화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.4, 1656-1667, 2020
Separation Strategies of Hydrogenation and Oxidation Products from Miscanthus for Bio-Ethylene Glycol Production
Miscanthus can be hydrogenated into ethylene glycol (EG) or can be oxidized into methyl glycolate (MG), a precursor of EG. For comparison, three-, two-, and four-column processes (I, II, and III, respectively) were established for the separation of hydrogenation (I) and oxidation products (II and III) in ASPEN PLUS. Oxidation products containing negligible and appreciable amounts of methyl levulinate (MLE) were separated by the processes II and III, respectively. The total heat duty (THD) and total cold duty (TCD) of process I were approximately 73% lower than those of processes II and III, and the E-factor of process I was relatively low, but the maximum operation temperature (MOT) was high. Process II (esters hydrogenation first) was both energy-saving and cost-effective because of low high-temperature heat duty (HTHD), less EG loss, and low total annual cost. Process III (esters distillation first) exhibited the largest THD, TCD, HTHD, and total annual cost. Sensitivity analysis results demonstrated that MLE greatly increased HTHD in process III. The appreciable amount of MLE could be extracted from MG with n-hexane with an MG yield of 93.7%, for EG production through process II.