Multiobjective Optimization of the Economic Efficiency of Biodegradable Plastic Products: Carbon Emissions and Analysis of Geographical Advantages for Production Capacity

The objective of this study was to address the limitations of biodegradable plastics—low economic benefits and marketing difficulties. To this end, this study analyzed the production processes of two biodegradable plastics: polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT). Based on this analysis, economic, technical, and environmental improvement indicators were constructed, and an optimization model with the three objectives of profit, carbon emission cost, and process risk was established. In this study, we embedded the improved NSGA-III algorithm to obtain the Pareto optimal solution set. We also proposed the entropy-weighted efficiency index (EWEI) for the analysis of transport advantages based on the distribution of biodegradable plastics production, road density, and regional prices. With a production line capacity of 10,000 tons and an 8% discount rate, the 10-year return of PBAT products was 7,039,931.23 yuan higher than that of PLA products. The profit of PBAT products was 488.92 yuan higher than that of PLA products per ton of production. However, PBAT products exhibited higher carbon-emission cost and process risk than PLA products, especially process risk, by 0.11%. The East China region has obvious geographical advantages, but the Southwest region is constrained by limitations in production capacity and the presence of mountainous terrain. Therefore, it is imperative to optimize China’s overall industrial layout of biodegradable plastics, strengthen the profit acquisition of biodegradable plastics, support the sustainable promotion of the biodegradable plastics market, and effectively minimize the environmental pollution caused by traditional plastics.