gases and combustion of the solid fuel in a mixing chamber, - an injection ( Vl) of oxygen in said pyrolysis and combustion gases to allow them to self-ignite, - an injection of an ignited gas mixture and a combustion (Vll) of this mixture in a combustion chamber, - an expansion valve (V111) gases burned in a controlled post-combustion chamber, and   - recovery (IX) of the thermal energy at the outlet of the burnt gases.   18. The method of claim 17, characterized in that the thermal energy required for thermolysis and pyrolytic reduction of organic matter is produced by burning plant biomass   densified ligno-fibro-cellulosic.   19. Method according to one of claims 17 or 18, characterized in that   that the gas mixture is injected into the combustion chamber under the   in the form of a cylinder of ignited gas which is exploded on a cone.   20. The method of claim 19, characterized in that flames resulting from the bursting of the flaming gas cylinder are relluses by   a parabola located at the base of the cone.   21. Method according to claim 20, characterized in that the exhaust of the burnt gases is effected by a peripheral space of the parabola.