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Acetone and n -heptane are common solvents in the pharmaceutical industry and they have been found in wastewater. Under atmospheric conditions, the mixture of these compounds creates a minimum-boiling azeotrope. The extractive distillation process with a high boiling solvent is commonly utilized to separate the azeotropes in the industry to minimize waste, reuse resources, achieve clean production, and preserve the environment. In this work, extractive distillation was applied to separate the binary azeotropic system of acetone and n -heptane in wastewater using butyl propionate as a solvent. The characteristics of the process are designed and simulated via Aspen Plus. The simulation results showed that to get a distillate containing at least 99.5 mass% acetone, a solvent-to-feed ratio of 1.4, a reflux ratio of 1.5, a number of stages of 30, a feed stage of 26, a solvent stage of 10, and a solvent temperature of 298.15 K were required. The optimum operating parameters of the process were also obtained using the NLP optimization method, with the minimum total annual cost as the objective function. While the process was operating in optimal mode, CO 2 emissions were calculated to be 0.0780 kg CO 2 /kg feed.

The production of natural gas from the gas hydrates has attracted significant attention over the last few decades. A continued challenge in gas hydrates is the estimation of the stored gas capacity. To alleviate this problem, this study uses the numerical modeling to provide insight into the distribution of hydrate in porous media and to obtain information about the application of high pressure for gas recovery. Hydrate dissociation process in porous media is modeled at the pore scale using pore network modeling by considering the uniform and non-uniform hydrate distribution. We explored the effect of gas clustering, saturation, and recovery, and their dependency on the underlying parameters including the pore size distribution, the applied pressure drops across the pore structures, and the initial hydrate saturation. We found that non-uniform hydrate distribution, larger pore sizes along with high-pressure drop, and higher initial hydrate saturations enhanced gas release. Additionally, our results confirmed the findings of the previous studies using 2D networks which studied pressure drop during hydrate dissociation in reservoirs.

A 3D pore network model was developed to simulate the removal of dextran from water. Advanced scanning electron microscopy combined with focused ion beam analysis was used to obtain the sizes of the different pore networks that represent the microscopic structure of a porous membrane. The required input transport parameters for modeling were obtained by performing dynamic experiments on dextran adsorption within the pores of a polysulfone membrane. The simulated flux changes demonstrated a good agreement with the experimental data showing that such a model can be used to study the effects of various parameters during the process. Specifically, the results showed an increase in the applied pressure, decreased membrane thickness, increased pore size, while small sizes of contaminant molecules lead to a rise of the flux passing through the membrane.

Background: Ethylene, propylene, and butylene as light olefins are the most important intermediates in the petrochemical industry worldwide. Methanol to olefins (MTO) process is a new technology based on catalytic cracking to produce ethylene and propylene from methanol. Aims and Objective: This study aims to simulate the process of producing ethylene from methanol by using Aspen HYSYS software from the initial design to the improved design. Methods: Ethylene is produced in a two-step reaction. In an equilibrium reactor, the methanol is converted to dimethyl ether by an equilibrium reaction. The conversion of the produced dimethyl ether to ethylene is done in a conversion reactor. Changes have been made to improve the conditions and get closer to the actual process design done in the industry. The plug flow reactor has been replaced by the equilibrium reactor, and the distillation column was employed to separate the dimethyl ether produced from the reactor. Result and Conclusion: The effect of the various parameters on the ethylene production was investigated. Eventually, ethylene is