A kinetics study of palm oil methanolysis was conducted at three different temperatures and three different concentrations of catalyst, sodium hydroxide, keeping constant the molar ratio of methanol to oil and the rotational speed of the impeller (6:1 and 400 rpm). The maximum conversion of palm oil and productivity to methyl esters were obtained at 60°C and 1 wt% of NaOH based on palm oil, and they were 100 and 97.6%, respectively. The statistical analysis of conversions of palm oil and productivities to methyl esters as functions of temperature and concentration of catalyst, after 80 min of reaction, allowed them to fit second order polynomial equations, which adequately describe the experimental behavior. The experimental data appear to be a good fit into a second order kinetic model for the three stepwise reactions, and the reaction rate constants and the activation energies were determined. In this article we present the kinetic constant and activation energies for the experiments with 0.2% wt of NaOH. The effect of molar ratio on the concentration of products was investigated, while the temperature (55°C), the concentration of catalyst (0.60 wt% of NaOH), and the rotational speed (400 rpm), were held constant. The results showed that the conversion and the productivity increased due to methanol excess, and were higher for the reactions with a molar ratio of 6:1.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.