1. Is this process continuous, batch, or semi-batch?
Problem 1: Test Problem 4.1, slightly edited
Water enters a 2.00 m3 tank at a rate of 6.00 kg/s as is withdrawn at a rate of 3.00 kg/s. The tank is initially half full.
Is this process continuous, batch, or semi-batch?
Is this process transient or steady state?
Write a general mass balance for the process.
Identify the terms in the general balance equation present in your analysis of the process and the reason(s) for omitting any terms.
How long will it take for the tank to overflow?

2. Sketch the process unit
Problem 2: Text Problem 4.4, slightly edited
A stream of 44.6 mole% benzene and 55.4% toluene is fed at a constant rate to a process unit that produces two product streams, one a vapor and the other a liquid. The vapor flow rate is initially zero and asymptotically approaches half the molar flow rate of the feed stream. Throughout the entire period, no material accumulates in the unit. When the vapor flow rate has become constant, the liquid is analyzed and found to be 28.0 mole% benzene.
Sketch the process unit
Sketch a plot of the liquid and vapor flow rates versus time from startup to when the flow rates become constant.
Is this process batch or continuous?
Is this process transient or steady state? If transient, does it become steady state?
For a feed rate of 100 mol/min, what are the flow rates and compositions of all the streams when the liquid is analyzed to be 28.0% benzene?

3. Problem 3: Modified from Basic Principles and Calculations in Chemical Engineering, by D. M. Himmelblau. 6th ed. Prentice-Hall, 1996
A novice manufacturer of alcohol for gasohol is having a bit of difficulty with a distillation column. The operation is shown in the figure below. Technicians think too much alcohol is lost in the bottoms product, which is a waste stream. But they only have data on the feed and product streams. Help the manufacturer by computing the amount and composition of the bottoms streams.

4. Sketch for Problem 3
Compositions are wt %

5. Problem 4: Modified from Basic Principles and Calculations in Chemical Engineering, by D. M. Himmelblau. 6th ed. Prentice-Hall, 1996
Fish caught by human beings can be turned into fish meal, and the fish meal can be used as feed to product meat for human beings or used directly as food. The direct use of the fish meal increases the efficiency of the food chain. However, fish protein concentrate, primarily for aesthetic reasons, is used mainly as supplementary protein food. As such, it competes with soy and other oilseed proteins.
In the processing of fish, after the oil is extracted, the fish cake is dried in rotary drum dryers, as shown in below, finely ground, and packed. The resulting product contains 65% protein by weight. In a given batch of fish cake that contains 80% water and the remainder the dry cake material, 100 kg of water is removed and it is found that the fish cake is then 40% water.
a) What type of process is this: batch, semi-batch, continuous?
b) Is the process steady state or transient?
c) Calculate the weight of the fish cake originally put into the dryer.

6. Sketch for Problem 4