Areas on which to focus when seeking to reduce the greenhouse gas emissions of commercial waste management. A case study of a hypermarket, Finland.

This study focuses on commercial waste, which has received less attention than household waste in regards to greenhouse gas emission research. First, the global warming potential (GWP) of commercial waste management was calculated. Second, the impacts of different waste fractions and the processes of waste management were recognised. Third, the key areas on which to focus when aiming to reduce the greenhouse gas emissions of commercial waste management were determined. This study was conducted on the waste generated by a real hypermarket in South-East Finland and included eight different waste fractions. The waste treatment plants were selected based on the actual situation. Three different scenarios were employed to evaluate the environmental impact of managing mixed waste: landfilling, combustion and more accurate source separation. The GaBi software and impact assessment methodology CML 2001 were used to perform a life cycle assessment of the environmental impacts associated with the waste management. The results indicated that the total GWP of commercial waste management could be reduced by 93% by directing the mixed waste to combustion instead of landfill. A further 5% GWP reduction could be achieved by more accurate source separation of the mixed waste. Utilisation of energy waste had the most significant influence (41-52%) on the total GWP (-880 to -860 kgCO2-eq./t), followed by landfilling of mixed waste (influence 15-23% on the total GWP, 430 kgCO2-eq./t), recycling polyethylene (PE) plastic (influence 18-21% on the total GWP, -1800 kgCO2-eq./t) and recycling cardboard (influence 11-13% on the total GWP, 51 kgCO2-eq./t). A key focus should be placed on treatment processes and substitutions, especially in terms of substitutions of energy waste and PE plastic. This study also clarified the importance of sorting PE plastic, even though the share of this waste fraction was not substantial. The results of this paper were compared to those of previous studies. The output of this analysis indicated that the total GWP can be significantly reduced by identifying an alternative recycling or incineration location for cardboard where it is used to substitute virgin material or replace fossil fuels respectively. In conclusion, it is essential to note that waste management companies have a notable influence on the emissions of commercial waste management because they choose the places at which the waste fractions are treated and utilised.

Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland.

How should greenhouse gas emissions be taken into account in the decision making of municipal solid waste management procurements? A case study of the South Karelia region, Finland.

The ongoing trend in the public sector is to make more sustainable procurements by taking into account the impacts throughout the entire life cycle of the procurement. Despite the trend, the only deciding factor can still be the total costs. This article answers the question of how greenhouse gas (GHG) emissions should be taken into account in municipal solid waste (MSW) management when selecting an incineration plant for source separated mixed MSW. The aim is to guide the decision making of MSW management towards more environmentally friendly procurements. The study was carried out by calculating the global warming potentials (GWPs) and costs of mixed MSW management by using the waste composition from a case area in Finland. Scenarios of landfilling and combustion in three actual waste incineration plants were used to recognise the main processes that affect the results. GWP results show that the combustion of mixed MSW is a better alternative than landfilling the waste. The GHG results from combustion are greatly affected by emissions from the combustion and substituted energy production. The significance of collection and transportation is higher from the costs' perspective than from the point of view of GHG emissions. The main costs, in addition to collection and transportation costs, result from the energy utilization or landfilling of mixed MSW. When tenders are invited for the incineration location of mixed MSW, the main focus should be: What are the annual electricity and heat recovery efficiencies and which are the substituted fuels in the area? In addition, in the case of a fluidized bed combustor it is crucial to know the combusted share of mixed MSW after preparing solid recovered fuel (SRF) and the treatment of rejects. The environmental criteria for the waste incineration plant procurements should be made in order to obtain clear instructions for the procurement units. The results can also be utilized more widely. The substituted fuels in the area and the effect of the plant location on the utilization of the produced energy can already be identified when planning an appropriate site for the waste incineration plant.

The composition, heating value and renewable share of the energy content of mixed municipal solid waste in Finland.

For the estimation of greenhouse gas emissions from waste incineration it is essential to know the share of the renewable energy content of the combusted waste. The composition and heating value information is generally available, but the renewable energy share or heating values of different fractions of waste have rarely been determined. In this study, data from Finnish studies concerning the composition and energy content of mixed MSW were collected, new experimental data on the compositions, heating values and renewable share of energy were presented and the results were compared to the estimations concluded from earlier international studies. In the town of Lappeenranta in south-eastern Finland, the share of renewable energy ranged between 25% and 34% in the energy content tests implemented for two sample trucks. The heating values of the waste and fractions of plastic waste were high in the samples compared to the earlier studies in Finland. These high values were caused by good source separation and led to a low share of renewable energy content in the waste. The results showed that in mixed municipal solid waste the renewable share of the energy content can be significantly lower than the general assumptions (50-60%) when the source separation of organic waste, paper and cardboard is carried out successfully. The number of samples was however small for making extensive conclusions on the results concerning the heating values and renewable share of energy and additional research is needed for this purpose.