PRINCIPE: Predictive chemical kinetics for biodegradable polymer gasification

Overview

PRINCIPE is a predictive chemical kinetics platform developed for the gasification of PET and biodegradable polymer mixtures (PET/PLA/PHA) into syngas and valuable chemicals. The solution addresses a critical need in chemical recycling by enabling accurate prediction of product distribution — including syngas, CO, H2, CO2, CH4, tars, and char — as a function of operating conditions. This predictive capability directly supports reactor design and process optimization for converting plastic waste into valuable chemical feedstocks, contributing to circular economy goals.

The platform is built on more than 20 years of pioneering research in plastic waste thermal degradation modeling, combined with recent experimental capabilities including TGA (thermogravimetric analysis) measurements with online MS and offline GC-MS for mass loss profiling and product speciation. It has been validated across multiple polymer types including PE, PP, PS, PVC, Nylon-6, and PMMA, demonstrating broad applicability to heteroatom-containing polymers.

Technical specifications

Core methodology:

• Reaction class and rate rule approach modeling polymer breakdown through radical chain and molecular reactions
• Homogeneous kinetic model describing secondary gas-phase evolution of released products
• Coupled heterogeneous/homogeneous kinetic mechanisms for gasification reactions of gases, tars, and char

Phase 1 deliverables:

• TGA-based experimental investigation of PET thermal degradation kinetics across a wide range of heating rates
• Product identification (gases, tars) and residual char characterization through elemental analysis, morphology, Raman spectroscopy, and XRD
• Liquid phase cracking model for PET describing mass loss profiles and product distribution
• Secondary gas-phase chemistry (gasification) model delivered in CHEMKIN format, suitable for parametric analyses and reactor design support

Phase 2 deliverables:

• Kinetic investigation of PET/PLA/PHA mixture thermal degradation
• Char gasification model incorporating heterogeneous reactions using temperature-programmed gasification experiments with H2O, CO2, and O2
• Extended secondary gas-phase chemistry model for polymer mixtures

Validation performance:

• Mass loss profile accuracy within 20–30 °C
• Char yield prediction within ±5% mass
• Gas product distribution accuracy within 30% on average

Technology readiness level

The underlying methodology has been extensively validated on PE, PP, PS, PVC, Nylon-6, PMMA, and polymer mixtures, with proven accuracy in mass loss profiling, char yield prediction, and gas product distribution. Recent unpublished studies confirm model reliability across a large experimental dataset.

The PRINCIPE project is currently advancing from proven methodology to targeted application on PET gasification (Phase 1) and PET/PLA/PHA mixture gasification (Phase 2). Phase 1 focuses on establishing PET-specific kinetic parameters and delivering a validated CHEMKIN-format chemistry model. Phase 2 extends the framework to polymer mixtures and char gasification kinetics. The project is positioned to deliver validated kinetic models suitable for industrial reactor design and process scale-up for chemical recycling applications.