Biomass is a fuel with a highly volatile content and due to that, pyrolysis as a part of the combustion process, has a dominant role in the overall process development, as well as on final products and the process efficiency. It is of key importance to investigate the influence of the process parameters; as temperature, furnace/reactor environment, fuel properties, type, particle size, geometry, and the structure of the pyrolysis process has an influence regards the design of the combustion/pyrolysis equipment and the final products of the processes. This paper gives some results of the investigation?s related to this problem, mainly focussing on wooden biomass as the most important biomass type, as well as a comparison with relevant documented literature. Besides that, pyrolysis based technologies are one of the key directions in synthetic fuels production based on biomass. Biomass pyrolysis process parameters are crucial in reactor design as well as the quantity and quality of the final products. This paper provides discussion dedicated to this aspect with a focus on slow pyrolysis, targeting charcoal as the key product, and fast pyrolysis, targeting synthetic gas as the key product.

The process of optimizing energy production is becoming increasingly important with the development and use of RES and energy efficiency measures. Given that these are optimization processes that require taking into account several indicators according to which the set of optimal technologies for energy production will be ranked, and take their percentage share in the total percentage of energy supply. Indicators describing the process of energy production and utilization include technological, environmental, economic, energy, and limiting domains of their application. From that aspect, when the energy supply process is optimized from several possible alternatives according to the optimization factors defined in this way and the percentage of participation from each is calculated, a very realistic picture of the optimal energy mix of a state or local community is obtained. In this paper, a comparison of the energy mix for Copenhagen, Denmark and Banja Luka, Bosnia and Herzegovina is made. The process of comparing energy mixes was made possible by a previously developed mathematical model for optimizing and searching for an optimal energy mix based on the compromise ranking method, also known as the VIKOR, as well as entropy and analytic hierarchy process methods for defining weight values of criteria describing energy mix. Since we know that the introduction of new RES and the replacement of fossil fuels with them is a process of transition of existing energy sectors, the approach presented in this paper would greatly facilitate the transition process itself.

This study proposes optimal supply chain models for agricultural biomass, focusing on straw and corn stalks. Four bioenergy chains, corn stalk pellets, corn stalk chips, straw bales, and straw pellets, were evaluated using multicriteria decision making tools and life cycle assessment. Key criteria included energy efficiency, investment costs, fuel production costs, and environmental impacts such as GHG emissions, acidification, eutrophication, and particulate matter formation. Results indicate that straw bales (L3) and corn stalk chips (L2) offer the most sustainable options, with straw bales demonstrating superior energy efficiency and lower environmental impacts. The VIKOR method, combined with the entropy weight method, identified straw bales as the optimal supply chain under various weighting scenarios. These findings provide actionable insights for sustainable bioenergy development and policy formulation.

The transition from outdated biomass boiler systems to modern, efficient district heating technologies represents a critical pathway toward sustainable energy production. In this study, the replacement of obsolete solid biomass-fueled boilers with a new wood chip-based heating system in the district heating plant of Pale, Bosnia and Herzegovina, was analyzed under real-world operational conditions. Historical operational data, including annual fuel consumption, were obtained directly from the facility. The degree-day method was applied to evaluate the thermal efficiency of the former heating system and to estimate the annual fuel demand for the newly installed wood chip-based infrastructure. A key component of this transition involves the reliability and efficiency of the wood chip supply chain. Therefore, the logistical feasibility of securing a continuous, local, and renewable wood chip fuel source was examined, including the assessment of storage capacity and supply chain resilience. Furthermore, a scenario-based simulation was conducted to project the cost of heat production under varying fuel price conditions and market dynamics. Through this integrated approach, a replicable methodology was proposed for replacing legacy biomass heating systems with environmentally sustainable, economically viable district heating technologies based on locally sourced wood chips. The findings offer a practical roadmap for municipalities aiming to achieve energy transition targets through the adoption of locally available renewable energy sources, with particular emphasis on operational feasibility, fuel logistics, and cost-effectiveness.

Water networks are critical infrastructure components, ensuring the continuous supply of high-quality drinking water to consumers. To secure such water supply, regular maintenance, including the replacement of deteriorating pipelines, is essential. In this study, a methodology has been developed for determining optimal pipeline replacement solutions in water supply systems at water utilities with limited data availability. Hydraulic analysis has been conducted on the segment of 25 km of the water supply network using the free software EPANET (Environmental Protection Agency, NETwork) Applying water network optimization, eight pipeline replacement projects according to 13 pre-defined criteria have been identified and evaluated. The paper outlines the methods for evaluating the criteria, including defining specific quantitative limits. The Analytical Hierarchical Process (AHP) method was used in the paper to determine the weights of the criteria. The reason for applying this method refers to problems that involve a set of criteria with a mixed structure, including both quantitative and qualitative aspects. Also, the paper describes the steps of the multi-criteria optimization method VIKOR (Serbian language – VIšekriterijumsko KOmpromisno Rangiranje), used to select the optimal project. The obtained results were also confirmed by the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) multi-criteria optimization method. This paper, considered as a case study, describes a method, i.e., application of a new principle and an innovative way to solve a problem for developing countries.

The paper analyzes the influence of the rotation speed of a DFIG (Doubly-Fed Induction Generator) wind turbine generator on the temperature in the operating mode and in the idle state, based on one-year data from the SCADA (Supervisory Control and Data Acquisition) system. The aim is to quantitatively determine the intensity and statistical significance of this relationship. The methodology includes data filtering, linear regression and correlation analysis, with the calculation of the Pearson coefficient (r) and the coefficient of determination (R²). The accuracy of the model was assessed by RMSE and MAE, while statistical validation was carried out by ANOVA analysis and residual analysis. The results show a moderately strong positive correlation between rotation speed and temperature (r = 0.7034), with R² = 0.4949 indicating that speed changes explain about 49.5% of the variability. In idle state, the temperature depends mainly on external factors (ambient temperature, wind, solar radiation, humidity and surrounding objects). The proposed model enables reliable temperature prediction in the operating mode and can be used for operation optimization, monitoring and predictive maintenance of wind turbines.