Ethyl
propionate is usually produced from esterification of propionic
acid and ethanol in the industry. However, the purification of ethyl
propionate remains a challenge because the unreacted ethanol forms
an azeotrope with ethyl propionate. In this work, extractive distillation
was adopted, and isobutyl acetate was chosen as the entrainer to separate
the mixture of ethanol and ethyl propionate. The vapor–liquid
equilibria for binary systems of ethanol/ethyl propionate + isobutyl
acetate were measured at atmospheric pressure, and the experiment
data were correlated with the nonrandom two-liquid model, universal
quasi-chemical model, and Wilson model. Then, the thermodynamic analyses,
using residue curves, isovolatility curves, and extractive composition
profile of the ethanol + ethyl propionate + isobutyl acetate ternary
system, were performed to confirm the feasibility of separating the
azeotrope with isobutyl acetate as the entrainer. The extractive distillation
process was designed and optimized by the sequential iterative procedure
based on the total annual cost. Results of the extractive distillation
simulation also verified the reliability of thermodynamic analysis.
Considering the separation of 1-butanol and water, extraction
has
received increasing attention because of the advantages of easy operation
and low energy consumption. In this work, deep eutectic solvents (DESs)
were introduced as hydrophilic solvents for 1-butanol dehydration.
The COSMO-SAC model was employed for DESs screening, and choline chloride–urea
1:2 DES (reline) was selected as the corresponding solvent. Via various
quantum chemical methods, hydrogen bonds were proven to be the main
molecular interactions, wherein a stronger interaction in water +
reline was the fundamental for achieving 1-butanol dehydration. Liquid–liquid
equilibria were measured at three temperatures, and the results indicated
that reline had excellent separation performance especially under
conditions of lower temperature or lower water content. Furthermore,
the NRTL model was used to correlate experimental data to obtain binary
parameters, and the extraction process was simulated. By the investigation
of operation parameters, high-purity 1-butanol was obtained via a
high recovery rate.
Methanol
and methylal form a minimum boiling point azeotrope and cannot be
separated by conventional distillation. In this paper, the azeotrope
was separated by extractive distillation with cyclohexanol as the
entrainer. First, the vapor–liquid equilibrium data of methanol
+ cyclohexanol and methylal + cyclohexanol were measured at 101.3 kPa,
and the thermodynamic consistency of the experimental data was tested
by the van Ness and pure component consistency test methods. The experimental
results were correlated by activity coefficient models, which are
nonrandom two-liquid (NRTL), universal quasichemical (UNIQUAC), and
Wilson. Then, the feasibility of separating the azeotrope with cyclohexanol
as the entrainer and the separation sequence were studied by thermodynamic
topological analysis of phase diagrams and residual curve map. Finally,
the appropriate operating conditions were obtained by sensitivity
analysis, and the extractive distillation simulation was carried out.
The results show that cyclohexanol can be used to separate methanol
and methylal by extractive distillation.
Facing the demand of strengthening the collaborative innovation ability of postgraduates under the background of emerging engineering education, the authors based on many years of teaching and scientific research experience carry out a series of teaching reforms on the teaching content, teaching methods, teaching means and assessment methods for the advanced separation engineering course. The project case base is established, case teaching and team cooperation are adopted to integrate multi-field professional knowledge and the latest scientific research achievements. Professional software is used to solve complex engineering problems, and the manual calculation and software calculation exercises are combined to strengthen the understanding and application of theoretical knowledge. The diversified assessment mode is taken to improve the study enthusiasm and autonomous learning ability. The practice shows that the teaching reforms and implementation of this course obviously improve the teaching effect, which is of great significance to the cultivation of postgraduates' comprehensive engineering ability, team communication and innovative thinking ability.
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.