Techno-Economic and Lifecycle Analysis of Green Colloidal Silver: Moving toward Scale-Up.

Silver particles (AgPs) are increasingly used across a range of industries, including personal care, household, and food packaging, but conventional synthesis methods involve high production costs and negative environmental impacts. Green synthesis using plant extracts offers a sustainable alternative, though limited comparative data on economic and environmental performance exist. This study evaluates three green methods-BX3 (a patented extract), lemon juice (LJ), and green tea (GT)-against a conventional method using sodium borohydride (NaBH₄). Equal-volume reactions are analyzed via ICP-MS, UV-vis spectroscopy, and dynamic light scattering. Techno-economic analysis and life cycle assessment (LCA) assessed costs and environmental impact. BX3 emerged as the most cost-effective and environmentally friendly option, producing AgPs at $13,000/kg with a 75% yield and a global warming potential of 1,900 kg CO₂-Eq/kg. In contrast, NaBH₄ yielded 7.35% at $195,000/kg, 15x more expensive than the BX3 method, and a global warming potential of 74,000 kg CO₂-Eq/kg. GT, while a green method, has the highest cost $690,000/kg, the lowest yield (1.13%), and the worst environmental impact, including a human toxicity value of 92,000 kg 1,4-DCB-Eq/kg-even surpassing the toxic NaBH₄ process. These findings highlight BX3's promise for scalable, low-impact AgP production and broader industrial use.