<bold>Techno-economic analysis of multiple bio-based routes to adipic acid</bold>

Techno-economic studies of four processes for production of adipic acid from glucose were used to compare the minimum cost of production by each route. We analyzed the purely biological production via reverse -oxidation in E. coli; a purely chemical process using oxidation of glucose via chemical catalysis to glucaric acid that undergoes catalytic hydrodeoxygenation to adipic acid; and two hybrid routes that biologically convert glucose to either 6-hydroxyhexanoic acid or 1, 6-hexanediol, that are subsequently converted chemically to adipic acid using a metal catalyst. All analyses were based on adipic acid production capacity of 80 000 metric ton/year. Estimated total capital investments were US$157 million, $81 million, $166 million, and $177 million for the purely biological, chemical, and two integrated hybrid routes, respectively. Catalyst costs were estimated as $72 million, $36 million, and $37 million for the purely chemical and two integrated routes, respectively. The estimated adipic acid minimum selling prices were $1.36, $1.56, $1.48, and $1.70 per kg for the purely biological, purely chemical, and two integrated routes, respectively. Co-product revenue and the use of unpurified sugars improved the economics of adipic acid production in the purely biological and two integrated routes. Comparison of the economics of the chemical catalytic steps shows that catalyst yields, turnover frequency, and catalyst life must be greater than 40% of theoretical, 0.01 s(-1), and 100 days to achieve economic viability of purely chemical and integrated routes to adipic acid. (c) 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.