ITVR20100201A1 - PROCEDURE FOR TREATING ORGANIC AND INORGANIC MATRIX, FOR SECONDARY RAW MATERIAL PRODUCTION - Google Patents

Description

Title: â € œPROCESS FOR THE TREATMENT OF WASTE OF ORGANIC AND INORGANIC MATRIX, FOR THE PRODUCTION OF SECONDARY RAW MATERIALâ €

FIELD OF APPLICATION

The present invention relates to a thermo-chemical treatment process of organic and / or inorganic sludge and solid waste containing organic substances, present with variable concentrations.

Said sludge and / or solid waste are more precisely described below:

- biological sludge from civil and industrial wastewater treatment plants;

- inorganic sludge polluted by organic sludge including solvents, hydrocarbons, organic and biological chemical processing residues;

- digestates from civil, animal and vegetable biogas production;

- aggregates such as sands, clays, drainage sludge from excavation and reclamation of watercourses, lake waters and sea waters;

- aggregates polluted by hydrocarbons, solvents, organic and biological chemical processing residues (eg train sleepers);

- residual bilge sludge;

- urban solid waste from separate collection and precisely the organic wet fraction;

- filter-pressed sludge from the reclamation of cesspools;

- filter-pressed or thickened sludge from bovine, equine, swine and poultry manure;

- filter-pressed or thickened sludge from the tanning industry;

- filter-pressed or thickened sludge from water treatment of the textile industry;

- organic residues (biomass) from agro-food processing such as sugar refineries, fruit juice processing, canning industry.

This process according to the invention is based on two successive drying and carbonization phases, which can be carried out continuously in two reactors operating in cascade, under vacuum, with a residual pressure lower than 0.2 absolute bar.

On the other hand, the drying and carbonization phases can be carried out in a single reactor which carries out the two operations under vacuum, with a residual pressure of less than 0.2 absolute bar, in a non-continuous way, for batches.

The resulting products of the process are:

a) a biochar coal;

b) an organic phase obtained from the separation with the evaporation and distillation systems of the condensed fluid, containing all the volatilized molecules; c) water.

The present invention is included in the field of processes for the treatment of waste, in particular in the thermal treatment of waste, of organic and inorganic matrix aimed at the production of secondary raw material.

STATE OF THE TECHNIQUE

It is known that the masses of organic and / or inorganic sludge and solid waste containing organic substances, present with variable concentrations, such as biological sludge from civil and industrial wastewater treatment plants, inorganic sludge polluted by organic sludge including solvents, hydrocarbons, residues of organic and biological chemical processing, digestates from the production of biogas of a civil, animal, vegetable nature, aggregates such as sands, clays, drainage sludge from excavation for the reclamation of water courses, lake waters and of sea water, are treated in plants that provide for their disposal with drying, pyrolysis, incineration processes, in order to recover their energy content and reduce the mass to be disposed of.

All these processes are inevitably characterized by emissions into the atmosphere of the resulting combustion products.

In fact, the traditional techniques used for this purpose and for these masses are based on drying processes that use hot air, combustion gases from thermal production, drying with superheated steam. The thermal energy of the combustion of the dried product may be sufficient for drying operations or in energy deficit.

Numerous publications and patents describe these techniques, such as MUJUMDAR A S ED - MUJUMDAR A S: "Chapter 19: Superhead steam drying" 1 January 2007 (2007-01-01), HANDBOOK OF INDUSTRIAL DRYING, CRC PRESS, US LNKD-D0I: 10.1201 / 9781420017618.CH19.

These processes are generally carried out in large plants due to the problems concerning the control of the environmental impact, in terms of emissions into the atmosphere.

DESCRIPTION OF THE INVENTION

The present invention aims to provide a thermo-chemical treatment process of organic and / or inorganic sludge and solid waste containing organic substances, capable of eliminating or at least reducing the drawbacks highlighted above, called thermo-chemical treatment process. being implemented in the total absence of emissions into the atmosphere.

