The formation of heterogeneous ternary
azeotropes poses a serious
challenge to the recovery of diisopropyl ether (DIPE) and isopropyl
alcohol (IPA) from the industrial effluent. To reduce the energy consumption
rates and improve the process efficiency of this energy-intensive
separation process, three novel intensified separation configurations
with pressure-swing heat integration are proposed, which include one
improved extractive distillation (ED) strategy and two heterogeneous
azeotropic distillation (HAD1 and HAD2) schemes. A comprehensive evaluation
of the three separation schemes is performed in terms of economics
and CO2 emissions. The heat-integrated configurations,
respectively, reduce the 29.78, 42.19, and 39.71% in energy consumption
rates. In addition, the heat-integrated HAD2 scheme demonstrates the
greatest energy-saving potential, wherein the total annual cost is
reduced by 1.61 and 7.37% compared to the ED and HAD1 schemes, respectively.
In general, these efforts provide a reference for recycling DIPE and
IPA from the industrial effluent.
N-Propanol (NPA) and n-propyl acetate (NPAC) can form
an azeotrope
under normal pressure, so their separation cannot be carried out by
conventional distillation. Therefore, 1-butyl-3-methylimidazole acetate
([BMIM][OAC]) and ethylene glycol (EG) were selected as entrainers
for extractive distillation of the two substances. Isobaric vapor–liquid
equilibrium data were obtained by experiments of NPA + NPAC, NPA +
NPAC + [BMIM][OAC], and NPA + NPAC + EG at normal pressure; the experimental
results showed that the separation effect of [BMIM][OAC] is significantly
better than that of EG. Finally, the data were fitted and correlated
with the NRTL model. The ARD (average relative deviation) of NPA +
NPAC, NPA + NPAC + [BMIM][OAC], and NPA + NPAC + EG is less than 5%,
indicating that the NRTL model has good applicability to the vapor–liquid
system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.