Daniel Rolph Schneider

Biofuels from waste

In recent years a number of issues prompted increased use of waste as a source of fuel (recovery of energy) or material (recycling). Societal challenges such as waste management, climate change, and environmental concerns regarding pollution and human health as well as diminishing fossil resources represent some of the most important issues to be tackled by our civilization now and in the (near) future. Exploiting waste, as often unwanted and always locally available substance, offers itself as a way to at least partially alleviate these issues. Many countries have realized the importance of treating waste as a resource and have set regulations that help give a ‘second life’ to waste. For example, the EU imposed a gradual phase out on landfilling of biodegradable waste and defined a share of the municipal solid waste that should be recycled ; there is legislation on limiting methane emissions from landfills and a number of other regulations and schemes regarding waste that are aimed at reducing pollution and emission of greenhouse gases (GHGs).

Utilization of biogas produced by anaerobic digestion of agro-industrial waste: energy, economic and environmental effects.

Anaerobic digestion of agro-industrial waste is of significant interest in order to facilitate a sustainable development of energy supply. Using of material and energy potentials of agro-industrial waste, in the framework of technical, economic, and ecological possibilities, contributes in increasing the share of energy generated from renewable energy sources. The paper deals with the benefits arising from the utilization of biogas produced by co-digestion of whey and cow manure. The advantages of this process are the profitability of the plant and the convenience in realizing an anaerobic digestion plant to produce biogas that is enabled by the benefits from the sale of electric energy at favorable prices. Economic aspects are related to the capital cost (€ 2,250,000) of anaerobic digestion treatment in a biogas plant with a 300 kW power and 510 kW heating unit in a medium size farm (450 livestock units). Considering the optimum biogas yield of 20.7 dm3 kg−1 of wet substrate and methane content in the biogas obtained of 79%, the anaerobic process results in a daily methane production of 2,500 kg, with the maximum power generation of 2,160,000 kWh y−1 and heat generation of 2,400,000 kWh y−1. The net present value (NPV), internal rate of return (IRR) and payback period for implementation of profitable anaerobic digestion process is evaluated. Ecological aspects related to carbon dioxide (CO2) and methane (CH4) emission reduction are assessed.

Municipal solid waste system analysis through energy consumption and return approach

Inappropriate waste management and poor resource efficiency are two of the biggest problems which European Union is trying to solve through Landfill Directive, Waste Framework Directive and Circular Economy Package by increasing recycling and reuse and reducing waste disposal. In order to meet set goals, new European Union member states must quickly change national legislature and implement appropriate solutions. In the circumstances of strong EU resource and energy dependence, decision makers need to analyse which of the considered waste management systems leads to higher overall benefits ie. which is more sustainable. The main problem in this kind of analysis is a wide range of possible technologies and the difference in inputs and outputs. Sustainability of these systems is analysed through single-score LCA based assessment, using primary energy used to produce materials and energy vectors as a common measure. To ensure reliable results, interoperability between different data sources and material flows of waste and its components are monitored. Tracking external and internal material, and energy flows enable modelling of mutual interactions between different facilities. Resulting PERI, primary energy return based index, is used for comparison of different waste management scenarios. Results show that time and legislation dependent changes have great influence on decision making related to waste management and interconnected systems.

Influence of legislative conditioned changes in waste management on economic viability of MSW-fuelled district heating system: Case study

District heating systems represents one of the ways by which the European Union is trying to reach set goals in energy efficiency and security field. These systems allow the use of different energy sources including local energy sources such as waste and biomass. This paper provides economic viability assessment of using these fuels in the district heating system. Economic evaluation is based on regression analysis from data of existing plants and on the locally dependent data. Some of parameters that are dependent of local parameters are price and available fuel quantity, therefore these values are separately modelled; biomass as a function of location of the plant while municipal waste as a function of location and the time changes in waste quantity and composition which depend of socio-economic trends and legislation. This methodology is applied on the case of district heating plants in the City of Zagreb where internal rates of return are calculated for four considered scenarios. Results indicate that waste powered plant can improve its profitability by co-combusting other local wastes while economic viability is achieved by introduction of region wide waste management system. Reducing plant capacity, based on prognosis of waste generation, showed that these plants can be competitive with biomass plants.

