FR2872719A1 - Regenerating ground polluted by any hydrocarbon, on site and at ambient temperature, where the pollutant and transfer matrix form a high-grade fuel - Google Patents

Abstract

A plastic matrix of any plastic excluding PVC, powdered to around 1.5mm, is used to clean up ground polluted by hydrocarbons, operating at up to 35 tonnes/hour and at ambient temperature. The cleaned soil contains less than 150ppm pollutants so the ecosystem can be re-established and the matrix, including pollutants, forms a high-grade fuel for industrial use with a PCI of 10,000kcal/kg : Process using a plastic matrix of high and low density or other plastic, excluding PVC, produced from recycling waste plastic such as telephone, computer or other plastic casings from domestic electrical equipment at the end of its life, powdered to around 1.5mm. This is used to clean up ground polluted by aromatic, paraffinic or olefinic hydrocarbons with the intention of using this matrix, including pollutants, as a high quality fuel with a PCI of 10000kcal.kg which can be used by industry as a replacement for conventional fuels. The process returns a soil containing less than 150ppm pollutants, with an ecosystem which can be returned to place. The process is carried out on site at ambient temperature without any emissions during the treatment. Independent claims are made for the plastic matrix, before and after it contains pollutants. The process involves excavating the soil and then sieving it to remove large bodies or those which will disturb the operation such as wood, metal, unpowdered plastic, textiles, electrical wires and large stones. The soil is then broken up in a grinder (2) to produce a granulometry of 100mm and transferred to a mixer (5) with a capacity of 10m3>. The plastic matrix (7) is also introduced into the mixer, together with a soil conditioner (6). After a mixing time of about 10min, the mixture is evacuated by a hydraulic emptying guillotine at the bottom of the mixer to an agitated tank (8) containing about 12m3> of water, provided with nozzles through which air jets are blown by a compressor (10). The tank also has a surface skimmer (11). The separation of the soil and the matrix is achieved by the blowing air, so the soil sinks and the matrix floats. The matrix containing the pollutant is removed to a hopper (13) by the skimmer and stored in a secure area (17) with the intention of selling it to industry as a fuel. The clean soil at the bottom of the tank is evacuted to another hopper (14) by an endless screw or bucket wheel (12) to be returned to its excavation site. The separating water is recycled (16) through a little press filter (9) which allows fine particles to be removed and added to the fuel. A control system (18) prevents deflagration. The treatment unit is mobile.

Description

Soil is one of the most important renewable natural resources on

  which is the basis of human production activity. That is why we must never forget that a badly treated soil deteriorates and can, in the extreme, die. It is important to know that in ldm3 soil live several thousand living beings (ecosystem). Organic substances influence the acidity of the soil, which is of great importance in terms of

  land use and their degree of pollution. Soil is declared fertile and healthy when the amount of pollutant it receives is equal to or less than it can eliminate.

  For this reason, the cleanup of hydrocarbon-polluted soils is a crucial problem in the industrialized countries, due to the growing nuisance caused by large oil processing plants, the wild degassing of ships, the oil industry, the break-up of pipelines. line, transport by sea of crude oil or refinery waste, etc. In addition, the contamination of beaches by wild degassing and accidental releases of hydrocarbons are increasingly frequent phenomena and involve the cleaning of these in a fast and efficient way, especially in areas where the main resource is tourism.

  For this type of pollution, the systems inventoried and currently used are the screening, the simple evacuation of sand and pebbles which are deposited in landfills and which must be replaced on site or the covering, polluted sand or pebbles, with sand imported from another site.

  With regard to soil treatment, the systems currently on the abatement market are as follows: Bioremediation, which is limited by pollution levels, the treatment is very long and climatic conditions play an important role.

  Venting, limited to volatile hydrocarbons, a difficult implementation and limited by pollution rates.

