Introductory Remarks

Winning the Energy Dilemma:

Carbon-Free Energy and Environmental
Sustainability

Simona Liguori – Department
of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA

Assistant Research Professor – Worcester Polytechnic Institute 2018 – present

Assistant Research Professor – Colorado School of Mines 2016 – 2018

Physical Science Research Associate – Stanford University 2014 – 2016

Post Doc – Institute on Membrane Technology (National Lab-Italy) 2012 – 2014

Motivation and Research Interests:

The
generation of carbon-free electricity and the production of low-carbon fuels
are urgent needs that must be addressed as the atmospheric concentration of
carbon dioxide (CO₂) continues to rapidly increase. The proposed solutions
for mitigating the effects of climate change are the deployment of low-carbon
fuels and improvements to the efficiency of current technologies for energy
conversion.

Carbon-free hydrogen is viewed as a promising long-term option for
tackling CO₂ emissions from distributed sources, as well as generating
electricity and energy as needed. Electrolytic processes such as water
electrolysis and photo-reduction combined with photovoltaic solar and/or wind
energy can be utilized to produce ‘carbon-free’ hydrogen. However, these
technologies suffer from various drawbacks such as the high electric energy
requirements, low efficiency, and very high hydrogen production cost compared to
the conventional methane steam reforming process. Furthermore, in some cases, significant
land area is required to deploy these technologies.

One of the
primary goals of my research is to advance the science of metallic membrane reactors for catalytic reactions to produce
various chemicals and feedstocks via non-traditional pathways. The proposed
technology presents a unique method to generate hydrogen through a catalytic
membrane configuration using hydrogen selective materials. Membrane reactors
make it feasible to combine the production and separation steps in one unit.
This leads to lower operating temperatures and pressures, higher yields, and lower
capital and operating expenses. The produced CO₂ can be easily
compressed and captured for geologic sequestration. The combination of these
state-of-the-art technologies will make it possible to produce carbon-free
hydrogen.

The concept
of membrane reactors can also be applied to produce ammonia using a nitrogen-selective
membrane. The central premise of this research is to physically separate the energy-intensive
nitrogen dissociation from the serial exothermic hydrogenation reactions (using
an atomic nitrogen-permeable catalytic membrane). In doing so, separate
catalysts and operating pressures can be utilized for each step in the
catalytic cycle.

The efforts
proposed herein leverage intensified reaction/separation engineering to synthesize
next generation ultra-selective metallic membranes. This will overcome the
perceived barriers associate with the traditional technologies by increasing
the hydrogen and ammonia production and eliminating the CO₂ emissions
through the use of catalytic membrane reactors.

Another area
of my research interests focuses on fostering scientific curiosity through negative
emission technologies, particularly mineral carbonation technologies. In mineral
carbonation, the CO₂ contained in the atmosphere chemically reacts
with calcium- and/or magnesium-containing minerals to form stable carbonate
materials. Mineral carbonation presents several fundamental engineering challenges.
This includes developing methods to effectively increase the carbonation rate
of these materials while intensifying the system to exploit the exothermic
nature of these reactions. Additionally,
these efforts must be performed within environmental constraints, such as minimal
energy and material losses.

In summary,
my research interests are focused on:

·     
Developing
the science of metallic membrane reactors, as well as synthesizing and testing
new materials for membranes and catalyst to

o  
Produce
carbon-free hydrogen, and capture CO₂

o  
Decouple
the ammonia reaction into two-half steps realized across a reactive membrane to
reduce operating pressure, increase yields, and decrease capital and operating expenditures

·     
Furthering
Negative Emission Technologies by

o   Improving mineral carbonation
pathways to remove CO₂ from the atmosphere and permanently store it
as a carbonate material.

Teaching Experience
and Teaching Interests:

I have taken
any opportunity to share my knowledge and experience with others to promote
science. To achieve this goal, I worked as a Teaching Assistant (TA) for Inorganic
Chemistry courses during my post-doctoral appointment in Italy. Additionally, I
was the co-instructor of a Carbon Capture course at Colorado School of Mines. During
these appointments, I realized that teaching could be both challenging and
rewarding. Teaching requires extensive planning, organizing materials,
prioritizing ideas, interacting with students, learning to monitor and adjust
to the atmosphere of a classroom, tailoring instructions for students with varying
levels of ability, and learning how to accomplish goals that sometimes seem
mutually exclusive. All this while keeping the attention of a class and meeting
the expectations of administrators and peers. Nevertheless, I am always
enthusiastic and passionate when I have the opportunity to share my knowledge
with students. Especially, when I can engage them in scientific activities. In
addition to formal methods of teaching, I have had the opportunity to serve as
mentor for three undergraduate students in Italy and two PhD students at
Stanford. I also currently mentor a PhD student at Worcester Polytechnic
Institute. During these years, I have given all the help I could to ensure my
mentees success in both academic and professional settings.

