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
  • C10B53/00—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
• • 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
  • C10B7/00—Coke ovens with mechanical conveying means for the raw material inside the oven
  • C10B7/10—Coke ovens with mechanical conveying means for the raw material inside the oven with conveyor-screws

Definitions

• the present invention has pou ⁇ a method and fuel device by continuous pyrolysis of crushed or pasty waste.
• the technical sector of the invention is the field of the production of waste recovery equipment for the production of energy.
• One of the main applications of the invention is the treatment of crushed or pasty industrial waste, but other applications are possible for other types of waste, also crushed or pasty, to transform these, without atmospheric pollution, into usable dry fuel. to produce energy at a profitable production cost, also with the minimum of residual pollution, either on site and immediately, or in any other place and at any time desired, the overall energy balance of the transformation of waste by the treatment method according to the invention, and the production of recoverable energy thereafter, being positive.
• Many processes and equipment are known which propose to treat waste to avoid its landfill which, on the one hand, degrades the environment on large surfaces, on the other hand, constitutes indirect sources of significant pollution, and finally represents increasingly heavy costs for the communities and / or manufacturers concerned.
• CHAUSSONNET there is described a "system for the treatment by thermolysis under vacuum of products (liquids or gases for the first request and solids for the second), the rejection of which is detrimental for the environment ": the vacuum allows an absence of oxygen preventing certain chemical reactions of oxidation but the system described requires a large reaction chamber and fairly significant energy supply, and does not allow simultaneous treatment of waste of different origin, heat transfers being difficult to control in a vacuum given the installation described.
• the problem posed is to produce fairly compact installations which can be fixed or mobile, for processing previously crushed or pasty waste, whatever their origin but of which it is known and its general composition in order to be able to extract therefrom products at least some of which are combustible, as well as others which are reusable in any other form depending on the composition of the treated waste and whose economic market value is at least equal, if not greater, than the whole the cost of treatment, including the amortization of the investment.
• Another objective of the invention is to reject nothing in nature, which is not polluting, both in the form of gas and of solid residues, whether during the treatment of the waste itself to produce said combustible products or other reusable residues, only during the combustion and use of the products thus obtained, in particular with regard to the elimination of any toxic gas, and the sequestration of heavy metals, so that any pollution later by the use of solid residues is discarded; this can be verified by analyzing the leaching water of the products obtained, which complies with the regulations on heavy metal content.
• One solution to the problem posed is a method of producing fuel by pyrolysis of ground or pasty waste, comprising at least a first step of kneading the latter with additives including at least lime, a second step of drying the mixture, a third step of decomposition of the products of this mixture by heating at high temperature and a fourth step of additional treatment depending on the nature of the initial waste and the desired finished product, in which:
• additives comprising, in addition to quicklime, metal oxides so that cage molecules or metal cation sensors are produced which trap and sequester those who might be present in the waste;
• reaction energy of the mixture obtained in the first step is used with the ground or pasty waste and the additives, and that mechanical friction of the kneading screws to dry, in the second step, said mixture;
• the third step of decomposition of the products is carried out by pyrolysis with heating bringing the temperature of the compartment corresponding, between 250 and 800 ° C;
• a separation of ferrous and non-ferrous metals is carried out before the first kneading treatment step, which is extracted from ground or pasty waste before their introduction into said reactor.
• the mixture obtained in the second drying step is heated by an external energy supply if the waste has a humidity rate greater than approximately 30%, in order to help their drying.
• the organic compounds are decomposed in the form of condensable pyrolytic oil gas and combustible gas
• other non-pyrolyzable compounds are sublimated which s 'evaporate under vacuum, all of these gases being recovered by at least one means for evacuating the reactor and from which the separations necessary to recover each gas for its specific use are carried out; at the end of this pyrolysis step, a solid residue is obtained which can be a fuel which is cooled during a fourth step of the process during which the reaction which started in the preceding pyrolysis step ends.
• a final treatment step is carried out during which additives determined depending on the product are added to the residual products from the previous step, which is either directly that of pyrolysis or that of cooling intermediate desired finish and the nature of the initial waste compounds.
