Green metrics examples

This example shows another simple green metric that can be used in helping to determine the greenness of a process-simple counting of types of material ... 

Chapter 5 gives a comprehensive overview of essential green metrics and their uses to evaluate reaction and synthesis plan performance. Full details are provided using illustrative examples where key spreadsheet algorithms are introduced to circumvent the dmdgery of calculations. Step-by-step instructions on their use are also given. 

This chapter presents several plots of correlations between key metrics parameters for the 1050 plans docnmented in the extensive synthesis database. Each trend is discnssed in the context of achieving optimum and green syntheses. Examples of synthesis plans that achieve some measure of greenness are highlighted. The reader is referred to Chapters 5 and 6 regarding the definitions of metrics parameters. 

The number of green metrics subsequently proliferated [20-23]. They can be divided into two types (i) metrics that are a refinement of the AE concept and (ii) metrics that are variations of the E factor (see Figure 1.2). Examples of the former are reaction mass efficiency (RME) and carbon efficiency (CE) introduced by Constable and coworkers [24] at GlaxoSmithKline (GSK). The RME is defined as the mass of... 

The writing of this book was undertaken because it was intended to be the first work that solely focuses on chemistry, and what appropriate metrics for Green Chemistry might be. We hope the book provides an up-to-date and authoritative text on the current development of environmental concepts in chemical technologies from clean and green to sustainable development. We also think it provides up-to-date information on the problems of metrics fundamental aspects of metrics, practical realisations and real-world case study examples. The concepts and approaches of metrics are related to the fundamental problems in chemistry and the main focus is on the use of metrics to promote the development and implementation of green chemistry and technology solutions. 

This metric is an attempt to define yield in terms of the mass of the product that is made from non-toxic materials. This was one of the first times that reagent and reactant toxicity were included as an important part of determining what is considered to be green, and it is something that was absent from traditional yield measures. Hudlicky et al. did make an attempt to define benign (i.e. those byproducts, reagents, or solvents that have no known environmental risk associated with them, for example, water, low-concentration saline, dilute ethanol, autoclaved cell mass, etc. ), but the explanation suffers from a lack of definitional clarity. 

Extensive statistical analysis of the mass intensity, yield, atom economy, and stoichiometry show that these data do not correlate with each other in any meaningful way. Because these metrics appear to be of discretely different types, following one metric in isolation from others may not drive the best behavior for greening reactions. This is illustrated in Table 2.2, which contains an example of three different chemistries of similar mass intensity that have generally different and conflicting data trends for the other metrics. 

Before we begin to discuss this, however, we need to think about a few important points as we attempt to apply a green perspective to metrics and cost. First, most people do not really consider what lies behind the goods and services that we extract from the environment for free. For example, we do not pay significantly for the air... 

Atom economy is a simple metric for the initial comparison between different reactions that is receiving considerable attention. In an ideal scenario, all the atoms in the starting materials are incorporated into the product with anything else needed in only catalytic amounts, and from this viewpoint, addition reactions are ideal green reactions. Many types of addition reactions are known, catalytic hydrogenation and hydroformylation are examples that are... 

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