Difference between revisions of "Talk:B1-Summary description of the project"
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The description should be structured, concise and clear. It should include: | The description should be structured, concise and clear. It should include: | ||
| + | |||
• Project objectives: Please provide a detailed description of all project objectives, listing them by decreasing order of importance. | • Project objectives: Please provide a detailed description of all project objectives, listing them by decreasing order of importance. | ||
These objectives must be realistic and clear. | These objectives must be realistic and clear. | ||
| + | |||
•Actions and means involved: Please explain clearly what means will be utilised during the project to reach the objectives indicated above. Please ensure that there is a clear link between the proposed actions and means and the project's objectives. | •Actions and means involved: Please explain clearly what means will be utilised during the project to reach the objectives indicated above. Please ensure that there is a clear link between the proposed actions and means and the project's objectives. | ||
| + | |||
• Expected results (quantified as far as possible): Please list the main results expected at the end of the project. These must directly relate to the environmental | • Expected results (quantified as far as possible): Please list the main results expected at the end of the project. These must directly relate to the environmental | ||
problems targeted and to the project's objectives. The expected results must be concrete, realistic and quantified as far as possible. | problems targeted and to the project's objectives. The expected results must be concrete, realistic and quantified as far as possible. | ||
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A climate change adaptation project is defined as a project where the main actions concern initiatives and measures that can be used to reduce the vulnerability of natural and human systems against actual or expected climate change effects. Applicants should be careful not to confuse climate change adaptation with the "Climate Change" project policy area indicated in form A1. | A climate change adaptation project is defined as a project where the main actions concern initiatives and measures that can be used to reduce the vulnerability of natural and human systems against actual or expected climate change effects. Applicants should be careful not to confuse climate change adaptation with the "Climate Change" project policy area indicated in form A1. | ||
| + | |||
| + | == COWS overall concept == | ||
| + | Anaerobic codigestion can be considered one of the most promising way to give a proper disposal to the organic fraction of municipal solid waste (OF-MSW) coming from source or separate collection systems. This approach is very interesting in Europe, where the EC regulations push towards the separation of collection strategies for MSW management: about 400.000 tons/year of OFMSW coming from source sorted or separately collection approaches are produced in Europe (Mata-Alvarez et al., 2000). At the same time, in the EC there are some 36.000 wastewater treatment plants which adopt the anaerobic stabilisation of sewage or waste activated sludge: very often these plants are oversized, due to the low sludge mass loadings originated from wastewater treatment and the low biogas yields of sludge (Bolzonella et al., 2005). This scenario suggests that, implementing wastewater and OF-MSW treatments through codigestion, the recovery of some 112.000 electrical MW and 180.000 thermal MW can be achieved. Italy is now moving in this field, thanks to the application of new laws (decree 22/97) about the separation of the so-called ‘wet fraction’ from the municipalities. In order to apply such an integration wastewater treatment plants should be conveniently up-graded to treat these streams of waste. The paper deals with two full-scale experiences carried out in central and northern Italy respectively, in which waste activated sludge and the OF-MSW were codigested in the anaerobic digestion units of two WWTPs. | ||
| + | |||
| + | The mixed fraction of MSW, the materials that remains after separate collection of the recyclable | ||
| + | components of the urban waste, still contains large quantities of energy. | ||
| + | The recovery of this energy is usually managed in incinerators, but the caloric value is | ||
| + | reduced by the organic fraction, that still contains large amounts of water (45 – 72 % TS). | ||
| + | The waste composition, after separate collection, is shown in Figure 1; they were measured in | ||
| + | two different situations, in Italy and Germany. | ||
| + | It is important to notice that the organic fraction is similar in the two situations, and still | ||
| + | represents a large percentage of the waste. | ||
| + | |||
| + | |||
| + | Anaerobic disgestion is the only process that can recover energy from wet material. | ||
| + | If the moisture content is over 30%, as it usually occurs in the case of food residues, the | ||
| + | energetic balance of combustion is negative. | ||
| + | The burning of these materials in incinerators is still possible, as the combustion is supported | ||
| + | by paper and plastic; but if their concentration is reduced by separate collection, the only way to | ||
| + | recover energy is the separation of the wet components and the production of biogas. | ||
| + | |||
| + | == Separation == | ||
| + | 2.2 Separation process | ||
| + | Among the several possibilities of separating the organic matter from the mixed waste, the | ||
| + | technology of pressure-separation was chosen. | ||
| + | With this technology, the separation is done through a specially designed extruder press, that | ||
| + | separates the input waste into two fractions: a dry one, to be sent to thermal conversion, and a | ||
| + | semi-solid one, that seems to be interesting for anaerobic digestion. | ||
| + | The municipal waste, fed into the extruder press, undergoes a very high pressure in a | ||
| + | perforated extrusion chamber: this results in a fluidization of the actual organic parts (food | ||
| + | residues, various putrescible fractions) which are pushed out by the difference in pressure | ||
| + | between the interior and exterior of the chamber and are, consequently, separated from the | ||
| + | mechanically more resistant parts (paper and carton, plastics, rubber etc.). | ||
| + | |||
| + | The press can be directly fed with the waste; it only requires the cutting of the sac; the use of | ||
| + | this kind of press do not requires the grinding of the material before the treatment. | ||
| + | This strongly reduces the contamination of the substrate by heavy metals and other dangerous | ||
| + | components. | ||
| + | The result is that the output material after anaerobic digestion shows a high quality of the | ||
| + | digested matter that can be analysed in view of a possible agronomic utilisation. | ||
| + | The energy consumption of the press is low, if compared with other separation systems, both | ||
| + | dry and wet. | ||
| + | The typical consumption is 12 kWh/t of input waste, which means almost 5% of the energy | ||
| + | that can be obtained by the conversion into electricity of the biogas produced by the process. | ||
| + | |||
| + | |||
| + | == OMG Organic matter gel == | ||
| + | 2.2.1 Organic matter gel (GMO) | ||
| + | The wet material has a consistency similar to a dense gel that does not release free water. | ||
| + | This is relevant for three reasons: first one is that it can be stored in tanks without leaking of | ||
| + | liquids. | ||
| + | The second one is that it can be easily pumped and mixed with the digestate, for a simpler | ||
| + | control of the process. | ||
| + | The third one is that there is no separation of the phases when fed into a plug-flow digester; | ||
| + | this is very important, as no separation occurs inside the digester, where the material is treated | ||
| + | for a long period, up to 50 days. | ||
Latest revision as of 01:56, 14 July 2011
Contents
Description of the project[edit]
The description should be structured, concise and clear. It should include:
• Project objectives: Please provide a detailed description of all project objectives, listing them by decreasing order of importance. These objectives must be realistic and clear.
