Sustainability metrics for eco-technologies assessment, part I: preliminary screening

Abstract

This work presents a preliminary screening of eco-technologies for dimethyl carbonate (DMC) production. Through sustainability metrics, the assessment of six different chemical routes allows comparisons according to economical and environmental criteria, to determine the most sustainable route. CO₂ sequestration potential is also considered. The alternatives are scored according to the adopted metrics, leading to the decision of a suitable route based on economic and environmental grounds, prioritizing pollution-preventing technologies herein referred to as eco-technologies. Casting of technologies was based on alternatives available in the literature: Route 1 production of DMC from methanol and phosgene [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 2 production of DMC from methyl nitrite and CO [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 3 production of DMC from CO and methanol [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 4 production of DMC from urea and methanol (Wang et al. in Ind Eng Chem Res 46:8972–8979, 2007); Route 5 production of DMC from ethylene oxide and CO₂ [Ono in Pure Appl Chem 68(2):367–375, 1996]; Route 6 production of DMC from CO₂ and methanol (Choi et al. in Green Chem 4:230–234, 2002). The analysis shows that Routes 4 and 5 combine intermediate values of the total (sustainability) score, CO₂ sequestration potential and industrial feasibility, therefore entitled as eco-technologies, based on the adopted metrics. Although the two technologies are potentially ecological, they are recommended for a more rigorous analysis on the grounds of process simulation and life cycle analysis.