In 2014 we charged fresh Copper oxide catalyst (vendor: Jonhson Matthey) into Low temperature shift converter (LTS is a reactor in which water gas shift conversion occurs and it is exothermic reaction).During Start-up LTS new catalyst has to be reduced before taking it into service.Hydrogen gas is used as reducing agent and natural gas is used as a carrier gas.Detailed report on our reduction activity is uploaded

1. REPORT ON LTS REDUCTION
Prepared By: Gulfam Khalid
Shift Engineer
AMMONIA PLANT

2. Standard Operating Procedure FOR LTS reduction
Introduction
Fresh/Newly charged LTS catalyst has to be reduced before taken it into service, by this
procedure stable copper oxide component of the new catalyst is converted into reactive
copper metal. During reduction and operation its zinc oxide and alumina components remain
unchanged and act as support, which stabilize the copper metal crystals that act as reservoir
for poisons. Hydrogen is used as reducing agent. The reaction of catalyst with hydrogen is
exothermic as given below:
CuO + H2 ↔ Cu + H2O ∆H = -81 Kj/mol
KATALCO 83-3 catalyst is based on copper oxide supported on a matrix of zinc oxide and
alumina.
Catalyst type: KATALCO 83-3 (CuO)
Form: cylindrical pellets
Length: 3.0 mm
Diameter: 5.2 mm
Charged bulk density: 1.38 kg/L or 86 lb/ft3
Vendor: Johnson Matthy
Total volume of catalyst: 39.6 m3
Bulk density: 1380 kg/m3
Total weight: 54648 kg
CuO in catalyst: 51 wt%
Plant condition before reduction
Plant load: 50%
Air to secondary reformer: Not started yet
Source to H2 rich gas: 103F
Steam to carbon ratio: 5

3. Reduction circuit:
1. Prepare the reduction circuit of LTS as follows:
2. SFS 1132, SFS 1143, SFS 1144, SFS 1139, SFS 1167, SFS 1168, SFS 1171 and
their associated valves should be close.
3. SFS 1165, SFS 1170 and EMV 1165 should be close.
4. Keep close by pass valve of exchanger A-133C1 of line no. 6PF1119.
5. SFS 1133, SFS 1145, and SFS 1172 should be in open position.
6. Open isolation manual valves associated with SFS 1172 and SFS 1145, and block
valve of line no. 6PF1121.
7. Establish flow of desulphurised natural gas through LTS slowly at the rate of 15000
Nm3
/hr minimum to maintain space velocity at 300/hr minimum so that gas
distribution through the catalyst bed is uniform. Use FI-1140 to measure the N.Gas
flow to LTS.
8. Increase the catalyst bed temperature up to 130O
C by the by pass valve of the
exchanger A-133C1 at the rate of 50O
C/hr. keep LTS back pressure at 6.0kg/cm2
g
with its manual vent valve on line no.10V1115.
9. Check correct working of hydrogen flow meter F-1168/ F-1169 when catalyst bed
temperature reaches 120 ̴130O
C. During checking of flow meter do not increase the
bed temperature.
10. Install online hydrogen analyzer by connecting it with inlet / outlet sample points S-
1165B & S-1165C of LTS. Before making it online, confirm its accuracy with chemical
laboratory results.
11. Increase the top LTS bed temperature up to 180O
C.
Catalyst reduction
When catalyst inlet temperature reached to 180O
C, introduce H2 from 103F.
1. Open 103F outlet valve to 104DB fully and open u/s of FI-1169 valve slowly in steps.
Keep LTS inlet temperature at 180O
C.
2. Establish H2 gas flow at the rate of 30 Nm3/hr initially by opening 1-1/2 ‘’ needle
valve. Watch LTS catalyst bed temperature (T-1230 ̴ T-1232, T-1181 ̴ T-1182) for 5
minutes.
3. If catalyst temperatures are not rising by abnormal reaction, increase hydrogen
gradually in steps up to 100 m3
/hr. watch LTS bed temperature for 5 minutes after
each step.
4. Bed temperature will start increasing when hydrogen starts reacting with CuO
catalyst.
HPNG BC4 101D 102DA/DB 133C1 LTS /104-DB
103F (H2)
VENT

