LPG and fuel gas. The product hydrogen can be further upgraded by PSA or
membrane. Cryogenic product hydrogen purities of 95–99 % and recoveries of
90–98 % of hydrogen are possible with appropriate process changes.
Cryogenic units are somewhat more difficult to operate and more expensive than
the alternative technologies if your primary objective is hydrogen recovery. These
units may be justified by the value of the other products recovered in some cases.
Because these are not common in refinery hydrogen systems, they are not
discussed further here. Refer to the available references for suppliers of these
systems.
Refinery Hydrogen Management
Ideally, all the hydrogen produced in a refinery would be used in upgrading the
refined products to more and cleaner fuels. In reality, some of the hydrogen is
inevitably lost to fuel or flare.
General Management Concepts
The purpose of hydrogen management is to minimize these losses through design,
monitoring, and allocation of hydrogen to the users.
There are a few principles that guide hydrogen management:
• Treat the hydrogen system like any other process system – have a process flow
diagram with critical controls shown and a material balance for the system.
• Meter all the hydrogen streams to and from units.
• Know the compositions of the hydrogen streams to and from units.
• Make or buy the lowest amount of “on-purpose” hydrogen possible.
• Preferentially use hydrogen in the highest value units.
• Minimize the need to recompress hydrogen by cascading from high to low
pressure where possible.
• Keep hydrogen out of the fuel gas system and flare.
• Recover hydrogen where feasible.
• In refinery planning, the refinery LP should consider hydrogen.
• With good practices, a refinery should be able to use more than 90 % of the
hydrogen generated.
• A periodic review by a company experienced in hydrogen system studies is
advisable (e.g., Air Liquide, UOP, Air Products, etc.).
An example of a hydrogen system in a full-conversion refinery is illustrated in
Fig. 24. There are a series of hydrogen generators (naphtha reformers, SMR plants)
connected to hydrogen headers. The headers distribute the hydrogen to the users.
There may also be intermediate hydrogen headers at different pressures and
purities. Headers may be sweet or sour, depending on the design choices made
Hydrogen Production and Management for Petroleum Processing
635
membrane. Cryogenic product hydrogen purities of 95–99 % and recoveries of
90–98 % of hydrogen are possible with appropriate process changes.
Cryogenic units are somewhat more difficult to operate and more expensive than
the alternative technologies if your primary objective is hydrogen recovery. These
units may be justified by the value of the other products recovered in some cases.
Because these are not common in refinery hydrogen systems, they are not
discussed further here. Refer to the available references for suppliers of these
systems.
Refinery Hydrogen Management
Ideally, all the hydrogen produced in a refinery would be used in upgrading the
refined products to more and cleaner fuels. In reality, some of the hydrogen is
inevitably lost to fuel or flare.
General Management Concepts
The purpose of hydrogen management is to minimize these losses through design,
monitoring, and allocation of hydrogen to the users.
There are a few principles that guide hydrogen management:
• Treat the hydrogen system like any other process system – have a process flow
diagram with critical controls shown and a material balance for the system.
• Meter all the hydrogen streams to and from units.
• Know the compositions of the hydrogen streams to and from units.
• Make or buy the lowest amount of “on-purpose” hydrogen possible.
• Preferentially use hydrogen in the highest value units.
• Minimize the need to recompress hydrogen by cascading from high to low
pressure where possible.
• Keep hydrogen out of the fuel gas system and flare.
• Recover hydrogen where feasible.
• In refinery planning, the refinery LP should consider hydrogen.
• With good practices, a refinery should be able to use more than 90 % of the
hydrogen generated.
• A periodic review by a company experienced in hydrogen system studies is
advisable (e.g., Air Liquide, UOP, Air Products, etc.).
An example of a hydrogen system in a full-conversion refinery is illustrated in
Fig. 24. There are a series of hydrogen generators (naphtha reformers, SMR plants)
connected to hydrogen headers. The headers distribute the hydrogen to the users.
There may also be intermediate hydrogen headers at different pressures and
purities. Headers may be sweet or sour, depending on the design choices made
Hydrogen Production and Management for Petroleum Processing
635