The continued expansion of cities in economic, population and geographical terms leads to significant environmental and infrastructural pressures, including the need for efficient municipal solid waste (MSW) management. This research focuses on the characterization of MSW generated in the city of Skopje and the investigation of its thermo-physical properties and energy utilization potential. The analyses cover physical and chemical properties, including density, moisture content, volatile matter, ash, and higher heating value, using adequate testing methods. The results indicate that MSW has a relatively high gross calorific value, surpassing typical MSW ranges comparable to those of solid fossil fuels. With approximately 79.42% volatile matter and a low ash content of 7.76%, the considered MSW demonstrates excellent combustibility. Chemical analysis reveals high carbon (53.12%) and hydrogen (7.69%) levels, supporting high energy value, while low nitrogen (0.84%) and sulfur (0.26%) levels ensure minimal NOx and SOx emissions. These characteristics position MSW as a suitable feedstock for energy production in incineration facilities. However, the heterogeneous composition of MSW presents challenges to process stability, necessitating prior waste preparation. The research concludes that harnessing waste energy potential could contribute to sustainability, reduce reliance on fossil fuels, and improve the environmental conditions in large urban areas.
Urban air pollution during winter is a major challenge in many cities, where emissions from residential heating lead to elevated particulate matter levels. Atmospheric dispersion modelling supports the understanding of spatial and temporal pollution behavior and enables the assessment of source contributions relevant for targeted mitigation. In this study, the ADMS-Urban dispersion model was applied to simulate hourly PM2.5 and PM10 concentrations across the city of Skopje, North Macedonia. Residential heating was the focus of the analysis, while emissions from road traffic and industrial activities were also included to ensure a realistic representation of the urban emission environment. A representative winter day was analyzed to examine the influence of wind patterns and diurnal boundary-layer height variability on particulate matter dispersion. Modelled concentrations were evaluated against measurements from urban air quality monitoring stations and showed good agreement in reproducing both night-time accumulation and daytime dispersion. The results indicate that household heating using biomass is the dominant contributor to wintertime particulate matter emissions, with PM10 prevailing over PM2.5. These findings underline the need for targeted emission reduction measures in the residential heating sector and demonstrate the usefulness of short-term dispersion modelling for supporting air quality management strategies in Skopje.
The decrease in conventional energy resources, environmental pollution issues and climate change are the leading factors inducing the increase of energy efficiency criteria. Trends to improve energy efficiency are mainly aimed at the construction sector as one of the leading sectors in energy consumption. In the paper the performance of the decentralized solar assisted heating systems (SAHS) for climatic conditions in Macedonia was analysed in order to assess its possibility to be integrated as part of the district heating system. The analysis is based on a holistic approach, in which the performance of the SAHS is generally functionally dependent on four factors: (1) the characteristics of each component, (2) the system structure and mutual interactions of the components, (3) the management method and (4) specific energy consumption for heating of the building. The specific analysis is directed toward the assessment of the solar fraction of the SAHS as a function of the building energy performance and system heating temperature range. The numerical modelling of the processes occurring in systems was performed with the dynamic simulation software TRNSYS. Both dynamic models of the solar bivalent system and reference building were developed. The dynamic model contributes to the flexibility of conducting parametric analysis. The obtained results from the parametric analysis were condensed in a general table upon which the analysis of system performance was performed.
The city of Skopje faces persistent inefficiencies in waste management, characterised by rising waste generation and limited progress in sustainable treatment solutions. This paper addresses the need for a structured approach to identify barriers to implementing Waste-to-Energy (WtE) technology, focusing on incineration-based energy recovery as a potential option for improving waste management while generating energy. Interpretive Structural Modelling (ISM) and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) were applied to six categories of implementation challenges: operational, technical, financial, regulatory, social, and environmental. ISM identified hierarchical relationships within each category, while MICMAC classified challenges according to their driving and dependence powers. The results revealed distinct structural patterns across categories, with underlying barriers including inadequate waste separation and collection, lack of integrated waste information, competitive renewable energy prices, regulatory preferences for waste reuse, recycling and reduction over WtE, institutional distrust, and combustion residue management. The findings reveal interconnected barriers with distinct structural roles, while conceptual mitigation measures and relevant SDG linkages are proposed based on the identified barriers and literature. The proposed ISM-MICMAC framework provides a structured approach for analysing WtE implementation barriers and can be adapted to other contexts following appropriate contextual and quantitative assessment.
30 May 2025 in Mechanical Engieneering – Scientific Journal
Construction and demolition waste (CDW) accounts for 25–30% of the total waste generated in the EU. In North Macedonia, CDW management is primarily based on collection and landfilling by public communal enterprises, with operations not fully aligned with EU standards. CDW generation is estimated at 460,000–500,000 tons/year nationwide and 142,434–154,820 tons/year in Skopje. Four scenarios for CDW treatment in Skopje are proposed: Full Treatment (FT), Selected Treatment (ST), Selected Treatment with Mobile Equipment (STM), and Do Nothing. FT offers high material recovery but requires significant investment and has a 12.2 year ROI. ST has lower costs with over 2 years of execution time, while STM provides the best ROI with a 6 month implementation timeline. All scenarios contribute to reducing GHG emissions (18,031,840 kg CO₂-e) and lowering landfilling by 449,000 tons. Implementation would also yield socio-economic benefits including job creation, improved public awareness, and advancement toward a circular economy.