FAUSSONE GIAN, Claudio Paolo (Corso Appio Claudio 229/5, Torino, 10146, IT)
| CLAIMS 1. Process for treating solid urban wastes (RSU) characterised in that it comprises the steps of: - providing (Fl) at least one amount of solid urban wastes RSU ( R ; - triturating (F3) said wastes ( R for providing at least one amount of triturated wastes ( R2 ) ; - separating (F5) said triturated wastes ( R2 ) from a component of metallic wastes ( RM ) and obtaining (F7) at least one component of non-metallic wastes ( R^ ) of said triturated wastes ( R2 ) ; - humid separating (F9) said non-metallic wastes (RUM) to obtain at least one component fraction of plastic wastes ( RP ) , at least one component fraction of organic- cellulosic wastes ( R0c) and at least one component fraction of inert wastes ( R ; - supplying (Fll) said component fraction of plastic wastes ( RP ) to at least one thermocatalytic system to obtain a combustible mixture; - supplying (F13) said component fraction of organic- cellulosic wastes ( ROC ) to a gassifying system to obtain a synthesis gaseous fuel. 2. Process according to claim 1, characterised in that said steps (Fll) and/or (F13) comprise the substep of providing (F15) said combustible mixture and/or said synthesis gaseous fuel to a cogenerating system for producing electric energy (EE) or thermal energy (ET) . 3. Process according to claim 1, characterised in that said solid urban wastes RSU (RJ are "as such" without differences .' 4. System for treating solid urban wastes RSU, preferably adapted to implement a process according to the previous clams, characterised in that it comprises: - means for triturating solid urban wastes RSU ( R into triturated wastes (R2) ; - means for separating said triturated wastes (R2) into a component of metallic wastes (RM) and a component of non- metallic wastes (RNM) ; - means for humid separating said non-metallic wastes (RNM) to obtain at least one component fraction of plastic wastes RP , at least one component fraction of organic- cellulosic wastes Roc and at least one component fraction of inert wastes Rx; - at least one thermocatalytic system adapted to produce a combustible mixture through a thermocatalytic process from said component fraction of plastic wastes (RP) ; - at least one gassifying system adapted to produce a synthesis gaseous fuel (syngas) through a thermochemical process from said component fraction of organic- cellulosic wastes (Roc) · 5. System according to claim 4, characterised in that it comprises cogenerating means adapted to produce electric energy or thermal energy from said combustible mixture produced by said thermocatalytic system and/or from said synthesis gaseous fuel (syngas) produced by said gassifying system. 6. System according to claim 4, characterised in that said means for humid separating are at least one idropulper . |
The present invention refers to a system and a process for treating solid urban wastes.
As known, the amount of solid urban wastes (RSU) produced by modern society, and mainly by the most advanced industrial societies, is constantly and worrysomely increasing, as well, in parallel, as the difficulties for managing such wastes within a territory.
Moreover, the progressive increase of dumps, the scarce availability, due to natural, political, economic or social reasons, of territories used for new dumps and the chronical delay in implementing plants with high potentiality for treating the RSU, will, in a short time, make the situation of urban and extra-urban communities dramatic, above all those of small sizes, that will have to find a solution to the request of disposing RSU, without anyway excessively burdening the economic resources of people.
Therefore, object of the present invention is solving the above prior art problems, by providing a system and a process for treating solid urban wastes RSU that allow exploiting the energy resources present in the wastes, giving values to combustible fractions of the wastes themselves.
Moreover, an object of the present invention is providing a system and a process for treating solid urban wastes RSU that allow treating the RSU wastes "as such", namely without the economic burden deriving from the differential collection.
Another object of the present invention is providing a system and a process for treating solid urban wastes that can allow providing a mean potentiality of treatment, thereby able to be a solution with high chances of being widespreaded on the territory, above all within small communities and in peripheral quarters of big urban or metropolitan cities.
The above and other objects and advantages of the invention, as will appear from the following description, are obtained with a process for treating solid urban wastes as claimed in claim 1.
Moreover, the above and other objects and advantages of the invention are obtained with a system for treating solid urban wastes as claimed in claim 4.
Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims. It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with equivalent functionality) can be made to what is described, without departing from the scope of the invention as appears from the enclosed claims.
The present invention will be better described by some preferred embodiments thereof, provided as a non- limiting example, with reference to the enclosed drawings, in which the only Figure 1 shows a flow diagram representing the steps of a preferred embodiment of the process according to the present invention.
