Process modelling for industrial scale polyhydroxybutyrate production using fructose, formic acid and CO2: Assessing carbon sources and economic viability

Polyhydroxybutyrate (PHB) is a biodegradable polymer that has potential to replace petroleum-derived plastics. However, the commercialisation of PHB is hindered by high production costs. In this study, the material flow and economics of an industrial scale PHB production process using fructose, formic acid and carbon dioxide (CO2) as carbon sources were simulated and analysed. The lowest breakeven price of 3.64 $/kg PHB was obtained when fructose was utilized as carbon source. When formic acid and CO2 were used, the breakeven price was 10.30 and 10.24 $/kg PHB due to raw material cost, respectively. Although using formic acid and CO2 is more expensive, they meet the emerging sustainable needs for plastic production and contribute to the circular economy via CO2 fixation. This study suggests that the use of formic acid and CO2 as feedstock for PHB production has potential to become competitive in the bioplastic market with further research.