Green dimethyl carbonate production feasibility based on technical and environmental considerations
Letitia Petrescu, Carina-Alina Iurian
Abstract
This study aims to provide insights into evaluating various dimethyl carbonate (DMC) production processes, balancing sustainability and industrial viability to meet the growing demand for this versatile compound. It presents a comparative analysis of three phosgene-free prominent methods for DMC synthesis: 1) indirect urea alcoholysis, 2) synthesis from methanol (MeOH) and carbon dioxide (CO 2 ), and 3) indirect synthesis via ethylene oxide (EO) and CO 2 . The annual desired productivity was set to 10,000 tons of DMC. CHEMCAD process simulator software was used as an engineering tool to generate the mass and heat balances on which various technical key performance indicators are based on and furthermore compared. Several details on process flow diagrams, simulation assumptions, as well as mass, and heat balances are provided. Each method’s advantages and disadvantages are evaluated in terms of productivity, DMC purity, electrical, and thermal energy consumption, and the number of pieces of equipment used. The technical comparison performed led to the conclusion that the indirect synthesis of DMC from EO and CO 2 , followed by its subsequent reaction with MeOH, stands out as the most favourable choice among the examined methods. This preference is attributed to several technical key performance indicators: the process achieves a high product purity of 99.84 %, overall yield reaches 99 % and it demonstrates the lowest thermal energy consumption of 8,993.50 MJ/ tDMC . Additionally, this method requires fewer processing units, which simplifies the overall process and can contribute to lower operational and maintenance costs. The three scenarios are also investigated from an environmental perspective using the Life Cycle Assessment (LCA) Methodology. LCA for Experts software and ReCiPe impact assessment method are used for the LCA study. The environmental results show that DMC production from EO and CO 2 using hydropower and steam generated from biomass leads to the best results in various environmental impact categories.