  - Thermal desorption, limited by pollution levels, generates an inert soil or soil at the end of treatment as well as volatile organic compounds, with a total absence of ecosystem. Incineration, limited in pollution rate, creates residues and it is a non-ecological and expensive process. The sale prices of incineration are prohibitive and are not aligned. Incinerators have almost the monopoly of the immense market of the destruction of Special Industrial Waste (DIS), among other polluted soils, which are their interest. The treatment by incineration therefore concerns small quantities and is intended for soils or soils that are refractory to conventional processes.

  This list is not exhaustive, but all of these techniques demonstrate the fragility of treatments and their harmful consequences on fauna, flora and the entire ecosystem.

  In order to preserve our soil and clean up the soil remediation treatment, ECS has developed a system that meets all these current environmental criteria, by including in its specifications the European recommendation of March 1999 concerning the reduction of Volatile organic compounds (VOC), constraint imposed by the DRIRES for the operation of a depollution unit, which justifies the choice of ECS not to use solvents and to work at ambient temperature. This system does not generate effluents, it allows a revaluation of the hydrocarbons, if necessary, and guarantees a residual pollution lower than 150ppm in the cleaned soils, also working on clay soils and clearing the market of bulky plastics, considering the use a plastic matrix.

  In addition to the high clearance rate, the ECS process has a number of advantages, demonstrating its performance: intact soil ecosystem - inexpensive process - simple and robust design and not requiring complex technologies low energy consumption transportable unit on the pollution site efficiency at room temperature rapid reaction is not limited by the nature of the hydrocarbons, nor by the tonnage to be treated use of ecological packaging reagents (*) and a plastic matrix - the hydrocarbons can be recovered or serve as a fuel, once adsorbed on the plastic matrix, their lower calorific value (PCI) being very high because of plastic compounds and hydrocarbons.

  the performance of the treatment is in line with the future French nun of 500ppm.

  significant operating margins low quantities of packaging reagents used recovery of high or low density plastic waste serving as a matrix analyzes at the end of the treatment demonstrating that: the process does not concentrate heavy metals, Polycyclic Aromatic Hydrocarbons (PAHs) are brought back at their acceptable thresholds, the absence of sulfur compounds, the intact process water and hydrocarbons with a high heating value.

  (*) The soil conditioning reagents are ecologically safe, considering the daphnia test, carried out according to the standard NF EN ISO 634105/96 Process Operation: Incoming products are first excavated and stored on a storage area secure near treatment equipment, using an excavator. These products (soils to be cleaned) are initially screened in order to evacuate large foreign bodies that could affect the proper functioning, such as metal, wood, plastics, textiles, electrical wires, large stones, etc. Then we reduce the grain size of this soil to about 100 mm, thanks to a grinding crushing system.

  This crushed soil is then introduced into a mixer with a capacity of up to 10 m3 using a backhoe, and mixed with a polymer matrix derived from the recovery of plastics. This phase lasts about 10 minutes and takes place at ambient temperature.

  After this first mixing, the transfer of the pollutant contained in the soil to be decontaminated on the plastic matrix will be obtained thanks to a conditioning of these soils, the transfer takes place only on the walls of the matrix which can not however be compared with a sponge. This matrix does not releasing the hydrocarbon after transfer.

  Then all the mixture is introduced into a large stirred tank containing a maximum of 12m3 water circulating in closed circuit.

  This agitation is induced by nozzles in the bottom of the tank through which is diffused compressed air, using a compressor, allowing us to phase out the ground of the plastic matrix, which means that the soil and The pollutant will remain at the bottom of the tank and the plastic matrix charged with the pollutant will rise to the surface. This one will be evacuated with its pollutant towards a place of safe storage knowing that this one does not religate after adsorption and is easy to transport, in order to be made available, is sold to the industry like fuel with a very high PCI (close to 10,000kca1 / kg), which will save the industry, which will use much less conventional fuel, which will have much higher costs.

  The treatment water will be permanently filtered on a small filter press connected to the dephasing tank, which will allow us to extract the fine particles suspended in this water which could disturb the results of depollution of the following grounds. The extraction of these fines is done on a low level of the tank and the purified water is reinjected on the top. The fines thus retained are removed with the fuel matrix. In very rare cases the hydrocarbons can be recovered and reused in refinery, it will then be necessary to undergo a treatment with the matrix that will return the hydrocarbons, but this case is only used when we are in the presence of a Hydrocarbon with a high added value.

