This assignment should be done by Aspenplus and excel programs, check files to know more
Microsoft Word - 2020 Sieve Column Design Assignment.edited.docx School of Engineering – Chemical & Environmental Disciplines PROC2089 PROCESS PLANT DESIGN & ECONOMICS Assignment - Sieve tray column design TOTAL MARKS 50 1. Submission date: Week 5, 19 August 2020 (Wednesday), 11.59 pm. A late penalty will apply 10% of marks per working day. Assignments submitted 5 working days after the due date will be returned unmarked. 2. This assignment is an individual assignment. 3. This assignment is worth 20% of the overall marks for each student. 4. You are suggested to complete this assignment using MS Excel and save the file using the file name format “lastname. student number”. Also, make sure that you show your full name and student number on all pages of your spreadsheet. 5. You are allowed to submit only one Microsoft Excel file for this assignment. • Please use two separate worksheets in your Excel file. • In the first worksheet, you may paste the ‘screenshots’ of your AspenPlus simulations. • In the second worksheet, you may show your design calculations. • Don’t forget to name your worksheets (on the worksheet tabs at the bottom) • Please note that your design calculations should show appropriate labelling so that the marker can easily understand the calculations. 6. Assignments must be submitted in Canvas using the link available on the assignment page. 7. You are reminded about University anti-plagiarism rules. Assignments suspected for any form of plagiarism will be returned without marking. 8. Please note that AspenPlus software is available in Mydesktop. 9. A tutorial on distillation column simulation is now available in Canvas in the assignment folder for this assignment. It will help you in doing the AspenPlus simulation part of this assignment. If you have further questions regarding the simulation, please contact me. Prof. Raj Parthasarathy Email:
[email protected] Assignment question In the manufacture of methyl ethyl ketone (MEK) from butanol, the product is separated from unreacted butanol by distillation. The feed to the column consists of a mixture of 0.87 mol fraction MEK and 0.13 mol fraction 2-butanol. The liquid feed rate to the column is 25 kmol/h, and the feed temperature is 30oC and 101.3 kPa. The specifications required are: the top product (distillate) with MEK mol fraction of 0.965; the bottom product with 2-butanol mol fraction of 0.985. Aspen Plus Shortcut distillation column simulation requires the ‘fractional’ recoveries of MEK and 2-butanol in the ‘distillate’. The fractional recoveries of MEK and 2-butanol in the ‘distillate’ can be calculated using mass balance and they are 0.998 and 0.242, respectively. You are required to design a sieve plate column for this separation. The column will be operated mostly at atmospheric pressure. The operating reflux ratio is 1.4 times the minimum reflux ratio. In Aspen Plus Shortcut column simulation, you have to specify the reflux ratio as -1.4 under ‘Column specifications. This assignment is to be completed using AspenPlus simulation and spreadsheet calculations. The AspenPlus simulation should be used to determine important design parameters (shown below) whereas the spreadsheet calculations should be used to complete the hydraulic design of the sieve plate. a) Use AspenPlus simulation to determine the following: (MARKS 20) i. Minimum reflux ratio ii. Number of theoretical stages iii. Flow rates of distillate and bottoms iv. Flow rates and composition (mole fractions of solute and solvent) of vapour and liquid at the top and bottom plates of the column v. Temperature and pressure at the top and bottom plates of the column vi. Physical properties of vapour and liquid at the top and bottom plates of the column vii. Any other data required for the plate design When you are simulating the column in AspenPlus, you will be required to specify a fluid property package. You may choose 'Braun K10' or NRTL package for this simulation. This package is suitable for most of the petrochemicals. If 'Braun K10' or NRTL package does not work, you may use SRK or Peng-Robinson or any other ‘equation of state (EOS)’ based property packages. You will also be required to specify condenser and reboiler pressure in the simulation. You may use 100 and 250 kPa for condenser and reboiler, respectively as initial estimates. Please include the relevant pages of AspenPlus simulation as part of your assignment. You may get screenshots AspenPlus simulation pages and paste them on worksheet 1 of your Excel Spreadsheet. If you cannot get screenshots, then you may create ‘pdf’ files of AspenPlus simulations, copy and paste them on worksheet 1. The following AspenPlus pages should be included in your submission. Shortcut distillation column (DSTWU column) simulation: • The PFD of the shortcut distillation column simulation. • The results summary page that shows the minimum reflux ratio, actual reflux ratio, the minimum and the actual number of stages. • The worksheet that shows the operating conditions and flow rates of feed and products. Full distillation column simulation: • The page that shows PFD of the full distillation column simulation. • The worksheet that shows the pressure, temperature, liquid flow rate, vapour flow rate, profiles for all stages in the column. • The worksheet that shows the properties like the density of vapour and liquid phases, and the viscosity and surface tension of the liquid phase for all stages in the column. You need not include any other pages from AspenPlus simulation in your submission. b) Use MSExcel spreadsheet for the following calculations: (10+10+10 = 30 MARKS) Use the AspenPlus simulation data obtained for the column bottom stage (plate) conditions to design the sieve plate. You may use the following initial values for the plate design. If these values are not suitable, choose appropriate values and complete the design. You must complete these calculations using a spreadsheet. 1. Liquid flow on the plate = cross-flow 2. Hole diameter = Plate thickness = 5 mm 3. Weir height = 50 mm 4. Tray spacing = 0.5 m 5. Hole area = 10% of active tray area 6. Segmental downcomer area = 12% of column cross-sectional area 7. Turn-down ratio = 72% 8. Calming zone width = Unperforated edge strip width = 50 mm i. Estimate the • column diameter taking that the actual vapour velocity is 72% of the flooding velocity. • pressure drop at the bottom plate and compare it to the pressure drop obtained from AspenPlus simulation (the two pressure drop values need not match). ii. Check • for weeping and liquid entrainment conditions • whether the tray spacing is satisfactory or not iii. Prepare a plate layout and calculate the • total perforated area • number of holes • hole pitch • Include a diagram of the plate layout showing the dimensions such as the plate diameter, calming zone and unperforated strip edge widths, and overflow weir length. Microsoft Word - 2020 Sieve Plate Column Design Assignment Assessment Criteria.docx SCHOOL OF ENGINEERING – CHEMICAL ENGINEERING PROC 2089 PROCESS PLANT DESIGN AND ECONOMICS SIEVE PLATE COLUMN DESIGN – ASSIGNMENT Assessment Criteria Criteria Fails to m eet expectations A dequate M eets all expectations Your m ark Comments Use of Aspen Plus simulation to determine the following design parameters: • Minimum reflux ratio • Number of theoretical stages • Flow rates of distillate and bottoms • Flow rates and composition (mole fractions of solute and solvent) of vapour and liquid at the top and bottom plates of the column • Temperature and pressure at the top and bottom plates of the column • Physical properties of vapour and liquid at the top and bottom plates of the column • Any other data required for the plate design 0 10 20 Use the Aspen Plus simulation data obtained for column bottom stage (plate) conditions to estimate the following. Estimation of • the column diameter taking that the actual vapour velocity is 72% of flooding velocity • the pressure drop at the bottom plate 0 5 10 Checking • for weeping and liquid entrainment conditions • whether the tray spacing is satisfactory or not 0 5 10 Prepare a plate layout and calculate the • total perforated area • number of holes • hole pitch 0 5 10 TOTAL MARKS /50 Problem Description: A column is to be designed to separate a mixture of ethylbenzene and styrene. The feed will contain 0.95 mol fraction ethylbenzene and the balance styrene and its flow rate is 100 kmol/h. The mol fractions of ethyl benzene in the distillate and bottoms are to be 0.997 and 0.444, respectively. The corresponding fractional recoveries of ethyl benzene and styrene in the distillate are 0.96 and 0.05, respectively. The column top and bottom pressures are to be 0.1 and 0.2 bar, respectively. Estimate the number equilibrium stages required at an external reflux ratio of 8. Simulation of distillation column in Aspen Plus - Tutorial • Click on “Aspen Plus V10” icon to open the software. Once you open Aspen Plus V10, you will find the following Aspen Plus main window. Launching Aspen Plus V10 Software • Click on ‘New, you will see the following window. • Create an Aspen Plus project by clicking ‘Chemical process’, then click ‘Specialty Chemicals with Metric Units’, then click ‘Create’. Creating