The Principles Of Green Chemistry – Sixth Principle: Design For Energy Efficiency  

The sixth principle of the ACS Twelve Principles, design for energy efficiency, is a critical focus area, often misunderstood by chemists. While heats of reaction are typically top-of-mind, the largest energy drains in synthetic methods often occur during solvent management—specifically, solvent removal, exchanges, and product isolation.

Reducing solvent use is a dual win: it minimizes hazardous material footprints and energy consumption. To mitigate energy usage related to solvents, chemists should explore utilizing fewer solvents (eliminating solvent swaps), employing alternative synthesis methods (like chemistry in water), or adopting alternative energy sources. Although traditional habits often dictate synthesis choices, recent advances have narrowed the gap between greener options and conventional methods, making sustainable practices more accessible.

These concepts, while most often applied to small molecule work, are equally vital for making large-scale processes like gene therapy manufacturing more sustainable through energy-efficient facility design, closed-loop systems, bioprocess intensification, and energy recovery.