Multidimensional evaluation for environment impacts of plastic straws and alternatives based on life cycle assessment

Abstract

The low price and excellent flexibility of plastic straws make them very popular, yet their short lifespan and improper disposal after use result in major resource waste and environmental burdens. To this end, paper straws and polylactic acid (PLA) straw alternatives have emerged on the market. Aiming to present a comparative sustainability study of drinking straws, this article provides a life cycle assessment of drinking straws made of polypropylene (PP), paper, and polylactic acid (PLA) based on Chinese context, as well as a scenario analysis of the availability of low-carbon electricity (LCE) and its recycling capacity (RC). The functional unit was set as a straw suitable for 500 ml milk tea cups, and the system boundary is from cradle to grave, including raw material preparation process, straw production process, usage process, waste process, transportation and recovery process. The comparative analysis revealed that the plastic straw alternative would not be superior in all indicators, but would lead to environmental problem-shifting, which will provide a basis for decision making and avoid bias caused by subjective choices. Scenario analysis shows that the synergistic effect of LCE and RC can minimize the environmental burden for paper straw, especially in terms of Primary Energy Demand (PED) which reduced by 27.9% with 100% RC and 50% LCE, and this is mainly due to RC. The findings of this work can offer theoretical justification, data references, and fresh perspectives for environmental evaluation of straws.