Influence of free fatty acid content in biodiesel production on non-edible oils

The use of alternative feedstock as waste cooking oils (WCO) and bovine tallow for biodiesel production has some advantages. It is cheaper than edible vegetable oils and it is a way to valorize a sub-product. Nevertheless, these oils possess some contaminants, specially free fatty acid (FFA) content, which can reduce the quality and yield of biodiesel production. This problem was solved by testing different operating conditions and different transesterification procedure and equipments for each stage of processing. Technological assessment of process was carried out to evaluate their technical benefits, limitations and quality of final product. In this work biodiesel was produced by an alkali-catalyzed transesterification and by a two step esterification/alkali-catalysed transesterification in cases which FFA content has above 3%. Evaluation of quality from raw materials and final biodiesel was performed according to standard EN 14214. Results show that all parameters analyzed meet the standard and legislation requirements. This evidence proves that in those operational conditions the biodiesel produced from WCO and bovine tallow can substitute petroleum-based diesel

Waste management in Portugal and Europe: an overview of the past, present and future

As word society has grown exponentially it was created more and more wastes. Each year European Union throws away 3 billion tons of waste, and some 90 million tons of that are hazardous. It is clear that treating and disposing of all this material - without harming the environment becomes a major trouble. In the early years 90 the amount of waste generated in Europe increased by 10%. Most of that was thrown away in incinerators, or dumped into landfill creating environmental damage. Landfill disposal not only takes valuable land space but also causes air, water and soil pollution, discharging carbon dioxide (CO2) and methane (CH4) into the atmosphere and chemicals and pesticides into the earth and groundwater. This situation is harmful to human health as well as to plants and animals. These events triggered urgency for a responsibility and appropriate legislation for correct waste management. EU and Portuguese policy main objective in the waste management are prevent and reduce waste production, and reduce their toxicity, through the reuse and modification of production processes, adopting cleaner technologies. Waste management must also avoid or at least reduce its risk to human health and to environment. In Portugal, wastes sector was suffered a revolution on the last years, due to the appearance of the Strategic Plan for Solid Waste I (PERSU I) in 1997 and by the constant pressure from the EU for their state members and waste producers. In December 2006 was created the PERSU II to correct all mistakes made in the previous plan. However soon realized that PERSU II had very ambitious goals and so unattainable that triggered the need to reformulate these objectives. The aim of this overview in waste management was to follow the goals outlined in PERSU II, identifying the progress of each operational system over the years. It was also the target compare those results to European statistics tracing possible ways to permit compliance with EU objectives in future

Adsorption process onto an innovative eggshell-derived low-cost adsorbent in simulated effluent and real industrial effluents

ISBN 978-989-97429-1-8As the current global trend towards more stringent environmental standards, technical applicability and cost-effectiveness became key factors in the selection of adsorbents for water and wastewater treatment. Adsorption is by far the most versatile and widely used method for the removal of pollutants due to its high removal capacity and ease of operation at large scale. Recently, various low-cost adsorbents derived from agricultural waste, industrial by-products or natural materials, have been intensively investigated. In this respect, the eggshells from egg-breaking operations constitute significant waste disposal problems for the food industry, so the development of value-added by-products from this waste is to be welcomed. The egg processing industry is very competitive, with low profit margins due to global competition and cheap imports. Additionally, the costs associated with the egg shell disposal (mainly on landfill sites) are significant, and expected to continue increasing as landfill taxes increase. The aim of the present was to provide an overview on the adsorption process both on simulated and real effluents onto eggshell-derived adsorbent. This was accomplished by analyzing the uptake potential for selected contaminants. Real wastewater effluents were studied to determine the effectiveness of this low cost adsorbent. Results obtained shown that eggshell can remove several pollutants from different types of aqueous systems, with great efficiency

Quality indices for (practical) clustering evaluation

WOS:000271584000004 (Nº de Acesso Web of Science)Clustering quality or validation indices allow the evaluation of the quality of clustering in order to support the selection of a specific partition or clustering structure in its natural unsupervised environment, where the real solution is unknown or not available. In this paper, we investigate the use of quality indices mostly based on the concepts of clusters' compactness and separation, for the evaluation of clustering results (partitions in particular). This work intends to offer a general perspective regarding the appropriate use of quality indices for the purpose of clustering evaluation. After presenting some commonly used indices, as well as indices recently proposed in the literature, key issues regarding the practical use of quality indices are addressed. A general methodological approach is presented which considers the identification of appropriate indices thresholds. This general approach is compared with the simple use of quality indices for evaluating a clustering solution

Biodiesel production by microalgae and macroalgae from north littoral portuguese coast

Biodiesel, as an alternative fuel, has many benefits. It is biodegradable, non-toxic and compared to petroleum-based diesel, has a more favorable combustion emission profile, such as low emissions of carbon monoxide, particulate matter and unburned hydrocarbons. In brief, these merits make biodiesel a good alternative to petroleum based fuel. Biodiesel feedstocks derived from microalgae and macroalgae have emerged as one of the most promising alternative sources of lipid for use in biodiesel production because of their high photosynthetic efficiency to produce biomass and their higher growth rates and productivity compared to conventional crops. In addition to their fast reproduction, they are easier to cultivate than many other types of plants and can produce a higher yield of oil for biodiesel production. In this work biodiesel was produced using the species of microalgae Chlorella emersonii and Botrycoccus braunii due to its high oil content. Biodiesel productions through macroalgae oil are in preliminary phase. Therefore, results and methodology will not be presented in this work. Technological assessment of process was carried out to evaluate their technical benefits, limitations and quality of final product. In this work biodiesel from microalgae oil was produced by an alkali-catalyzed transesterification and it was achieved 93% of mass conversion. The evaluation of quality from raw materials and final biodiesel was performed according to standard EN 14214. Results show that all parameters analyzed meet the standard and legislation requirements. This evidence proves that in those operational conditions the biodiesel produced from microalgae can substitute petroleum-based diesel