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Glass Recovering Revolution: High performance Optical Sorter for glass collection from Waste

Periodic Reporting for period 2 - SEEGLASS (Glass Recovering Revolution: High performance Optical Sorter for glass collection from Waste)

Reporting period: 2017-04-01 to 2018-01-31

The SEEGLASS technology represents a new, automated and innovative solution of glass recovery from municipal solid waste (MSW) being processed in mechanical and biological treatment (MBT) plants.
The SEEGLASS project is mainly composed of a new optical sorter and a process line where the new optical sorter is included at the end of the waste treatment process.
The SEEGLASS solution is the first of this kind in Europe, using a combination of mechanical sorting and machine vision technologies to separate glass waste (mainly containers glass waste) from household and commercial waste as well as from residues issued from the refining process of the compost.
The SEEGLASS project also includes the construction of a 800 sqm fully-equipped demonstration facility, located at the PICVISA premises in Calaf (Barcelona, Spain), where the glass sorting equipment is tested for a wide range of materials.
Glass is an ideal material for recycling and can be used repeatedly without any deterioration in its physical properties. Besides, the use of recycled glass to manufacture products results in a reduction in the use of energy and raw materials. In Europe, new legislative and fiscal drivers have contributed to increasing the desirability of recycling glass. However, although kerbside glass collection is a common practice in Europe, the glass content in the mixed household waste stream remains too high. Public efforts in communication and waste collection practices, during the last ten years, have shown their limitations when facing usual practices of the population who continue throwing out the glass waste with the commingled and organic streams.
In Europe, it has been observed that the glass waste which is mixed to the commingled stream remains steady around 5% to 7% of the commingled stream (in weight). This glass currently contaminates the recyclables and, in the case of a composting facility, it also contaminates the compost as output. In the cases of mechanical and biological treatment (MBT) processes, where the compost is screened, most of the glass waste finishes at the landfills.
The SEEGLASS project is in line with the environment action plans of the European Community, providing an effective new solution of glass recovery and residues reduction at the waste treatment and material recovery plants, maximising the glass recycling and reducing the amount of waste to be sent to landfills, while phasing-out landfilling and incineration to non-recyclable waste.

The work performed from the beginning of the SEEGLASS project until the end of the first half of the project (referred to the period covered by this report) may be summarised as follows:
1) Design and manufacturing of a new optical sorter (machine-vision equipment) that will be tested by the beginning of the second period of the project.
2) Design and construction of a fully-equipped process line where the new optical sorter will be integrated by the beginning of the second period of the project.
On the other hand, the first commissioning of the demonstration facility, which was built by PICVISA, has provided promising results for the final commissioning of the SEEGLASS solution (to be carried out with the new optical sorter at the end of the second and final period of this project).
Main results achieved so far are as follows:
a) A demonstration facility was constructed, and is being commissioned, for testing different sorts of wastes with a throughput up to 10 t/h.
b) The machine-vision solution (under commissioning phase) identifies glass as a target material to be withdrawn from a wide range of income streams of waste with a throughput up to 7 t/h.
c) Size control of the income stream and its particle stabilisation are successfully provided with mechanical treatments for a better singulation of particles before the material detection by the optical sorter.
d) The machine-vision sorting (currently under commissioning) may separate and purify glass and other recyclables issued from the waste being treated at mechanical and biological treatment (MBT) plants.
The SEEGLASS solution represents a new product in the existing market of mechanical and biological treatment (MBT) of municipal solid waste (MSW), but also represents a new product attempting to re-segment existing markets of waste treatment where the glass recovery did not represent a technical, economical or environmental concern.
As a new technical response, the expected potential impact of the SEEGLASS solution concerns firstly large amounts of recovered glass at the waste treatment plants and its subsequent valorisation.
At the same time, competition for raw materials has increased as a result of the rapid growth of emerging economies and the lack of natural resources. Containers’ glass is mostly constituted of silicate glass based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Formed by erosive processes over thousands of years, enormous amounts of sand are being extracted (close to rivers, quarrying areas) at a rate far greater than their renewal. Change of water flows, flood and impact on biodiversity are thus irreparable damages currently observed all over the world.
The SEEGLASS project provides new streams of reclaimed glass that otherwise would have not been recovered. Glass recycling provides for unmatched production efficiencies and significant environmental benefits, such as saves of raw materials (over a ton of natural resources are conserved for every ton of glass recycled), reductions of energy demands, cuts of greenhouse gas - CO2 emissions (for every six tons of recycled container glass used, a ton of carbon dioxide is reduced), reductions of emissions (particulates, nitrogen oxide, sulphur oxides), decreasing residues and by-products and furnace life extension of glass manufacturing.
Another important impact of this project is centred on the reduction of the waste being sent to landfills as far as glass and other small particles of recyclable materials are withdrawn from the waste streams which are currently sent to the landfills.
In fact, the SEEGLASS technology drives to valuable sub-products directly withdrawn from the municipal solid waste (MSW), such as small hard and light plastics and small metallic particles that can be recycled, as well as refuse derived fuel (RDF), which would have been otherwise landfilled.
Direct environmental impacts will be obtained by increasing recycling and reducing both landfilling and incineration. Socio-economic impacts and societal implications are also directly driven by the SEEGLASS solution, such as better environmental conditions having an impact in population health and wildlife (by reducing the exploitation of raw materials and CO2 emissions), better use of the public money in waste treatment plants by increasing their effectiveness and reducing the filling rate of landfills, creating new employment linked to this new solution, etc.
Progress beyond the state of the art may be assured as no similar solutions have been observed in the world. The SEEGLASS solution is completely automated, uses environment-friendly solutions (e.g. mechanical agitation, pneumatic sorting, machine-vision without X-rays), is easy to build (modular unit, fast installation, small footprint) an to operate (high precision computer control, conventional maintenance procedures), and provides high recovery rates of materials.