The invention also proposes to provide a suitable treatment of various waste, both of organic and inorganic matrix, capable of providing for the removal of various pollutants, both organic and inorganic.

For some types of waste the process can allow an interesting surplus of energy or secondary raw material with calorific value.

For other types of waste, it allows the reuse of the treated material in the environment instead of placing it in landfills, with obvious environmental and economic advantages.

The process is essentially free of emissions into the atmosphere (excluding the fumes from the combustion of the heat generator).

The process returns a significant amount of purified and recovered water to the environment, a good that is increasingly precious.

Everything that is recoverable inside the waste is recovered, the fraction to be sent for disposal is only that deriving from the combustion of the steam generator.

1. Removal of pollutants from waste of any matrix, organic and inorganic.

2. Obtaining, at the end of the process, one or more secondary raw materials, to be reused. 3. Obtaining at the end of the process, an aqueous fraction, free of contaminants to the extent necessary to be relocated into the environment.

4. Obtaining, at the end of the process, a substantial reduction in the quantity of waste to be sent for disposal, as non-reusable waste

5. Elimination of any gaseous emissions into the environment, with the exception of the thermal energy generator.

6. Reduction of the amount of energy necessary for the treatment process itself.

ILLUSTRATION OF DRAWINGS

Other characteristics and advantages of the invention will become evident upon reading the following description of an embodiment of the invention, provided by way of non-limiting example, with the aid of the drawings illustrated in the attached tables, in which:

- figure 1 represents the view of a block diagram of the process according to the invention;

- figure 2 shows a schematic view of the plant according to the invention as a whole;

- Figures 3 to 8 illustrate schematic views of the plant according to the invention in its various perspectives and details.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION With reference to the attached figures, and in particular to fig. 1, the plant according to the invention, globally indicated with 10 is schematically composed of a storage section 11 of the waste to be treated, a volumetric adjustment section 12, a metering section 13, a reactor 14 of dehydration and first treatment, and from a molecular over-extraction and recombination reactor 15.

The plant also includes a cooling hopper 16, a treated material storage section 17, a thermal energy generation section 18, a vacuum generation section 19, a condensation section 20 for the transport and reaction steam, a condensate treatment section 21, and finally a condensation water treatment section 22.

The process starts from the waste storage section to be treated 11, where the material to be treated is stored and accumulated before treatment, in a controlled and confined manner in order to classify it for the purposes of subsequent treatment.

The material passes to the volumetric adjustment section 12, in which the same material to be treated is reduced to the size suitable for the treatment, by means of mechanical shredding, this operation not always necessary.

In the next phase, the material passes into the metering section 13, where it is weighed in order to control the metering in the reactor. The dosed material is sent to the reactor by means of conveyor belts.

Now the material passes into the dehydration and first treatment reactor 14, ie inside a first reactor, called dehydration.

For this purpose, this reactor is closed and kept under vacuum. Inside the reactor there is a system of blades with double horizontal shaft, which keeps the material subjected to the treatment agitated.

The reactor 14 is kept at a controlled temperature by means of a jacket which allows the passage of eutectic salts. The internal temperature is controlled by a system of probes and is kept above the equilibrium temperature of the water-steam system at about 120 - 140 ° C in order to allow the evaporation of all the water and low boiling substances present in the ™ internal part of the waste to be treated.

Inside the reactor, water vapor is made to flow in countercurrent, which has the function of transporting and extracting the volatile substances and of the water contained in the material being treated and as a function of the volatile substances even in the absence of water. The temperature control indicates when the water present in the waste to be treated is completely evaporated, and the material is ready for the passage to the second reactor.

Now the material passes through the molecular over-extraction and recombination reactor 15. Following the dehydration step, the material is transferred to a second reactor. Inside this reactor a system of blades with double horizontal shaft keeps the material subjected to the treatment in agitation. The reactor is kept at a controlled temperature by means of a jacket which allows the passage of eutectic salts. The internal temperature is controlled by a system of probes. The temperature inside the reactor is kept at about 350 - 420 ° C in order to allow the extraction of the decomposition and volatile substances present inside the waste to be treated. Inside the reactor, water vapor is made to flow in countercurrent, which has the function of transporting and extracting volatile substances and water. Depending on the type of pollutant and the waste matrix, in this phase at a higher temperature, in addition to the stripping of the substances that pass into the gaseous phase, a molecular recombination also takes place, which changes the chemical speciation of many elements contained in the waste from to deal.

