Chemical Engineering May 2023 - 14

Ketjen
FIGURE 3. Artificial intelligence technology is being employed
in the development of refinery catalysts
soe.com) to use Topsoe's SynCOR
autothermal
reforming
technology
for the planned Baytown facility, and
with Honeywell UOP (Des Plaines,
Ill.; uop.honeywell.com) to use Honeywell's
CO2 Fractionation and Hydrogen
Purification System at the
integrated complex.
For its part, Honeywell is also
working with Johnson Matthey plc
(JM; London, U.K.; www.matthey.
com) on low-carbon H2 technology.
In December 2022, the two companies
announced they would be
working together to offer JM's LCH
autothermal
reforming
technology,
coupled with Honeywell's carboncapture
technology to produce blue
hydrogen at scale. According to calculations
from
JM and Honeywell
UOP, the combination enables direct
process emissions to be less than
0.1 kg CO2 per kg of H2 by capturing
carbon at rates above 99%. This
provides eligibility for production tax
credits within the IRA.
Autothermal reforming (ATR) generates
hydrogen by combining the
endothermic SMR reaction with
exothermic partial oxidation. It is potentially
attractive because it can be
more efficient than SMR and facilitates
carbon capture in some ways.
Hydrogen hubs
Low-carbon H2 production at petroleum
refineries is also a component
of several " regional clean-hydrogen
hubs, " many of which are currently
under development. Industrial hydrogen
hubs are usually public-private
partnerships defined as " a network
of clean-hydrogen producers, potential
clean-hydrogen consumers, and
connective infrastructure located in
close proximity. "
In the U.S., as part of the IIJA, Con14
gress
allocated $8 billion for the
creation of multiple " H2Hubs, " to
support low-carbon H2 generation.
The Department of Energy
(DOE; Washington, D.C.; www.
energy.gov) is administering the
awards, and received 79 concept
papers for H2 hubs as part
of the program. DOE encouraged
full proposals from a portion
of the initial submissions and
the awardees (as many as 10)
will be announced in fall 2023.
A substantial portion of the applicants
to the program involve major
petroleum refiners. For example,
the HyVelocity Hub (www.hyvelocityhub.us)
on the U.S. Gulf Coast
includes Chevron and ExxonMobil,
along with a host of other academic
and industrial partners. Organized
by GTI Energy, Center for Houston's
Future and the University of Texas
at Austin, the HyVelocity Hub will
pursue DoE's goal of limiting carbon
emissions to less than 2 kg of carbon
per 1 kg of H2 produced, and
reducing the cost of clean H2 production
to $1/kg. Another example
is the H2ALO Hub (h2alo.org), a
partnership among the states of Arkansas,
Louisiana and Oklahoma,
along with a host of participants that
includes Shell and TotalEnergies.
Meanwhile, in Europe, H2 hubs involving
refineries are moving ahead,
and many involve traditional
refiners.
An example is the Humber Industrial
Cluster (HICP; U.K.; www.
humberindustrialclusterplan.org). As
part of the HICP, Shell and Uniper
are developing a low-carbon H2 hub
at Uniper's Killingholme, U.K. site. In
March 2023, Uniper and Shell UK
Ltd. awarded Shell Catalysts & Technologies
a contract to deliver a process
design package for the HICP
project, using the Shell Blue Hydrogen
Process (SBHP). Two other
companies are also working on plant
design proposals for the project, and
the one that is selected will become
the Humber H2ub project's preferred
low-carbon H2 production technology
provider.
The proposals involve building a
blue-hydrogen production unit at
Uniper's Killingholme site, capable of
generating 720 MW of low-carbon
hydrogen from natural gas. The CO2
produced (~1.6 million ton/yr) would
be captured and stored in a geological
formation in the North Sea.
SBHP is an alternative to autothermal
reforming and SMR. It uses Shell
gas partial oxidation technology and,
compared to SMR and ATR, it captures
CO2 at higher pressures and at
larger scales, which results in a lower
levelized cost of H2, Shell says.
Artificial intelligence
Another pathway for refineries to reduce
GHG emissions is to optimize
processes. The variability of feedstock
slates and complexity of refining
units offers many opportunities to
improve process efficiency and consistency.
And artificial intelligence (AI)
technology has emerged as tool to
help achieve that.
An example of how AI is being
used in refinery settings comes
from Hexxcell Ltd. (London; www.
hexxcell.com), which is using AI to
do predictive maintenance of heat
exchangers in refineries. As a subset
of AI, machine learning (ML) approaches
have been used previously
for predictive maintenance of rotating
machinery, for example, but predicting
maintenance for heat exchangers
that undergo fouling deposition
on thermal surfaces is more difficult
because of the complex and varying
compositions of crude oils and process
conditions. Fouling on heat exchange
surfaces reduces efficiency
and increases pressure drop, requiring
more energy input and emitting
more CO2 for the the same barrel of
oil processed.
" Since there is no single solution
for heat exchanger fouling, refiners
take a largely reactive and preventive
approach, but it is often unclear
which exchangers to clean, and
when, and which cleaning method
will be most cost-effective, " says
Hexxcell co-founder and CEO Francesco
Coletti. " We have developed a
hybrid AI software that combines ML
with physics-based models to generate
insights about heat-exchanger
maintenance and cleaning. "
The combination of ML with
physics-based models can offer insights
on system-specific fouling that
would not be possible with either ML
or models alone, Coletti says. " The
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM MAY 2023
http://www.energy.gov http://www.topsoe.com http://www.hyvelocityhub.us http://uop.honeywell.com http://www.hyvelocityhub.us http://www.matthey.com http://www.hexxcell.com http://www.h2alo.org http://www.humberindustrialclusterplan.org http://WWW.CHEMENGONLINE.COM
Chemical Engineering May 2023

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