Green chemistry metrics measures efficiency in a chemical process. Having made a green chemistry improvement to a chemical process, it is important to be able to quantify the change. By quantifying the improvement, there is a tangible element or benefit from the new technology introduced. This is likely to aid the communication of the work and potentially facilitate the transfer to industry. For a non-chemist the most attractive method of quoting the improvement would be a decrease of £X per kilo of compound Y. This however is an oversimplification and does not allow a chemist to visualise the improvement made or make allowance for toxicity/hazard. For yield improvements and selectivity increases, simple percentages are suitable, but this simplistic approach may not always be appropriate. For example, when a highly pyrophoric reagent is replaced by a benign one, a numerical value is difficult to assign but the improvement is obvious, if all other factors are similar.
Numerous metrics have been formulated over time and their suitability discussed at great length.
The problem observed is that the more accurate and universally applicable the metric devised, the more complex and unemployable it becomes. A good metric must be clearly defined, simple, measurable, objective rather than subjective and must ultimately drive the desired behavior.
Read more about Green Chemistry Metrics: Effective Mass Yield, Carbon Efficiency, Atom Economy, Reaction Mass Efficiency, Environmental (E) Factor, Comparison of Metrics, The EcoScale
Famous quotes containing the words green and/or chemistry:
“May they turn sour. May many mean things
happen upon them, no shepherds, no dogs,
a blight of the skin, a mange of the wool,
and they will die eating foreign money,
choking on its green alphabet.”
—Anne Sexton (1928–1974)
“Science with its retorts would have put me to sleep; it was the opportunity to be ignorant that I improved. It suggested to me that there was something to be seen if one had eyes. It made a believer of me more than before. I believed that the woods were not tenantless, but choke-full of honest spirits as good as myself any day,—not an empty chamber, in which chemistry was left to work alone, but an inhabited house,—and for a few moments I enjoyed fellowship with them.”
—Henry David Thoreau (1817–1862)