Sustainability metrics for eco-technologies assessment, Part II. Life cycle analysis

This work presents a sustainability analysis of CO₂ reuse to produce dimethyl carbonate (DMC) via ethylene oxide (ROUTE A) and via urea methanolysis (ROUTE B). Two different technologies are considered in ROUTE A: reaction followed by separation and reactive distillation. Life cycle analyses of the ROUTES are presented employing sustainability analysis performed in HYSYS process simulator, along with WAR Algorithm. Process economical optimization is performed to maximize the processes profitability. A sustainability function, defined as a 2D indicator involving both economical and environmental aspects, is calculated for the optimized processes. Additional sustainability indexes are evaluated: material index, energy index, and ecoefficiency. The results, under both economical and environmental aspects, show that ROUTE A is the most sustainable. The study also points to the relevance of the frontier set between the domains cradle-to-gate and gate-to-gate in assessing process sustainability during LCA.