Abstract
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polymer with excellent thermal and mechanical properties comparable to fossil-based plastics. Scaling up the production of this polymer could provide a viable solution for reducing the use of fossil-based materials. However, its current production capacities are limited, with only a few facilities implementing the process at pilot or semi-industrial scales. The primary challenge lies in the high production costs, with 40% of the expenses attributed to the feedstock used for fermentation. Additionally, the energy required for sterilization in processes using pure methanotrophic cultures further reduces its economic viability. In this study, the economic aspects of the PHBV production process were assessed at an industrial level (100,000 t/y PHBV), using cheap and renewable substrates such as valeric acid and methane. A mixed methanotrophic consortium was used to reduce the need for sterility. The techno-economic analysis was based on estimating both fixed investment and operating costs. Then, a sensitivity analysis was performed to analyse the effect that the polymer content has on the final selling price: the initial biomass concentration was set to 30 g L-1, and the PHBV content was considered to be 20, 30, 40, 50 and 70% wt on a dry weight basis. The results revealed that increasing the polymer content beyond 40% wt led to a more competitive PHBV selling price, thus opening significant market opportunities.
