Extracting tons of glass shards from mixed waste

We share an article about glass waste sorting, published on the “Delfi” portal. It was prepared in collaboration with the packaging waste management organization “Žaliasis taškas.” Glass is one of the most problematic wastes. Although it is not harmful to the environment, failing to extract it from the general waste stream results in the loss of valuable raw material and increases landfill volume.

Mixed waste is also sorted

The director of Zaliasis taskas, Almontas Kybartas, says that packaging waste thrown into mixed municipal waste containers becomes a headache for producer and importer organizations aiming for maximum packaging waste collection and recycling. The good news is that all mixed waste first goes to Mechanical Biological Treatment (MBT) facilities, where it is sorted. This process aims to separate packaging suitable for recycling or other reusable materials.

The spokesperson regrets that, so far, only a relatively small percentage of packaging in mixed waste can be separated.

“We are responsible for the proper management of packaging waste. In Lithuania, most packaging waste is collected through the container waste sorting system, but many recyclable packages still end up in the mixed municipal waste stream. Separating packaging from this stream is challenging because they are mixed with other household waste, and separated packages need to be sorted further by material and recycling possibilities. Thus, it involves twice the work, making the process complicated and often problematic. Consequently, only a portion of packaging found in mixed municipal waste containers is separated and recycled, while the rest is incinerated or used to produce a special SRF product utilized by the industry in cement production,” explains the head of Zaliasis taskas, expressing regret that many people still have a lax attitude towards sorting.

According to Kybartas, one of the biggest problems is glass thrown into mixed waste. “Glass containers break in the municipal waste containers, making it very difficult to extract glass shards from the entire mixed waste mass. If plastic cannot be collected, it is incinerated or used in further production, but glass cannot be incinerated and becomes a burden on the entire system. Meanwhile, glass separated from the general stream is an excellent material that can be recycled indefinitely, returning to the cycle as raw material for packaging repeatedly,” he explains.

However, the latest technological solutions can address this problem – it is possible to extract glass shards from the mixed waste stream if they are larger than one centimetre. Zaliasis taskas and UAB Energesman, responsible for sorting and processing mixed waste in the Vilnius region, plan to implement such an ambitious project.

“We hope for smooth cooperation: our expectation is that the new equipment will start operating next year, enabling us to ensure a greater amount of glass packaging collection and management for our clients,” anticipates Kybartas.

More glass could be collected

UAB Energesman director Algirdas Blazgys says that the current glass packaging collection levels do not meet the needs of producers and importers.

“Lithuania has set goals to reduce the amount of waste going to landfills. It is hoped that someday they will be closed entirely. However, the current capacities for recycling raw materials, producing new products from waste, and waste incineration are not sufficient to completely abandon landfills,” he explains.

The Energesman director says that today it is essential to sort as much waste as possible, both by properly distributing it and extracting it from the mixed waste stream using Mechanical Biological Treatment (MBT) facilities.

In Lithuania, there are ten such facilities serving different regions. Energesman operates the Vilnius region waste sorting plant (MBT).

“About 220 thousand tons of mixed municipal waste come to us annually, from which we extract about 4-5 thousand tonnes of glass. However, ongoing morphological studies (where waste is carefully hand-sorted to determine its composition) show that a lot of glass remains,” explains Blazgys.

He estimates that up to 13 thousand tons of glass might be in the waste, of which about 6-7 thousand tons could still be collected.

“Of course, these are very approximate figures because the waste composition varies even depending on the season. However, it is clear that not all glass is currently being collected,” he states.

According to him, the biggest problem is the shards that cannot be collected. “Many glass shards appear not only because broken glass is thrown away but also because glass packaging breaks when it is thrown or transported,” he says.

The situation should change next year

Blazgys explains that while searching for solutions to increase glass collection from mixed waste, they had to explore practices in other countries, attend various exhibitions, and analyze applied innovations:

“We conducted experiments with our waste samples at a waste management plant in Spain and found that using a specific set of equipment, it is possible to achieve up to 98.82% extraction of glass shards from the general waste stream. We decided this was a very suitable solution for us.”

He is pleased that an agreement was reached for cooperation with Zaliasis taskas, a packaging waste management organization established by producers and importers, ensuring and financing the collection and proper management of packaging waste from the mixed municipal waste stream.

“We received funding and ordered the equipment, which we hope to install at the beginning of next year. We will provide Zaliasis taskas with the collected glass next year,” says Blazgys about the mutually beneficial cooperation.

He promises a breakthrough in glass raw material sorting: “If glass shards are larger than one centimetre, we will be able to extract them from the entire mixed waste stream using the new equipment. Currently, we extract 77% of all glass sorted from the mixed municipal waste stream in all Lithuanian sorting facilities.”

According to the Environmental Protection Agency, last year Energesman extracted 4239 tons of glass from the total of 5494 tons of glass sorted in the country, making up 77%.

“If the other nine MBT/MA centres do not change anything, by implementing the new equipment, we will collect over 90% of glass separated from the mixed waste stream nationwide,” says Blazgys.

Blazgys is also pleased with another technological innovation: “The new equipment will not only extract glass from mixed waste but also sort the extracted glass shards by color and size.”

The head of UAB Energesman emphasizes the impact of technological innovations and the expanding cooperation opportunities.

“Previously, the glass we collected went to Poland for recycling, but now it will stay in Lithuania. We have renewed our cooperation with Kauno stiklas, which uses our raw material to produce glass containers,” he explains the practical application of circular economy principles.