Analysis of a sustainable system for energy recovery from municipal waste in Croatia

Purpose – This paper seeks to focus on energy recovery from municipal solid waste (MSW) in Croatia. The state strategy is based on the mechanical and biological treatment of waste in the future waste management centers (WMC). Left over after the treatment is waste that can be used as fuel (e.g. RDF).Design/methodology/approach – Starting from the geographical distribution of waste generation (quantities and transport distances), taking into account the costs of collection, transfer and thermal treatment, recommendations on optimal number and size of the dedicated waste‐to‐energy (WtE) plants in Croatia as well as their potential locations are given. The opportunity of the cement industry to utilize ash from thermal treatment of waste in the process of the cement production and the RDF as a substitute fuel is also examined.Findings – By varying the number of WMCs, the minimal specific cost of waste collection of €33 is obtained, for maximal number of WMCs, which is 21. The optimal capacity of WtE facility ...

What is the right level of recycling of plastic waste

One of the main objectives in waste management is the recycling of waste and thereby making use of resources contained in waste to save primary resources and reduce the environmental impact of all activities involved in making primary resources available for the production of goods. Enabling recycling starts with (1) design of products for recyclability, (2) collecting the end-of use material (often called waste), (3) processing the waste in order to get intermediate secondary materials that can substitute primary materials, and finally (4) the actual utilisation of these secondary resources to produce new products. Depending on the material to be recycled and type of waste looked at as well as the prevailing structures of waste management in different parts of the world, the processes involved and opportunities at hand differ very much and need a comprehensive understanding of the situation to enable optimisation of a system that answers the question posed in this article’s title. This special issue of Waste Management & Research focuses on plastic waste and this is one waste stream that warrants further study. It is paramount that all feasible measures need to be taken in order to avoid plastic waste entering the environment and end up as marine litter (Velis, 2014) and cause all the unwanted detrimental effects to the ecosystems without using the resource potential. As pointed out in Rujnić-Sokele and Pilipović (2017) bio-based plastics might improve the situation, but could also even worsen it as ‘bio-based’ does not necessarily mean ‘biodegradable’. So getting hold of the plastic waste once it is generated needs to be the first focus. Furthermore, resources should be recovered to the highest possible extent. Plastic is a material with a very wide range of applications in short-lived as well as long-lived products. Furthermore, besides raw oil being the major constituent, many additives and fillers, and for example reinforcing fibres, are used to optimise the material properties of plastic products. These substances may allow minimising production costs and optimising plastic properties for the use-phase, but also pose challenges for the end-of-life phase, especially when it comes to recycling. Most of the time recyclability is not yet a major driver for product design and this results in technical constraints regarding the recycling either owing to the practical feasibility of processing the plastic waste in such a way that marketable recyclables can be produced, or owing to the costs involved in the processing. However, what is the right level of recycling of plastic waste and when should energy rather than material recovery be the desired option? Answering this question does not only include a technical dimension, but also economic, ecological, organisational, and social considerations. Looking at the technical dimension it becomes clear that the technical viability not only depends on the technical feasibility as a matter of the product design and the state-of-the-art of processing technology. It also very much depends on financial issues determining the processing equipment that can be applied. Technical viability therefore, is very closely linked to financial boundary conditions that are addressed below. Although technical solutions are often the core of recycling systems, it must be kept in mind that any technical process involves losses, i.e. the quantity of usable output is typically reduced for the sake of minimising impurities and improving the quality of the resulting product, as discussed by Feil et al. (2017). Higher quality output streams allow for higher valued use of the recyclates and, therefore, oftentimes also go along with higher prices for these output products. The additional financial effort in processing must be offset by higher revenues at the end in order to make sense from an economic point of view. There are also other limitations to technology. For example, lead, cadmium, and other additives used as stabilisers for polyvinyl chloride (PVC) cannot be removed from this type of plastic. In order to avoid negative health effects associated with these types of contaminants one needs to (1) eliminate the use of deleterious additives to plastics as a means to improve the quality of subsequent plastic wastes, (2) design the waste collection schemes accordingly in order to exclude problematic wastes from the recycling stream to improve the quality of current plastic waste, (3) optimise technical processes for recycling to remove contaminants at least indirectly, for example by removing the polymer PVC potentially containing lead and cadmium as contaminants (see Pieber et al., 2012), and (4) match the type of recycled plastics to specific uses (and reuses) that can tolerate feedstocks with known chemical constituents. High-valued applications for recyclables, such as for packaging in the food and beverage sector, demand a much higher quality secondary plastic than, for example, the use of polymers in bulk applications; e.g. pallets and crates. Even when considering only technical aspects of plastic recycling, we see that recycling quotas cannot be discussed independently from the quality of recyclables. On the one hand there is a point when recycling quotas can only be increased to the detriment of the quality of the recyclates produced; on the other hand, if we are able to produce recyclate of the different qualities demanded by specific applications of recycled plastics, and if we successfully direct the various recyclate qualities to the appropriate applications, we might be able to maximise overall recycling rates. Furthermore, there must be a common understanding of what is to be considered recycled in that context. From the natural science point of view, recycling involves the actual substitution of primary resources by recirculation of secondary resources gained from waste. For plastic waste this most often needs several What is the right level of recycling of plastic waste? 687928WMR0010.1177/0734242X16687928Waste Management & ResearchEditorial editorial2016

