DEVELOPING A NEW INITIALIZATION PROCEDURE FOR DISTILLATION COLUMN SIMULATION

The simulation of distillation columns is an essential step in design, optimization, and rating. In this paper, a new procedure has been proposed for the initial estimation of column profiles based on modified Kremser’s group method for simple and/or complex columns. The effect of this initialization algorithm on simulation procedure has been studied through two examples. The results show significant improvement in convergence and considerable saving in execution time up to 30%. The proposed method can be used in problems which require numerous simulation runs to find the optimum conditions such as distillation column sequencing and the optimum design of distillation columns. The proposed method could also be used as an approximating simulation method for simple and complex distillation columns considering constant relative volatility and constant molar overflow assumptions. <br /

Prediction of the Products Yield of Delayed Coking for Iranian Vacuum Residues

In this work, new correlations are proposed to predict the products yield of delayed coking as a function of CCR and temperature based on the experimental results. For this purpose, selected Iranian vacuum residues with Conradson carbon residue (CCR) values between 13.40-22.19 wt.% were heated at a 10 °C/min heating rate and thermally cracked in a temperature range of 400-500 °C in a laboratory batch atmospheric delayed coking reactor for 2 hours. The amount of distillate (C5+-500 °C) and coke yield were measured in all the experiments, and the gas (C1-C4) product yield was calculated based on mass balance between products and feedstock in each experiment. According to the developed functions, products yield changes with CCR value linearly and is a power function of temperature. The further investigation of the results show that by a 1 wt.% increase in CCR value, the distillate yield decreases by about 2.1 wt.%, but the amount of coke and gas yields rise by 1.2 wt.% and 0.9 wt.% respectively

Three-component Distillation Columns Sequencing: Including Configurations with Divided-wall Columns

In the present work, the exergy analysis and economic study of 3 different samples of threecomponent mixtures have been investigated (ESI>1, ESI≈1, and ESI<1). The feed mixture has been tested under three different compositions (low, equal, and high contents of the intermediate component). A quantitative comparison between simple and complex configurations, considering thermally coupled, thermodynamically equivalent, and divided-wall column (DWC) has been carried out. The results present that the best sequence could be found by TAC or exergy loss rate analysis. Complex sequences have greater exergy losses in comparison to simple sequences. Despite expectations, the Petlyuk sequence only performs well in a few cases and poorly on others. According to the results, as the amount of intermediate component in the feed increases, both TAC and exergy losses of each sequence increase. The results also demonstrated that the occurrence frequency as the best sequence for DWC, thermodynamically equivalent, thermally coupled, and basic sequences are 36%, 28%, 25%, and 11% respectively. According to authors’ best knowledge, a quantitative exergy and cost comparison (based on rigorous simulation and optimization) between these configurations have never been carried out all together before

Aluminum Oxide Nanoparticles for Highly Efficient Asphaltene Separation from Crude Oil Using Ceramic Membrane Technology

The effects of aluminum oxide nanoparticles on the removal of asphaltenes from an Iranian crude oil (Soroush) using a ceramic membrane with pore size of 0.2 µm were investigated. In order to achieve superior asphaltene separation by ultrafiltration, it is essential to make some changes for destabilizing asphaltene in crude oil. The asphaltene destabilization was done using crude oil contact with an acid containing dissolved metal ions. Metal oxide nanoparticles adsorbed asphaltene molecules and increased their molecular size. The nanoparticle of aluminum oxide was applied to alter precipitation and peptization properties of asphaltenes. Dynamic Light Scattering (DLS) was used to measurement of the asphaltene molecular size dissolved in toluene. Raman spectroscopy and the Tuinstra equation were used to determine the aromatic sheet diameter (La) via the integrated intensities of the G and D1 modes. This revealed that the asphaltene particles react with nano aluminum oxide and the average molecular size of asphaltene was raised from 512.754 to 2949.557 nm and La from 5.482 to 13.787. The obtained results showed that using nano aluminum oxides, asphaltene separation increased from 60–85 wt% to 90–97 wt% based on the asphaltene content of crude oil

Aluminum Oxide Nanoparticles for Highly Efficient Asphaltene Separation from Crude Oil Using Ceramic Membrane Technology

The effects of aluminum oxide nanoparticles on the removal of asphaltenes from an Iranian crude oil (Soroush) using a ceramic membrane with pore size of 0.2 µm were investigated. In order to achieve superior asphaltene separation by ultrafiltration, it is essential to make some changes for destabilizing asphaltene in crude oil. The asphaltene destabilization was done using crude oil contact with an acid containing dissolved metal ions. Metal oxide nanoparticles adsorbed asphaltene molecules and increased their molecular size. The nanoparticle of aluminum oxide was applied to alter precipitation and peptization properties of asphaltenes. Dynamic Light Scattering (DLS) was used to measurement of the asphaltene molecular size dissolved in toluene. Raman spectroscopy and the Tuinstra equation were used to determine the aromatic sheet diameter (La) via the integrated intensities of the G and D1 modes. This revealed that the asphaltene particles react with nano aluminum oxide and the average molecular size of asphaltene was raised from 512.754 to 2949.557 nm and La from 5.482 to 13.787. The obtained results showed that using nano aluminum oxides, asphaltene separation increased from 60–85 wt% to 90–97 wt% based on the asphaltene content of crude oil