Economic and Environmental Evaluation for Purification of Diisopropyl Ether and Isopropyl Alcohol via Combining Distillation and Pervaporation Membrane

Abstract

Diisopropyl ether and isopropyl alcohol have attracted interest as promising raw materials. Finding an environmentally friendly and sustainable production is a goal that people are constantly pursuing. Extractive distillation is a traditional technique for separation of the mixture diisopropyl ether/isopropyl alcohol/water. The traditional technique should be improved due to its high energy consumption. In this work, feed preheating and hybrid membrane distillation are explored as two alternatives for separation and evaluated from the economic, environment, and human health points of view. Two different solvents (ethylene glycol and dimethyl sulfoxide) are considered and compared. To analyzethe thermodynamic efficiency, condenser exergy analysis, stage enthalpy, and exergy loss are studied. Life cycle assessment is used to assess the effects of extractive distillation, feed preheating, and mixed membrane distillation on human health and the environment. In terms of energy consumption and the total annual cost, hybrid membrane distillation is superior to extractive distillation and feed preheating. At the same time, hybrid membrane distillation produces the lowest human toxicity and environmental impact. Thus, in the process of separation, the combination of distillation and pervaporation membrane should be considered because it is an environmentally friendly process.

Process Optimization of Heat-Integrated Extractive Dividing-Wall Columns for Energy-Saving Separation of CO2 and Hydrocarbons

“…Exergy analysis combines the first and second laws of thermodynamics to reflect the amount of energy used and available. , Figure shows the typical exergy flow diagram for a separation process, in which Q in and Q out are the heat flows crossing the boundary of the system, W min is the required minimum separation work, and LW is the exergy loss of the system. Consequently, the thermodynamic efficiency, η, can be expressed by eq , where W min and LW are calculated by eqs and , respectively. − Here, n (kmol/h) is the molar flow rate of streams, Q R (kJ/h) and Q C (kJ/h) are the heat duty of reboilers and condensers, respectively, and b (kJ/h) is the availability of streams, i.e., exergy of streams. Exergy is defined as b = H – T 0 S , where H (kJ/kmol) and S (kJ/(kmol K)) are the molar enthalpy and entropy of the stream, respectively.…”

Energy-Saving Exploration of Mixed Solvent Extractive Distillation Combined with Thermal Coupling or Heat Pump Technology for the Separation of an Azeotrope Containing Low-Carbon Alcohol

“…To further compare the differences between these processes, the thermodynamic analysis profiles for the stage-enthalpy deficit and stage-exergy loss were studied. The corresponding tray sketch is shown in Figure , and a detailed expression for the rate of exergy loss was calculated as follows: where the last term represents the thermal exergy of an energy stream, which is given as follows: …”

Energy-Efficient Hybrid Reactive-Extractive Distillation with a Preconcentration Column for Recovering Isopropyl Alcohol and Diisopropyl Ether from Wastewater: Process Design, Optimization, and Intensification

“…Figure depicts the four-column extractive distillation (FCED) reproduced from the work of Qi et al, which is the base case in this work. Qi et al appears to be the pioneer in separating DIPE/IPA/water since the feed flowrate and composition from their work are widely used in the later studies. ,, The percentage difference of the TAC between the reproduced FCED (Figure ) and ref is less than 10%, which highlights the accuracy of our reproduced model. Before the CED, it is mandatory to add a preconcentration column (i.e., first column in Figure ) to remove most of the water content since the initial water content in the feed stream is 60 mol %, which far exceeds the azeotropic composition.…”