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General outline of the process
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Our transformation process is obtained by mixing the pulverized SUR in a proper machine (screw mixer), together with a polymer binder and a specific catalyst which, interacting with the perishable components, in 180/260 seconds of time destroy the bacteria flora and neutralizes the product. |
The process takes place always "at a cold temperature" reaching a maximum temperature of 40°C during the polymerization of the product, with the only exception of the drying phase that is obtained at a temperature of 100-130°C, in order to dry the SUR and sludge mixture and to obtain a steam recovery through proper heating systems or a purifying system with the help of a scrubber. |
Being a final product of the transformation of SUR, besides different sizes of granules, it is possible to obtain materials of different form and utility, either for building trade or for general urban furnishment. |
The physical - mechanical tests on the samples obtained by the transformation, carried out by the laboratory "Istedil Spa" of Guidonia (Rome), by the department of Structural and Geo technical Engineering (experimental laboratory) of the University of Rome "La Sapienza" and by the laboratory of chemical analysis "SEA" (Ecological and Environmental Services) of the Prof. Andrea Binotti- Tolentino (MC), permitted us to verify the resistance and the reaction of the material at a breakage stress, in relation to: the flexion resistance (28 kg/cm2), the density (1,473 g/cm3), the form (no deformation), the linear thermal dilation ( extension value of 1041 um/m ), sliding friction owear and tear ( abrasion coefficient = 8.68 mm), compression (610 kg/cm2). The resulting test values written above are absolutely superior to those achieved by the traditional materials! |
It has been established that the separation and the recycling of many of the SUR's marketable components is not convenient, either for the high power consumption or for the negligible market returns from the recycled end-products. Besides, it is thought not worthwhile to recover the recycled part, which represents the 45% of the organic fraction. |
Several industries that treat the separation process are not able to get rid of the recovered product, which besides being unsold it remains in the industry's stock-rooms because of the high regeneration costs necessary for it's recycling. |
The compost does not find a placement as a fertilizer, this because containing microscopic quantities of plastic, glass and heavy metals it presents Iow fertilizing effects; all this makes the farmers reluctant to use it. |
These materials, not having a good placement in trading, are loaded and brought back again to the landfills causing higher costs for the consumer. |
Better luck has the power recovery during the transformation process of SUR, obtained by the extraction of the highest heat power fraction: you so have what is called the RDF (Refuse Derived Fuel) which can be used as an alternative fuel in thermo-electric power stations, cement industries, etc., at very low economic costs. |
| After all that has been said till now we argue that it is convenient to grind all the substances which are part of the SUR marketable component groups, either the dry fraction or the moist fraction; this in case the dry fraction grinding (the recycling part) is determined economically valid. |
| Depending on the market needs and requirements, the transformation plant can be realized in two technologically different ways: |
a) Transformation process of the SUR through the recovery of the recyclable fraction; |
| This process demands the realization of separating machines for the recovering of recyclable parts (glass, paper, wood, heavy metals, etc.) using a detector to select on a specific weight basis, or through a manual gathering. |
b) Transformation process of the SUR without the recovery of the recyclable fraction. |
| This process will not need the machineries indicated above, obtaining remarkable lower costs in machinery, personnel and power consumption. |
| Studying the transformation phases of every SUR granule, composed by vegetable fibers, protein organic fragments, inorganic materials (iron, various metals, glass, etc.), it has been noticed that when these are attacked by the polymer additive and by the specific catalyst, they undergo a chemical transformation, which creates all around it a protective pellicles, making it waterproof and highly dehydrated. |
| If used with chalk ( CaCO3, which, as well known, has a very high pH, between 11 and 12), the granule is totally free from bacteria flora. |
| It has been verified a very high concentration of hydroxyl groups which, during the mixing together of chalk and water, help the dehydration process of the chalk itself; and after the chemical phenomenon, gives at the material a high impermeability. |
