Lab 2 HYSYS Full Report

7/24/2019 Lab 2 HYSYS Full Report

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1.0 INTRODUCTION

The production of methanol is carried out in a moderate-pressure synthesis loop by direct

hydrogenation of carbon dioxide, which generates a liquid product that contains a binary

mixture of methanol and water in approximately equal proportions. To provide

commercial methanol that is nearly free of water, dehydration is achieved commonly by

distillation. The simulation considered an equimolar mixture of 2700 kmol/hr at 25 oC

and 5.2 bar. It is then split and fed to two distillation columns, one at reduced pressure,

with the design specification shown in the following table:

Condition DC1 DC2

Pressure (bar) 5.2 1.01

Number of trays 16 13Feed Tray* 12 9

Reflux ratio 1.26 0.834

Distillate to feed ratio 0.96 0.96

*Count from the top of DC

Pressure Relief Valve

Valve used during this process is to reduce the pressure of methanol water mixture that

discharged from the separator. Valve is a technical device that been used to control the

flow of the fluid by regulating or directing. There are too many different types of valve.

Every different valve has their own design, working principle and function. The type used

in this process is the pressure relief valve. It controls the pressure limit for the system in

order to avoid any hazard due to over limit of pressure.

Distillation Column

An apparatus used widely for countercurrent contacting of vapor and liquid to effect

separations by distillation or absorption. In a column that can be applied to distillation,

a vapor condenser is used to produce liquid (reflux) which is returned to the

top, and a liquid heater (reboiler) is used to generate vapor for introduction at the bottom.

Distillation works by the application of change in composition which will lead to removal


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of heat to exploit differences in relative volatility. The heat causes components with lower

boiling points to be vaporized, leaving less volatile components as liquids. This changes

make differences of flow rate from point to point.

2.0 OBJECTIVE

1. Understand the usage of valve and distillation specification

3.0 THEORY

The Peng-Robinson Equation Of State

This equation is popular among the petroleum industry for natural gas system. It had been

presented and developed by Peng and Robinson in 1976. The original equation are:

b2bVV

a(T)

bV

RTP

22

Where, a(T) = [1 + (1- Tr

)] A

A = [a= 0.45724]Pc

TcR 22

B = [b=0.07780]Pc

TcR

Where is a dimensionless parameter such that

0.49: = 0.37464 + 1.54226 - 0.26992

> 0.49: = 0.379642 + 1.48503 - 0.164423 + 0.016666

With new variables, A = a(T)P/RT and B = bP/RT it could be rewritten in terms of

Z + (B - 1)Z + (A - 2B - 3B)Z + (B + B - AB) = 0
http://encyclopedia.che.engin.umich.edu/Pages/SeparationsChemical/DistillationColumns/Hotspot/RelativeVolatility.htmlhttp://encyclopedia.che.engin.umich.edu/Pages/SeparationsChemical/DistillationColumns/Hotspot/RelativeVolatility.html


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4.0 PROCEDURES

1. The new project was selected by using ICON software.

2. For the starting, the fluid package was being chosen as mentioned in the manual

which was Advanced Peng-Robinson property package in Figure 1 below.

3. Then the components was filled up by selecting methanol and water in Figure 2.


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4. Based on the question given, the equipment that should be used was arranged thus,

the condition of each equipment then was filled up one by one to complete the

process. Starting by arranging the equipment in, then, the composition and

condition of methanol and water was added in the information column in Figure 3.

5. The condition of separator then was completed up and connected to the stream 1.


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6. Two distillation column was connected to the outlet of separator with bottom outlet

was connected to the valve first in order to reduced the inlet pressure of second

distillation column from 5.2 bar to 1.01 bar.

7. The condition of the distillation column was filled up one by one starting from the

number of tray, feed tray, and also split ratio.


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8. Finally, when the system was calculated as solved, all the information was

observed and taken from the stream summary tables. All the questions then been

answer based on the information taken.


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5.0 RESULTS


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MOL SUMMARY TABLE

Name S1 S2 S3 S4

Description

Upstream Op SP-1.Out1 SP-1.Out0 Vlv-1.Out

Downstream Op SP-1.In C-1.Feed_12_feed Vlv-1.In C-2.Feed_8_feed

VapFrac 0.00 0.00 0.00 0.00

T [C] 25.0 25.0 25.0 25.1

P [kPa] 520.00 520.00 520.00 101.00

MoleFlow/Composition Fraction kmol/h Fraction kmol/h Fraction kmol/h Fraction kmol/h

METHANOL 0.5000 1350.00 0.5000 675.00 0.5000 675.00 0.5000 675.00

WATER 0.5000 1350.00 0.5000 675.00 0.5000 675.00 0.5000 675.00

Total 1.00 2700.00 1.00 1350.00 1.00 1350.00 1.00 1350.00

Mass Flow [kg/h]67577.1

433788.5

733788.5

733788.5

7

Volume Flow [m3/h] 78.814 39.407 39.407 39.416

Energy [W]

-2.287E+

7

-1.144E+

7

-1.144E+

7

-1.144E+

7H [kJ/kmol] -30494.8 -30494.8 -30494.8 -30494.8

S [kJ/kmol-K] 82.041 82.041 82.041 82.089

MW 25.03 25.03 25.03 25.03

Mass Density [kg/m3]857.420

4857.420

4857.420

4857.230

3

Name S5 S6 S7 S8

Description

Upstream OpC-1.LiquidDraw_0_c

ondenserLC-1.LiquidDraw_17

_reboilerLC-2.LiquidDraw_0_c

ondenserLC-2.LiquidDraw_12_r

eboilerL

Downstream Op

VapFrac 0.00 0.00 0.00 0.00

T [C] 123.4 153.1 73.0 99.9

P [kPa] 520.00 520.00 101.00 101.00

MoleFlow/Composition Fraction kmol/h Fraction kmol/h Fraction kmol/h Fraction kmol/h