  Given that the matrix represents a very small part of the cost of treatment and that its low chemical is that of hydrocarbons this system allows us to claim that we are in the presence of a soil remediation system economically unbeatable and can work with a minimum of personnel, without the addition of solvent or other product harmful to the use of the future fuel and be used on highly polluted soils and on any type of hydrocarbons: aromatic, parafficic, olefinic hydrocarbons.

  It can be used in this all-plastic system of low and high density, but PVCs that would be inconvenient for incineration are excluded.

  This invention avoids additional manipulations such as centrifugation, very costly investment, energy and service and gets rid of bulky plastic end of life, for example, phone carcasses, computer or other plastic cover of Hi-Fi articles or appliances in a useful way. Soils that have been cleaned up can be reinstalled because they are cleansed below 150ppm and the ecosystem is preserved.

  Components of the depollution plant: Crusher crusher Mixer up to 10m3 of volume, provided with a receptacle for floors (funnel) and a receptacle to introduce the plastic matrix and the soil conditioner and finally provided with a hydraulic dumping guillotine.

  É 12m3 phase shift water tank, equipped with air-blowing nozzles connected to a compressor, with a soil drain removed and decanted to a receiving hopper using a screw without wheel or wheel bucket and finally equipped with a surface scraper to evacuate the plastic matrix charged with pollutant, connected to a receiving hopper.

  É Several storage silos, in battery, to store the ready-to-use plastic matrix, all equipped with backsplashes.

  Storage silo soil conditioning reagent, equipped with a dosing pump.

  É Closed circuit water recirculation system using transfer pump.

  ^ All motors explosion-proof Tableau Electrical explosion-proof control panel with emergency stop.

  Secure storage area of the plastic matrix having adsorbed hydrocarbon pollutant, which will be used as fuel, given the very high PCI, and which will be sold as fuel to the industry.

  Hydraulic spill guillotine compressor and air blowing in the phase shift tank.

  The installation as described above is transportable on two semi-trailers lowered on site, with an encroachment on the ground of approximately 120m2, it will be able to clean up to 35 tons of soil / hour, without having to take into account pollution rate beforehand and leaving the soil ecosystem intact.

  PROCESS: (according to the diagram in appendix fig.1 / 1) The grounds are excavated (1), they are then crushed and crushed (2) to be brought back to a granulometry of 100mm, they are then stored on an intermediate storage (3 ), to be transferred (4) into the mixer (5) and to be mixed with a plastic matrix (7) and a conditioner (6), then they will be transferred to a phase shift tank (8) provided with nozzles blowing air connected to a compressor (10) and also connected to a small filter press (9) for recycling the water (16) and to remove the particles in suspension, the fines, (15) the scraper surface (11) also located above this phase shift tank makes it possible to evacuate the plastic matrix containing the pollutant to a receiving hopper (13) which it will be evacuated to a secure storage area (17) while waiting for the sale of this matrix as an excellent fuel for the industry and finally the soil cleansed of at the bottom of the tank (8) is evacuated by means of a worm or by means of a bucket wheel (12) to an intermediate receiving hopper (14) which will return to the excavation of the soil. The control panel (18) will be used to start and stop the entire installation. On this explosion-proof board an emergency stop has been planned.

Claims (13)

-6-CLAIMS   1. Process using a high and low density plastic matrix or any other plastic, excluding PVC, from the recovery of bulky plastics, such as telephone casings, computers or other plastic enclosures of household appliances, at the end of life, micronized to 1,5mm approximately used to clean up the soils polluted by hydrocarbons of the aromatic, paraffmic or olefinic type in order to use this matrix, including pollutant, as a very high quality fuel with a PCI of about 10,000kcalikg , and which will be sold to the industry in replacement of the conventional fuel used and restore a polluted soil less than 150ppm with its ecosystem that can be put back in place. The treatment is carried out on site, at room temperature without any emanation during treatment with pollution control rates of up to 35 tonnes / hour, without using other techniques than the one described and reaching the a residual pollutant rate as indicated.   2. Method according to claim 1, characterized in that said plastic matrix of high or low density comes from plastic bulky life fm preferably 1.5 mm micronized.   3. Transfer plastic matrix obtained after micronization transformation according to one of claims 1 or 2.   4. Transfer plastic matrix containing the pollutant, sold for use as fuel for the industry, and having an ICP of about 10,000kcal / kg according to claim 1.   5. Method according to one of claims 1 to 4, characterized in that the polluted soils polluted by aromatic, paraffinic or olefinic hydrocarbons with this micronized plastic matrix.   6. Method according to claim 1, characterized in that one restores the soil cleaned up to less than 150ppm and which have preserved their ecosystems, after their treatments at room temperature and on the site.   7. Process for the depollution of soils polluted by hydrocarbons of the aromatic, paraffinic or olefinic type, characterized in that the following steps are carried out: 1) The polluted soil must be excavated.   2) The excavated soil must then be screened in order to evacuate large foreign bodies or those which could disturb the proper functioning of the depollution such as metal, wood, non-micronized plastic, textiles, electrical wires or the big stones.   3) The soil must then be reduced to a grain size of 100mm using a crushing mill.   4) This soil, crushed and crushed, is transferred to a mixer that can have a capacity of 10m3 useful, using a backhoe by a receptacle provided for this purpose.   5) It is then introduced into the mixer a plastic matrix and a soil conditioner, which are mixed with the soil introduced in phase 4.   6) After a mixing time of about 10 minutes the mixture is evacuated by a hydraulic spill guillotine located on the bottom of the mixer, to a stirred tank containing about 12 m3 of water, provided with nozzles by which the water is blown. powerful jet air through a compressor, the tank is also equipped with a surface scraper.   7) The dephasing between cleaned soil and matrix is realized thanks to this insufflation of air, that is why the ground settling at the bottom of the tank and the supernatant matrix, containing the pollutant, which is evacuated in a hopper provided for this purpose to Using the surface scraper, it is then stored on a secure area waiting to be sold as fuel to the industry.   8) The decontaminated soil decanted at the bottom of the tank is evacuated to a hopper provided for this purpose using an endless screw or a bucket wheel, to be put back on the place of its excavation.   9) The water of phase shift is recycled permanently thanks to a small press filter which allows us to evacuate the fine particles which will be added to the fuel.   8. A method according to claim 7 and the implementation steps of 9 characterized in that it restores a soil polluted with hydrocarbons with a residual pollution of less than 150ppm after the treatment and a fuel with a very high PCI that can be resold in industry.   9. A method according to claim 7 and steps 1 to 9, characterized in that a plant comprising upstream downstream: a) a crushing mill (2) to obtain a grain size of 100mm b) a mixer (5) in which the polluted soil, the plastic matrix (7) and the soil conditioner (6) are mixed; c) a dephasing tank (8) equipped with air blowing nozzles and connected to a compressor (10) with a surface scraper (11) also connected to a filter press (9) for removing fine particles from the process water and finally a soil extraction screw or buckets cleaned (12) d) The scraper surface (11) discharging to a hopper (13) and the extraction screw or bucket (12) discharging to another hopper (14) e) recirculation of the water circuit is carried out by means of the return (16) f ) the evacuation of fines (15) contained in the filter press (9) will be done automatically and they will be evacuated to the storage area (17) to be mixed g) the contents of the hopper (13) are discharged to a secure storage area pending sale as an industrial fuel h) an explosion-proof electrical panel and control panel (18) 10. Method according to one of claims 9, characterized in that the different steps are carried out at room temperature.   11. Method according to one of claims 1 to 10 characterized in that the sequencing of the treatment makes it possible to achieve a rate of pollution of up to 35 tons / hour, without taking into account the initial pollution rate.   12. Method according to one of claims 1 to 11, characterized in that the processing unit is movable.   13. Method according to one of claims 1 to 12, characterized in that it uses no other depollution technique than that described, to reach the final results of 150ppm.