Page 134 - Analysis, Synthesis and Design of Chemical Processes, Third Edition

10.

Table P3.10(b) Specific Reactor/Mixer Volumes for Processes A, B, and C

Referring to the batch production of amino acids described in Project 8 in Appendix B, the batch
reaction times and product filtration times are given in Table P3.11.

Table P3.11 Batch Step Times (in Hours) for Reactor and Bacteria Filter for Project 8 in
Appendix B

The capacity of the reactors chosen for both products is 10,000 gallons each. The precoating of the
filters may occur while the batch reactions are taking place, and hence the critical time for the
filtration is 5 h. It should be noted that intermediate storage is not used between the reactor and filter,
11.
and hence the batch times for the reactors must be extended an additional 5 h while the contents are

fed through the filter to storage tank V-901. It is desired to produce L-aspartic acid and L-
phenylalanine in the ratio of 1 to 1.25 by mass. Using a campaign period of 1 year = 8000 h and
assuming that there is a single reactor and filter available, determine the following.

a. The number of batches of each product that can be produced in a year, maintaining the desired ratio
of the two products, if one single-product campaign is used for each amino acid per year.

b. The amount of final product storage for each product assuming a constant demand of each product

over the year. Express this amount of storage as a volume of final solid crystal product (bulk density
3
of each amino acid is 1200 kg/m ). You may assume that the recovery of each amino acid is 90% of
that produced in the reactor.

c. By how much would the answer to part (b) change if the single-product campaigns for each amino
acid were repeated every month rather than every year?

Referring to Problem 3.11, by how much would yearly production change if the following applied?

a. The reaction times for L-aspartic acid and L-phenylalanine were reduced by 5 hours each. Use the