COMPARATIVE-STUDY OF RECOVERING ACETIC-ACID WITH ENERGY INTEGRATED SCHEMES

The heat pumping and multi-effect distillation techniques were evaluat ed for recovering acetic acid from aqueous solutions with low boiling solvents, methyl tert-butyl ether (MTBE) and ethyl acetate (EtOAc). Th e overhead vapour recompression and two types of column cascading tech niques are compared to the conventional acetic acid recovery scheme. I t was found that (1) by switching the solvent to MTBE, approximately a 57% reduction in utility cost can be reached; (2) by using mechanical vapour recompression, as well as two different multi-effect distillat ion arrangements, further utility cost reduction can be obtained. For the best configuration, a 68% reduction in the utility requirements fo r recovering acetic acid is achieved. The pay-back time for the best c onfiguration is calculated as 9 months. The calculated theoretical red uction in CO2 emission is approximately 404 kg CO2/h, corresponding to a 70 wt% reduction. Copyright (C) 1996 Elsevier Science Ltd.