• said waste is ground before its introduction into said reactor by any known means giving them a particle size dimension equal at most to the thread height of the kneading screws at the inlet of the reactor; in each compartment of the reactor, the profile and the pitch of the threads of said screws may be different, and in the first mixing compartment, these preferably shear the waste into particles of less than one tenth of a millimeter.
• the energy balance is improved: this in fact, at least, balances and compensates for all the energy needs of the process according to the invention, thus that the investment and operating costs necessary for the execution of the present process and which may even, in certain cases, depending on the type of waste treated and recovered, in addition to the supply of combustible gas allowing said energy recovery and to obtain other combustible and / or recoverable products.
• the vacuum allows the control and the complete anti-pollution treatment of the gases and water resulting from the process, just as the clean technology of the present invention allows '' carry out all of the treatment operations without generating pollution, without any discharge of dust or gas into the atmosphere and the fully treated waste is transformed into solid, oil, gas or water, usable in materials raw materials or property materials identical to the substituted products.
• the present invention takes advantage of the known method of sequestering heavy metals in a cage molecule such as a hydrated calcium silico-aluminate matrix, insoluble in water and resistant to corrosion: thanks to this process step included in the present invention, the heavy metals are no longer soluble in the aqueous phase and the leaching phenomena no longer have the consequence of polluting the groundwater.
• the present invention also inhibits the production of any acid rejection by in situ neutralization of the acid generating compounds and the basic reaction medium is produced by the use of lime and transforms for example hydrochloric acids into saline chloride and sulfuric acids into sulfate.
• Another essential characteristic of the invention is to make it possible to offer, by a simple modification of the treatment parameters in the different compartments where the different stages of the process according to the invention are carried out, a different recovery depending on the type of waste treated and according to local needs; an installation according to the invention makes it possible to treat and recycle many types of waste other than radioactive, such as residues from car wrecks, used tires, petroleum residues, forest, agricultural and urban bioraasses, household waste and residues from the paper industries , tanning, plastics, industrial, purification plants, etc.
• the process according to the present invention makes it possible to choose, whatever the treated waste, and this in the same reactor, by a simple modification of the parameters and additives, and in addition to gases at least part of which is combustible, the nature of the solid product and more or less dried out, which can be indifferently used as fuel, inert materials or edaphic products such as fertilizers or composts, or a combination of gas, oil and solids, and may possibly give rise to mixed recovery in the form energy products and chemicals.
• part of the products resulting from the process of the present invention in either gaseous, liquid or solid form, is combustible.
• the present invention thus aims to improve the existing waste treatment methods, in particular allowing continuous treatment in the same reactor, successively ensuring the functions of mixing, drying, stabilization or transformation of incoming products, which considerably reduces the installation and operating costs: the various process stages are thus grouped together in the same compact machine, also making it possible to obtain optimal compliance with the treatment parameters specific to each type of waste, which is stored in the form of program in the memory of an automaton or a microcomputer which then controls the entire device and which makes it possible to produce and extract, products, on the one hand combustible and energetic, and on the other hand inert and / or reusable for other uses; the parameters thus recorded are for example the temperature, the speed of treatment, the dosage of chemical additives and / or complementary products as well as the regulation of the internal vacuum pressure.
• the device according to the invention indeed comprises a system for extracting and filtering the vapors produced, supplemented by one or more condensers, and one or more vacuum systems by pump, for example, with liquid ring.
• the gases thus recovered are treated chemically in such a way that there is no acid rejection of the hydrofluoric type.
• sulfurous or sulfuric in the atmosphere and that the gases collected are reusable without external pollution, nor any release of smoke or vapor, in particular by an immediate use of their energy at least of turbination.
• the obtained combustible products whatever their form, they can be stored and their use can be postponed.
• Another advantage of the present invention is that the basic process thereof can be dissociated from the primary preparations for pre-grinding, iron removal and demetallization: this basic process can thus be carried out in a compact reactor, the elements of which are transportable from one site to another on mobile equipment, for example.
• the single attached figure is a longitudinal sectional view of an example of a reactor for carrying out the process of the present invention.
