New mechanical-biological treatment plant Milà waste management area (Menorca)

The Milà Waste Management Area now has a new mechanical-biological treatment plant for waste management and recovery. The facility was inaugurated at the beginning of April on completion of the upgrading works carried out by the UTE Es Milà consortium, the concessionaire made up of PreZero España and Adalmo, along with a number of local companies.

The Consorci de Residus i Energia de Menorca’s new treatment plant will enable management of waste produced in Menorca, in both peak and off seasons. The plant upgrading project began in January 2019 and has been the subject of investment of over 20 million euro (including VAT). The upgraded plant will enable optimisation of organic matter treatment processes and enhance the separation of the different materials in the five waste fractions for subsequent recycling, thus minimising the quantity of waste sent to landfill.

The mechanical-biological treatment plant processes 50,000 tonnes of rest fraction waste per annum (35 tonnes per hour), from which more than 70% of the material is recovered for recycling or valorisation. The plant also processes more than 4,000 tonnes per annum of light packaging, with 90% of this waste being recovered for subsequent recycling.

The facility is designed to reduce reject sent to landfill to 30% of the rest fraction (mixed waste) and to 10% of the light packaging fraction.

During the first year of operation (2021), it was possible to achieve performance that exceeded the design parameters, with only around 26% of the waste entering the plant being sent to landfill, rather than the 30% initially estimated.

The facilities consist of the reception and feed-in area, an area for separation by size, density, colour and composition, an organic matter stabilisation and refining area and a compaction area for producing bales of the different types of recovered waste to be sent for valorisation.

The end result is the recovery and/or preparation for recycling of different types of waste, such as biostabilised waste, composite packaging materials, natural plastic, coloured plastic, PET, film, mixed plastic, metal containers, aluminium, tetrabriks, glass, paper and board.

A distinctive feature of the new plant is that it envisages the potential recovery of part of the waste as solid recovered fuel (SRF), which would reduce the percentage of waste sent to landfill.

Introduction

On April 6th, Menorca, declared a Biosphere Reserve in 1993, celebrated the inauguration of its new mechanical-biological treatment plant, located in the Milá Waste Management Area, a complex on the island which receives the domestic and commercial waste produced on the island, in addition to some of the industrial waste

The new plant replaces facilities that were over 25 years old. The upgraded plant has double the treatment area and features cutting-edge machinery and best available technologies to improve waste treatment and minimise the quantity of reject sent to landfill.

The new facilities are a key element in terms of achieving the recovery and disposal reduction targets set out in the Menorca Sectorial Master Plan for Non-Hazardous Waste Prevention and Management (2020-2026). This plan sets time milestones in line with those established in Balearic Islands Act 8/2019 on Waste and Contaminated Land, thereby clearly defining the roadmap for waste management in Menorca.

The facilities belong to the Consorci de Residus i Energia de Menorca, an entity formed by the eight municipalities of the island, along with the Menorca Island Council. The complex is operated by the UTE Es Milà consortium (PreZero – Adalmo) under the terms of a 25-year public service administrative concession agreement.

The works for the upgrading of the mechanical-biological treatment plant commenced in January 2019 and were carried out by the UTE E.ARQ and Lurgintza consortium, within the framework of the aforementioned concession agreement. These works included the demolition of practically all the existing facilities and the construction of a mixed line for separate treatment of the light packaging fraction and the rest fraction (mixed waste). The goal was to enable a waste recovery rate of over 70%, and to minimize the fraction sent to landfill in order to extend the service life of these materials.

The operating tests for the waste treatment plant began at the end of August 2020 for the purpose of making the adjustments required to achieve the plant performance targets. Treatment buildings 6 and 9, associated with organic waste reception and composting, were the subject of a project modification to enable complete renovation of these buildings. Due to this modification, execution of the work on these buildings was pending at the time and this work has now been completed.

The project had an overall budget of €16,674,284.32 (plus VAT) / €20,175,884.03 (including VAT), an investment envisaged in the Milà Waste Management Area concession agreement.

The new facility is an automated mixed type plant that allows the rest fraction (RF) and the light packaging fraction to be treated in the same line, but in different shifts. The mechanical material recovery processes are very similar for both types of waste, differing only at certain points of the line and basically in accordance with the characteristics of the recoverable materials.

The plant is designed with the following parameters:

– Input: 50,000 t/annum RF and 4,000 t/annum light packaging

– Capacity: 35 t/h RF and 4 t/h light packaging

– Total operating time: 1,681 h/annum RF and 1,324 h/annum light packaging

– Equipment availability (85%): 1,429 h/a RF and 1,125 h/a light packaging

– Recovered by-products: 7% RF and 75% light packaging

– Biostabilised material and/or compost: 45% RF and 100% OFMSW

– Solid Recovered Fuel: 17.33% RF and 15% light packaging

– Reject sent to controlled landfill: 30.67% RF and 10% LIGHT PACKAGING

The following is a description of the stages in the treatment process:

Published in: Nº 90 FuturENVIRO – May-June 2022