Thermal coupled extractive distillation sequences with three entrainers for the separation of azeotrope isopropyl alcohol + diisopropyl ether

Abstract

BACKGROUND During the synthesis of isopropyl alcohol (IPA) by hydration of propylene, diisopropyl ether (DIPE) is usually produced as a by‐product. Because IPA and DIPE can form a binary homogeneous azeotrope with the minimum boiling temperature at atmospheric pressure, it is difficult to separate the binary mixture by simple distillation. RESULT For separating the azeotrope IPA + DIPE, side‐stream extractive distillation column (SSED) and extractive dividing wall column (EDWC) processes with three entrainers [2‐methoxyethanol (2‐MEA), 2‐ethoxyethanol and propylene glycol ethyl ether (PGEE)] were simulated and optimized based on the minimal total annual cost (TAC). Moreover, CO2 emissions of the six sequences were calculated and the impact on the environment evaluated. CONCLUSIONS The sequence of SSED with PGEE as entrainer can reduce TAC by ≤34.48%, but EDWC with PGEE can offer TAC reduction of ≤52.46%. The results demonstrate that the EDWC sequence with PGEE as entrainer is favourable for separating the binary azeotrope IPA + DIPE. © 2020 Society of Chemical Industry

Evaluation and control of energy‐efficient processes for separating epichlorohydrin‐oriented quaternary system

“…This makes it challenging to separate ECH from this quaternary system, as conventional distillation cannot effectively separate high-purity ECH from the azeotrope. 12,13 Therefore, there is an urgent need to develop a simple and efficient process to separate this quaternary azeotropic mixture, to recover ALC and MET while purifying ECH. This is of great significance in promoting the industrialization of direct epoxidation of ALC, achieving resource recycling and environmental protection.…”

“…This ECH/H 2 O/ALC/MET quaternary system is composed of three binary azeotropes, 11 ECH/H 2 O, ALC/H 2 O and ALC/MET, among which ECH/H 2 O has the highest boiling point. This makes it challenging to separate ECH from this quaternary system, as conventional distillation cannot effectively separate high‐purity ECH from the azeotrope 12,13 . Therefore, there is an urgent need to develop a simple and efficient process to separate this quaternary azeotropic mixture, to recover ALC and MET while purifying ECH.…”

Evolutional Design and Plant-Wide Control for Dimethyl Ether Production by Combining Dynamic Process Intensification and Pervaporation Membranes

“…The application of process intensification (PI) technology is an effective approach for reducing energy consumption. Larger equipment, high investment, and energy-intensive processes are replaced with smaller equipment, cost saving, and more efficient processes with PI technology, − which is carried out using one or more techniques in the spatial domain, thermodynamic domain, functional domain, and temporal domain at different scales. , For instance, reactive distillation (RD) is a static PI technique in the functional domain. It has been employed in the DME production process by methanol dehydration, which has the advantages of small equipment investment, overcoming the restriction of balance and increasing the conversion. , Temporal domain-based intensification is implemented by operating the device in a nonsteady state, which is referred to as dynamic process intensification (DPI).…”

Ethanol Dehydration with Ionic Liquids from Molecular Insights to Process Intensification

“…Therefore, reducing the loss of available energy in the distillation process is an effective means of saving energy according to the thermodynamic analysis. Some researchers have proposed some energy saving technologies for the distillation processes, such as thermal coupling of columns, 31 divided-wall column, 32 heat-integrated distillation, 33 and heat pump distillation. 34 Li et al 35 retrofitted the separation process of a benzene/cyclohexane mixture with sulfolane as the entrainer through the efficient use of the entrainer-sensible heat.…”