WEBLOG OF DR. ISTADI

Problem: Propylene glycol is produced from propylene oxide and water in a continuously-stirred-tank reactor (CSTR). The propylene oxide and water feed streams are combined in a mixer. The combined stream is fed to the reactor, operating at atmospheric pressure, in which propylene glycol is produced.

The reaction between water and propylene oxide to produce propylene glycol is as follows:

 H2O + C3H6O ==> C3H8O2 (E=3.24E4 Btu/lbmole; A=1.7E13)

Propylene oxide stream is fed to the reactor at 75 F and 1.1 atm (150 lbmole/h), while the water is fed to the reactor at 75 F and 16.17 psia (11000 lb/h).

Task: How many Actual Percent Conversion of the reactor ? What is the reactor temperature ? Adjust the reactor temperature to achieve 95% conversion. Continue reading →

Problem: Production of hydrogen from methane can be carried out by Partial Oxidation of Methane (POM). Usually carbon monoxide produce from the POM reactor is reacted to the steam to increase the hydrogen product and to reduce carbon monoxide by Water Gas Shift (WGS) reaction. The reaction are:

• POM: CH4 + 1/2O2 ==> CO + 2H2; conversion: 40%
• POM: CH4 + O2 ==> CO2 + 2H2O; conversion: 60%
• WGS: CO + H2O <==> CO2 + H2 (equilibrium)

Steam feed is entered 100 C and 2 bar with flow rate of 100 kgmole/h. Meanwhile, methane and air are fed to the partial oxidation reactor at 25 C and 2 bar with flow rate of 100 and 260 kgmole/h, respectively. Continue reading →

Problem: The conversion of methane to hydrogen can be carried out by the partial oxidation of methane. The partial oxidation method relies on the reaction of the fuel (methane) with air in order to produce carbon monoxide and hydrogen by the following reaction:

• CH4 + 1/2O2 ==> CO + 2H2; conversion: 40%
• CH4 + O2 ==> CO2 + 2H2; conversion: 60%

Methane and air are fed to the partial oxidation reactor at 25 C and 2 bar with flow rate of 100 and 260 kgmole/h, respectively.

Develop a model that represents the partial oxidation of methane to produce hydrogen. Continue reading →

Problem: Simple Condensate Stabilizer as the following figure (click on figure to enlarge).

Task: Simulate the simple condensate stabilizer in the figure with single recycle.

Guidelines:

• Define Components and Fluid Package
• Build Stream and Unit Operations, and connect them as in figure
• Define Feed condition, and following unit operations (heat exchanger, cooler, flash, valve, and distillation column
• Disconnect the recycle stream, provide two stream, and connect with Recycle tool

Problem: Hot water at 250 C and 1000 psig is used  to heat a cold stream of water in a shell an dtube heat exchanger. The inlet temperature and pressure of the cold stream is 25 C and 130 psig, respectively. The outlet temperature of the cold and hot streams are 150 C and 190 C, respectively. If the flow rate of the hot stream is 100 kg/h, determine the flow rate of the cold stream passing through the exchanger.

Guidelines:

• Use unit operation Shell and Tube Heat Exchanger in HYSYS / UNISIM to model the process
• Define inlet and outlet conditions for the streams as given
• Define pressure drop of shell and tube of heat exchanger using Rule of Thumb
• Obtain the mass flowrate of the cold stream Continue reading →