Waste as a resource: when differentiated and waste-to-energy plants make the difference

(by Alberto Azario) According to the World Bank's "What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050" report, by that date we will produce 70% more solid waste than today. The complaint makes us understand that, in the absence of an economic model aimed at encouraging reuse and recycling, we risk moving from 2,01 billion tons of 2016, to 3,14 billion in 2050 with unimaginable damage to the health of man and our planet.If not collected and managed properly, these wastes risk compromising the health of entire ecosystems for thousands of years; if we consider, for example, the oceans, the data are dramatic with at least 90% of the marine waste made of plastic.

According to the Report examined here, it will be fundamental to improve the entire management of the waste chain, to rethink it from a circular economy perspective, in which the products are designed to be recycled and reused. It is important now to equip the countries with adequate and adequate facilities to treat waste so that it is not a problem, an emergency, but a resource. "What a Waste 2.0" also shows that waste management is neglected in low-income countries; in fact, only 4% of production is recycled, an abysmal difference if we consider that in high-income countries, more than a third of waste is recovered through recycling and composting. A delicate situation that must be tackled with wide-ranging planning and rigorous scientific bases: solutions exist, we need only make them feasible and easily reproducible and accessible. In no European country, in fact, waste is considered a problem and if we make common sense prevail, even at the level of decision makers, and we use the available technologies, even in Italy it will no longer be.

Speech that perhaps in Northern Italy they already do since, to find the last time in which there was talk of "waste emergency" in the city of Milan, we must go back to 1995. A crisis that in a few weeks poured into the streets of Milan more than twenty thousand tons of waste due to the blockage of the Cerro Maggiore landfill (in the Milanese area). Since then in the Lombard capital, now one of the most visited European capitals for business and tourism, that terrible phrase, too often heard in the media for many other areas of Italy, practically no longer has a meaning. Indeed, Milan has even become a model in the world, for example, for separate waste collection. In 2017, over 670 thousand tons of waste were collected, about 2.200 per day. Of these 362.331 tons (equal to 59,6% of the total) were sent for material recovery, precisely through separate collection. In particular, in 2017 77.900 tons of paper and cardboard, 44.615 tons of plastic and metals, 65.501 of glass, 141.281 tons of organic waste were disposed of and, finally, another 33.034 tons of "differentiated fractions".

Milan has always insisted on the cleanliness of the city and several solutions have been introduced over the years to improve the situation. For example, so-called 'recycleries' have been created where citizens can bring waste that they usually cannot dispose of at home, such as broken furniture or appliances, a service also provided at home for those who have difficulty moving. great items from home. With an additional look at technological innovation, the positioning in the city of the first smart baskets (8.000 by the end of 2018), developed with Cefriel - Politecnico di Milano, has also recently begun. The "smart bins" are a technological solution that has the purpose of continuously monitoring the filling status of the containers located throughout the territory. The credit for all this goes, however, not only to the administrations that have followed one another over time, obviously also to the civic sense of the Milanese who try to respect the rules of decorum and living together.

The Milan model is also studied in other parts of the world, as in New York by the municipal administration of Bill De Blasio, to be exported in its efficiency and functionality thanks to a model based on integrated management of the entire waste chain , from collection to treatment, from material recovery to energy production. In addition to the differentiated, and the large numbers of waste that interests, the part that can not be brought back to new life is, in fact, used to produce energy. In fact, these wastes end up in waste-to-energy plants capable of treating over 500 thousand tons per year by cogenerating electricity, useful to cope with the annual energy consumption of about 130 thousand families, and heat for district heating, sufficient to heat over 30 thousand families producing water hot that is conveyed under pressure, through underground pipes, to homes.

From the Italian town to the sky, the use of waste to produce energy is a practice studied for some time, but the news of the first commercial flight powered by recycled waste is fresh news of the day. In the United Kingdom, a Virgin Atlantic flight flew from Orlando to Gatwick fueled by a mixture of fuel made from a part of normal jet fuel and a part of ethanol produced from the exhaust gases. A compound that could replace the normal propellants up to a 50% at least according to current technologies and knowledge and reduce the greenhouse gas emissions of 65% compared to conventional oil. This was only the first flight, but any new strategy to change course and consider waste more and more as a resource is welcome.

Waste as a resource: when differentiated and waste-to-energy plants make the difference