•Actions and means involved: Please explain clearly what means will be utilised during the project to reach the objectives indicated above. Please ensure that there is a clear link between the proposed actions and means and the project's objectives.
• Expected results (quantified as far as possible): Please list the main results expected at the end of the project. These must directly relate to the environmental problems targeted and to the project's objectives. The expected results must be concrete, realistic and quantified as far as possible.
Can the project be considered to be a climate change adaptation project?[edit]
A climate change adaptation project is defined as a project where the main actions concern initiatives and measures that can be used to reduce the vulnerability of natural and human systems against actual or expected climate change effects. Applicants should be careful not to confuse climate change adaptation with the "Climate Change" project policy area indicated in form A1.
COWS overall concept[edit]
Anaerobic codigestion can be considered one of the most promising way to give a proper disposal to the organic fraction of municipal solid waste (OF-MSW) coming from source or separate collection systems. This approach is very interesting in Europe, where the EC regulations push towards the separation of collection strategies for MSW management: about 400.000 tons/year of OFMSW coming from source sorted or separately collection approaches are produced in Europe (Mata-Alvarez et al., 2000). At the same time, in the EC there are some 36.000 wastewater treatment plants which adopt the anaerobic stabilisation of sewage or waste activated sludge: very often these plants are oversized, due to the low sludge mass loadings originated from wastewater treatment and the low biogas yields of sludge (Bolzonella et al., 2005). This scenario suggests that, implementing wastewater and OF-MSW treatments through codigestion, the recovery of some 112.000 electrical MW and 180.000 thermal MW can be achieved. Italy is now moving in this field, thanks to the application of new laws (decree 22/97) about the separation of the so-called ‘wet fraction’ from the municipalities. In order to apply such an integration wastewater treatment plants should be conveniently up-graded to treat these streams of waste. The paper deals with two full-scale experiences carried out in central and northern Italy respectively, in which waste activated sludge and the OF-MSW were codigested in the anaerobic digestion units of two WWTPs.
The mixed fraction of MSW, the materials that remains after separate collection of the recyclable components of the urban waste, still contains large quantities of energy. The recovery of this energy is usually managed in incinerators, but the caloric value is reduced by the organic fraction, that still contains large amounts of water (45 – 72 % TS). The waste composition, after separate collection, is shown in Figure 1; they were measured in two different situations, in Italy and Germany. It is important to notice that the organic fraction is similar in the two situations, and still represents a large percentage of the waste.
Anaerobic disgestion is the only process that can recover energy from wet material.
If the moisture content is over 30%, as it usually occurs in the case of food residues, the
energetic balance of combustion is negative.
The burning of these materials in incinerators is still possible, as the combustion is supported
by paper and plastic; but if their concentration is reduced by separate collection, the only way to
recover energy is the separation of the wet components and the production of biogas.
Separation[edit]
2.2 Separation process Among the several possibilities of separating the organic matter from the mixed waste, the technology of pressure-separation was chosen. With this technology, the separation is done through a specially designed extruder press, that separates the input waste into two fractions: a dry one, to be sent to thermal conversion, and a semi-solid one, that seems to be interesting for anaerobic digestion. The municipal waste, fed into the extruder press, undergoes a very high pressure in a perforated extrusion chamber: this results in a fluidization of the actual organic parts (food residues, various putrescible fractions) which are pushed out by the difference in pressure between the interior and exterior of the chamber and are, consequently, separated from the mechanically more resistant parts (paper and carton, plastics, rubber etc.).
The press can be directly fed with the waste; it only requires the cutting of the sac; the use of this kind of press do not requires the grinding of the material before the treatment. This strongly reduces the contamination of the substrate by heavy metals and other dangerous components. The result is that the output material after anaerobic digestion shows a high quality of the digested matter that can be analysed in view of a possible agronomic utilisation. The energy consumption of the press is low, if compared with other separation systems, both dry and wet. The typical consumption is 12 kWh/t of input waste, which means almost 5% of the energy that can be obtained by the conversion into electricity of the biogas produced by the process.
OMG Organic matter gel[edit]
2.2.1 Organic matter gel (GMO) The wet material has a consistency similar to a dense gel that does not release free water. This is relevant for three reasons: first one is that it can be stored in tanks without leaking of liquids. The second one is that it can be easily pumped and mixed with the digestate, for a simpler control of the process. The third one is that there is no separation of the phases when fed into a plug-flow digester; this is very important, as no separation occurs inside the digester, where the material is treated for a long period, up to 50 days.
