What if... you were asked to rework Example 1-2 to calculate the time to reduce the number of moles of A to 1% if its initial value for a constant volume BR, what would you say? Would you do it? If your answer is “yes,” go ahead and calculate it; if your answer is “NO, I won’t do it!” then suggest two ways to work this problem incorrectly.

 

Transcribed Image Text:

Let's consider the liquid phase cis-trans isomerization of 2-butene H H H CH3 CH3 CH3 V=0 CH3 cis-2-hutene trans-2-butene The molecular structures of cis-2-butene and trans-2-butene are shown. A double bond exists between two carbon atoms. Each of these carbon atoms is single bonded with a hydrogen atom and a methyl group (CH3). In cis-2-butene, the methyl groups are on the same side (below the carbon atoms). In trans-2-butene, the methyl group is on opposite sides (above and below) of the carbon atom. which we will write symbolically as A B The reaction is first order in A (-A = KCA) and is carried out in a tubular reactor in which the volumetric flow rate, u, is constant, that is, u = Up- CAO CA=0.1 CAO U₂ A → B V H V The properties of the liquid entering and leaving a tubular reactor of volume V is shown. The initial concentration of liquid entering the tube is C subscript AO and the concentration leaving the reactor is C subscript A, which equals 0.1 times C subscript A0. The initial volumetric flow rate while entering the reactor is v subscript 0 and while leaving the reactor is v. The initial volume is V equals 0 and at the end is V subscript 1. A transition from A to B is shown within the reactor. 1. Without solving any equations, sketch what you think the concentration profile (CA as a function of V) would look like. 2. Derive an equation relating the reactor volume to the entering and exiting concentrations of A, the rate constant k, and the volumetric flow rate up- 3. Determine the reactor volume, V₁, necessary to reduce the exiting concentration to 10% of the entering concentration, that is, CA = 0.1CA0, when the volumetric flow rate up is 10 dm³/min (i.e., liters/min) and the specific reaction rate, k, is 0.23. min-¹.