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Waste-to-energy plants

With the rapid growth of waste and sewage, not only in quantity but also in terms of varieties and hazardousness, between the sixties and the seventies, the areas surrounding cities are no longer able to absorb and metabolise the enormous amount of waste generated by modern living. A new solution is called for which will initially be, at least in its intent, technological: the "age of the plants" begins. These are the large industrial plants able to render the great quantity of waste that a technologically advanced society churns out at an increasing pace inert and non-hazardous to people and the environment.
The waste-to-energy process, as a method for treating municipal solid waste, spread throughout the country in the decade between the end of the 1960s and the end of the 1970s, to then undergo a sharp slowdown in the 1980s. In that period of time, Emilia-Romagna was at the forefront in Italy, with five plants comprising a total of 11 thermal treatment lines, including two in Reggio Emilia (1968), three in Bologna (1973-1974), two in Rimini (1976), two in Forlì (1976) and two in Modena (1980). These plants lacked any type of energy recovery system.
The cities of Trieste and Padua, whose waste-to-energy plants became part of the Herambiente Group on 1 July 2015, have an extremely long tradition of waste management through waste-to-energy.
The local story of the city of Trieste in the daily newspaper "Il Piccolo" on 23 February 1915 was already talking about the inauguration of a "waste incinerator", which for the modest sum of 1 million crowns was already designed in those days for energy recovery. After a long break, the new Giarizzole incinerator, which will serve the city of Trieste until the end of 1999, was inaugurated in 1972. In the meantime, legislative changes induced the Trieste Municipality to speed up the building of the new waste incineration plant with energy recovery, which incorporated the best technologies available.
The first waste-to-energy plant in Padua was built in the San Lazzaro district in the 50s and became operational in 1962. It was a real innovation at the time: the first Italian plant where energy was also recovered. The nominal capacity of the incinerator was 140 t/day and the boiler and thermal unit generated 1.4 MWh/day. A second combustion line with a capacity of 150t/day was built at the end of the 60s and later updated to adapt it to the increasingly more stringent regulations and inspections until it took on its final format in 2000.

  • The sector rallied at the beginning of the 1990s following regulatory and technological developments, resulting in the installation of new plants, the enhancement of existing plants, improved pollution abatement systems and the introduction of energy recovery systems.
    The rules on waste management were first established by Presidential Decree 915 of 10 September 1982 on the disposal of waste. As well as introducing a number of principles for defining systems to limit waste production, this subdivided waste into four types: municipal, special, toxic and harmful. In February 1997, this decree was superseded by Legislative Decree 22 (the "Ronchi Decree"), which focuses on preventing and reducing the quantity and hazardousness of waste.
    In April 2006, Legislative Decree 152 (the "Consolidated Environmental Act") came into force. This profoundly changed the legislative framework by introducing a wide range of innovations into the rules on environmental impact assessments and strategic environmental assessments, soil protection, water pollution prevention and water resources management, waste treatment and management, reclamation of contaminated sites, and pollution. These new regulations set forth that "the installation and management of new plants will be authorised only if the relative combustion process ensures a high level of energy recovery", effectively approving the conversion of these plants from simple incinerators into modern waste-to-energy plants.
    A waste-to-energy (WTE) plant is one that does not confine itself to incinerating unseparated waste, squandering the heat produced by the combustion process, but is also capable of "adding value" to the waste by recovering energy from it.
    Herambiente and its subsidiaries offer themselves as a concrete answer to waste problems, including at national level, thanks to investments in technologies that guarantee development, transparency and innovation, in a sector which in Italy is fragmented and constantly stricken by emergencies.
    The eight waste-to-energy plants for municipal waste which covers a catchment area of 4 million people in the provinces of Ferrara, Modena, Bologna, Forlì-Cesena, Rimini, Isernia, Padua and Trieste and F3 waste-to-energy plant in Ravenna for C&I waste, managed by Herambiente Group, are not limited to incinerating waste, squandering the heat produced by the combustion process, but are capable of "adding value" to the waste by recovering energy in the form of electricity, which is injected into the national grid, and heat, which is piped into homes or other premises in the area via a suitable distribution system, the district heating network. They can produce 860 GWhe of electricity, equivalent to the average consumption of around 300,000 families, and 156 GWhth of heat, equivalent to the average consumption of over 10,000 homes - an energy production that would have required the use of 165,000 tonnes of oil.
    The only types of waste produced by the incineration and purification of the combustion fumes are ashes (approximately 20% of the treated waste weight) and particulates left over from the fume filtration process (approximately 3% of the treated waste weight). The ashes, consisting of mineral and metallic components left over from the combustion (non-hazardous waste), are normally sent for recovery using special processes to separate the metals and produce secondary raw materials for the cement industry. The particulates (hazardous waste) are pre-treated with a neutralisation process for subsequent disposal at an authorised plant.
    The rigorous monitoring of emissions is not only aimed at complying with legal requirements, but is, above all, a clear responsibility towards the stakeholders (citizens and institutions). This is why Herambiente publishes real-time emissions data on the appropriate dedicated section of its website. With the same aim of providing the best possible guarantee of quality and reliability, all emissions monitoring equipment is certified by TUV, one of the most authoritative certification bodies in the world.

    In addition to the above, the following measures for controlling emissions and environmental impacts are taken every year:

    • spot checks on flues, wastewater, waste, soil and subsoil at frequencies defined in the integrated environmental authorisation, carried out by certified laboratories;
    • checks on the impacts of pollutants on the soil: through external monitoring programmes in collaboration with universities and research bodies, analyses are carried out on soil depositions (land, plants, etc.) in order to ensure that the emissions, even if they are within the stringent legal limits, do not produce any significant impact on the surrounding environment.

    Particular emphasis is given to the Moniter programme, a joint initiative by the Emilia-Romagna Region and ARPA, with the main aim of "organising a system of environmental surveillance and epidemiological assessment in the areas around the incineration plants in Emilia-Romagna".
    All the waste-to-energy plants managed by Herambiente are monitored by this programme, thus providing the local population with additional information and knowledge.
    A summary of the Scientific Committee´s results and assessments is published on the website: http://www.arpa.emr.it/moniter/.

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