Process Simulation of 1,4-Cyclohexanedimethanol Production from Waste PETs

Area of Science:

• Chemical Engineering
• Materials Science
• Sustainable Chemistry

Background:

• Growing plastic waste, especially poly-(ethylene terephthalate) (PET), demands innovative recycling solutions.
• Chemical recycling offers a pathway to convert PET waste into valuable chemicals.
• Valorization of post-consumer PET is crucial for a circular economy.

Purpose of the Study:

• To design and simulate a chemical recycling process for producing 1,4-cyclohexanedimethanol (CHDM) from post-consumer PET.
• To evaluate the technical and economic feasibility of CHDM production via PET glycolysis and bis-(2-hydroxyethyl) terephthalate (BHET) hydrogenation.
• To provide an environmentally friendly valorization route for plastic waste.

Main Methods:

• Process design and simulation using Aspen Plus and Aspen EDR.
• Application of thermodynamic models (POLYUF, POLYSL, NRTL-HOC).
• Kinetic parameter derivation from literature and simulation databases.
• Equipment sizing, energy integration, and economic analysis using CAPCOST.

Main Results:

• A process design for producing 5000 tons/year of 97.4% pure CHDM from 7920 tons/year of PET.
• Estimated total production cost of 46.7 million USD.
• Profitability analysis showing a net present value of 4.39 million USD and a discounted cash flow rate of return of 16.14%.

Conclusions:

• CHDM production from PET waste is technically feasible and economically viable.
• The proposed process offers a sustainable valorization pathway for plastic waste.
• The study highlights the potential for circular economy approaches in plastic recycling.