This study investigates an innovative method to produce dimethyl ether (DME) by direct synthesis from syngas derived from biogas. The proposed process was rigorously simulated in Aspen Plus, highlighting the main sections: (i) biogas tri-reforming, (ii) dimethyl-ether synthesis, and (iii) DME purification. The tri-reforming section has a CO₂ and CH₄ conversion of 27.3% and 96.2%, respectively A novel catalyst suitable for CO₂-rich feed was chosen for the DME production to allow 60% conversion of CO₂. Product separation is achieved via several absorption and distillation columns, ensuring that the operating conditions are kept mild to avoid expensive refrigeration. An optimization analysis was performed to identify the most suitable layout of the downstream process. This was identified through the evaluation of performance indicators such as utility usage and operating expenses. A wide range of purification strategies have been evaluated, and two scenarios are proposed based on the results. Configuration A produces 5.34 ktpy DME and 1.26 ktpy methanol, while Configuration B produces exclusively 6.21 ktpy DME. The process configurations were analysed by means of key techno-economic indicators and sustainability metrics. Both processes have an energy intensity of 14.5 kWh/kg. The reforming unit has a negligible footprint as it is thermally sustained from biogas combustion, but the reboilers are the main contributors for plant CO₂ emissions. Configuration B has the best economic value with 11,634 k€ of NPV after 25 years and a payback time of 4 years.

The constant development of new alternatives to treat waste aids in closing material loops towards the circular economy and improving sustainability through the use of new renewable materials and energy. This fact leads to the increasing need for decision-making tools for process synthesis and assessment, which can be addressed with an integrated framework that employs ontologies for knowledge management and optimization tools to perform a hierarchical assessment of alternatives. The systematization of these procedures raises the need for tools to automate techno-economic and life cycle analyses. In this work, such a challenge is addressed through the additional integration of add-on modules such as the CapEx-Opex estimation tools and surrogate modeling within this framework. A case study on plastic waste is proposed with the inclusion of several pyrolysis and gasification alternatives. Results show pyrolysis, followed by the subsequent purification of its products, as the best alternative and helped identify main drivers for technologies feasibility such as feedstock purity and energy consumption.