Investigação
Adélio A. S. C. Machado, Green Chemistry Education: Towars a Systems Approach, 4th International IUPAC Conference on Green Chemistry, Foz do Iguaçu, Brazil, Agosto, 2012.
2012-08-26
Autores:
Adélio A. S. C. Machado
Instituições:
Departamento de Química e Bioquímica da Faculdade de Ciências da Universidade do Porto.
Resumo:
Some of the main features of the efforts developed at the Chemistry Department of the Science Faculty of Oporto University since about 2000 to teach Green Chemistry (GC) will be discussed. GC started to be taught as sections in two courses for the 4th year BSc Chemistry degree (1st semester: Industrial Chemistry; 2nd semester: Industrial Ecology and Sustainability) and their applied objectives conditioned the development of the teaching activities which involved often a systems approach. Later, by the middle of the decade, GC was included as a stronger component in educational degrees for preparation of secondary school teachers, in which increasing laboratory activities have been added. The following items will be discussed.
First, a review of the history of industrial chemistry since the 18th century allows the identification of several instances where “early GC” was practiced before its time, for instance: Alfred Nobel might be named the “first green chemist” as he applied several of the 12 principles, namely the 12th principle, when developing the safe use of nitroglycerine as an explosive; the replacement of the Solvay process for the Leblanc Process for the soda manufacture exemplifies not only a process substitution aimed at greenness, but also the importance of eco-industrial systems for the life of industrial chemicals and the extra-chemistry factors that may introduce barriers that slow substitution. This historical approach based on the chemistry of industrial systems provides some useful strategic lessons for the present development of GC – and, especially, a propaganda conclusion addressed to students: if their early colleagues used GC without knowing what it was, it will be much easier for the new generations of chemists aware of GC to develop it as a systematic practice.
Second, discussing the re-shaping of chemistry by GC under a systems approach (considering matter, energy and information together) shows how complex the task is. It involves changes along a greenness chain from the laboratory to the final use of chemicals, different greenness metrics being required along the chain to evaluate whether greenness is kept
Green (Laboratory) Chemistry → Green scale-up/process development → Green Chemical Engineering → Green Chemical Industry → Green formulation → Green (Society) use
The development at Oporto of simple holistic metrics covering the 12 GC principles to be used in the teaching laboratory (GREENSTAR and others) will be briefly presented.
Third, the strategy developed for the laboratory teaching of GC will be discussed, which basically consists in challenging the students to improve synthesis protocols available in texts of laboratory experiments to increase their greenness. Typically the students are assigned a synthesis, perform it following a literature protocol, evaluate its greenness with mass, energy and holistic metrics, and scrutinize the protocol to identify how to improve it; then, they repeat the experiment under the better conditions they proposed and assess the greenness again to determine the degree of accomplishment they reached (if any!). This type of experiment requires creative thinking along multidimensional lines to devise improvements and stresses that GC is a systems strategy that has to be fought for.
http://www.congresscentral.com.br/sbq/ufscar/icgc4/program.php
PRESENTATION.pdf