1. 50% CAPACITY INCREASE OF AN – 72 PLANT UTILIZING THE ORIGINAL PRILLING TOWER
MAXIM FERD
OAO GIAP, MOSCOW, RUSSIA
VASIL GRANCHAROV
NEOCHIM PLC, DIMITROVGRAD, BULGARIA

2. 50 % CAPACITY INCREASE
Features of a typical AN – 72 plant:
Design capacity 1360 MT/Day
One - stage neutralization in reactors operating under atmospheric pressure.
One - stage evaporation under atmospheric pressure in air current.

3. 50 % CAPACITY INCREASE
Ammonium nitrate melt is pumped from the ground level to the top of the prilling tower. Steel - made prilling tower with a rectangular cross - section is employed. The fluidized bed cooler is placed outside the prilling tower.

4. 50 % CAPACITY INCREASE
Air coming from the evaporator and the prilling tower, together with the steam exiting the secondary steam recovery system, undergo scrubber treatment prior to being vented to the atmosphere.

5. 50 % CAPACITY INCREASE
There are a total of 19 AN – 72 plants built in the period 1977 – 1987, all of them in the FSU countries and a single one outside the FSU, built in Dimitrovgrad, Bulgaria, and operated by Neochim PLC.

6. 50 % CAPACITY INCREASE

7. 50 % CAPACITY INCREASE
The sole significant improvement of the AN - 72 plants until nowadays, has been the addition of filter packs as a final stage in the scrubbers at the top of the prilling tower.

8. 50 % CAPACITY INCREASE

9. 50 % CAPACITY INCREASE

10. 50 % CAPACITY INCREASE Replacement of the three fans supplying air to
Engineering decisions for the prilling tower include:
Replacement of the three fans supplying air to
the tower’s bottom and the six exhaust fans at
the top of the tower by new ones with total
capacity 30 % greater than this of the original
ones.
Replacement of the original 3 static granulators
by 2 vibro - granulators with a rotating basket,
aiming at a narrower size distribution and to a
greater - extent elimination of dust carryout
expected as a result of the increased air
velocity in the tower’s cross - section.

11. 50 % CAPACITY INCREASE Engineering decisions for the prilling tower
include:
Increase of the filter surface of the six
scrubbers at the tower’s top by 10 % and use
of three - layer packs of filtrating material with
different layer characteristics.
Washing of the frontal filter pack’s surface with
finely - spread secondary steam condensate .

12. 50 % CAPACITY INCREASE Engineering decisions for the prilling tower
include:
Introduction of preliminary purification of the
secondary steam and air from the evaporators
in a separate scrubber prior to the steam air
stream being fed to the tower’s scrubbers.
Introduction of additional ammonia air cooling
at the second stage of the fluidized bed cooler.

13. 50 % CAPACITY INCREASE Engineering decisions for the “wet” part
include:
Addition of a new neutralizer identical to the
existing ones, an evaporator with modified
design, and of all necessary equipment for their
operation.

14. First neutralization in the “new” wet part carried out
50 % CAPACITY INCREASE
Project Milestones
June 1st 2007
First earth moved
First neutralization in the “new” wet part carried out
June 16th 2008
July1st 2008
Plant at full swing

15. 50 % CAPACITY INCREASE

16. 50 % CAPACITY INCREASE
Comparison of the plant’s major operational parameters before and after the revamp.
Item
Before revamp
After revamp
Ammonia
214.0 Kg/MT
211.5 Kg/MT
Nitric acid
780.0 Kg/ MT
777.3 Kg/ MT
17 Bar Steam
0.236 T/MT
0.181 T/MT
Power
20 kW/MT
22.9 kW/ MT
AN emission exit tower
Less than 70Mg/NM3
12.8 Mg/NM3
Ammonia emission exit tower
Less than 20 Mg/Nm3
5.4 Mg NM3
Granulometry
73% between 2-3 mm
90% between 2-3 mm
95 % between 1-4 mm
99 % between 1-4 mm
Maximum achieved capacity
1550 MT/Day
2350 MT/Day

17. 50 % CAPACITY INCREASE Better consumption figures were achieved
The improved granulometry allowed bypassing the originally installed sieve section and thus discontinuing reprocessing of off spec material.
Emission levels for both AN and ammonia were reduced to BAT levels.
Capacity increase of more than 70 %, based on name plate, and more than 50 %, based on best log, was achieved.

18. 50 % CAPACITY INCREASE 50 % CAPACITY INCREASE CONCLUSIONS
Proven now commercially, is the possibility to increase the production capacity of a typical AN – 72 plant, from 1360 MT/Day(name plate) to 2350 MT/Day utilizing the existing prilling tower and keeping the AN and ammonia emissions at BAT levels.
The revamp leads to an Improvement of both Ammonia and Nitric acid consumption figures.
Better product granulometry is also achieved.
Capex for such a revamp is significantly lower than that needed for the addition of the same incremental capacity using the existing AN – 72 design or the known granulation process.
CONCLUSIONS

19. Спасибо мАКСИМ Ферд ! сПасибо “гиап “ !
THANK YOU !
Спасибо мАКСИМ Ферд ! сПасибо “гиап “ !