With reference then to Figure 1, it is possible to note that the process for treating solid urban wastes RSU according to the present invention comprises, in particular, the steps of:
- providing Fl at least one amount of solid urban wastes RSU Ri "as such" without differences;
- triturating F3 such wastes R x for providing at least one amount of triturated wastes R 2 ;
- separating F5 such triturated wastes R 2 from their own component of metallic wastes R M and obtaining F7 at least one component of non-metallic wastes R m of such triturated wastes R 2 ;
- humid separating F9 such non-metallic wastes NM to obtain at least one component fraction of plastic wastes R P , at least one component fraction of organic-cellulosic wastes R oc and at least one component fraction of inert wastes R^ In particular, as known, such step F9 allows obtaining the separation of non-metallic wastes R m into three different fractions R P , R oc and R lf exploiting their different behaviour when an acqueous phase is present;
- supplying Fll such component fraction of plastic wastes R P to at least one thermocatalytic system. As known, a thermocatalytic system implements, through a thermocatalytic reactor, a process that allows, by using a catalyst, obtaining, at a temperature of about 400°C, the demolition of polymeric chains of plastics to obtain hydrocarbons with shorter chains (equivalent to the composition of gas-oils) cmposing a combustible mixture;
- supplying F13 such component fraction of organic- cellulosic wastes Roc to a gassifying system. As known, gassifying systems implement a thermochemical process that allows the direct transformation of the biomass composed of the component fraction of organic-cellulosic wastes R oc into synthesis gaseous fuel (syngas) mainly composed of methane, C0 2 and H 2 .
Preferably, such steps Fll and/or F13 comprise the substep of providing F15 such combustible mixture and/or such synthesis gaseous fuel to a cogenerating system substantially known in the art for producing electric energy E E or thermal energy E T (heat) .
The step F9 of humid separating then operates on wastes RSU "as such" after the triturating step F3 and the separating step for metallic F5 and non-metallic components F7. Such step F9 therefore allows making an eterogeneous mixture composed of water and non-metallic wastes R NM and extracting from such mixture the three components R P , R oc and R T continuously, due to their different behaviour in water determined by their own weight. As previously stated, in the process according to the present invention, the various fractions advantageously have different destinations:
- the lighter fraction, composed of the component of plastic wastes R P , is sent to the thermocatalytic process for producing a combustible mixture that can be used for producing electric or thermal energy through the cogenerating system;
- the fraction of organic-cellulosic wastes R oc is sent, possibly after a previous dehydrating step, to gassification for producing a synthesis gas and afterwards producing electric or thermal energy through the cogenerating system;
- the remaining heavy fraction of wastes R IF composed of inerts and glass, is instead disposed of F17, for example in a dump according to traditional methods.
The present invention further refers to a system for treating solid urban wastes RSU, preferably adapted to implement the process according to the present invention as previously described. In particular, the system according to the present invention comprises:
- means for triturating solid urban wastes RSU R x into triturated wastes R 2 ;
- means for separating such triturated wastes R 2 into such component of metallic wastes R M and such component of non-metallic wastes R^;
- means for humid separating such non-metallic wastes R m to obtain at least one component fraction of plastic wastes R P , at least one component fraction of organic- cellulosic wastes R oc and at least one component fraction of inert wastes R^-
- at least one thermocatalytic system adapted to produce a combustible mixture through a thermocatalytic process from such component fraction of plastic wastes R P ;
- at least one gassifying system adapted to produce a synthesis gaseous fuel (syngas) through a thermochemical process from such component fraction of organic- cellulosic wastes R oc -
Possibly, the system according to the present invention further comprises cogenerating means adapted to produce electric energy or thermal energy from such combustible mixture produced by the thermocatalytic system and/or from such synthesis gaseous fuel (syngas) produced by the gassifying system.
Preferably, the means for humid separating are composed of an apparatus (idropulper) substantially known in the art and composed of a horizontal cylinder in which the eterogeneous mixture composed of water and non- metallic wastes R NM is inserted and removed in its three components R P , R OC and R z (lighter plastics, organic- cellulosic component, heavier inerts-glass ) in a continuous way.
The thermocatalytic system comprises at least one primary reactor adapted to transform, through the intervention of a catalyst, preferably arranged on the bottom of the reactor itself, the component fraction of plastic wastes R P (substantially composed of polyolefins) into liquid hydrocarbons, that contain petrol, light oils, fuel oils, waxes, microwaxes, in addition to, in a gaseous form, butane and propane composing the combustible mixture. The thermocatalytic system further comprises at least one secondary reactor adapted to refine the fraction of hydrocarbons of the produced combustible mixture and improve its combustible properties . The gassifying system is instead adapted to produce the synthesis gaseous fuel (syngas) in which there are also not completely oxidised substances to be possibly used in a following step, for example in internal combustion engines or in cogenerating means for producing electric or thermal energy, through a partial oxidation of the fraction of organic-cellulosic wastes R oc . The synthesis gaseous fuel (syngas) produced by the gassifying system is essentially composed of carbon monoxide (CO) , hydrogen (H 2 ) , metane (CH 4 ) , in addition to carbon dioxide and water deriving from the complete oxidation reactions, and nitrogen (N 2 ) deriving from combustion air: the composition of the synthesis gaseous fuel (syngas) obviously depends on the operating process conditions. The solid residue that is obtained at the end of the gassification process can be:
- inert, in case of complete gassification, namely when, at the end of the process, the whole organic carbon present in the fraction of organic-cellulosic wastes R oc can be found in the synthesis gas;
- carbonious, when gassification is incomplete.