The new Arico waste plant discards the ‘incineration’

The winning joint venture focuses its offer on the recycling and biomethanation processes, treatment operations by biodegradation of organic matter that, contrary to the other systems contemplated in the tender –pyrolysis, gasification and plasma–, do not use high temperatures, but rather a biological process that, in the absence of oxygen and over several stages in which microorganisms intervene, allows the most degradable fraction of organic matter to be transformed into biogasa mixture of gases formed mainly by methane and carbon dioxide and by others to a lesser extent.

Arico Green Gass will treat more than 90,000 tons per year of organic fraction from the mechanical treatment plant, 24,702 tons per year of sewage sludge and 14,100 tons per year of livestock waste, which adds up to 129,256 tons per year, an amount equivalent to the weight of two and a half boats like the Titanic.

This closes a public tender that began last year to award the management of a plant with which the Cabildo intends to provide “an industrial infrastructure” to the Tenerife Environmental Complex that “processes a quantity of garbage that is currently deposited in the dumping cells”, where all the waste that is not recycled ends up. “This tender has been endorsed three times by a study by the University of La Laguna and by two reports by technicians from the Service for Sustainable Development and the Fight Against Climate Change,” says the island Corporation in a statement.

Excess garbage without recycling

The Cabildo of Tenerife has resorted to this new plant to deal with the excess garbage that accumulates in Arico without being reused. The Cabildo exposes it in the documentation of the conditions of the contest. The Island Corporation itself ensures that of the 542,320 tons that the Environmental Complex treated in 2019, 226,756 came from domestic waste generated by the Tenerife municipalities. And of these 226,756 tons, 150,756 “are destined for disposal in the dumping cells”, 60%. “The purpose of the tender is precisely to promote the recovery of this waste in order to reduce the amount destined for disposal,” appears in the administrative specifications.

The controversy arose when the tender included three methods that, without being legally considered incineration, do use high-temperature treatments. They are pyrolysis, gasification and plasma, systems that are part of what is known as energy recovery. What is energy recovery? They are methods of decomposing garbage through chemical and electrical processes in which an energy yield is obtained. The energy is extracted from the heat generated by the treatment itself or from the resulting waste in its different forms: gas, liquid and solid. But not all of the waste creates energy, nor does all of the waste become fuel. A part is discarded.

heat in the absence of oxygen

These three methods are based on heat in the absence of oxygen (pyrolysis, with temperatures from 300 to 800 degrees), oxygen to destroy matter (gasification, with temperatures above 750 degrees) and an electric field (plasma process, with temperatures of 4,000 degrees and above). The latter, unlike the previous ones, allows the treatment of gases and hazardous waste. The winning company, however, discards these thermal treatments and opts for recycling and biomethanization, which is a biological process embedded in what is called material recovery, obtaining new materials or recycling part of them.

“There was never a cremation”

The president of the Cabildo de Tenerife, Pedro Martín, already indicated in January that in the reports that endorse this new plant in the Arico complex «it is clearly explained that in this tender there has never been room for incineration, because it is expressly excluded, leaving Of course, in addition, it complies with European regulations, with national legislation, with the regulations of the Autonomous Community and, of course, with the Waste Plan of the island of Tenerife».

The Minister for Sustainable Development and the Fight Against Climate Change, Javier Rodríguez Medina, pointed out that with the approval of this contract by the Governing Council, “Tenerife will take a step forward in waste management, because it is the beginning of change of model, obsolete and outdated that continues to function on the island, and that is clearly unsustainable ». The counselor pointed out that “after all the controversy generated from little contrasted and interested information, it has been possible to carry out the tender and thanks to this, more than 130,000 tons of waste per year will no longer be buried to obtain new resources.”