16 indicates the cooling hopper in the block diagram of Figure 1. At the end of the molecular extraction and recombination phase, the treated material is discharged into a cooling hopper. Cooling is necessary for the subsequent transport and storage of the treated material, in safe conditions. The vacuum is also maintained in this hopper to avoid the possible triggering of uncontrolled combustion.

With 17 in the block diagram of Figure 1 the treated material storage section is indicated. The treated and cooled material is transported with belts or augers to suitable storage areas or the like for subsequent use. The treated material, free from pollutants, can be reused as fuel, if it has the necessary calorific value, or it can be used as building material, if it has the necessary mechanical characteristics, it can be used as a suitable material for environmental recomposition or reclamation.

The number 18 indicates the generation section of the thermal energy necessary for the process, for the heating of the eutectic salts and for the generation of steam necessary for the process takes place through a burner. Keep in mind that if the thermal power plant is not present, mains electricity can be used, however with an increase in the energy balance.

Said burner can be powered by fossil fuel, external to the process, or by secondary raw material originating from the process itself. (with obvious benefit of the energy balance). The eutectic salts necessary for heating the two reactors 14 and 15 are heated with the combustion fumes of the same burner, and the transport vapor is produced which is introduced in countercurrent into both reactors. The combustion fumes of the burner, once their function is finished, are discharged in a controlled way into the atmosphere. The waste resulting from the combustion process (ashes) are the only waste produced by treatment that need to be disposed of.

The vacuum generation section 19 allows to generate the vacuum inside the reactors and the discharge and cooling hopper, which is maintained by means of liquid ring pumps.

20 indicates the condensation section of the transport and reaction steam, where the steam stream used in the reactors 14 and 15 is sent for treatment. Preliminarily it is passed through a cyclone for the separation of the heavier particles present in the flow, subsequently the vapor is condensed, always in a vacuum condition and without emission into the atmosphere.

In the condensate treatment section 21 the condensate thus obtained is treated in an evaporation and enrichment cell in which two streams are separated, always under vacuum, one containing organic acids, nitrogenous components, etc. called â € œorganic flow or oilâ €, intended for reuse and recovery, the other consisting of water to be subjected to subsequent treatment before discharge.

Finally, in the condensation water treatment section 22, the water deriving from the previous section, before discharge, must be treated in a chemical-physical and biological purification plant, to eliminate any pollutants present, before discharge. The resulting mud, if any, can be subjected to the same treatment that originated it. This phase therefore does not produce waste, and returns controlled water to the environment.

Referring to figure 2, 13 indicates the hopper, where the material to be treated can be weighed, and is dosed for sending, via conveyor belt 23, to the dehydration reactor 14.

At the end of the reactor charging phase, the system is closed and put under vacuum by means of the high vacuum group 19. The material in the reactor 14 is kept at a controlled temperature by means of a jacket that allows the passage of thermo-controlled eutectic salts by means of suitable probes, in order to allow the evaporation of the water and therefore to carry out the first phase of dehydration. At the end of this phase, the material is transferred, still under vacuum, to the second reactor 15 where the molecular recombination is carried out. Both reactors have a double shaft mixing blade system to homogenize the material they contain. In the second reactor too, the temperature is controlled by a system of probes that drives the heating system with eutectic salts.

The substances that pass to the gaseous phase are sent to the stripping column 24. The material thus treated is then discharged into the cooling hopper 16, always in vacuum conditions to avoid the risk of uncontrolled combustion, when the safety temperature is reached, the material is sent by screw conveyors, belts, elevators or pneumatic conveying systems, to the storage section 17.

