Economic Impact of Recycled and Bioplastic Packaging Production in Australia - A Monte Carlo Simulation Model

. The shift towards sustainable packaging necessitates evaluating alternatives such as recycled polyethylene terephthalate (rPET) and bio-based polylactic acid (PLA) against conventional PET, particularly with respect to economic viability and environmental trade-offs in specific regional contexts, such as Australia. This study presents a comparative techno-economic analysis of PET, rPET, and PLA packaging production in Australia, employing an integrated assessment framework combining deterministic analysis, stochastic Monte Carlo simulation (10,000 runs), and long-term scenario analysis (to 2030). By integrating these three complementary approaches, this work offers a novel, uncertainty-aware assessment of sustainable packaging alternatives in the Australian context, addressing a gap in the literature where such comprehensive multi-method comparisons remain limited. Cost data were sourced from peer-reviewed literature and Australian market reports, accounting for variations in feedstock, energy, capital, and collection systems (Door-to-Door vs. Return-Deposit). Deterministic analysis showed that rPET (RDS: AUD 0.80/kg; D2D: AUD 1.00/kg) can be cost-competitive with virgin PET (AUD 1.00/kg), whereas PLA (AUD 2.82/kg) remains significantly more expensive due to high fermentation and feedstock costs. Stochastic analysis confirmed PLA's higher cost uncertainty (mean total cost: AUD 3.50/kg; SD: 1.34) compared with PET (mean total cost: AUD 1.15/kg; SD: 0.36) and rPET (D2D Mean: AUD 1.58/kg; SD: 0.02). Long-term scenarios indicate potential cost reductions for PLA and rPET through productivity gains; however, energy price volatility remains a key factor. While rPET offers a cost-competitive pathway for sustainable packaging in Australia, PLA faces significant economic hurdles that require substantial process-efficiency improvements and supportive policies. Optimised recycling systems (RDS) enhance the viability of rPET. This study presents a quantitative, uncertainty-aware framework for comparing packaging materials in Australia, underscoring the critical need for integrated techno-economic assessments to guide policy and investment toward a circular economy for plastics.