To analyze the prices of materials destined to recycling, was analyzed the market of the materials obtained from the selective and unselective waste collection, in Portuguese, Resíduo Seletivo (RS) and Resíduo Indiferenciado (RI), respectively. That prices are regulated by Sociedade Ponto Verde (SPV), namely: the ones categorized as Metal, Aluminum and Steel; the one categorized as Paper/Cardboard, just Paper/Cardboard was taken into account; PET, PEAD, Plastic Film, EPS, and Mixed Plastics go under the Plastic umbruela; finally, the Glass category, which only has one material.
Each one of the above mentioned materials, which are sorted on each Urban Waste Management Plant, in portuguese, Sistema de Gestão de Resíduos Urbanos (SGRU), are auctioned on a three month period basis, apart from a few exceptions that will be discussed later.
In this auction, there are three participants: the SPV, who has the role of regulating and, for that research needs, of attributing for each material a Base Value (EUR per ton) for each SGRU seller; the SGRU, who has the responsibility to give an estimate of the total amount it will be collected in the time period that the auction refers to; the buyer, who bids for the collection of the sorted waste.
The information regarding to the auctions can be get on the auctions’
annoucement of each material aforementioned. That research’s sample corresponds to what was sold by Tratolixo along the period between jannuary 2018 and June 2020. Some caveauts before proceding to the financial assessment:
• first, some materials are not retreived from unselective waste and, therefore, are just sold in the selective waste market;
• second, in the case of glass, the auction period changed from an trimestral basis to an annual basis;
• third, in some instances, for example paper, there can be different auctions depending on the typology of the material that is being sold (i.e. how pure is the selling lot);
• forth, the given Base Value assumes that the transport costs of the sold materials are taken by the buyer (as it’s stated on each auction announcement);
• fifth, the total amount of material recollected by the SGRU, as long it falls under the technical specifications required for such material, must and will be sold and restrived, according chapter 3, section 1, article 5, point a of Despacho n.º 14202-E/2016 (“Despacho n.º 14202-E/2016”, 2016/Nov.).
All the above information is acessible at the Sociedade Ponto Verde (SOCIEDADE PONTO VERDE, 2020a) for the categories: metal (category 2), paper (category 3), Plastic (category 4) and Glass (category 5). With the data available on that website was possible to construct the tables bellow
After the collection of all this data, it was possible to compare the base prices of the materials that were gathered the waste either collected from RS or RI and see if there’s a key difference between them. A glaring conclusion that can be reckoned is that the materials that come from RI tend to be sold for a lower price than the material coming from RS, as can be illustrated on the following graphs.
Graphic 9 – Base value for pet.
The authors.
Graphic 10 – Base value for PEAD.
The authors.
Graphic 11 – Base value for Wrap
The authors.
Graphic 12 – Base value for paper
The authors.
Graphic 13 – Base value for steel
The authors.
The missing graphs correspond to the materials that were studied and that come from both of the types of collection. With this information, it is possible also calculated the averages prices of each auction of 2019 per type of material. This allows to draw an estimative of the revenue of the screening facilities, given that the total amount of materials sold by each SGRU is publicly available (SOCIEDADE PONTO VERDE, 2020b).
The BitBin project aims to make Waste Management more efficient and, in particular, can allocate the waste that comes from RI to RS, making that materials more valuable. Since in the report above the amounts of materials sold are discriminated by source, RS and TMB (RS), it’s possible to calculate the current revenue and the potential revenue if this solution were to be implemented.
6 BitBin: improving waste quality
By using blockchain technology, our project intends to bring together citizens, the private waste management sector and the public sector to work together with the aim to improve better sorting of urban waste by rewarding citizens, in digital tokens called IBI coins, for good waste sorting habits.
Blockchain is an important tool in achieving this goal as it serves as a way to connect all the intended stakeholders through the use of nodes and digital wallets in a transparent and secure way, bringing trust and power to citizens while the private and public sector improve their public image and work towards sustainable goals.
There are many types of Blockchain available, however, after researching the options, a hard fork Ethereum and its smart contracts demonstrated to be a good starting point for a proof of concept of our project. Eventually, due to our focus on minimizing the costs of implementation and scalability, we realized that using Ethereum’s smart contracts would open the field for third party contracts to be run in our network. This would eventually create a competition for the nodes’ processing power.
While developing our forked Ethereum network, another network was being developed using the recent, however, proven framework called Substrate which allows for a fast development of a deeply configurable blockchain network while providing functionalities to connect with other blockchain such as Bitcoin or Ethereum through the Polkadot platform.
In our forked Ethereum network, the logic and reward system of our project would be implemented through smart contracts. However, they have been proven to be less effective than the capabilities the Substrate framework provides us. In the future, the logic will be embedded in our blockchain through lower level configurations called pallets and our reward system will work as a separate network (parachain) in an attempt to spread the workload and alleviate the number of transactions in the main chain which will process all the non-monetary transactions.
Through these implementations and improvements we plan to have two blockchains (system logic transactions network and monetary transactions network) configured using Substrate and running in parallel over the Polkadot platform.
Eventually, our blockchain will be connected to a web platform where the public sector will be able to check statistics of the system and citizens will be able to interact with the blockchain through the use of a dApp mobile application.