H2Tech - Q1 2022 - 37

GREEN HYDROGEN PRODUCTION
The challenges of delivering
a large-scale green H2
In Q1 2021, the co-authors' company
delivered a front-end engineering design
(FEED) for the Arrowsmith Hydrogen
Plant (AHP), a staged development by
Infinite Blue Energy (IBE) Group. Located
in Western Australia, this plant
uses wind and solar energy to produce
green H2
a 25-metric tpd H2
. While Stage 1 of the project is
production facility,
the design for AHP includes a roadmap
for scaling up green H2
production to a
capacity of 300 metric tpd by Stage 3.
Several unusual engineering challenges
were encountered while designing
these processing facilities. This article
highlights these design challenges and
provides recommendations for successfully
dealing with them. Some of the recommendations
apply to both blue and
green H2
production.1
of green H2
The deployment
is also explored to identify
the critical factors that will promote or
hinder proliferation of this technology.
Part 1 of this article, published in the
Q4 2021 issue of H2Tech, discussed the
design challenges and solutions for electrolyzer
technology selection, the intermittency
of renewable power generation
and wastewater management.
Large-scale H2
storage: Challenges
facility involved
as a high-pres-fueled
buses,
at 350 barg,
at
as
and approach. The original design for
the 25-metric tpd H2
storing the produced H2
sure (HP) gas at 370 barg in a 4-d storage
system before selling it to the Australian
market. This is because H2
vans and trucks require H2
while passenger vehicles require H2
700 barg. It is also cheaper to store H2
a gas than as a cryogenic liquid. Depending
on the storage pressure, only about
a third of the energy required for liquefaction
is used for compression. However,
large-scale storage of H2
gas is more
project-Part 2
C. BILIYOK, M. CZARNECKI and A. DAR, Petrofac, Woking, UK;
and S. J. GAULD, Infinity Blue Energy, Perth, Australia
challenging in terms of volume/size and
pressure of storage required compared to
liquid H2
(LH2
be stored at lower pressures. LH2
), a denser fluid that can
was
initially only considered as an option for
further expansion for exports.
HP H2
gas can be stored in pressure
vessels, from which it can be loaded onto
tube trailers and delivered to the off-takers.
However, design stress limitations
exist related to the diameter and internal
gas pressure for these vessels, and as
a result, HP H2
gas is typically stored in
composite vessels-this was identified
as the preferred solution during the conceptual
study. Unfortunately, these vessels
are only available on a small scale,
with the largest holding less than 1 metric
t of H2
to store 100 metric t of HP H2
be prohibitively expensive; an alternate
storage method suitable for such large
amounts of H2
was therefore required.
The focus of the 25-metric tpd H2
facility was to produce H2
for immediate
consumption in the domestic Australian
market as a road fuel. The H2
storage opgas
tions
were therefore limited to HP H2
and LH2, as conversion to ammonia (or
other chemical storage options) would
introduce insurmountable complexities
to the off-takers. As a result, LH2
first solution implemented. Dry H2
was the
gas
can be liquefied and stored in insulated
tanks at a temperature of -253°C. Due
to the scale of H2
production, liquified
natural gas (LNG) and industrial gas
design procedures were combined to implement
a robust design for a continuous
storage (along with boil-off compressors)
and loading system.
About 80% of the produced H2
stored and transported as LH2
was
to the
domestic market. Due to offtake agreements,
HP H2
gas storage was still reFIG.
8. HP H2 gas storage piping.
H2Tech | Q1 2022 37
quired for the remaining 20%. The diameter
limitation of pressure vessels and the
prohibitive cost of composite vessels for
storing such large volumes of HP H2
gas
led to the consideration of unorthodox
storage solutions, such as large-diameter,
full-welded, stainless-steel piping. This
resulted in a few km of piping arranged
compactly in a corner of the facility
(FIG. 8) with a line packing approach,
which was then routed to truck loading
stations for loading into tube trailers for
delivery to off-takers.
Equipment supply chain: Challenges
and approach. Although H2
electrolysis technology for H2
O
producat
high pressures. Using these
would
tion has been around for decades, only
a handful of companies operate mature
and proven electrolyzer units. What was
once a niche sector is now experiencing
exponential growth. Consequently,
some equipment items have long-lead
procurement times. Most established
vendors are also used to dealing with
market requirements for smaller units
(up to 5 MW of electrolysis) and are now
facing the challenge of scaling up their
manufacturing facilities to meet growing
demand. As a result, equipment such as
an electrolysis package and H2
liquefaction
package are long-lead items with
procurement challenges.
Plant capacities have also caused challenges
for original equipment manufacturers
(OEMs) in providing the appropriate
solutions for H2
compressors and
LH2 loading pumps for this application.
H2Tech - Q1 2022

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