METHANOL 0.52083 675.00 0.00001 0.00 0.52083 675.00 0.00001 0.00

WATER 0.47917 621.00 0.99999 54.00 0.47917 621.00 0.99999 54.00

Total 1.001296.0

0 1.00 54.00 1.00 1296.00 1.00 54.00

Mass Flow [kg/h] 32815.74 972.83 32815.74 972.83

Volume Flow [m3/h] 42.830 1.063 40.193 1.015

Energy [W] -7.708E+6-3.684E

+5-9.413E+

6-4.316E+

5

H [kJ/kmol] -21410.5 -24559.7 -26146.4 -28770.0

S [kJ/kmol-K] 108.113 98.406 95.395 87.885

MW 25.32 18.02 25.32 18.02

Mass Density [kg/m3] 766.1795915.270

5 816.4473 958.8348


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MASS SUMMARY TABLE

Name S1 S2 S3 S4

Description

Upstream Op SP-1.Out1 SP-1.Out0 Vlv-1.Out

Downstream Op SP-1.In C-1.Feed_12_feed Vlv-1.In C-2.Feed_8_feed

VapFrac 0.00 0.00 0.00 0.00

T [C] 25.0 25.0 25.0 25.1

P [kPa] 520.00 520.00 520.00 101.00

Mole Flow [kmol/h] 2700.00 1350.00 1350.00 1350.00

MassFlow/Composition Fraction kg/h Fraction kg/h Fraction kg/h Fraction kg/h

METHANOL 0.6401143256.5

1 0.6401121628.2

6 0.6401121628.2

6 0.6401121628.2

6

WATER 0.3598924320.6

3 0.3598912160.3

1 0.3598912160.3

1 0.3598912160.3

1

Total 1.0067577.1

4 1.0033788.5

7 1.0033788.5

7 1.0033788.5

7

Volume Flow [m3/h] 78.814 39.407 39.407 39.416

Energy [W]-2.287E+

7-1.144E+

7-1.144E+

7-1.144E+

7

H [kJ/kmol] -30494.8 -30494.8 -30494.8 -30494.8

S [kJ/kmol-K] 82.041 82.041 82.041 82.089

MW 25.03 25.03 25.03 25.03

Name S5 S6 S7 S8

Description

Upstream OpC-1.LiquidDraw_0_c

ondenserLC-1.LiquidDraw_17_

reboilerLC-2.LiquidDraw_0_c

ondenserLC-2.LiquidDraw_12_

reboilerL

Downstream Op

VapFrac 0.00 0.00 0.00 0.00

T [C] 123.4 153.1 73.0 99.9

P [kPa] 520.00 520.00 101.00 101.00

Mole Flow [kmol/h] 1296.00 54.00 1296.00 54.00

MassFlow/Composition Fraction kg/h Fraction kg/h Fraction kg/h Fraction kg/h

METHANOL 0.65908 21628.24 0.00001 0.01 0.65908 21628.24 0.00002 0.01

WATER 0.34092 11187.50 0.99999 972.82 0.34092 11187.50 0 .99998 972.82

Total 1.00 32815.74 1.00 972.83 1.00 32815.74 1.00 972.83

Volume Flow [m3/h] 42.830 1.063 40.193 1.015

Energy [W]-7.708E+

6-3.684E

+5-9.413E+

6-4.316E+

5

H [kJ/kmol] -21410.5 -24559.7 -26146.4 -28770.0

S [kJ/kmol-K] 108.113 98.406 95.395 87.885

MW 25.32 18.02 25.32 18.02

Mass Density [kg/m3]766.179

5915.270

5 816.4473958.834

8


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1. What is the molar flow before entering DC1 and DC2?

DC1: 1350 kmol/h DC2: 1350kmol/h

2. How to reduce pressure in DC2?

By using valve. This valve will reduced the pressure from the outlet stream of

separator (5.2 bar to 1.01 bar).

3. What is the temperature at the bottom of DC1 and DC2?

DC1: 153.1C DC2: 99.9C

4. Did the process achieve a methanol that free from water? What is the purity of the

methanol? How to increase the purity?

Yes, the process to remove the water from the methanol is achieved since the both

bottom outlet of distillation contains 0.999 composition of water. The purity of the

methanol can be checked by using simplest method which is by measuring its specific

gravity, methanol purity =(1 - specific gravity) divided by 0.2087. The purity is less

than 1. In order to increase the purity of methanol, the impurities must be removed by

formation of resin and the most important is it must be free from water since its purityis dependent on the water.


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6.0 DISCUSSIONS

Based on the process simulation had been done using ICON software, the usage of valve

and the distillation column can be understanding better. The pure liquid methanol was

produced at the end of process. The component fed are water and methanol that passed

through splitter with ratio 0.5 then into two distillation column.

The first distillation column was fed with no pressure drop while the second column with

P = 4.19 bar. The function of distillation column is to achieve the highest purities in

both top and bottom outlet. The purity of methanol is determined by the composition of

methanol from the distillation process. In order to increase the purity of methanol, the

number of tray can be added to the column.

The product leaving the column can be said as free from water since the both bottom

outlet of distillation contains 0.999 composition of water. The process to get the pure

methanol product is achieved.

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Lab 2 HYSYS Full Report