As shown in Figure 3, the thermal generator with which both the heating of the molten salts for the 2 reactors and the generation of steam used to transport the volatile elements to the abatement system is represented by 18.

In the more complete system, the heat generator can also be equipped with heat recovery units 25. The steam streams are made to pass through cyclones 26 to the condensate treatment section 21 where it is divided into two flows: the organic or oil flow destined for the reuse or recovery and the flow of water that is sent to the water treatment section 22 consists of chemical-physical and biological treatment tanks 27 from which purified sludge water derives which are further compacted by means of a filter press 28 and reintroduced into the cycle of initial treatment.

The plant is managed with a supervision system installed in the control cabin 29, while the electrical panels are installed in the panel room 30.

The invention has been previously described with reference to a preferential embodiment thereof. However, it is clear that the invention is susceptible to numerous variants that fall within its scope, within the framework of technical equivalences.

Claims (10)

Title: â € œPROCESS FOR THE TREATMENT OF WASTE OF ORGANIC AND INORGANIC MATRIX, FOR THE PRODUCTION OF SECONDARY RAW MATERIALâ € CLAIMS 1) Thermo-chemical treatment process of organic and / or inorganic sludge and solid waste containing organic substances, present with variable concentrations, characterized by being suitable for the treatment of various waste, both of organic and inorganic matrix, and being suitable for the removal of various pollutants, both organic and inorganic, and by the fact of including various work phases in the following components: a) Waste storage section to be treated; b) Volumetric adjustment section; c) Dosing section; d) Dehydration reactor and first treatment; e) Over-extraction and molecular recombination reactor; f) Cooling hopper; g) Section for storage of treated material; h) Thermal energy generation section; i) Vacuum generation section; j) Condensation section of the transport and reaction vapor; k) Condensate treatment section; l) Condensation water treatment section. 2) Thermo-chemical treatment process of organic and / or inorganic sludge according to the preceding claim, characterized by the fact that for certain types of waste the process can allow a surplus of energy (or of secondary raw material with calorific value). 3) Thermo-chemical treatment process of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that for other types of waste, it allows the reuse of the treated material in the environment instead of placing it in landfills, with obvious environmental advantages and cheap. 4) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that the hopper (13) allows the weighing of the material to be treated, and its sending, by means of a conveyor belt (23), to the dehydration reactor (14). 5) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that, once the reactor charging phase is completed, the system is closed and put under vacuum by means of the high vacuum unit (19 ), and by the fact that the material in the reactor (14) is kept at a controlled temperature by means of a jacket that allows the passage of thermo-controlled eutectic salts by means of suitable probes, in order to allow the evaporation of the water and therefore implement the first phase of dehydration. 6) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that the material is transferred, always under vacuum, to the second reactor (15) where the molecular recombination is carried out, by the fact that both reactors have a double shaft mixing blade system to homogenize the material they contain. In the second reactor too, the temperature is controlled by a system of probes that drives the heating system with eutectic salts. 7) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized in that the substances which pass to the gaseous phase are sent to the stripping column (24) and that the material thus treated is then discharged into the cooling hopper (16), always in vacuum conditions to avoid the risk of uncontrolled combustion, when the safety temperature is reached, the material is sent via augers, belts, elevators or pneumatic transport systems, to the storage section (17) . 8) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized in that the heat generator (18) determines the heating of the molten salts for the two reactors, and the generation of the steam used for the transport of the volatile elements to the abatement system. 9) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that the heat generator can also be equipped with heat recovery units (25), where the steam streams are made to pass through cyclones (26) to the condensate treatment section (21) in which it is divided into two flows: the organic or oil flow destined for reuse or recovery and the water flow that is sent to the water treatment section (22) Ã It consists of chemical-physical and biological treatment tanks (27) from which purified water and sludge derive which are further compacted by means of a filter press (28) and reintroduced into the initial treatment cycle. 10) Process of thermo-chemical treatment of organic and / or inorganic sludge according to one of the preceding claims, characterized by the fact that the plant is managed with a supervision system installed in the control cabin (29), while the are installed in the switchboard room (30).