Methanation Catalyst VULCAN Series VSG-N101/102 SHUTDOWN CATALYST DISCHARGE NICKEL CARBONYL HAZARD REDUCTION PROCEDURE

1. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
GBH Enterprises, Ltd.
DISCHARGE AND REDUCTION
PROCEDURES FOR METHANATION
CATALYST
Process Information Disclaimer
Information contained in this publication or as otherwise supplied to Users is
believed to be accurate and correct at time of going to press, and is given in
good faith, but it is for the User to satisfy itself of the suitability of the Product for
its own particular purpose. GBHE gives no warranty as to the fitness of the
Product for any particular purpose and any implied warranty or condition
(statutory or otherwise) is excluded except to the extent that exclusion is
prevented by law. GBHE accepts no liability for loss or damage resulting from
reliance on this information. Freedom under Patent, Copyright and Designs
cannot be assumed.

2. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
VULCAN Series VSG-N101/102
SHUTDOWN
During a plant shutdown, VULCAN Series VSG-N101 catalyst may be left under
process gas for short periods, so long as the temperature remains between
about 300o
F and 750o
F. Below 300o
F there is a danger of nickel carbonyl
formation, and the reactor must be purged with a gas that does not contain
carbon monoxide.
CATALYST DISCHARGE
The catalyst is usually discharged without stabilization and care must be taken to
ensure that air does not enter the reactor. Normally, it is adequate to ensure that
only the catalyst discharge manhole is open and that a positive pressure of
nitrogen is maintained in the vessel. The pyrophoric catalyst is usually drenched
with water on discharge to eliminate the danger associated with overheating of
the catalyst on reaction with air. If preferred, the methanator may be filled with
water as soon as the catalyst temperature is below 200o
F and the whole
discharge carried out with the catalyst under water.
NICKEL CARBONYL HAZARD
Catalysts containing metallic nickel must not be exposed to gases containing
carbon monoxide at temperatures below 302o
F. Observation of this rule avoids
the risk of the formation of nickel tetracarbonyl, Ni(CO)4, an extremely toxic,
almost odorless gas which is stable at low temperatures. It is most likely to be
formed in methanation reactors when the plant is cooled down, unless the
system has been thoroughly purged with nitrogen.

3. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
REDUCTION PROCEDURE FOR VULCAN SERIES VSG-N101
METHANATION CATALYST
Reduction of this catalyst is simple, because it reduces easily without causing a
temperature rise. The whole operation may be carried out using process gas as
soon as the shift converter(s) and CO2 removal plant have been commissioned
and are lined out. Pressurization may take place at any convenient stage in the
reduction.
1. Purge the methanator of air with process gas, nitrogen, or natural gas.
2. The catalyst may be heated with process gas, nitrogen, or natural gas. It
is advantageous to keep the heating rate below 100o
F per hour so that
any water that has been absorbed on the catalyst during storage is slowly
removed without placing the catalyst under stress.
3. Reduction starts between 390o
F and 480o
F, and any carbon oxides in the
gas will methanate simultaneously. The methanation reaction is
exothermic. In hydrogen and ammonia synthesis gas streams, the
temperature rise will correspond to 108o
F for each 1% CO2 and 133o
F for
each 1% CO that are methanated. The concentration of carbon oxides in
the gas, usually process gas, for the next stage of reduction should be
below 1%. The inlet temperature must be controlled with care. It is
usually better to lower the heating rate to about 50o
F per hour.
4. Heating is continued until the inlet temperature reaches 650o
F, if possible.
However, the maximum temperature of the catalyst should not exceed
750o
F. At the end of reduction, the temperature may be raised so that as
much of the bed as possible is at 650o
F - 700o
F to make absolutely sure
that maximum activity is achieved.
CARBON OXIDE CONTENT
In some plants the initial start-up sequence is to commission the methanator
before the low temperature shift converter and to use the methanator product gas
as the hydrogen source for the low temperature shift reduction. If a new
methanator catalyst must be reduced in this way, using gas that is not passed
through the low temperature shifter converter, it may not be possible to reduce
the carbon oxides content below 1%.

4. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
A reduction may be undertaken with higher carbon oxide contents in the reducing
gas, but more careful temperature control is required. Normally it should be
possible to establish operation in an inlet temperature of about 450o
F. With a
maximum outlet temperature of 750o
F - 800o
F, this represents a carbon oxide
level of about 2.5%, equivalent to about 2% carbon monoxide in the high
temperature shift exit gas. If this carbon oxide level is not obtainable by either
reducing the gas rate or increasing the steam ratio in the high temperature shift
converter, the low temperature shift catalyst should be commissioned before the
methanator.
NICKEL CARBONYL HAZARD
Catalysts containing metallic nickel must not be exposed to gases containing
carbon monoxide at temperatures below 302o
F. Observation of this rule avoids
the risk of the formation of nickel tetracarbonyl, Ni(CO)4, an extremely toxic,
almost odorless gas which is stable at low temperatures. It is most likely to be
formed in methanation reactors when the plant is cooled down, unless the
system has been thoroughly purged with nitrogen.

5. Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com