SOAL EVALUASI 3

OPERASI TEKNIK KIMIA KELAS B

Hari/ Tanggal: Jumat / 12 Juni 2015

Dosen

: Lestari Hetalesi Saputri, ST., M.Eng

1. Gas from a petroleum distillation column has its concentration of H2S reduced from 0.03 kmol H2S kmol of inert hydrocarbon gas to 1% of this value by scrubbing with a triethanolamine-water solvent in a countercurrent tower, operating at 300 K and at atmospheric pressure. H2S is soluble in such a solution and the equilibrium relation may be taken as y = 2.x, where y is kmol of H2S/kmol of inert gas and x is kmol of H2S/kmol of solvent. The solvent enters the tower free of H2S and leaves containing 0.013 kmol of H2S/kmol of solvent. If the flow of inert hydrocarbon gas is 0.015 kmol/m2.s of tower cross section and the gas phase resistance controls the process, calculate:

a. The height of the absorber (packing) necessary

b. The number of transfer units required.

2. Acetone is to be recovered from a 5% acetone-air mixture by scrubbing with water in a packed tower using countercurrent flow. The liquid rate is 0.85 kg/m2.s and the gas rate is 0.5 kg/m2.s. The overall absorption coefficient KGa may be taken as 1.5 x 10-4 kmol/s.m3 partial pressure difference and the gas film resistance controls the process. What should be the height of the tower to remove 98% of the acetone?

The equilibrium data for the mixture are:

Mol fraction acetone in gas0.00990.01960.03610.0400

Mol fraction acetone in liquid0.00760.01560.03060.0333

Ketentuan:

Jawaban dikumpulkan ke Bagian Perkuliahan paling lambat hari ini tanggal 12 Juni 2015 pukul 15.30.