| The heavy metals and their hydroxides which are present in the structure result immobilized, this because the transport movements of the polar molecules happen only under two conditions: by electric gradient or by concentration gradient which, in our case, cannot happen because the obtained element is strongly inhibited by the solid structure of the chalk (CaCO3.) |
| This technology permits us to transform civil and sedimentary sludge too, through the use of proper machines built on barges, in order to gain a double advantage: recovery of the sedimentary sludge and transformation of these into inert material. |
| It will be then possible to gain from the selling of inert granules and materials a new self-financing source for public interests (environmental preservation, and many more.) |
| This technology allows the transformation of Solid Urban Refuse and Wastewater Sludge through a cold process, by means of an exclusive chemical, using a polymeric additive, plus a specific catalyst, into an inert material. |
| With the sole exception of oil-based sludge and other highly toxic refuse, every type of refuse (solid, urban, agricultural, industrial), can be processed. Therefore, apart from SUR, other refuse such as automobile tarpaulins, construction, industrial, and agricultural remains can be included. |
| Moreover, the resulting products exhibit unusually strong physical-mechanical properties. |
| The patented process consists essentially of the treatment of waste of all types present in solid urban refuse and/or wastewater sludge, with the addition of a "polymeric additive", plus a specific catalyst that, interacting with the perishable components, destroys the micro-bacterial flora and renders the final product inert. Furthermore, with the mixing of CaCO3 (Calcium Carbonate) or inert material obtained from building demolition waste, the product can be made highly fire-resistant for even > 500oC |
| The transformation process always occurs as a cold process, with the exception of the drying phase, which occurs at a temperature of from 100 - 130oC. In this phase the mix of SUR and wastewater sludge is dried in an oven with a modulating methane gas burner, using a suitable ventilator to recover processing air, placed behind a dehydrator and a filter to guarantee that no dust or odor escape into the environment. After the filter is saturated, then the filter will be transformed together with the S.U.R. |
| The final product obtained from SUR and wastewater sludge with this facility is bacterially inert, waterproof, displays optimum characteristics of structural resistance (especially to compression=610kg/cm2), and is therefore suitable for use in buildings. It has the advantage of a specific weight of from 1,200 to 1,500 kg/m3, depending on the composition of the original materials and the percentage of polymeric additive |
| We have also verified the high concentration of "ox hydrogen groups" which, when united and mixed with cement dust and water, facilitate the hydration process of the cement itself, resulting, after the chemical reaction, a high level of impermeability of the manufactured product. In addition, heavy metals found in the internal structure are immobilized, like the respective hydroxides, because the phenomenon of the transfer of polarized molecules happens only under two possible conditions: |
 Through electric gradients; Through concentration gradients. |
| These two requirements, in our case, are not possible to verify because the element obtained is strongly inhibited from the solid structure, activated through the phenomenon of polymerization. Polymerization happens when simple molecules combine and form complex molecules, together with a specific catalyst, which increases the speed of the chemical reaction |
| The addition of the polymeric additive to the product of SUR and/or wastewater sludge for transformation can be either in suspension or in solution, and leads the results of interaction in different ways. |
| The treatment in "suspension" happens when the granule of SUR and/or wastewater sludge, is inertized with the polymeric additive that works essentially as a transparent varnish, giving to the transformed granule a slight permeability and penetrability in the micro porous structure. In practice, it is like a micro covering or "membrane". |
| Treatment in "solution", (used for the neutralization process with the polymeric additive), is to position the macromolecule and all of its molecular qualities, at the internal of micro and macro porosity. Secure, valid effects are obtained (insulation, permeability, cohesion, etc.) with regard to the single membrane established by the application of the polymeric additive in suspension. |
| The product from SUR and/or wastewater sludge, in the treatment and transformation stage to obtain inertization, becomes completely soaked with the polymeric additive and its specific catalyst. In this way polymerization occurs, reproducing inside the granule, almost at a molecular level, the polymerization process done in the industrial facility. |
| With this process, it is like "wrapping" a whole container filled with caramels - taking them singly and wrapping them one by one. |
| The processing time to encapsulate each of the particles of SUR and/or wastewater sludge, finely micronized, is from 180 to 260 seconds. |
| The transformation process takes place in an industrial facility that will be functionally designed, based on the quantity of original material to be received and transformed. |
| The completed plant poses no risk of atmospheric pollution. In effect, the final process of treatment takes place at ambient temperature, and therefore produces a simple exothermic reaction; it is important to state here that the quantity of solvent resulting from the polymerization reaction is minimal since the vapor tension at this temperature is low. |
| In fact, in the polymerization, process the styrene (aromatic solvent used in the mixing phase) reacts with the catalyst; part of it enters into the reaction of polymerization, and so creates a union between molecules of resin. This obtains a macromolecule strongly bonded and only small parts escape to the atmosphere. |
| The organic substances used are of polystyrene type, that substances containing only the elements C,H,O,N and not those or which (like chlorine) could negatively influence environment and health. |
| We should point out that the residue of emitted vapor from the mixer cannot evaporate in the external environment, due to recovery through an active coal aspiration facility. Once saturated, the filter is changed for a new one, and put into the transformation process after being crushed. |
| A collection of pathogenic's is absent because they are eliminated by the "sterilization" process. Therefore, there are no sanitary concerns about the utilization of the materials. |
| The inertization going on in the process, through polymerization, does not give off emissions nor does it affect environmental hygiene. That is because polymerization lasts a short period of time (about 3 minutes) and the reaction temperature, as said before, is low. |
| In these conditions, the production of emissions from inside the mixer is minimum and is completely recovered by an active coal filter, even if odors are controlled into low limits. |
| During the mechanical pretreatment, the situation in our plant is the same as of any other plant. Because pretreatment is the only operation done to the refuse in our plant before the polymeric inertization, the odor emissions last for only a short time. Even these emissions are almost neutralized by the recovery, and reduced by means of the scrubber during the polymerizing process. At the end of inertization, the final product is almost odorless. |
| The qualities of the product itself and its technical characteristics such as hardness, flexibility, etc., are another factor that determine the environmental compatibility of the product. |
| Being polymeric material, with a strong resistance to biological degradation, the biodegradation of the products used in the transformation process is comparable to that of other polymers. The total absence of alteration favors the versatility of the product. |
| Analyses results confirm that only a meaningless part escapes to the environment. The lack of heavy metals, chloride composts or other components that give off toxic substances to the environment (ground, water or air), eliminate eventual problems in the phase of utilization. |
| The building structures, present openings of different size and shape, useful for natural air exchange. Moreover, air exchange inside the structures is guaranteed by electromechanical means, which activate air movements in the environment (exhaust ventilator). |
| Artificial ventilation will be secured by a centralized system that emits pure air and expels stale air through a series of distribution conducts and extractors connected to the central system controlling the conditioning of the air. |
| In fact, the basal criteria is not to subject people to the direct effect of cold air at high velocity, but to ensure an effective change of air with regard to the hygiene and sanitary security of people working in the industry. |
| With reference to the landscape, the projected facility is designed based on correlation between the facility and the site on which it is placed; it responds to the requirements of neutral environmental impact, as well as to geomorphologic facts. |
| All this allows the differentiation of the process of wrapping the inerts with cement, which results in homogeneous mixing of the separate parts, thus enhancing compatibility. The manufactured product so obtained shows optimum technical-mechanical results regarding: |
| Specific weight Porosity Permeability to the air
Gelativity Thermal conductivity Fire resistance Resistance to compression Workability Hardness |
| This technology permits, moreover, looking at refuse not as something to disappear into the cement, but as a classical constituent of concrete. Every test has shown the quality of the product in use, substantially strengthening its chemical-technological characteristics. |
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