developments may change this picture, but widespread use of electrolytic hydrogen
in refineries is not likely in the near future.
Manufacturers of commercially available units include:
• Avalence LLC – high-pressure and ultrahigh-pressure hydrogen, small units;
brand name: “Hydrofiller,” focus on hydrogen fueling (www.avalence.com)
• Proton Onsite – fuel hydrogen and renewable focus, backup power systems
integrated with fuel cells; brand name: “HOGEN RE” (www.protononsite.com)
• Teledyne Energy Systems – PEM units to 150 Nm
3 /h (134,000 scfd); brand
name: “TITAN” (www.teledynees.com)
• NEL Hydrogen AS (Norsk Hydro) – atmospheric pressure units, 50–485 NM3/h
(45,000–434,000 scfd); brand name: NEL-A (www.NEL-hydrogen.com)
• Hydrogenics – alkaline and PEM cells; brand name: “HySTAT” (www.
hydrogenics.com)
Olefin Cracking By-Product Recovery
The furnaces that make olefins from refinery feedstocks like ethane, propane, and
naphthas make hydrogen as a by-product according to Eq. 30, using ethane cracking
as an example:
Table 10 Types of electrolytic cells for making hydrogen
Type of technology
Key elements
Solid oxide electrolysis cell
(SOEC)
Operate at high temperatures ($800
C); outside heat sources
(waste heat) can reduce electrical requirement, long start-up
times, and material differential expansion issues
Polymer electrolyte
membrane cell (PEM)
Operate at low temperatures (<100
C), simple, commercially
available, variable voltage input capabilities, no KOH required,
high pressures
Alkaline electrolysis cell
(AEM)
Operate at intermediate temperatures ($200
C), high
electrolyte (20–30 % KOH or K 2 CO 3 ) concentrations
Hydrogen
To Users
Raw Water
Compressor
KOH
Electrolyte
Solution
Oxygen By product
Water
Purifier
Purified
Water
StorageTk
KOH
Mix
TK
Electrolyzer
Module
Hydrogen
Storage
Fig. 19 Simplified typical electrolysis flow sheet for low-pressure electrolyzer (Source: Ivy 2004)
622
S.A. Treese