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In the last decade several scientific papers have dealt with the damages fossil fuels did to our environment. Carbon dioxide has been blamed the chief culprit since it is produced by the automobile fleet that uses diesel or gasoline as a fuel. As a result, several countries are implementing public policies aimed at the replacement of fossil fuels by renewable ones, such as biodiesel. Brazil has become one of them, since the biodiesel production has increased from 736 m 3 to 3,419,838 m 3 in less than ten years. Therefore, this paper intends to briefly review the literature on the history, evolution, and the environmental aspects of biodiesel in Brazil in order to show its positive economic impact on the Brazilian economy, in addition to showing how important this biofuel is to the environment by providing an overview of its advantages when compared to fossil diesel. [ABSTRACT FROM AUTHOR]

The production of biodiesel through enzymatic routes has attracted significant attention, mainly because this can be regarded as a "green route" for the manufacture of fuels. In this way, an advanced bibliometric analysis comprising the global scientific production of biodiesel through immobilized enzymes was conducted. Thus, 923 papers were retrieved, analyzed, and classified according to the reported substrates, enzymes, supports, immobilization procedures, and reactors. Researchers from 748 institutions of 64 distinct countries authored the analyzed articles, showing the widespread interest in these technologies, although 10 countries concentrate more than 80% of the total number of documents published in this area, including China (23%), Brazil (17%), and India (11%). Particularly, most papers reported the use of vegetable oils (67%) as raw materials. In the last decade, approximately 80% of the published research focused on the use of supports to manufacture immobilized and insoluble biocatalysts. Enzymes have been obtained mostly from fungal sources (64%), especially lipases produced by Thermomyces lanuginosus (14.4%). Among the available commercial immobilized biocatalysts, Novozym 435 is certainly the one cited most frequently (55.9%) followed by Lipozyme RM IM (13.7%) and Lipozyme TL IM (16.7%). Additionally, the majority of the manuscripts reported the use of stirred tank reactors (83.0%) to perform the enzymatic reactions. Based on the surveyed literature, research trends indicate that new technologies are being developed to turn the enzymatic production of biodiesel more sustainable and economically viable, based mainly on the use of more active biocatalysts, more sustainable enzyme supports, and low-cost residues as raw materials. • Advanced bibliometric review about the production of biodiesel by immobilized enzyme was performed. • Chinese and Brazilian scientific communities are the most active in this field. • Novozymes 435 is the commercial biocatalyst used most often in this field. • Emerging technologies were identified for the synthesis of enzyme supports. • Sustainable supports and low-cost feedstocks are trends in the biodiesel production field. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a study based on the Systems Thinking and Scenario Planning (STSP) method, focusing the biodiesel production chain of Rio Grande do Sul State. The aim of the study was to identify key elements to comprehend the systemic structure of interaction among the ties of this chain. The study was held by a team of specialists over five months, including 15 meetings. Discussions were based on quantitative and qualitative data and a systemic map was constructed and refined. Based on this modeling, four different prospective scenarios were comparatively analyzed in order to propose strategic actions to promote the sustainability and competitiveness of the chain. The results were then presented to two different groups of external specialists in order to validate the conclusions drawn and the proposals. Both groups agreed with the ideas presented. The paper is constructed as follows: a brief introduction focusing on contextual elements of the biodiesel production in Brazil and in Rio Grande do Sul; some background material regarding agroindustrial production chains and an overview of the biodiesel production chain of interest; a description of the method used to perform the research; main results and discussion; and conclusions. With this paper the authors also hope to contribute to the discussion regarding competitiveness and sustainability of biofuel chains in Brazil. [Copyright &y& Elsevier]

The modern world is highly dependent on energy. Biodiesel is recognized as a green and alternative renewable diesel fuel, and Brazil is the world׳s third largest producer of biodiesel, which in this country is mainly produced from soybeans. As the demand for biodiesel is increasing due to the increasing use of transportation fuel, it is advisable to look for other sources that would not need a vast cropland. Recently, microalgae have emerged as a source than can play the dual role of bioremediation of wastewater and generation of biomass for biodiesel production. This paper focuses on the feasibility of utilizing wastewater to cultivate algae for the production of biodiesel in Brazil. By using only domestic wastewater from 40% of Brazilian municipalities, the production of biodiesel would increase by 21.4%. Moreover, the use of wastewater treatment becomes an economically attractive alternative as the revenue from selling biodiesel overcomes the production costs by at least 10%. As a result, Brazil could easily increase its current biodiesel production and simultaneously amazingly improve its index of sanitation. [ABSTRACT FROM AUTHOR]

Abstract: This paper assesses 13 different inputs for biodiesel production and shows that the highest cost currently associated with the processing of residual resources, as well as their small production scale, are compensated by their smaller procurement costs, by their immediate availability in the urban centers and by their larger potential for greenhouse gas emission reduction. Biodiesel production from residues can meet all technical international specifications, even the esterification process. Data Envelopment Analysis (DEA), the methodology used in this study, allows for the building of an efficiency index up through linear programming with multiple inputs and outputs, enabling the integration of sustainable development dimensions. The experts' conclusions were arrived at through restrictions on virtual weighting, with findings that allow the grading of alternatives. [Copyright &y& Elsevier]