CHAPTER 1: GENNERAL DESCRIPTION OF DEETHANIZER
(A-502)Deethanizer column is designed purposely to separate between
C2 Product (Ethane, Ethylene, Acetylene) as top product and C3+
(propane, propylene, 1-3, butadiene) as bottom. The feed is coming
from the Demethanizer. Several advantages of distillation include
its ability:1. To produce a product with high purity.2. To handle a
wide range of throughput.3. To handle a wide range of feed
concentrations.
By operating at pressure of --- kPa, the deethanizer (A-502) is
operated at temperature of --- oC. Sieve tray method has been
selected to design the distillation column. Based on the
calculations results, there are --- trays overall in the column to
achieved the desired product quality with the assumptions of ---%
trays efficiency. Stainless steel is chosen as the designed and
tray material due to the ability of corrosion resistance. Tray
columns generally provide satisfactory operation over a wide range
f liquid and vapor loadings. The vapor and liquid rates can vary
independently over a broad range and the column can operate
satisfactorily. The basic requirement of a sieve tray is that it
should: 1. Provide good vapor-liquid contact2. Provide sufficient
liquid holdup for good mass transfer.3. Have sufficient area and
spacing to keep entrainment and pressure drop within acceptable
limits.4. Have sufficient downcomer area for the liquid to flow
freely from plate to plate.
CHAPTER 2: PROCESS DESIGN OF DEETHANIZER (A-502)2.1
Multi-Component DistillationDetailed process design of deethanizer,
A-502 which includes determination of column operating parameters
and sizing of column internals are shown on this
section.Determination of Column Operating ConditionThe first
assumptions made in order to determine the column operating
condition are that nothing heavier than heavy key appears at
distillate and nothing lighter than light key in bottom. The
summary of component distribution is as below:Table 1: Distribution
of ComponentComponentFeed flow (kmol/hr)Feed Fraction, xfDistillate
flow (kmol/hr)Distillate Fraction, xdBottom flow
(kmol/hr)BottomFraction, xb
Ethane4298.774254.4245.39
Ethylene5889.025890.500.01
Acetylene55.3655.280.08
Propane27.60027.60
Propylene103.080103.14
1-3, Butadiene255.550255.68
Total
For the distillation column, the heavy key (HK) component is ---
while the light key (LK) component is the ---. The vapor pressure,
P* for pure component can be obtained from extended Antoine
Equation below:
Where the value of A, B, C, D and E constant obtained from the
appendix C in Coulson & Richardson Chemical Engineering Volume
6 (Fourth Edition). The relative volatility of each component is
calculated by using the formula.
Relative volatility,
ComponentABC
Ethane
Ethylene
Acetylene
Propane
Propylene
1-3, Butadiene6.84999930.546238.854
Total
Table 2: Distribution of ComponentComponentP*KRelative
Volatility,
Ethane
Ethylene
Acetylene
Propane
Propylene
1-3, Butadiene
Total
