Techno-Economic Assessment of a Closed-Loop Circular Economy for Polylactic Acid

Abstract

As the global demand for polylactic acid (PLA), a biodegradable plastic, continues to increase, both its production and consumption have been increasing steadily each year. This growth poses challenges for managing PLA waste disposal, highlighting the need for innovative solutions. In this study, techno-economic simulations were performed to recycle waste PLA using three distinct processes across seven different scenarios. These processes not only address waste management issues but also promote a transition from a linear to a circular plastic economy. The findings demonstrate that, compared to conventional industrial processes, the proposed recycling method using a TiO2/SiO2 catalyst has significantly increased PLA yield by 59.87% while reducing costs by 22.87%. The primary factor driving this improved yield is the choice of catalyst, which plays a critical role in determining the activity and selectivity of the direct conversion of methyl lactate to lactide in the gas phase. This research provides a sustainable and economically viable solution for recycling PLA waste, aligning with the growing demand for environmentally friendly alternatives in the plastics industry. The findings are essential for advancing the development of a circular plastics economy and emphasize the importance of catalyst optimization in improving the efficiency and sustainability of PLA recycling processes.