There may be condensation of steam in the HTS converter initially, but the
converter will dry out. Do not heat the shift converter too fast to avoid
catalyst damage.
If the initial heat up to 800
F did not use inert gas flow, then the HTS
converter should be bypassed and heated up with steam at a controlled rate
once the main flow is stable.
– Continue increasing temperature and steam rate to feed gas inlet conditions at
no more than 100
F per hour – normally about 1,200–1,300
F on the process
outlet from the SMR furnace.
– Start clean feed gas.
If the system has a low-temperature shift converter, the converter is bypassed.
Adjust the feed gas purification conditions to clean up the feed gas. You
should have no detectable H 2 S in the reformer feed gas (<0.01 ppm).
– Maintain a high steam/carbon ratio (>$6.0) in the reformer as the reforming
catalyst and HTS converter catalyst are activated over a few hours.
– Continue heating to 1,350–1,550
F process outlet temperature from the SMR
furnace with the high steam/carbon ratio. Adjust the SMR and HTS temperatures to your start-of-run targets.
– If the hydrogen plant uses PSA purification, the PSA can be purged out with
nitrogen and then started up, initially taking no product.
Once the product hydrogen is on spec, the product can be sent to the users.
The PSA off-gas can be sent to the SMR furnace for firing once the PSA is
stable.
– If the hydrogen plant uses wet chemical purification, the absorber system can
be started and stabilized.
The methanator can be heated up before being brought on line at the initial
target temperature. Nickel carbonyl formation is a potential concern here.
The methanator temperature must be over 400–450
F before introducing
gases containing CO.
CO 2 production can start when the system is stable.
– Once the main process is stable, the low-temperature shift converter is
normally activated and brought on line. This may be a couple of days after
the main process.
– Finally, move the steam/carbon ratio to the target level and begin adjusting
operating conditions to targets.
Adjust the SMR furnace to achieve the desired methane slip.
Adjust the HTS and LTS converters to obtain the target CO slip.
Adjust the PSA cycle or the solvent system conditions to obtain and maintain
targets.
Export surplus steam.
• Routine operations
There are not a lot of major adjustments required for hydrogen plant operating
conditions normally. The rate may be increased or decreased with corresponding
adjustments, but certain targets stay the same. Note that hydrogen plants operate
602
S.A. Treese
converter will dry out. Do not heat the shift converter too fast to avoid
catalyst damage.
If the initial heat up to 800
F did not use inert gas flow, then the HTS
converter should be bypassed and heated up with steam at a controlled rate
once the main flow is stable.
– Continue increasing temperature and steam rate to feed gas inlet conditions at
no more than 100
F per hour – normally about 1,200–1,300
F on the process
outlet from the SMR furnace.
– Start clean feed gas.
If the system has a low-temperature shift converter, the converter is bypassed.
Adjust the feed gas purification conditions to clean up the feed gas. You
should have no detectable H 2 S in the reformer feed gas (<0.01 ppm).
– Maintain a high steam/carbon ratio (>$6.0) in the reformer as the reforming
catalyst and HTS converter catalyst are activated over a few hours.
– Continue heating to 1,350–1,550
F process outlet temperature from the SMR
furnace with the high steam/carbon ratio. Adjust the SMR and HTS temperatures to your start-of-run targets.
– If the hydrogen plant uses PSA purification, the PSA can be purged out with
nitrogen and then started up, initially taking no product.
Once the product hydrogen is on spec, the product can be sent to the users.
The PSA off-gas can be sent to the SMR furnace for firing once the PSA is
stable.
– If the hydrogen plant uses wet chemical purification, the absorber system can
be started and stabilized.
The methanator can be heated up before being brought on line at the initial
target temperature. Nickel carbonyl formation is a potential concern here.
The methanator temperature must be over 400–450
F before introducing
gases containing CO.
CO 2 production can start when the system is stable.
– Once the main process is stable, the low-temperature shift converter is
normally activated and brought on line. This may be a couple of days after
the main process.
– Finally, move the steam/carbon ratio to the target level and begin adjusting
operating conditions to targets.
Adjust the SMR furnace to achieve the desired methane slip.
Adjust the HTS and LTS converters to obtain the target CO slip.
Adjust the PSA cycle or the solvent system conditions to obtain and maintain
targets.
Export surplus steam.
• Routine operations
There are not a lot of major adjustments required for hydrogen plant operating
conditions normally. The rate may be increased or decreased with corresponding
adjustments, but certain targets stay the same. Note that hydrogen plants operate
602
S.A. Treese