Reaction Kinetics - Methanol Production

ABSTRACT

In this Project manufacturing methanol is studied. We made investigations for methanol manufacturing process. The flow chart for the process, reactor configurations are asked.Firstly, Using thermodynamic properties of C0,H2 and CH3OH, equilibrium line is plotted and 100 bar is selected. Constant rate curves are obtained by using reaction rate expression which is given at termproject part.The operating lines goes through the extremums of these curves.Adiabatic energy balance equation for each reactor gives adiabatic line equations.These adiabatic line equations plotted each after until the reaching desired conversion of 0.55.To remove the heat, 5 heat exchager is used between the reactors. This conversion is attained with 6 plug flow reactors.Reactor Design Project


Methanol is considered as a potential source of energy and as an intermediate to produce
alternative motor vehicle fuels, fuel additives and number of petrochemicals. Conventionally,
methanol is produced from synthesis gas (gas mixtureof carbon monoxide and hydrogen
produced by reforming of natural gas) in a series offıxed bed catalytic reactors at a relatively high pressure. It is also possible to produce synthesis gas by gasification of biomass or coal.

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In this project you are asked to design the reactor(s) to be used for a methanol production
at a rate of 400 tons/day:

(A) Seaıch the literature for methanol production.Discuss the operating conditions of the
process and the critical pointsfor pressure selection.

(B) Considering a feed composition of 30% CO and 70% H2 ,examine the thermodynamics of
methanol synthesis reaction in order to decide on the operating pressure. Plot equilibrium
conversion versus temperature graphs in a pressure range of 50-120 bars. In the
equilibrium calculations you should use the fugacities.

(C) Taking the pressure as 100 bars and consideringa target conversion of CO as 55% decide
about the reactor configurations, operation mode (adiabatic, non adiabatic, isothermal),
reactor inlet temperature(s).

(D) Design the reactor(s) to find the catalyst volume and total reactor volume.

In methanol synthesis, a catalyst containing Cu/ZnO system, with the addition of
aluminum is generally used. You may use the rate expression given inthe datapage.


DATA

For systems where the synthesis gas is composed of only CO and H2, the following rate equation was proposed for the hydrogenation of CO over a Cu/Zno on alumina catalyst for a temperaturen range between 450-650K and pressures 50-100 bar.

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[pic] at 250 [pic]
E = 80 kJ [pic](activation energy)
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The catalytic packed bed bulk density was givenas 1120 kg [pic]



1.INTRODUCTION
1.1 Methyl Alcohol as an Industrial Chemical
Methanol (methyl alcohol), CH3OH, is clear, water- white liquid with a mild odor at ambient temperatures. From its discovery in the late 1600s, methanol has grown to become the 21st largest commodity chemical with over 12x106 metric tons annually produced in the world. Methanol has been called woodalcohol (or wood spirit) because it was obtained commercially from the destructive distillation of wood for over a century. However, true wood alcohol contained more contaminants (primarily acetone, acetic acid, and ally alcohol) than the chemical- grade methanol avaible today.
Table 1.1 Physical Properties of Methanol
|Property|Value |
|Freezing point oC |-97,68 |
|Boiling point oC |64,70 |
|Critical temperature oC |239,43 |
|Critical pressure kPa...