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Department of Chemical Engineering

Indian Institute of Technology – Bombay

CL415 (RKM) Process Equipment Design & Economics 2015-2016

MINI PROJECT I

(Due on September 28, 2015)

No late submissions will be permitted

Important Note: Use any source of information except another person. Please note

that use of any commercial process simulator is strictly prohibited and you must carry

out all the calculations by yourself.

Preliminary Process Design and Costing of

A De-Butanizer Distillation System

The following hydrocarbon feed mixture is to be separated by a simple distillation

process to recover most of the butanes in the distillate. The feed is at 30oC and 6 kg/cm2,

and the molar flow rates of feed constituents are given in the following table:

Component Flow rate kgmol/h

Propane 25

i-Butane 75

n-Butane 125

i-Pentane 100

n-Pentane 175

The column is to be designed for a 99 % recovery of n-Butane in Distillate and 95%

recovery of i-Pentane in the Bottoms. The feed will be supplied to the column at its

bubble point and hence a preheater may be required. First establish an approximate

material balance and a tentative pressure profile using the heuristics. Carry out a

preliminary process design of the distillation system using the Fenske-Underwood-

Gilliland (FUG) method to establish the number of stages and operating reflux ratio

(use R/Rmin = 1.25). Use the Fenske’s method to distribute non-key components and

Kirkbride method to fix the location of the feed. For height and diameter calculations,

use the procedure given in the book by Peters and Timmerhaus. Choose the type of

internals with proper justification and appropriate efficiencies. Carry out the

preliminary sizing of condenser, reboiler, and preheater (if any). Estimate the purchased

and installed costs of all key equipment components of the distillation system.

Design Basis

1. Cooling water will be available at 30oC as Cold Utility.

2. Maximum permissible rise in temperature as well as ∆Tmin is 10oC.

3. The distillate will be withdrawn as saturated liquid.

4. The column should be designed for 80% of flooding conditions.

5. Kettle type reboiler will be used.

6. Saturated LP Steam will be available at a pressure of 3.5 kgf/cm2 as Hot Utility.

7. DePriester’s Charts should be used for obtaining the K-values.

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Items for Submission (All items as part of a well-structured PROJECT REPORT).

1. A well-drawn schematic of the distillation system with complete material and

energy balance. All calculations must be included in the report.

2. A complete record of all process design calculations including the sources of

data used, and assumptions made, if any.

3. A tabulation of calculated and used key design parameters for Distillation

Column, internals, condenser, reboiler, and preheater (if necessary).

4. A complete record of capital cost estimates including the sources of data and

cost laws. Costs should be presented in INR and must be recent.

5. A summary of utility consumption rate.

6. A listing of references used.

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