Complex Systems of Distillation Columns Used in the Production of the Propylene Oxide

Complex systems of distillation columns were intensively studied within last decades and continue to show interest for researchers and for industrial application. The first designed complex distillation column with heat integration was the Petlyuk column and the development of complex systems of columns continued up to dividing wall columns (DWC) which are increasingly being used in industry. DWC are usually used to separate three products, components or fractions, from a multicomponent mixture. This study attempts to find the best fitting of complex systems of columns in the process of propylene oxide (PO) obtaining using the method of propylene chlorination and presents a proposed variant of separation which can lead to a reduced energy consumption. The fabrication of PO through this method lead to a multicomponent mixture which is separated in two main products: propylene oxide (PO) and heavier components containing as valuable compound 1,2 dichloropropane (DCP). Both products, PO and DCP, have important uses in the chemical industry. The study of complex schemes of columns used for PO separation was assessed by simulation using a simplified method based on Fenske � Underwood - Gilliland correlation (F.U.G.) [1]. The systems studied in this work include the following configurations of columns: column with prefractionator, column with partially coupled prefractionator, the Petlyuk column, the dividing wall column, column with side striper, column with side rectifier, the direct and the indirect sequence.

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Reducing Energy Consumption in Propylene-Propane Separation with Heat Coupled Distillation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.225-226.500 ◽

2011 ◽

Vol 225-226 ◽

pp. 500-503

Author(s):

Lan Yi Sun ◽

Jun Li ◽

Xue Nuan Liu ◽

Qing Song Li

Keyword(s):

Energy Consumption ◽

Distillation Column ◽

Pressure Ratio ◽

Internal Heat ◽

Thermodynamic Efficiency ◽

Total Annual Cost ◽

Heat Integration ◽

Internal Heat Integration ◽

Vapor Recompression ◽

Reducing Energy

The heat coupled distillation column which applies the principle of internal heat integration between the rectifying section and the stripping section of a distillation column by increasing the temperature of the rectifying section with a compressor attracts extensive attention worldwide for its high thermodynamic efficiency. In this study, the economic features of a heat coupled distillation column (HCDC) are investigated and compared to a conventional column and a commercial column with vapor recompression system (VRC) for the separation of propylene-propane mixture. The economic analysis indicates that HCDC has 10 – 20 % total annual cost (TAC) saving associated with VRC, which appeared to be strongly sensitive to the pressure ratio.

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Towards further internal heat integration in design of reactive distillation columns—Part III: Application to a MTBE reactive distillation column

Chemical Engineering Science ◽

10.1016/j.ces.2008.01.006 ◽

2008 ◽

Vol 63 (8) ◽

pp. 2119-2134 ◽

Cited By ~ 16

Author(s):

Kejin Huang ◽

San-Jang Wang ◽

Wenming Ding

Keyword(s):

Distillation Column ◽

Reactive Distillation ◽

Internal Heat ◽

Heat Integration ◽

Distillation Columns ◽

Internal Heat Integration

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OPTIMIZATION OF A PETROLEUM FRACTIONAL DISTILLATION COLUMN USING DISTOP CALIBRATION AND STATISTICAL METHODS

Brazilian Journal of Petroleum and Gas ◽

10.5419/bjpg2020-0017 ◽

2021 ◽

Vol 14 (04) ◽

pp. 221-237

Author(s):

M. B. M. M. Nobrega ◽

A. S. Zimmermann ◽

S. Mattedi ◽

O. Chiavone-Filho

Keyword(s):

Energy Consumption ◽

Distillation Column ◽

Energetic Efficiency ◽

Vapor Flow ◽

Calibration Technique ◽

Distillation Columns ◽

Energy Demands ◽

Separation Equipment ◽

Crude Oil Distillation ◽

Feed Temperature

Distillation columns are important separation equipment that comprise most of the investment needed in a petroleum refining plant. Utilities and energy demands, though, are a concerning factor in the current economic and environmental scenario. The present work proposes a methodology to optimize the energy consumption of a crude oil distillation column using the Distop Calibration technique that allows faster convergence than the Tray-to-Tray method. The methodology presented involves process simulation, sensitivity analysis, factorial design, and the use of response surface methodology. Results show that it is possible to achieve significant gains by changing feed temperature and rectifying vapor flow, causing a relevant reduction in energy consumption. Hence, the methodology can be used as an optimization tool to increase energetic efficiency.