Impacts and limitations of recycling

The availability of goods as a consequence of an existing demand and thereby the level of consumption and the consumption behaviour of people is one of the main distinctions with relevance from the waste sector’s perspective for differentiating highly developed from less developed societies. Apart from any regulatory pressure recycling has a high priority in less developed societies as a consequence of scarcity of resources, potential revenues from secondary material and availability of work- force at low costs for collection and handling of waste. In highly prospering societies the boundary conditions and motivations are different to that. Many times recycling is mainly driven by legal stipulations. The most prominent legal basis has been laid down by the waste hierarchy defined in the EU Waste Framework Directive. Right after waste avoidance and re-use recycling has to be considered prior to other ways of recovery and disposal.

GHG reduction potential in waste management in Croatia

Purpose – The purpose of this paper is to examine a greenhouse gas (GHG) emission reduction potential from different waste management practices in Croatia. Energetic, environmental and economic benefits can be accomplished by utilizing municipal solid waste (MSW) and landfill gas as fuel in industry and energy sector, which is emphasized in this paper. The paper gives an overview of measures for energy recovery from MSW and landfill gas that could be implemented in Croatia. These measures also represent measures for an additional GHG emission reduction by decreased use of fossil fuels.Design/methodology/approach – A methodology used for emission calculation (kinetic model) is explained. Three different scenarios of GHG reduction in waste management were defined. Implementation of best available techniques in waste management is envisaged by cross‐sectoral impact and effect of respective measures. Findings –This paper gives maximum achievable potential of GHG emission reduction with defined measure impleme...

Recycling and incineration, contradiction or coexistence?

Many times when discussing the implementation and optimisation of municipal solid waste (MSW) management in countries and regions all over the world, one faces arguments like ‘the proposed technological and organisational solutions are too expensive’, or ‘incineration of waste kills recycling and is detrimental to the human health’, and so on. These arguments reflect a black-and-white thinking and a partial view of the situation, and overlook technological advances during the last decades, as well as the globalisation of waste management and its changing role in becoming a resource-supplying sector.