ABSTRACT
This chapter describes the challenge of determining energy metrics for individual reactions and synthesis plans. It also describes various computational methods used to estimate thermodynamic parameters for substances when they are not available in handbooks. The chapter explores various energy metrics that have been put forward in the green chemistry literature that are applicable to individual reactions and synthesis plans. The cumulative energy demand of a product represents the direct and indirect energy use in units of MJ throughout the life cycle, including the energy consumed during the extraction, manufacturing and disposal of the raw and auxiliary materials. The absolute energy input consumption for an individual reaction or an entire chemical process is determined based on two main considerations: thermodynamic and operational. Energy intensity is the ratio of total process energy needed to produce a given product to the mass of that product.