• the waste 6 is ground by any known means giving them a particle size dimension equal at most to the thread height of the first compartment 1 of the kneading screws 7 of said reactor 20, such as for example with a maximum volume for each grain or particle of crushed waste corresponding to a parallelepiped of 50 mm x 50 mm x 20 mm approximately, or must be in a pasty form which can be the form in which they are rejected by industry producer; similarly, upstream of the device in the attached figure, the waste 6, once ground, or put into pasty form, is freed from any possible ferrous or non-ferrous metal part, such as for example the action of a magnetic field according to any known process which even makes it possible to make magnetic and therefore eliminable by attraction, the parts which are not ferrous.
• the fuel production device comprises at least a first step 1 of kneading them with the additives 9 including at least lime, a second step 2 of drying the mixture, a third step 3 of decomposition of the products of this mixture by heating 17 at high temperature and a fourth step 4, 5 of additional treatment depending on the nature of the initial waste and the desired finished product 19.
• the device according to the invention comprises:
• At least one reactor 20 comprising at least two corotative kneading axes forming screw 7 of Archimedes and enclosed in a sealed enclosure 25, driven by any means of rotation 22, at the speed and with the desired and necessary and divided torque in as many successive compartments 1, 2, 3. 4, 5 --- As many steps of the treatment process, continuously arranged one behind the other in the order of said steps and crossed by the same kneading axes 7;
• the device according to the present invention makes it possible to acquire a flow rate of 5 to 10 tonnes / hour of waste per continuous reactor 20; - Means 11, 12, 13. 14, 15 ... for evacuating each of the compartments of the reactor 20;
• the first step of the process according to the invention is carried out in compartment 1, which is the so-called grinding and kneading zone between the different returning products that are waste 6 and the liquid and solid additives 9 ensuring stabilization and pollution control. and the synthesis of the molecular structures necessary for the sequestration of heavy metals according to the known process for the preparation of cage molecules, namely essentially quicklime and metal oxides whose chemical transformation and hydration allow synthesis. These additives also have secondary function of promoting the drying of wet waste.
• the second step of the process according to the invention is carried out in the second compartment 2 succeeding the previous 1, and which makes it possible to obtain rapid drying by combining a pressing action promoting the extraction of liquids from the core of the material, with a heating to ensure vaporization facilitated by the vacuuming of the zone by any extractor 11.
• Said heating can simply be the recovery of the friction energy of the kneading screws 7 and which is sufficient when the humidity of the waste introduced 6 is less than 0%; when this rate is higher, an additional auxiliary heating 8 is necessary, such as by induction, and makes it possible to obtain the desired result.
• Reducing the pressure also allows energy savings by reducing the enthalpy of vaporization, that is to say the amount of energy required for the passage of water from the liquid state to the gaseous state, and a pressure is sought which makes it possible to obtain this vaporization with the only energy mechanical grinding and transport of the material naturally transformed into heat in the reactor by said kneading screws 7.
• the fineness of the grinding and possibly the quality of the preliminary kneading with the additives thanks to the use of such kneading screws 7, especially when it is a twin screw, combined with the vacuum, the pressing and the decrease in surface temperature due to the significant heat loss caused by vaporization, make it possible to considerably accelerate the drying time, which can then commonly be less than 60 seconds.
• the vaporization rate is directly linked to the average particle size and that the smaller the average diameter, the shorter the path that will allow the water molecules to exit their solid matrix, and the more the greater the diffusion of water out of the particle, the better the efficiency of evaporation.
• the third step of the process according to the invention, carried out in compartment 3. is a variable temperature treatment zone, depending on the desired final product 19: this temperature can vary over a wide range, such as 200 to 800 ° C., and thus reaching the conventional pyrolysis temperatures; depending on the waste treated, in fact a maximum of 650 ° C. would be sufficient thanks to the present invention, since it is in a vacuum.
• the additional heating 17 required is provided from the outside by an electromagnetic induction system for example, or by a system such as heating rods. The objective is to be able to carry out a total or partial pyrolysis of the waste, which can usefully lead to a separation of certain metals present, by vaporization / condensation under vacuum, or sublimation.
