If the waste law and policy determine the waste management goals, which must be taken into account while preparing a construction or a modernization of a sorting plant, and the market creates the conditions of actions, then technology is a tool, on which the burden of actually achieving the goals is focused on. The real, daily, ecological and economic effects depend on technology.
The importance of technology
Technology is the subject of an investment, which means that it is the thing decided in the process of building or modernizing a sorting plant. The importance of such an investment is not only the incurred cost, but also the time spent on preparing the project and the time during which the technology will be exploited. It is also the space, the place subordinated and adapted to the technology; the land use that was once made will be difficult to change and will impact further functioning and possible future investment. In the long run, the technology determines the effects of ecological goals achieved (balance of recovered products and process residues), as well as economic outcomes.
The formation and selection of technology combines all the factors discussed so far: connected to the law and the waste management policy conditions, economic, market and these specific for an entity. A formation of technology begins at the stage of specifying the purpose of an investment, which results from the existing state, studies of waste streams, their morphology, technological and economic analysis. The next step is creating a technological concept, and after receiving the required decisions and permits – designing a project and implementing a technological line. The preparation stage determines the success of the investment.
A modernization of a sorting plant. The two aspects: technological and technical
Speaking of technology, attention should be paid to the two aspects: technological and technical. The technological aspect concerns technological solutions, that is, a variety of possibilities or variants of sorting, but above all the technological process – which is a sequence of sorting stages with a usage of proper techniques. The technological process is fundamental for an efficient sorting process. The quality and flexibility of technological solutions determine the ecological and economic effects and the level of these effects. The second aspect concerns technical solutions, that is, the design and production quality of each device, technological equipment of a sorting line (for instance: a conveyor system, a screening system, a separator set, sorting cabins, installations), supporting and platform structure that facilitates access to and service of devices.
It should be noted that the quality of devices and the entire installation determines a sorting line’s service life. Over the time of its operation, the initial construction and technological development costs become less significant. Consequently, the technology’s quality and the durability of technical solutions take precedence. If the technology enables achieving great results, the technical quality is crucial for sustaining these outcomes. An example: two lines in two different plants were put into operation 12 years ago. Currently, in both plants a modernization investment is being implemented. In the first plant, the investment involves dismantling the existing line, due to its technological maladjustment to current conditions and the exploitation of devices. In turn, in the second plant the twelve-years-old line will be retrofitted and expanded with additional devices, because the technological solutions, despite the passage of time, are still proper, and the condition of devices, which results from, among others, their quality, is still great. Such situations are currently common in Poland.
For both technological and technical aspects, the reliability of actions is crucial. The certitude arises from: applying proven solutions, coupled with experience and practically acquired knowledge. The certitude significantly increases the probability of obtaining the desired outcomes.
Achieving process goals is the task of technology
The task of technology is to achieve process goals. For instance, in the case of mixed waste, the technology will pursue separating a fine, biodegradable fraction. A medium over-sieve fraction will be subjected to raw material separation processes. The residues will be transformed into fuel for thermal use. However, the further treatment, separating raw material fractions on the line or transferring them to another installation for separation, depends on the conditions of a given plant. Of course, the scale, i.e. the size of the mixed waste stream for sorting, will have an impact on the technological system.
The specificity of selectively collected waste is different from the specificity of mixed waste. Mixed waste contains far less sub-sieve fraction and much more raw materials, and is also characterized by significantly lower density. The problems with manual sorting are: a limited throughput, a necessity to employ a lot of workers in order to recover most of raw materials. The purpose of the process will be to separate a fine fraction, constituting contamination of raw materials. It will be also important to separate plastics from other materials, separating paper, of which a big amount can usually be found in a waste stream. Moreover, the purpose will also be to separate ferrous and non-ferrous metals, sort and clean plastic raw material fractions, and prepare a high-calorie residue for further treatment. Specific solutions depend on individual conditions such as the size of a waste stream, spatial conditions, and so on.
