Techno-economic assessment of microbial limonene production.

• A novel microbial limonene production process at industrial plant scale is designed. • Limonene is recovered by a new combined gas-stripping/solvent-scrubbing method. • Multi-parameter techno-economic analysis is conducted to assess economic viability. • Minimum selling price is $19.9/kg as limonene productivity reaches 0.7 kg/(m3·h). • Uncertainties of parameters used in TEA were addressed by sensitivity analysis. To satisfy the growing demand for limonene, novel pathways for microbial production of limonene have been sought. A techno-economic analysis is carried out for one such process producing limonene from sugar at an industrial plant scale to assess potential economic viability. A conceptual design of the process is developed, in which a gas stripping-solvent scrubbing method is chosen for recovering limonene from bioreactors based on consideration of payback time and process operability. Minimum limonene selling prices are estimated over a range of fermentation productivity based on the calculation of net present value using discounted cash flow method. Under 45% of the maximum theoretical yield, the selling price reaches $19.9/kg, which could be competitive with established production processes when fermentation productivity is above 0.7 kg/(m3·h). Reduction of cost could be realised through improvement of microbial strains, utilisation of cheaper feedstocks, reduction in capital investment and strategic business planning. [ABSTRACT FROM AUTHOR]