Benofitsof Installation of additional Trays in Urea Reactor

1. Prem Baboo
Sr. Manager(Prod)
National Fertilizers Ltd.,Vijaipur, India
The installation of five additional high efficiency trays are giving an increased production of urea and
reduced steam consumption, the financial benefits are determined by the urea sales and energy prices.
It has been demonstrated that the installation of high efficiency reactor trays in existing urea plant is
very profitable. The pay out time for the investment is in the order of few months.
Reactor Height Top Temperature must not be
more than 190
0
C
Top So,
Temp. Bottom Temp Shifted to Left
Density as solid line. To maintain Top
Temperarature
ΔT=180
C
10 old HET ΔT=110
C
After H.E.T.
Installation Before H.E.T installation
5 New HET. Bottom
Temp.
Reaction
Started
170 180 190 200 210 220 0
C
CO2. Temp.
NH3.
"Purpose" 1.-The main purpose HET.to improve the redistribution
of unreacted carbon dioxide inside the liquid phase rich in free
ammonia.
2.-To reduce the back mixing phenomenon due to density
increase of carbamate and urea solution from bottom to reactor
top
3.-To reduce also channeling which has a negative effect on the
solution residence time.
4.-All the five No. trays are made up of 2-Re -69
"Advantages" 1.-Urea production increase upto 5% referred to the
production before trays installation.
2.- Co2 conversion rate increase about 2 %.
3.-Energy saving about 0.002G.Cal/ton of Urea
4.- Recycle decrease 25-30 kg/t of urea.
5.-Reactor top temperature increase 5-70
C
"Conclusion" The density of solution increase bottom to top. The
Temp.of top increase about 6-7
0
C after installation of
HET it shows increase of conversion. To maintain
NH3/CO2 ratio. top temp kept constant 1900
C and
bottom decrease by increasing ammonia .
"Operation with High Efficiency Trays"