• Energy Research

Combustion of fossil fuels in the transport sector represents the second largest source of greenhouse gas emissions. For this reason, governments are fostering diversification of energy sources by creating a set of governmental environmental policies and initiatives. In this context, biofuels are expected to represent a substantial part of source diversification, but it is necessary to assess the sustainability of their market to explore its effect on economical, technological, social, political and environmental dimensions. This research presents a dynamic simulation modelling of the Colombian biodiesel market and analyzes the policy support instruments for creating and managing it. A system dynamics based model is proposed to enable decision-makers to understand the influences between the different variables that describe the system and the impact of the biodiesel government policy in Colombia. The primary focus of this paper is to establish the characteristics of each sustainability dimension for the case of study and apply the system dynamics methodology with different types of validation. Finally, the Colombian market status and a sensitivity analysis are developed. The results show that in order to support the development of this sector, it is necessary to diversify the raw materials for the production of biodiesel in the medium term, which means raw materials without competence for the primary rainforest or competition with food productive lands.

Within the aim of supporting territories to create more sustainable systems, road infrastructure plays a paramount role, not only because road shoulders represent a non-negligible land area, including their own biodiversity, but also because this represents the interface with the territory's ecosystems. For this reason, future road management systems should include all the different dimensions of sustainability. However, sustainable management of roadsides can be considered a complex and dynamic process. It requires access to data, from communities, maintenance services, suppliers of mowing equipment, and the roadsides themselves (physiognomy of the terrain, the composition of the soil, biodiversity, the composition of the area to be mowed and pruned, etc.). Therefore, the current development of Industry 4.0 opens opportunities to capture, aggregate, and analyze the information needed to support decision-making by territory planners and to provide the network's various stakeholders with complete visibility. Although generic models for decision-making in big data environments have been proposed in the scientific literature, they fail to deal with the specific characteristics and data requirements of such a system. In this context, this paper proposes the integration of a process based on the dynamic systems theory and the Industry 4.0 paradigm to achieve sustainable management of roadside processing. It will enable us to identify and manage in a proper manner the varying and heterogeneous amount of data that this type of system entails. The proposed model will support territory policy-makers to take sustainable actions in order to ensure efficient decisions with a long-term view, to assess the current situation and future opportunities, and then to contribute to the evolution of territories towards a circular economy.

Sustainability assessment is a critical issue for the biodiesel production chain. The constant growth of the biodiesel industry has generated important sustainability concerns, such as competition with food production, indirect land use change, and impacts on water, biodiversity and social values. Government policies consider that quantitative, robust and independent sustainability assessment is vital to estimate the extent to which the biodiesel industry impacts sustainability issues. However, weaknesses in the definition of adequate indicators to measure the sustainability of biodiesel production have been identified. In this context, this work proposes a hierarchical assessment framework based on sustainability dimensions, principles, criteria and indicators. To do this, after a systematic literature review, a first version of the framework was proposed. Then, to define the final framework, a validation strategy based on expert survey consultations and a descriptive statistical analysis were developed. In order to define the principles and criteria importance for sustainability assessment of biodiesel, 62 experts answered an online survey assessing three attributes: relevance, ease of measurement and reliability. The first result of the validation analysis was the definition of a framework composed of five dimensions (social, economic, environmental, political and technological), 13 principles, and 30 criteria that would be part of a sustainability assessment of biodiesel production. The second result was the identification of potential groups and relationships between principles and criteria represented through data visualization techniques. The validated framework provides the basis for defining future studies about interdimensional principles and criteria. Also, the proposed sustainability assessment framework could be adapted and applied to biodiesel production in specific contexts.

Sustainability assessment of biodiesel production is a topic of increasing importance due to the interest of governments to define sovereignty strategies and diversification of their energy matrix, and to set up the impact of biofuels production. In this context, this work aims to propose a hierarchical structure of sustainability assessment that integrates dimensions of sustainable development with principles, criteria and indicators (PC&I). The method employed to define the hierarchical structure was a comprehensive literature review, based on information search strategy and classification. About 400 documents were reviewed and 103 documents were ultimately selected, including laws, policy documents, certificates, directives and other normative documents and papers published in peer-reviewed journals. The first result of the analysis was the need to strengthen identification of the sustainable development assessment, adding the political and technological dimensions to the three traditional dimensions, social, economic and environmental, studied in this kind of evaluation. The second result was the proposal of a hierarchical framework for the sustainability assessment of biodiesel production, organized in four levels: the first level comprises the five dimensions associated with sustainable development evaluation, the second includes 13 principles, the third contains 40 criteria and the fourth level corresponds to a set of indicators that describes each criterion. Outcomes of this work provide a foundation for further discussion of sustainability assessments for biodiesel production and its potential application in specific contexts.