The cracking furnace of the ethylene plant of a
petrochemical company increases the processing capacity of light hydrocarbons, reducing
the production of mixed C
4 to 8.5 t/h, which can be used to produce
about 4 t/h of butadiene in the butadiene plant. The requirement of butadiene feed
for the full-load operation of two lines in butadiene rubber plant is 5.4 t/h,
with a gap of about 1.2 t/h. With a high TBC concentration, the butadiene
product from the new area cannot be directly used by the butadiene rubber plant
in the old area, so it needs to be recycled to the
butadiene plant of the ethylene plant No.2 for re-refining to ensure its
reaction performance. At present, the butadiene with
high TBC concentration from the butadiene plant of the ethylene plant No.1 is
sent to the butadiene storage tank of the ethylene plant No.2, and then 1.2 t/h
of butadiene with high TBC concentration is recycled via the re-refining line
into butadiene distillation tower for TBC removal to meet the butadiene demand
of the butadiene rubber plant. Therefore, a recycled stream of butadiene feed is
added to the conventional distillation system. The storage temperature of
butadiene product tank not only affects the consumption of freezing liquid, but
also affects the heat balance of butadiene distillation tower and the load of
tower kettle reboiler. In this paper, by controlling the temperature of Tank T-902A
during the re-refining of 1,3-butadiene product with high TBC concentration
from the new area, the energy consumption of the plant can be reduced, and cost
reduction, efficiency increase and high quality development can be achieved.
