20 2. EXPANDING VIEW OF BAT DETERMINATION THROUGH A VALUE CHAIN PERSPECTIVE Certain principles of green chemistry may impact value chains in a variety of ways. For instance, substitutions of input materials with renewable or safer alternatives occur through changes in upstream material supply and may impact downstream activities such as waste management or product use. It is key to carefully evaluate these downstream impacts to avoid regrettable substitutions. Principles such as designing for waste prevention and resource efficiency may also impact downstream activities; the quantity and characteristics of waste can have a dramatic impact on the efficiency of treatment operations. Similarly, designing for degradation may affect the types of materials available for downstream reclamation, reuse, and recycling. Considering BAT determination through a green chemistry lens might result in identification of alternative chemicals and technologies that are economically competitive and offer advantages for industry and consumers, and (of course) are environmentally advantageous. Figure 4 illustrates how chemical use can be optimized through a green chemistry approach. In a ‘typical’ conventional chemicals process (in grey), a large amount of waste is produced relative to the amount of product. Implementation of green chemistry principles (in green) can lead to greater resource and energy efficiency, waste minimization, and recycling and regeneration of certain inputs.
Figure 4. Green Chemistry Example
Source: Adapted from: Green Chemistry (Organic Chemistry, n.d.[13])
Resource efficiency While definitions of resource efficiency may vary greatly depending on scope and scale, the European Commission notes that the goal of resource efficiency is to “deliver greater value with less input” (EC, 2020[14]). As such, resource efficiency can be considered as the ratio of the benefits derived from a process (generally as value added) to quantity of resources used and/or the environmental impact associated with resource use (Huysman, Sofie et al, 2015[18]). In common terms, resource efficiency can be defined as a unit of resource input per unit of product output (EC, 2016[15]), e.g., kilogram clay (input) per kilogram ceramic tiles (output), and cubic meter water (input) per ton meat produced (output). Therefore, maximizing for resource efficiency can achieve cost savings and reduce emissions. The concept of resource efficiency is illustrated below, in Figure 5. At the scale of the individual installation, resources include natural and processed natural resources (industrial resources). These resources generally include some combination of the following: raw materials,
BEST AVAILABLE TECHNIQUES (BAT) FOR PREVENTING AND CONTROLLING INDUSTRIAL POLLUTION © OECD 2022
