service, more than one combustor is normally installed to permit servicing of the
equipment.
These systems will not be discussed in further detail here. The POX system
suppliers are the best references.
Concluding Remarks on POX
POX hydrogen plants are not common, but this is a viable option to make hydrogen
and it has been used on a commercial scale. The costs are high compared to making
hydrogen in an SMR. Still, POX units can feed solids and residual materials that are
not feasible to run in an SMR. There are times POX may be favored.
We will not go into further discussion of POX at this time. Several vendors offer
this technology, including Linde, Lurgi, and Shell.
Electrolytic Hydrogen
Introduction
Hydrogen can be made by electrolysis of water. There are packaged units
available for this service. These are generally limited in size, so they are not
commonly used in refineries. They are being considered for renewable energy
applications.
The following discussion provides only a broad brush background for this type
of unit. Contact the suppliers of these units for additional information.
Process
Electrolytic production of hydrogen occurs in an electrolytic cell. The overall
process is simple, as described in Eq. 29:
H 2 O l
ð Þ þ power ! H 2 g
ð Þ þ
1
= 2 O 2 g
ð Þ
(29)
The reaction requires an electrolyte. Normally, potassium hydroxide is used, as
noted in the flow diagram below.
There are three types of cells available, as summarized in Table 10.
The general flow sheet for an electrolysis hydrogen plant is shown in Fig. 19.
Concluding Remarks on Electrolytic Hydrogen
No further details about electrolytic hydrogen production are offered here, because
of the limited opportunities for refinery application at this time. Future renewable
Hydrogen Production and Management for Petroleum Processing
621
equipment.
These systems will not be discussed in further detail here. The POX system
suppliers are the best references.
Concluding Remarks on POX
POX hydrogen plants are not common, but this is a viable option to make hydrogen
and it has been used on a commercial scale. The costs are high compared to making
hydrogen in an SMR. Still, POX units can feed solids and residual materials that are
not feasible to run in an SMR. There are times POX may be favored.
We will not go into further discussion of POX at this time. Several vendors offer
this technology, including Linde, Lurgi, and Shell.
Electrolytic Hydrogen
Introduction
Hydrogen can be made by electrolysis of water. There are packaged units
available for this service. These are generally limited in size, so they are not
commonly used in refineries. They are being considered for renewable energy
applications.
The following discussion provides only a broad brush background for this type
of unit. Contact the suppliers of these units for additional information.
Process
Electrolytic production of hydrogen occurs in an electrolytic cell. The overall
process is simple, as described in Eq. 29:
H 2 O l
ð Þ þ power ! H 2 g
ð Þ þ
1
= 2 O 2 g
ð Þ
(29)
The reaction requires an electrolyte. Normally, potassium hydroxide is used, as
noted in the flow diagram below.
There are three types of cells available, as summarized in Table 10.
The general flow sheet for an electrolysis hydrogen plant is shown in Fig. 19.
Concluding Remarks on Electrolytic Hydrogen
No further details about electrolytic hydrogen production are offered here, because
of the limited opportunities for refinery application at this time. Future renewable
Hydrogen Production and Management for Petroleum Processing
621