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An Approach for Development of Materials for Green Chemical Catalytic Processes: Green Catalysis
Published in Neha Kanwar Rawat, Iuliana Stoica, A. K. Haghi, Green Polymer Chemistry and Composites, 2021
Rimzhim Gupta, Akanksha Adaval, Sushant Kumar
Two measures defining the greenness of the process are E factor and atom economy. E factor represents the amount of waste generated during the process and can be calculated by the mass ratio of the waste divided by the mass ratio of the desired product. While atom economy is calculated by the molecular weight of the desired product divided by the total sum of the molecular weights of all the products generated during the reaction in the stoichiometric equation.4 Water is not usually included in the calculation of the E factor; however, the organic and inorganic content present in the aqueous phase or in water are included.
Atom Economy
Published in Aidé Sáenz-Galindo, Adali Oliva Castañeda-Facio, Raúl Rodríguez-Herrera, Green Chemistry and Applications, 2020
Kunnambeth M. Thulasi, Sindhu Thalappan Manikkoth, Manjacheri Kuppadakkath Ranjusha, Padinjare Veetil Salija, Nisha Vattakkoval, Shajesh Palantavida, Baiju Kizhakkekilikoodayil Vijayan
The concept of atom economy was developed by Barry M. Trost in 1991. Organic synthesis requires multiple reagents, facilitating agents and solvents to obtain the desired product. At the end of the reaction everything except for the desired product and reagents that can be recycled, like solvents and catalysts, will end up as wastes, mostly hazardous wastes. Conceptually, if the desired product contains all the atoms making up the reagents there will be no waste generated. The concept of atom economy can be used to identify synthetic methodologies that will retain the maximum number of atoms from the reactants in the final product and thereby reduce wastage. The atom economy concept allows quantification of the efficiency of a reaction with respect to the number of atoms transferred from the reactants to the final desired product (Trost, 1995; Trost, 2002). The concept of atom economy can be applied to every synthesis and be used to define new pollution prevention benchmarks (Cann and Dickneider, 2004; Song et al., 2004). Atom economy calculation, broadly presents a measure of the greenness of a chemical reaction. The commonly used indicator for efficiency of a reaction in organic synthesis is the percentage yield, which neglects mass flow (Cann and Dickneider, 2004). A synthetic chemist records the yield of a particular reaction as percentage yield. The percentage yield can be calculated as %yield= Actual yield of the product Theoretical yield of the product ×100 A yield above 90% is considered good.
Microwaves and Green Chemistry of Biofuels
Published in Veera Gnaneswar Gude, Microwave-Mediated Biofuel Production, 2017
Atom economy is a measure of the proportion of reactant atoms which are incorporated into the desired product of a chemical reaction. Calculation of atom economy therefore also gives an indication of the proportion of reactant atoms forming waste products. Atom economy is defined as the ratio of molecular mass office desteed produhtii divided Dy tire’ molecLila1 mass of the reactants. For example, the atom economy for the antlowmg reaction can +e axpressed. as:
The Green Chemistry Initiative’s contributions to education at the University of Toronto and beyond
Published in Green Chemistry Letters and Reviews, 2019
Alexander E. Waked, Karl Z. Demmans, Rachel F. Hems, Laura M. Reyes, Ian Mallov, Erika Daley, Laura B. Hoch, Melanie L. Mastronardi, Brian J. De La Franier, Nadine Borduas-Dedekind, Andrew P. Dicks
The GCI envisioned an innovative pedagogical approach for explaining the Twelve Principles of Green Chemistry through an open access YouTube video series (22) (www.youtube.com/user/GreenChemUofT). The three- to four-minute videos summarize each of the principles using an appropriate analogy to effectively communicate how to make more sustainable chemistry decisions. Scripts were written to present broadly accessible content to a science literate audience. The most impactful video thus far has been the one highlighting Principle #2: Atom Economy, with approximately 9000 views to date (23) (www.youtube.com/watch?v=plbmxQLa_-M). Atom economy is the measurement of the percentage of atoms from the reactants which are incorporated into the desired product during a chemical transformation. In this video, each atom is associated with a specific Canadian coin to visualize the synthesis of ibuprofen through two different synthetic protocols. As each synthesis proceeds, any “wasted” atom (coin) is placed in the waste collection pile. Summation of the coin waste demonstrates that the modern synthetic protocol for ibuprofen is significantly more atom economical than the original one.
A comprehensive review of sustainable approaches for synthetic lubricant components
Published in Green Chemistry Letters and Reviews, 2023
Jessica Pichler, Rosa Maria Eder, Charlotte Besser, Lucia Pisarova, Nicole Dörr, Martina Marchetti-Deschmann, Marcella Frauscher
What is green chemistry? The concept of green chemistry is defined as ‘the design of chemicals and products and processes that reduce or eliminate the use or generation of hazardous substances’ by the US Environmental Protection Agency (EPA) (2). Most important in this sense is the life cycle of a chemical product, to help with the design of such next-generation products, 12 principles of green chemistry are formulated (3): Prevent waste instead of treating or cleaning up in hindsight.Maximize atom economy so that few or no atoms are wasted through synthesis.Design less hazardous chemical syntheses to pose little or no health risk for humans and the environment.Reduce toxicity by a safer chemical product design.Solvents and auxiliaries should be safer when needed and avoided when possible.Increase energy efficiency to reduce the negative impact on the environment and economy, chemical syntheses should be conducted at room temperature and ambient pressure.Use renewable raw materials and feedstocks.Minimize or completely avoid unnecessary derivatization products.Use catalysts instead of stoichiometric reagents.Design chemical substances for degradation at the end of their function.Implement real-time, in-process monitoring, and control to prevent hazardous product formation.Minimize the potential risk of accidents such as fires, explosions, releases, etc. by choosing safer chemistry.