1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Chromatography Scale-up

  1. May 1, 2010 #1
    1. The problem statement, all variables and given/known data
    The problem requires the scale up of a linear gradient ion exchange chromatography column by a factor of 150 (throughput). The lab scale column is 1 cm (ID) x 20 cm (bed height) with 20 micron particle size and 30 cm/hr superficial velocity. Resolution must be kept constant in the plant scale column. The scale up uses a 40 micron particle size and we
    have a choice of 2 columns: 14 cm (ID) x 50 cm (length) and 18 cm (ID) x 50 cm
    (length). Add'l info: viscosity of mobile phase = 1.0 cp, void fraction for resin in plant scale = 0.33
    Determine which column to use, resin bed height, and superficial velocity.

    2. Relevant equations
    (Q1/V1)dp1 = (Q2/V2)dp2 (Q = inlet flow rate, V = column volume, dp = particle diameter).

    3. The attempt at a solution
    Q1 = A * u = Pi * r2 * 30 cm/hr = 3.14 * 0.52 * 30 = 23.6 cm3/hr
    V1 = Pi * r2 * l = 3.14 * 0.52 * 20 = 15.7 cm3
    dp1 and dp2 are known. Therefore V2 and Q2 are unknown.

    I have come up with answers in a few different ways to solve the whole problem but I just don't know which one is right! In order to keep resolution constant, I should keep superficial velocity constant, right? I believe that since the particle size is changing, I don't need to keep bed height constant. The 150 scale-up factor should be for both the V2 and Q2 but none of my solutions have both of them at 150x. Can anyone help me solve this problem? Thanks!!
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted