Adv. Design of Chem Systems Presentation_Hitesh Vaid(L20007882)

8/6/2019 Adv. Design of Chem Systems Presentation_Hitesh Vaid(L20007882)

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OPTIMIZATION OF METHANOLOPTIMIZATION OF METHANOLTO DME PROCESSTO DME PROCESS

Department of Chemical Engineering

Lamar UniversityBeaumont, TX 77710

SUBMITTED BY:

Thomas Zacharia (L20261221)

Hitesh Vaid (L200000882)Preeti Gangadharan (L20239920)

SUBMITTED TO

Dr. Helen Lou


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OverviewOverview

INTRODUCTION

PROBLEM DESCRIPTION

SOLUTION IDENTIFICATION, RESULTSAND DISCUSSION

ECONOMIC EVALUATION

CONCLUSIONS AND FUTURE WORK


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IntroductionIntroduction

y DME, is colorless gaseous ether with an

ethereal odor

y It can be made from natural gas, coal, or

biomass.

PHYSICAL AND CHEMICAL PROPERTIES:

Molar mass: 46.07 g/mol

Appearance: Colorless gas with typical smell

Density: 1.97 g/L, gas (1.59 that of air) 668

Kg/m3, liquid

Melting point: 138.5 C (134.6 K)/ (217.3 F)

242.37 R

Boiling point: 23

C (254 K)/ (12.82

F) 446.85

RSolubility in water: 328 g/100 mL (20 C)


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METHOD OFMETHOD OF

PRODUCTIONPRODUCTIONy DME synthesis from hydrogen and CO

gas, also known as syngas.

y The methanol dehydration method

2CH3

OH CH3

OCH3

+ H2O

Methanol dimethyl ether + water


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APPLICATIONSAPPLICATIONS

A refrigerant

A (co-)blowing agent for foam

A

propellant for aerosol productsA solvent

A fuel for welding cutting and brazing

A

multi-purpose fuel


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PROCESS FLOWSHEETPROCESS FLOWSHEET--

BASE CASEBASE CASE


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Heat integration to save utilityHeat integration to save utility

costscostsProblemMethanol feed stream is heated from 25 0C to 250 0C before entering the

DME reactor.

The product from the reactor which is at 343 0C is then cooled to 125 0C

prior to separation in the distillation column.Thus we have a very good opportunity to exchange heat between these

two streams.

Benefit

By exchanging heat between these two streams we were able to

eliminate one cooler and improve profit


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Remove Unnecessary UtilitiesRemove Unnecessary Utilities

Based on sensitivity analysis carried out for temperature of COOL2

against operating profit, we were able to eliminate COOL2. Thus

improving plant profit


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OPTIMIZED PROCESS FLOWOPTIMIZED PROCESS FLOW

DIAGRAMDIAGRAM FINALFINAL


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STREAM TABLE (FINAL)STREAM TABLE (FINAL)


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Economic EvaluationEconomic Evaluation

Base Case Modified Process

Heating Cost (@$0.5 per kg

Gas)

$296.59 $195.81

Cooling Cost

(@ $0.1/ GJ)

$1.98 $2.09

Electricity

(@$0.10 per kWh)

$339.30 $1.28

Total Utility $637.86 $199.19

Feed Cost $1406.96 $1406.96

Product Sales $4626.41 $4611.64

Operating Profit $2,582 $3,005


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Base Case Modified Process

COOL1 $74,100 --

COOL2 $74,100 --

HEAT $74,100 $74,100

HEX -- $90,700

PUMP $29,300 $29,300

PUMP2 $23,400 $23,400

REACT $245,300 $245,300

RIG-COL $250,800 $235,900

RIG-COL2 $263,600 $261,200

TOTAL $1,034,700 $959,900

Economic EvaluationEconomic Evaluation contd.contd.


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CONCLUSION AND FUTURE WORKCONCLUSION AND FUTURE WORK

y Methanol dehydration is one of the most efficient methods available todayfor production ofDME.

y The commonly used methanol dehydration process was simulated in AspenPlus (v7.1) for a feed of ~7000 kg/hr methanol. The base case was studiedin detail, and improvements were suggested.

y The process was subjected to various sensitivity analyses and heatintegration to improve the profitability of the plant. Upon incorporatingthe design modifications, there was a marked improvement in the hourlyoperating profit of the plant, as well as a decrease in the capital cost.

y

The conversion of methanol is 62.88% when alumina is used as thedehydration catalyst. This conversion can be improved by using acombination of alumina and zeolite catalyst. (Reference: Vishwanathan et al,Vapor phase dehydration ofMethanol to DME over Na modified H-ZSM-5catalyst). This would make a good topic for future work.


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REFERENCESREFERENCES

y R. S. Schiffino and R. P.Merrill,A mechanistic studyof methanoldehydration on alumina catalyst, J. Phys.Chem. 1993,97, 6425-6435

y

V. Vishwanathan,K. W. Jun, J. W. Kim,H. S. Roh,Vaporphase dehydration of crude methanol to dimethylether over Na-modified H-ZSM-5 catalysts,AppliedCatalysisA: General 276 (2004) 251255

y

E.Y.Lee,Y. K. Park,O.S.Joo ,K.D. Jung,Methanoldehydration to produce dimethyl ether over g-Al2O3,Reaction KineticsAnd Catalysis Letters,Vol 89 ,No: 1,115-121


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Adv. Design of Chem Systems Presentation_Hitesh Vaid(L20007882)

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