ERIC Number: EJ1154135
Record Type: Journal
Publication Date: 2017-Sep
Abstractor: As Provided
Reaction Scale and Green Chemistry: Microscale or Macroscale, Which is Greener?
Duarte, Rita C. C.; Ribeiro, M. Gabriela T. C.; Machado, Adelio A. S. C.
Journal of Chemical Education, v94 n9 p1255-1264 Sep 2017
The different ways microscale and green chemistry allow reducing the deleterious impacts of chemistry on human health and the environment are discussed in terms of their different basic paradigms: green chemistry follows the ecologic paradigm and microscale the risk paradigm. A study of the synthesis of 1-bromobutane at macro- ? microscale (109.3 ? 10.9 g of the limiting reagent, butan-1-ol) showed that green chemistry mass metrics (AE, atom economy; RME, reaction mass efficiency; MI, mass intensity; E-factor, environmental factor; CEE, carbon efficiency) are unsuitable for evaluating the advantages of micro- versus macroscale. Poorer values of mass metrics at the microscale and the same green star at both scales showed that green metrics do not recognize that microscale improves safety. As so far no metrics have been proposed for evaluating this purpose, a new risk index (scale risk index, SRI) was developed for assessing the improvement of safety on downsizing the scale of synthesis experiments in chemistry teaching laboratories. The performance of SRI to show the benefits of microscale was assessed for syntheses of 1-bromobutane, tetramminecopper(II) sulfate monohydrate, and dibenzalacetone.
Descriptors: Science Instruction, Organic Chemistry, College Science, Undergraduate Study, Problem Solving, Conservation (Environment), Scientific Concepts, Risk, Science Experiments, Laboratory Experiments, Science Laboratories, Test Construction, Safety
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Authoring Institution: N/A
Grant or Contract Numbers: N/A