A systems dynamics approach for supporting regional decisions on the energetic use of regional biomass residues.

This article presents the definition, building, calibration and application of a system dynamics simulation model to quantify the present and future comparative advantages and disadvantages of using forest and agricultural residual biomass for energetic purpose through different processes and technologies, on a regional basis. A dynamic structure of the agricultural and forestry biomass process activities (i.e. production, transport, conversion and consumption) based on regional time-series data was built, implemented into and calibrated within a dynamic simulation tool (Vensim software) within a Hungarian county. Besides the agriculture and forestry sectors, the model includes data about demography, economy, environment and land use, among others. For carrying out the assessment, realistic scenarios of future biomass processes and of biomass use were formulated, characterised by quantitative sustainable development indicators and simulated within the dynamic model. The results prove that the introduced model supports decision making of biomass utilisation in a regional scale, through comparing and analysing quantitative changes of economic, social and environment indicators, which characterise a sustainable regional development. The model therefore allows analyses and evaluation of not only partial prosperous or adverse characteristics of biomass processes and use, but also to relate regional components and their development over time. The developed dynamic tool is therefore a powerful method to model complex systems, such as a regional energy system, considering the framework of the regional preferences stated by the regional stakeholders. It can thus provide useful decision support, especially when used as a priority-based screening of potential regional development programmes in the energy field.

Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia.

The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories.

Lessons learned for a more efficient knowledge and technology transfer to South American countries in the fields of solid waste and contaminated sites management.

The present paper describes the development, performance and conclusions derived from three know-how and technology transfer projects to South American countries. The first project comprised a collaborative study by European and South American universities to find sustainable solutions for Chilean and Ecuadorian leather tanneries which had underachieving process performances. The second project consisted of investigations carried out in a Brazilian municipality to enhance its municipal solid waste management system. The final collaborative programme dealt with the initial identification, evaluation and registration of suspected contaminated sites in an industrial region of Chile. The detailed objectives, methods and procedures applied as well as the results and conclusions obtained in each of the three mentioned projects are presented, giving special attention to the organizational aspects and to the practical approach of each programme, concluding with their main advantages and disadvantages for identifying a set of qualitative and quantitative suggestions, and to establish transferable methods for future applications.