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Modeling, Simulation, and Thermally Optimization of Thermally-Coupled Distillation Columns

International Journal of Chemoinformatics and Chemical Engineering ◽

10.4018/ijcce.2016010101 ◽

2016 ◽

Vol 5 (1) ◽

pp. 1-11

Author(s):

Fatemeh Safari ◽

Arjomand Mehrabani-Zeinabad

Keyword(s):

Energy Consumption ◽

Distillation Column ◽

Direct Sequence ◽

Thermally Coupled Distillation ◽

Distillation Columns ◽

Modeling Simulation ◽

Heating And Cooling ◽

Reduce Energy Consumption ◽

Thermally Coupled Distillation Column ◽

Backward Integration

Distillation is one of the most widely used separation units that consumes the largest amount of energy in chemical and petrochemical industries. Heat integration of thermally coupled distillation column is one of the methods to reduce energy-consumption. This paper provides a comparison between two simple columns with direct configuration and thermally coupled distillation column with direct sequence backward integration arrangement for separation of a ternary mixture based on energy-consumption. The influence of changing numbers of first and second column trays on heating and cooling rate of each column are investigated based on a developed mathematical model using conservation law of mass and energy and bubble-point method. The average relative error between calculated and industrial temperatures in some trays is about 0.74%. The condenser duty of high pressure column is about 9.73×109 kJ/h to provide heating of low pressure column. According to the simulation results, the thermally coupled construction saves energy about 50% more.

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Towards further internal heat integration in design of reactive distillation columns—Part IV: Application to a high-purity ethylene glycol reactive distillation column

Chemical Engineering Science ◽

10.1016/j.ces.2009.04.031 ◽

2009 ◽

Vol 64 (15) ◽

pp. 3498-3509 ◽

Cited By ~ 26

Author(s):

Fanghong Zhu ◽

Kejin Huang ◽

Shaofeng Wang ◽

Lan Shan ◽

Qunxiong Zhu

Keyword(s):

Ethylene Glycol ◽

High Purity ◽

Distillation Column ◽

Reactive Distillation ◽

Internal Heat ◽

Heat Integration ◽

Distillation Columns ◽

Internal Heat Integration

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Integrated Multiscale Latent Variable Regression and Application to Distillation Columns

Modelling and Simulation in Engineering ◽

10.1155/2013/730456 ◽

2013 ◽

Vol 2013 ◽

pp. 1-17 ◽

Cited By ~ 6

Author(s):

Muddu Madakyaru ◽

Mohamed N. Nounou ◽

Hazem N. Nounou

Keyword(s):

Feature Extraction ◽

Latent Variable ◽

Prediction Accuracy ◽

Distillation Column ◽

Selection Criterion ◽

Process Data ◽

Distillation Columns ◽

Latent Variable Regression ◽

Multiscale Filtering ◽

Modeling Algorithm

Proper control of distillation columns requires estimating some key variables that are challenging to measure online (such as compositions), which are usually estimated using inferential models. Commonly used inferential models include latent variable regression (LVR) techniques, such as principal component regression (PCR), partial least squares (PLS), and regularized canonical correlation analysis (RCCA). Unfortunately, measured practical data are usually contaminated with errors, which degrade the prediction abilities of inferential models. Therefore, noisy measurements need to be filtered to enhance the prediction accuracy of these models. Multiscale filtering has been shown to be a powerful feature extraction tool. In this work, the advantages of multiscale filtering are utilized to enhance the prediction accuracy of LVR models by developing an integrated multiscale LVR (IMSLVR) modeling algorithm that integrates modeling and feature extraction. The idea behind the IMSLVR modeling algorithm is to filter the process data at different decomposition levels, model the filtered data from each level, and then select the LVR model that optimizes a model selection criterion. The performance of the developed IMSLVR algorithm is illustrated using three examples, one using synthetic data, one using simulated distillation column data, and one using experimental packed bed distillation column data. All examples clearly demonstrate the effectiveness of the IMSLVR algorithm over the conventional methods.

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Comparison of Different Synthesis Schemes for Production of Sodium Methoxide from Methanol and Sodium Hydroxide

Engineering Journal ◽

10.4186/ej.2020.24.6.63 ◽

2020 ◽

Vol 24 (6) ◽

pp. 63-77

Author(s):

Natthiyar Aeamsuksai ◽

Thirawat Mueansichai ◽

Pongtorn Charoensuppanimit ◽

Pattaraporn Kim-Lohsoontorn ◽

Farid Aiouache ◽

...

Keyword(s):

