che_november-2023 - 12

Newsfront
Commercial Progress on
Turquoise Hydrogen
Producing hydrogen via methane pyrolysis - termed 'turquoise hydrogen' - has thus far
received less attention than 'blue' and 'green' H2, but it may offer advantages over both
W
hile the vast majority of
current hydrogen production
occurs by steam
reforming of methane,
there is an ongoing global effort to
increase production of low-carbon
hydrogen (hydrogen generated with
minimal or zero associated emissions
of carbon dioxide). The possibilities for
low-carbon H2 include steam-methane
reforming (SMR) coupled with
carbon capture and storage (CCS)
- known as " blue " H2 - and direct
electrolysis of water using renewable
energy - so-called " green " H2.
Another option for sustainable
H2 production without CO2 emissions
is methane pyrolysis (MP),
the breakdown of CH4 bonds in the
absence of air to form H2 and solid
carbon. Known as " turquoise H2, "
the set of processes being explored
around methane pyrolysis have received
less attention than green
and blue hydrogen thus far, but the
technique offers compelling benefits
over the other two, including zero or
minimal CO2 emissions with lower
costs than green H2 and a potentially
valuable co-product.
On p. 21 of this issue, readers can
find an article on the fundamentals of
the methane pyrolysis reaction and
some of the main technical challenges
with producing H2 in this way. Here,
the various approaches to commercializing
turquoise H2 are discussed,
along with the progress to date.
" There are many ways to produce H2
by methane pyrolysis - all differing
in terms of the heat-delivery mechanism,
catalyst, process conditions
and type of solid carbon produced, "
says Chingis Idrissov, technology analyst
at IDTechEx (Cambridge, U.K.;
12
www.idtechex.com). " And now, a
large number of players worldwide
are developing this technology, including
many startup companies and
academic research groups, along
with some large companies as well. "
Table 1 provides brief descriptions
several company-led and acaof
demic
efforts in developing turquoise
H2 processes, as found in recently
surveyed literature and through contacts
with technology developers. An
expanded version of the table can
be found in the online version of this
article at www.chemengonline.com.
Commercial production
Emerging methane-pyrolysis technologies
can be categorized by their
approach to breaking down CH4.
Among the methods are thermal and
catalytic reactors employing plasma
(hot, warm and cold), molten-media
bubble columns, fluidized beds, moving
beds and hybrid arrangements.
Other developing technologies encompass
compression heating using
shock waves and pulsed-flow reactors,
as well as chemical decomposition
employing redox reactions.
Thermal plasma-arc reactor technology
has the longest history of development
and is the only one being
commercially implemented at present.
Monolith Inc. (Lincoln, Neb.;
www.monolith-corp.com), widely
considered to be the leader in commercial
development of turquoise H2,
purchased and further developed
intellectual property from Kvaerner
(now Aker Solutions) to produce H2
using a plasma-arc approach.
Monolith currently operates the
first commercial MP facility for turquoise
H2, known as Olive Creek 1
Monolith
FIGURE 1. Monolith's Olive Creek 1 facility is currently
producing H2 and carbon black in Nebraska
(OC1; Figure 1), in Hallam, Neb. The
first-of-its kind commercial facility is
designed to produce hydrogen and
up to 14,000 metric tons of carbon
black per year with virtually zero
emissions from operations. Monolith
will begin construction on Olive
Creek 2 at the same site in 2024.
The expanded facility will have 12
additional MP reactors. To allow for
the expansion of clean H2 production,
along with carbon black and
NH3, Monolith received conditional
approval for a $1.04 billion loan from
the U.S. Department of Energy in
December 2021.
OC1 has allowed the company
to make significant improvements
to the process prior to the planned
scaleup in OC2. Monolith co-founder
and CEO Rob Hanson says making
the scaled up plant work reliably for
commercially relevant periods of time
required diligent work, but they company
has made hundreds of tweaks
to improve production. OC2 will add
an ammonia plant that will make approximately
300,000 ton/yr of ammonia
from the hydrogen generated.
Two major areas of focus at Monolith
have been to develop a highly detailed
understanding of the methane
pyrolysis reaction, and to control the
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
NOVEMBER 2023
http://www.idtechex.com http://www.chemengonline.com/commercial-progress-on-turquoise-hydrogen/ http://www.monolith-corp.com http://WWW.CHEMENGONLINE.COM
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