4. 5. Keep on increasing hydrogen flow from 1% to 3% in the inlet Natural Gas gradually
by watching bed temperatures. Maintain hydrogen flow maximum till the bed
temperature stops rising.
6. Monitor LTS inlet and outlet H2 gas content with online analyzer continuously. Verify
these results with laboratory analysis after 1 ̴ 2 hrs. So special arrangements for H2
gas analysis is necessary during LTS catalyst reduction.
7. When 1st
bed temperature is coming down the reaction will start in 2nd
bed and its
temperature will rise. Control the temperature by controlling the hydrogen flow into
the N.Gas LTS inlet. Similar steps are to be followed for all the beds till the
temperature of the last bed starts decreasing after reaching to peak temperature.
8. Confirm hydrogen consumption which is more than 90% if 1st
bed temperature comes
down to 1st
bed inlet temperature (180O
C) one by one.
9. If H2 is not consumed more than 90%, increase inlet temperature of LTS 3O
C at every
step until 90% hydrogen is consumed. However maximum limit of inlet temperature is
215O
C.
10. If H2 is consumed more than 90%, keep that temperature and increase hydrogen
contents from 3% to 50% volume gradually. Increasing rate of H2 is 1.5 times of
existing hydrogen contents. That is 2% × 1.5 = 3%, 3% × 1.5 = 4.5%
11. During catalyst reduction, watch catalyst bed temperature carefully and if any
abnormal temperature rise is found cut H2 supply.
12. Under LTS inlet temperature 215O
C and inlet hydrogen contents 50%, if each bed
temperature is less than LTS inlet temperature (180O
C) and H2 consumption is
almost zero, LTS reduction has completed.
Soaking
When reduction of LTS catalyst completed soaking period started, for this gradually increase
the hydrogen concentration in the inlet gas up to 15% incrementally and watch very carefully
bed temperatures for 5 ̴10 minutes. Bed temperature neither allows increasing abruptly nor
exceeding to 230O
C. However, for small duration increase is not harmful for the catalyst.

5. Actual Operating Procedure
LTS catalyst blowing
To remove entrapped dust particles from catalyst bed, catalyst is blown with desulphurized
natural gas for 3 to 4 hours. It was done to avoid increase in pressure drop along the bed
and these dust particles cause foaming problem in the CO2 removal system.
Circuit for LTS blowing
Heating
Desulphurized natural gas is used for heating of LTS catalyst. Established the flow of N.Gas
to heat the bed up to 130O
C at the rate of 50O
C per hour and keep the back pressure 5-6
kg/cm2
g. Ensure that both the hydrogen flow meter and analyzer are operating satisfactorily
as the temperature approaches 130O
C. Continue heating the catalyst until top of bed is at
180O
C. The temperature of the gas should not exceed 210O
C during the initial heating if
natural gas space velocity is less than recommended more care is necessary as there can
be poor gas distribution which can lead to localized overheating. Start recording the bed
temperature during warm up to confirm that the gas is well distributed through the bed.
Circuit for heating
 SFS 1132, SFS 1143, SFS 1144, SFS 1167, SFS 1168, SFS 1171 and their
associated valves were close.
 SFS 1165, SFS 1170 and EMV 1165 should be close.
 Used A-133C1 by pass route for heating of LTS.
 SFS 1133, SFS 1145, SFS 1177, and SFS 1172 should be open.
102 DA,DB A-133C1 by pass A-104DB
Vent