Energy Consumption ◽

Total Energy ◽

Flow Rate ◽

Sodium Methoxide ◽

Distillation Column ◽

Reactive Distillation ◽

Flow Ratio ◽

Total Energy Consumption ◽

Pervaporation Membrane ◽

Simulation Parameters

This research investigates the process simulation of sodium methoxide (NaOCH3) synthesis from methanol (CH3OH) and sodium hydroxide (NaOH) under three synthesis schemes: schemes A, B, and C. Scheme A consisted of one equilibrium reactor and two distillation columns, scheme B one reactive distillation column and one distillation column, and scheme C one reactive distillation column and pervaporation membrane. The simulation parameters included CH3OH/NaOH feed flow ratio (1.2-1.6), number of stages (5-30), bottom flow rate (1400-1600 kg/h), and feed stage location (5, 10, 15, 20, 21, 22, 23, and 24). The simulation parameters were varied to determine the optimal NaOCH3 synthetic conditions under different schemes with 0.01 wt% water content, maximum 45 wt% NaOCH3, and the lowest total energy consumption. The results showed that scheme C had the lowest total energy consumption (34.25 GJ/h) under the optimal synthetic condition of 1.4 for CH3OH/NaOH feed flow ratio, 25 for the number of stages, 1550 kg/h for the bottom flow rate, and the 24th feed stage location, with the NaOCH3 flow rate of 675 kg/h. Scheme C thus holds promising potential as an energy-efficient alternative for synthesis of NaOCH3. The novelty of this research lies in the use of pervaporation membrane in place of distillation column to separate CH3OH from water and to lower energy consumption and capital cost.

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USING EXERGY LOSS PROFILES AND ENTHALPY-TEMPERATURE PROFILES FOR THE EVALUATION OF THERMODYNAMIC EFFICIENCY IN DISTILLATION COLUMNS

Revista de Engenharia Térmica ◽

10.5380/reterm.v4i1.3553 ◽

2005 ◽

Vol 4 (1) ◽

pp. 76 ◽

Cited By ~ 1

Author(s):

S. H. B. Faria ◽

R. J. Zemp

Keyword(s):

Energy Balance ◽

Distillation Column ◽

Enthalpy Of Solution ◽

Exergy Loss ◽

Thermodynamic Efficiency ◽

Consistency Test ◽

Distillation Columns ◽

Water Distillation ◽

Ideal Solutions ◽

Thermodynamic Excess

In this work the temperature-enthalpy profile and the exergy loss profile are used together to improve thermodynamic efficiency of distillation columns, by identifying possible benefits of using side exchangers. The method proposed is to compute the exergy loss profile and to analyse the distribution of the losses across the column stages. The present work aims at applying the stage-by-stage exergy analysis to the distillation of non-ideal mixtures, e.g. methanol/water. For these systems the use of thermodynamic excess properties is required: Gibbs free energy for phase equilibrium and enthalpy of solution for energy balance. Initial studies showed that the enthalpy of solution has a small effect on the overall energy balance of the distillation column, but a significant impact on the exergy loss profiles. Some profiles even showed a violation of the second law of thermodynamics, with entropy being destroyed on some stages, clearly indicating that a wrong approach to exergy calculation was being used.A model for exergy calculations of non-ideal solutions is presented. The exergy values so computed are then checked by a consistency test, using the reversible column profile. Finally, the exergy procedures are used to study a typical methanol/water distillation columns, where the exergy profiles are used to identify scope for intermediate heat exchange.

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Analyzing the Energy Consumption, GHG Emission, and Cost of Seawater Desalination in China

Energies ◽

10.3390/en12030463 ◽

2019 ◽

Vol 12 (3) ◽

pp. 463 ◽

Cited By ~ 18

Author(s):

Xuexiu Jia ◽

Jiří Klemeš ◽

Petar Varbanov ◽

Sharifah Wan Alwi

Keyword(s):

Energy Consumption ◽

Water Supply ◽

Reverse Osmosis ◽

Process Integration ◽

Ghg Emissions ◽

Water Desalination ◽

Heat Integration ◽

Seawater Desalination ◽

Ghg Emission ◽

Product Cost

Seawater desalination is considered a technique with high water supply potential and has become an emerging alternative for freshwater supply in China. The increase of the capacity also increases energy consumption and greenhouse gases (GHG) emissions, which has not been well investigated in studies. This study has analyzed the current development of seawater desalination in China, including the capacity, distribution, processes, as well as the desalted water use. Energy consumption and GHG emissions of overall desalination in China, as well as for the provinces, are calculated covering the period of 2006–2016. The unit product cost of seawater desalination plants specifying processes is also estimated. The results showed that 1) The installed capacity maintained increased from 2006 to 2016, and reverse osmosis is the major process used for seawater desalination in China. 2) The energy consumption increased from 81 MWh/y to 1,561 MWh/y during the 11 years. The overall GHG emission increase from 85 Mt CO2eq/y to 1,628 Mt CO2eq/y. Tianjin had the largest GHG emissions, following are Hebei and Shandong, with emissions of 4.1 Mt CO2eq/y, 2.2 Mt CO2eq/y. and 1.0 Mt CO2eq/y. 3) The unit product cost of seawater desalination is higher than other water supply alternatives, and it differentiates the desalination processes. The average unit product cost of the reverse osmosis process is 0.96 USD and 2.5 USD for the multiple-effect distillation process. The potential for future works should specify different energy forms, e.g. heat and power. Alternatives of process integration should be investigated—e.g. efficiency of using the energy, heat integration, and renewables in water desalination, as well as the utilization of total site heat integration.

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