• Pyrolysis at high temperature and under low oxygen pressure allows rapid separation by distillation of condensable vapor resulting from the decomposition of organic materials.
• the secondary oxidation reactions which characterize pyrolysis are minimized in the present invention; and the condensates obtained composed of primary fragments are of better quality.
• Vacuum pyrolysis is typically carried out in the present invention, at temperatures of the order of 450 ° C. for an absolute vacuum pressure of the order of 150 millimeters of water, or 15 kPa, but could be also in a range of 10 to 0 kPa.
• These operating conditions notably more favorable than those found during conventional pyrolysis at atmospheric pressure and incineration, make it possible to obtain large quantities of pyrolytic oil as well as solid residues which have the properties of reactivity. superior to fuels such as coal from processes known to date.
• This compartment 3 is also connected to a vacuum installation 13, different from the previous one, because the condensed vapors are of different types.
• the fourth step of the process according to the invention is carried out in a compartment 4 which is essentially a cooling and final degassing zone which can also be connected to a vacuum installation 14, which can be the same as that of the compartment previous 3 •
• the fifth step of the process according to the invention is carried out in a compartment 5 which is an ultimate treatment zone allowing, by possible addition of solid and / or liquid additives 16, to produce the desired finished product by enriching it for example, such as for fuels to increase their calorific value, edaphic products, their enrichment in nitrogen, phosphate and potassium, nutri-elements, trace elements, etc., or by neutralizing them by acid-correction basic pH for example the 15
• additives 16 are delivered from any buffer storage means 23 closed by a metering and sealing valve 10 and supplying the desired quantity to said compartment 5.
• the evacuation of residual terminal products 19 to all evacuation system is produced by any watertight means 24, such as a rotary valve.
• the different zones and compartments of the reactor 20 are therefore connected to different degassing and vacuum means, preferably by means of one or more condensers and one or more liquid ring pumps.
• the condensers may also allow the injection of one or more bactericidal, fungicidal, algicidal, etc., or neutralizing substances, depending on the temperature adopted in the process and the type of waste 6 introduced in order to eliminate any toxicity of the gases. recovered products.
• Each compartment of the reactor 20 is equipped with a temperature and / or internal humidity pressure sensor 18, in order to transmit all of the temperature pressure and humidity values, to a central computer which is programmed to control all the means of operation of said reactor 20 according to the process of the present invention, for a treatment defined with respect to the desired outgoing products 19.
• a temperature and / or internal humidity pressure sensor 18 in order to transmit all of the temperature pressure and humidity values, to a central computer which is programmed to control all the means of operation of said reactor 20 according to the process of the present invention, for a treatment defined with respect to the desired outgoing products 19.
• organic or non-organic sludge 6 fuel, with or without edaphic products
• industrial sludge fuel with or other recyclable materials
• bio-medical waste fuel and products for cement manufacturers
• examples of yield by vacuum pyrolysis can be presented as a percentage of the initial weight treated, such as:
• (1) includes 3 / - + carbon black and 1/4 steel
• a reactor 20 as described above and whose vacuum compartments correspond to the stages according to the method of the present invention, can also be divided into several successive reactors corresponding to the combination of one or more of said compartments, and always arranged continuously but with drive systems which can then be different. Some of these compartments can even be placed not under vacuum but at ambient pressure or even under overpressure, as can the entire reactor in its embodiment as shown in the attached figure, but then with a different objective of treatment of waste.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Processing Of Solid Wastes (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

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• 1994
  • 1994-03-18 FR FR9403499A patent/FR2717490B1/fr not_active Expired - Fee Related
• 1995
  • 1995-03-13 AU AU19538/95A patent/AU1953895A/en not_active Abandoned
  • 1995-03-13 DE DE69514255T patent/DE69514255T2/de not_active Expired - Fee Related
  • 1995-03-13 EP EP95912305A patent/EP0819156B1/de not_active Expired - Lifetime
  • 1995-03-13 WO PCT/FR1995/000290 patent/WO1995025779A1/fr active IP Right Grant
  • 1995-03-13 AT AT95912305T patent/ATE188236T1/de not_active IP Right Cessation

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