Techno-economic analysis and life cycle assessment of sustainable farnesene production by genetically engineered cyanobacteria utilizing carbon dioxide: a step towards commercial viability

Abstract

Escalating atmospheric carbon dioxide from anthropogenic activities, notably fossil fuel combustion, deforestation, and industrial processes, represents a significant global challenge, impacting climate, ecosystems, and human health. CO₂ is a prominent component found in flue gas. Autotrophic organisms like cyanobacteria sequester CO₂ to produce value-added products. Farnesene is a terpenoid with a wide range of applications in various sectors like cosmetics, biofuel, pesticides/insecticides and lubes. Recently, we have demonstrated the highest farnesene productivity from genetically engineered Synechococcus elongatus UTEX 2973 when grown in 5% CO₂. The lab-scale results show promising prospects for the commercial viability of the process utilizing CO₂. Therefore, in the present study, a techno-economic analysis of the process was conducted with calculated capital expenses (CapEx), operating expenses (OpEx), minimum farnesene selling price (MFSP), net present value (NPV), internal rate of return (IRR), and payback period time. The estimated CapEx for the plant amounts to $28.16 million (MM), encompassing equipment, installation and other costs. Considering both fixed and variable operating costs, the total annual OpEx is projected to be $30.75 MM. The key cost drivers of the MFSP were determined by single-point sensitivity analysis. The study identified that farnesene productivity and the cost of electricity, isopropyl myristate and the inducer, mainly influence the MFSP. A NPV of $12.87 MM was calculated for the plant with an IRR of 12%. Moreover, a life cycle assessment of the conceptual process is conducted, indicating that the process is carbon neutral. The study provides future insight into the commercialization of sustainable farnesene production by cyanobacteria.