Techno-economic and environmental assessment of triacetin production from crude glycerol at industrial scale

This work presents the techno-economic and environmental assessment of a large-scale continuous process to produce high-purity triacetin (99.6 wt %) from low-quality glycerol from 2nd generation biodiesel. Overall, the process achieves a glycerol conversion and triacetin yield of 96.4 % and 75.4 %, respectively, generating 18,000 tons yr −1 of triacetin and approximately 5000 tons yr −1 of technical grade diacetin (63.33 wt %) as by-product. In terms of waste, 0.34 kg kg TA −1 and 0.58 kg kg TA −1 of wastewater and indirect CO 2 emissions are produced, respectively. The process requires 177.7 MJ kg TA −1 of cooling and 177.7 MJ kg TA −1 of heating. Regarding economics, to achieve the breakeven point, the minimum selling prices of triacetin and the by-products are £1754.0 ton −1 and £877.0 ton −1 , respectively. An increase in the market value of triacetin up to £2000 ton −1 leads to a simple pay-back time of 3.4 years with a return on investment of 29.7 %. Environmentally, the primary energy demand of the process is 369.5 MJ∙kg TA −1 with a global warming potential of 22.8 kg CO2,eq ∙kg TA −1 and fossil depletion of 8.2 kg oil,eq ∙kg TA −1 . Finally, the E-factor, process mass intensity and carbon economy are 0.21, 1.34 and 0.93, respectively. These results show the promise of the process for triacetin production.