Machine-translated by Google. Questions are authored in English.
Top

Discussion

A first order reaction with rate constant 0.2 per minute is run in a CSTR at 90 per cent conversion. What space time is needed?

  • A.0.45 minutes
  • B.45 minutes
  • C.11.5 minutes
  • D.4.5 minutes

Answer: B

Correct answer: 45 minutes

For a first order reaction in a CSTR, \[ \tau = \frac{X}{k(1-X)} = \frac{0.9}{0.2\times0.1} = \frac{0.9}{0.02} = 45\ \mathrm{min}. \] The 11.5 minutes offered is the PFR answer, \( -\ln(0.1)/0.2 \) - and the comparison is worth noting: at 90 per cent conversion the CSTR needs almost four times the volume, exactly the penalty described in the first item of this topic.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.