Looking at the technology from the point of view of required, constantly increasing, levels of recovery, it will be essential to implement solutions focused on maximizing the level of recovered raw material fractions.
Modernization of sorting plants and the introduction of the deposit system and EPR.
The deposit system will cause a change in waste’s morphology, mainly in the stream of selectively collected waste. The mixed waste stream, due to its specificity, will not be so vulnerable to the introduced change. The change in morphology of selectively collected waste will force a different look at the sorting process. The distribution of materials in the process will change, and it will be essential to focus on material fractions other than PET and aluminum cans. The downsides of the deposit system, resulting from a decrease of PET and aluminum cans in the stream, will be felt by installations processing plastics. The effects will be felt the most in simple, manual installations, in which the sorting process is oriented around separating PET and aluminum cans. It is high time that owners of such installations prepared their businesses and installations to effectively separate additional materials.
With the context given, our considerations go back to the Extended Producer Responsibility (EPR). Depending on the adopted solutions, EPR may save installations, give them a chance to revive, modernize and evolve, or be a proverbial “nail in the coffin”. If EPR subsides are given to installations, then, at the appropriate amount of the support, the subsidies will motivate to invest in, expand, modernize or build installations oriented around sorting selectively collected waste. In such a case, they will incentivize the maximization of raw material recovery rates, as every additional ton will generate financial rewards. This is especially important when we realize that the market is volatile, which, due to increases and decreases of raw materials prices, might lead to a periodic destabilization. The EPR subsidy should be a factor that stabilizes the market. Such a mechanism will benefit not only the installations but also lead to the development of technological infrastructure, which is currently in short supply, through investments made by more willing owners. As a result, the entire system will pursue achieving higher and higher recovery levels, which means it will meet the legal requirements. Unless the funds will be given to installations, the whole mechanism focused on investments and achieving goals will not be able to exist. Investments’ profitability will decrease, the entities will be less likely to modernize or construct plants. Guided by economic calculations, they will limit their investments, and municipalities will be left with the problem of unreached recovery levels. In consequence, there will be an increase in municipal burdens associated with achieving recovery levels, the construction and maintenance of technological installations.
EPR subsidies given to installations bring back profitability and motivate
Technological and economic analysis in this area were conducted, among others, for the Czech market. After taking into account a variety of conditions regarding the effectiveness of projects in the field of construction or modernization of plastic waste sorting plants, the conclusion resulting from the analysis was as follows: the deposit system causes a decrease in an investment’s efficiency. However, the inclusion of EPR subsidies completely changes the situation. If the subsidies are given to installations, they bring back profitability, motivate to get, during the technological process, every additional raw materials ton contained in the waste stream, encourage to invest in recovery and preparing waste for recycling. Importantly, the Czech ministry responsible for waste treatment is aware of the mechanism and uses it. As a result, a lot of Czech entities are preparing for investments. This is additionally supported, as the private owners may also receive a subsidy for an investment. These two mechanisms (EPR subsidies given to installations and the subsidies available for private entities) give the Czech Republic a chance to quickly build technological infrastructure for yellow-sack waste (plastics). Importantly, this will happen with a limitation on the need for public funds, thanks to the involvement of the private sector.
Towards efficiency
The analysis conducted in the article (in this and previously published parts) has made it possible to identify the factors influencing the direction of sorting plant modernization. It is time to focus on the criterion that will serve to assess and select the appropriate direction of sorting plant modernization. Such a criterion is the efficiency of the project. It is an economic category and is defined as the ratio of real effects in the dimensions: social (response to real needs), environmental (ensuring expected recovery levels) and economic (ensuring high economic effects of the sorting process) to investment costs.
Given that, efficiency is a relative category and depends on the entity to which it applies (what is effective for one entity may not be effective for another), it is not possible to indicate one correct model for the implementation, adaptation or modernization of the waste-sorting technological infrastructure, i.e. for carrying out an investment.
Six dimensions, one vision: an efficient sorting plant.
A correctly defined efficiency is therefore crucial – it allows for the practical setting of investment goals and directions. It also enables the assessment of a project before incurring investment costs (ex ante assessment) and the making of such an assessment after the completion of the project and the commencement of operation (ex post assessment). However, the possibility of achieving broadly understood efficiency in the environmental, economic and social dimensions (for infrastructure investments in the construction or modernization of waste sorting technology lines) is determined by technological efficiency in six dimensions. These are:
1. Multifunctionality and specialization of a line.
The fundamental condition of technological efficiency is a line adjusted to the needs, to both: the type of waste, for which the line is for, and its amount. Depending on the individual conditions and the size of a waste stream, a line should be more or less specialized. For instance, if a plant receives different, small-sized waste streams, then the multifunctionality of a line, understood as the ability to process different types of waste, will be its advantage. However, if the sizes of waste streams are bigger, then it is justified to direct mixed waste to one installation, and plastics to another that is properly configurated. In such a case specialization of a line will be its strength.
2. Sorting plant’s throughput.
The throughput is another efficiency factor. As a general rule, higher throughput contributes to efficiency, provided that the installation is not oversized relative to the size of the streams that can be directed to it. This is due to the law of scale, according to which an investment cost in every additional ton sorted per hour decreases, as the efficiency increases. It enables to generate higher revenues as, among others, unit profits from processing the next ton of waste increase.
3. The recovery rate.
A higher recovery level of raw material fractions, measured by the proportion of recovered raw material fractions from the processed waste stream, results in a higher efficiency of the sorting process. The recovery level translates into economic benefits: it enables revenue generation from the sale of recyclable materials on the market, obtaining income for DPR (document confirming the recycling), , and savings from avoiding the cost of disposing of the calorific fraction.
4. The number of sorted raw material fractions.
The greater the number of separated raw material fractions, the more efficient the sorting process. Better sorting of raw material fractions by material type and color allows for the preparation of higher-value products and the achievement of better selling prices for raw materials on the market.
5. The quality of workmanship is decisive for the lifespan of the installation.
The cumulative effects over the operating period of the installation can be defined as the product of: the level of average annual effects and the time (years) of achieving such effects. The durability and lifespan of the equipment and the facility are influenced by factors such as construction quality, ongoing maintenance, and operation.
6. Possibilities of further expansion.
Depending on the foreseeable future (legal, market, and individual conditions), the potential for expanding the technological line, planned already at the concept and design stage, allows for better adaptation to future needs and appropriate adjustment of performance parameters.
An efficient sorting line is the one that provides not only an adequate throughput, or an appropriate recovery level, or only proper sorting. The technological efficiency of a line depends on every single one of its dimensions and must meet a total of the six conditions: be appropriately adjusted to the needs, have an adequate throughput, meet the recovery requirements, meet the requirements for separating raw materials, be of high quality, have a possibility to expand, that is, adapt to future, changing conditions.
The modernization of municipal waste sorting plants – a few words of summary
Efficiency is a relative concept, dependent on the entity to which it refers and the adopted reference criteria. It is an economic category and states that there are no effects without inputs. On the other hand, inputs must yield outputs. The technological efficiency of an installation is determined by its technological efficiency, which is expressed in the six dimensions specified above. However, an efficient installation must also take into account the legal, economic, market, and individual conditions for a given entity, as discussed in the previous two parts of the series.
Many conclusions can be drawn from this article. However, the most important seems to be that it is up to the regulatory authorities, who shape the conditions for the operation of the waste processing system, to create a well-designed, effective, and coherent legal system and market mechanisms. The achievement of waste management goals at the national level will depend on this, and in practice, it will be carried out by entities in the real economy, i.e., waste processing plants.
In turn, waste processing entities, when determining the direction of modernization of municipal waste sorting plants (or their construction), should take into account the conditions of their operation, i.e., legal regulations, as well as market, technological, and individual conditions. In decisions related to the construction or modernization of sorting plants, a guideline may be the six factors determining technological efficiency specified in the article.