6. H2 injection
1st
bed reduction
When the temperature of top 3rd
bed reached 159O
C introduced hydrogen through FI 1169 at
the rate of 65 Nm3
/hr. To maintain the inlet temperature of N.Gas 180O
C at the inlet increase
the H2 flow 65 ̴100 Nm3
/hr then 100 ̴160 Nm3
/hr, 16 ̴ 220 Nm3
/hr, 220 ̴ 280 Nm3
/hr within 4.5
hours of reduction started when the hydrogen concentration at online analyzer reached 7.6%
first bed reduction completed and exotherm of first bed was at 224O
C, at its peak. Actually
hydrogen concentrations at online analyzer 7.6% was more than expectations, the reason
was that hydrogen analyzer was giving the results of HTS out let combined, later on analyzer
position was changed, HTS outlet blinded, and so H2 analyzer concentrations came to
normal.
2nd
bed reduction
Reduction of 2nd
bed completed within 10.5 hours of reduction started, H2 concentration at
online analyzer was 2.09% and temperature of 2nd
bed was 208O
C at that time.
150
160
170
180
190
200
210
220
230
0 2 4 6 8
H2 ConcVS 1st bed temperature
1stbedtemperatures
H2 concentration
200
205
210
215
220
225
2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7
H2 concentration
2ndbedtemperatures

7. 3rd
bed reduction
Reduction of 3rd
bed completed within 17 hours of reduction started, H2 concentration at
online analyzer was 2.40% and temperature of 3rd
bed was 206O
C at that time.
4th
bed reduction
Reduction of 4th
bed completed within 27.5 hours of reduction started, H2 concentration at
online analyzer was 2.40% and temperature of 3rd
bed was 215O
C at that time.
150
160
170
180
190
200
210
220
230
2.15 2.2 2.25 2.3 2.35 2.4 2.45 2.5
H2 ConcentrationVs 3rd bed temperatures
H2 Concentration
3rdbedtemperatures
214
214.5
215
215.5
216
216.5
217
2 2.05 2.1 2.15 2.2 2.25 2.3 2.35 2.4 2.45 2.5 2.55 2.6 2.65 2.7
H2 ConcentrationVs 4th bed temperatures
H2 Concentration
4thbedtemperatures

8. 5th
bed reduction
Reduction of 5th
bed completed within 29 hours of reduction started, H2 concentration at
online analyzer was 2.54% and temperature of 3rd
bed was 213O
C at that time.
Soaking
At 34 hours of reduction started temperature 1st
,2nd
,3rd
,4th
,and 5th
bed were
191.5,192,192.4,192.2 and 197 respectively then H2 soaking started for this gradually
increase the inlet H2 concentration up to 19.08% at that time temperature of inlet gas and all
the beds were 219, 219.6, 220.6, 221.5, 223 and 221.8 respectively, since all the beds now
were almost same temperature then H2 flow to LTS restricted to zero inlet concentration at
LTS inlet and hold for 3.5 hours and after this isolated LTS and hold up it at 30 kg/cm2
g all
this activity took 41 hours. At 39 hours of reduction front end load increase started and air to
secondary reformer fed at 50% plant load to achieve the desired composition of HTS outlet
for taking LTS in service.
Circuit for LTS reduction
 SFS 1132, SFS 1143, SFS 1144, SFS 1167, SFS 1168, SFS 1171 and their
associated valves were close.
 SFS 1165, SFS 1170 and EMV 1165 should be close.
 Used A-133C1 for LTS reduction.
 SFS 1133, SFS 1145, SFS 1177, and SFS 1172 should be open.
 H2 flow for reduction was maintained through FI 1169 and later through both FI 1169
and 1168
196
198
200
202
204
206
208
210
212
214
216
2.1 2.2 2.3 2.4 2.5 2.6 2.7
H2 ConcentrationVs 5th bed temperatures
H2 Concentration
5thbedtemperatures

9. LTS in service
When LTS took in service then temperatures of all the beds shooted abruptly after 12
minutes of taken it into service temperature of 1st
bed was 216◦C at its peak, after 15
minutes of service temperature of 2nd
bed was 256◦C, after 17 minutes of service
temperature of 3rd
bed was 287.4◦C, after 23 minutes of service temperature of 4th
bed was
300◦C, and after 26 minutes of service temperature of 5th
bed was 297◦C. And after that
temperatures of all the bed started to come down.