Complete Green Metrics Evaluation of Various Routes to Methyl Methacrylate According to Material and Energy Consumptions and Environmental and Safety Impacts: Test Case from the Chemical Industry

In this paper we present a standardized protocol for the complete evaluation of greenness of 18 industrial routes to methyl methacrylate (MMA) covering material and energy consumptions and environmental and safety impacts. A methodology for estimating energy consumption for chemical reactions and synthesis plans from published journal and patent literature procedures is fully described. A new energy metric pertaining to enthalpic changes from standard state conditions (298 K, 1 atm) to reaction conditions (Trxn, prxn) for all input materials used in a synthesis plan for the production of 1 mol of product is defined with respect to the heating and evaporation of 1 mol of water from 298 K and 1 atm. Limitations and best practices of running the protocol are discussed. The present study serves as a template for implementing the protocol to the green metrics analysis of high volume industrial chemicals. Results of plan rankings are compared with previous work on inherent safety indexes. Based on these findings, the isobutylene and t-butyl alcohol routes to MMA are found to have the overall greenest attributes among the 18 routes examined.