hysys simulation

HYSYS SIMULATION

Presented by:Badriya Al-Abdulmohsen

Ghadeer MirzaZahra Meraj

Kuwait UniversityCollege of Engineering and PetroleumChemical Engineering Department

Supervised by:

Prof Mohd. Fahim

Eng. Yousif Ali

INTRODUCTION

• Phosgene Process

2CH3OH + COCL2 DMC + 2HCL

• Carbon monoxide Process

2CH3OH+CO+½O2 → (CH3O)2CO+H2O

•Carbon dioxide Process

2CH3OH + CO2 → (CH3O)2CO + H2O

Programming DMC into HYSYS

Adding a hypothetical component

Click create a Hypo Component then click UNIFAC

•Select number according to structural formula of DMC

DMC = C3H6O3

•Add groups

•Click on “Estimate Unknown Properties”

•Add group so it’ll be added to the component list

Phosgene Process

•Considered an old technique and unreliable since phosgene is toxic.

2CH3OH + COCL2 DMC + 2HCL

•The stream goes through a mixer and a heater to prepare it for the reactor

•The stream is heated to 130°C before it enters the conversion reactor at an assumed conversion of 95%

•The stream leaving the reactor has the following compositions

•The first distillation column is used to separate DMC from HCL

•The top stream contains pure HCL while the bottom contains DMC

•Only 81% of DMC purity in the bottom stream, therefore it undergoes further purification through another distillation column

•The second distillation column is used to separate DMC from all the other components

•The bottom stream contained 99% purity of DMC whilst the top stream is taken through a recycle.

The top stream undergoes cooling to return the temperature back to initial temperature. A tee is used to prevent accumulation.

•Before the recycle stream is mixed with the feed stream, a pump is used to increase the pressure from 1800kpa to 2000kpa.

Carbon monoxide Process

2CH3OH + CO + ½O2 → (CH3O)2CO + H2O

The three streams and the recycle stream(84) then go through a mixer and a heater to be prepared for entering the reactor.

The stream is heated to 130˚C before entering the conversional reactor

The streams leaving the reactor go through a mixer and then are cooled to 45˚C in a cooler, stream (7) enters the separator which is used to separate the gases.

The stream leaving the bottom of the separator then enters the distillation column (T-100) which is used to separate the DMC from the rest of the components

The bottom stream leaving the distillation column contains 95% purity of DMC whilst the overhead outlet stream is taken through a recycle.

Stream(8) is recycled by passing it through a tee which is used to prevent accumulation. Before the recycle stream is mixed with the feed stream, a pump is used to increase the pressure from 1800kpa to 2000kpa.

CO is produced from CO2 in the following reversible reaction:

CO2 + H2 ↔ CO + H2O

The conditions for the reaction are:

•T = 25°C

•Keq = 5x104

Carbon dioxide Process

It’s known as the direct synthesis of Dimethyl carbonate from carbon dioxide and attracted attention because it’s a non toxic intermediate and able to substitute phosgene since DMC is low in toxicity and quickly biodegradable plus the low cost of production.

2CH3OH + CO2 → (CH3O)2CO + H2O

The process conditions should be at a very high supercritical pressure 30000 KPa, however I have found by many trials the following relation between pressure and conversion of the reactor.

0

10

20

30

40

50

60

70

80

90

100

0 5000 10000 15000 20000 25000 30000 35000

Series1

Highest conversion

The stream goes through a mixer and a heater to prepare it for the reactor.

The mixed feed is then heated to 180 °C which the temperature required to operate the conversion reactor to achieve 93.42% conversion.

The stream leaving the reactor has the following compositions will be cooled to 45°C to be fed to the distillation column:

The first distillation column is used to separate DMC and water from CO2.

The top stream contains almost pure CO2 while the bottom contains DMC with water and small amount of methanol.

So another distillation column will be used to purify DMC from water while CO2 will be

recycled by sending it to a tee first to remove the small portion of methanol.

Then it will be compressed from 1800KPa back to the initial pressure 4000KPa and cooled to the initial temperature

Of the feed as well.

The second distillation column is used to separate methanol from DMC and water.

The bottom stream contained 50% purity of DMC while the top stream is taken through a recycle to recycle methanol.

Before the recycle stream is mixed with the feed stream, a tee is used to prevent accumulation then it’s cooled to be pressurized by a pump from 1800kpa to 4000kpa.

The third distillation column is used to separate DMC from water.

The top stream contained 99.7% purity of DMC while the bottom contains mostly water.

For all the 3 different processes we used a base case of 100 ton/day of feed and after comparing the product rate of DMC exiting from each processes we found that:

ComponentTemperature

°C

PressurekPa

Feed compositio

n

DMCcomposition

Phosgene23.802000100 ton/day90.33 ton/day

CO19.812000100 ton/day101.09 ton/day

CO218030000100 ton/day103.715 ton/day

The best option would be using CO because of:

•CO is very common.•The process doesn’t require any supercritical condition.•The process uses the syn gas reaction which is very common•easily performed.•Less toxic and more efficient.•Can be obtained from CO2.•Very high productivity.

END OF PRESENTATION

THANK YOU