Environmental footprint performance improvement of black tea using the life cycle assessment approach

Abstract

The cultivation and production of black tea are associated with significant energy consumption and adverse environmental concerns, largely stemming from inefficient practices, equipment incompatibility, and suboptimal cultivation methods. In response, this study employs a comprehensive life cycle assessment (LCA) to address these issues and identify potential environmental improvements across the entire black tea system, encompassing both the cultivation and production phases. The primary focus of this analysis is the evaluation of key environmental metrics, including global warming potential (GWP), primary energy demand (PED), and water usage (WU). The study's findings highlight that a reduction in the use of chemical fertilizers during the black tea cultivation stage can effectively mitigate GWP, PED, and WU. A sustainable approach involves shifting towards a fertilization scenario that incorporates 70% organic fertilizers and 30% chemical fertilizers. This adjustment makes the cultivation stage more environmentally friendly, resulting in reduced resource depletion and water consumption. Furthermore, the analysis reveals that the application of artificial grass covering, as opposed to herbicides, has a significantly more negative impact on GWP, PED, and WU. Similarly, the use of insecticides during black tea cultivation leads to higher values for GWP, PED, and WU in comparison to employing solar pest control lamps. Additionally, the LCA analysis underscores the effectiveness of integrating solar pest control lamps and herbicide treatments during the black tea cultivation stage to achieve lower GWP and reduced resource consumption. On the other hand, the black tea production stage makes a substantial contribution to the system's GWP, PED, and WU, primarily due to the heated withering and natural fermentation processes. However, transitioning to frozen withering and aerobic fermentation processes presents a more environmentally friendly approach, resulting in a black tea production method that is lower in carbon emissions and energy-efficient, with minimal adverse environmental impact.