Methyl Methacrylate Production Processes: A Comparative Analysis of Alternatives Using the Life Cycle Assessment Methodology

Green chemistry is part of the chemical industry's response to calls for improved environmental responsibility. It is also one of the industry's several paths to redemption from its erstwhile infamous reputation as one of the most polluting sectors. We studied the impacts of implementing some of these principles on the production of methyl methacrylate (MMA), the monomer of PMMA popularly known as acrylic glass. This study used life cycle assessment (LCA) methodology to compare the potential environmental impacts of three different approaches to the production of MMA. Two of these are established industrial pathways: the acetocyanohydrin process (ACH-MMA) and the Alpha Lucite process (AL-MMA), which represent the conventional and a fast-rising industrial route, respectively, while the third, the in situ formaldehyde process (inFAL-MMA) is a lab-based process. The scenarios were evaluated using cumulative energy demand (CED) and the ReCiPe 2016 impact assessment methods. The results obtained highlighted some hotspots that can benefit from process improvements and careful material and energy source selection. It also underscored that AL-MMA can record significant improvements in environmental performance by reducing the overall resource intensity of the process. inFAL-MMA synthesis was adjudged to be the most evolved of the three alternatives with respect to green chemistry principles; hence, the study sought to investigate possible environmental gains attributable to this. Some limitations of the methodology uncovered during the study necessitated the use of an additional tool for further assessment of the potential risk. Thus, the GREEN MOTION was adopted to examine this relationship. Overall, the study established hotspots and areas for process improvements in the scenarios examined. It also confirmed the importance of different factors like data quality, degree of process optimization, energy source, and others on the results that can be obtained in a LCA.