Over these
years I have developed a growing interest for chemical engineering subjects,
including fluid mechanics, transport phenomena, thermodynamics, energy
conversion processes, and chemical reaction and kinetics. As a future faculty,
I intend to combine my research experience with newly developed techniques for
interactive learning to create a positive and engaging classroom atmosphere
where everyone feels included and empowered to pursue their educational goals.

Research
Experience:

My research
experience spans multiple topics, including chemical reactors and reaction analysis,
reaction kinetics, heat and mass transport processes, reactive diffusion
through catalysts, gases separation and membranes.

For my PhD
research, I focused on both experimental and simulation investigations into the
reforming reactions of bio-fuels in both membrane reactors and fixed-bed
reactors for hydrogen production. After completing my PhD, I continued my
research in membrane science and technology as a Post-Doctoral Research Fellow
at the Institute on Membrane Technology in Italy, as a Physical Science
Research Associate at Stanford University, and as a Research Assistant
Professor at Colorado School of Mines. During these years, I have published
numerous peer-reviewed articles and registered one scientific patent with the
U.S. patent office on an alternative, novel method to produce ammonia via a
nitrogen-selective membrane reactor.

Additionally,
I applied years of my research experience in the areas of membrane technology,
hydrogen production, and CO₂ mitigation to set up two new research
laboratories at Colorado School of Mines and Worcester Polytechnic Institute.
As a Research Assistant Professor, I currently work on synthesizing new
membranes and developing new catalysts for ammonia and hydrogen production to
mitigate CO₂ emissions.

Future Direction:

As a
faculty member I would like to continue applying membrane science and
technology to different areas of engineering, as well as industrial
applications. I believe the interdisciplinary research activities that I
performed in the areas of chemical engineering and environmental science have
equipped me with the essential tools to advance my research toward mitigating the
greenhouse gas emissions, such as CO₂, by producing lower-carbon
fuels.

Three of
the areas that I have found myself very fascinated about are the development of
organic membranes for gas separation processes, metal organic frameworks (MOFs)
with the purpose of carbon capture, and, finally, improving the mineral
carbonation mechanism with the aim of permanent removal of CO₂ from
the atmosphere.

Selected
Publications:

1.     S. Liguori (corresponding Author), K. Lee, J.
Wilcox, “Innovative N₂-selective metallic membranes for the
potential use of CO₂ capture”, J.
Membr. Sci., 585 (2019) 52-59

2.     Z Zhang, S Liguori, TF Fuerst,
JD Way, CA Wolden, “Efficient ammonia decomposition
in a catalytic membrane reactor to enable hydrogen storage and utilization”, ACS Sust. Chem.
Eng., 7 (2019) 5975-5985

3.     K Kian, C Woodall,
J Wilcox, S. Liguori (corresponding
Author), “Performance of Pd-based membranes and effects of various gas
mixtures on H₂ permeation”, Environments
5 (2018) 128

4.     B. Anzelmo, J. Wilcox, S.
Liguori (Corresponding Author), “Hydrogen production via natural gas steam
reforming in a Pd-Au membrane reactor. Investigation of reaction temperature
and GHSV effects and long-term stability”, J.
Membr. Sci, 565 (2018) 25-32

5.     B. Anzelmo, J. Wilcox, S.
Liguori (Corresponding Author), “Hydrogen production via natural gas steam
reforming in a Pd-Au membrane reactor. Comparison between methane and natural
gas steam reforming reactions”, J. Membr. Sci, 568 (2018)
113-120

6.    
S. Liguori, J. Wilcox, “Membrane
considerations and plant design for post-combustion CO₂ capture”,
Ch. 14, In Current Trends and Future Developments on (Bio-) Membranes, A.
Basile, E. Favvas (Eds.), (2018) Elsevier, ISBN 9780128136454

7.    
J
Wilcox, S. Liguori “Ammonia synthesis
using nitrogen-selective membrane” – (2018),
US Patent No 15/707,007

8.    
B.
Anzelmo, J. Wilcox, S. Liguori (Corresponding Author), “Natural gas steam reforming
reaction at low temperature and pressure conditions for hydrogen production via
Pd/PSS membrane reactor”, J. Membr. Sci., 522 (2017)
343-350.

9.    
S. Liguori, J. Wilcox, “Silica
membranes application for Carbon Dioxide separation”, Ch. 11, In Current Trends
and Future Developments on (Bio-) Membranes, A. Basile, K. Ghasemzadeh
(Eds.), (2017) Elsevier, pp. 265-294,
ISBN 9780444638663

10. 
J.
Wilcox, P.C. Psarras, S. Liguori, “Assessment of
reasonable opportunities for direct air capture”, Env. Res. Lett., 12 (2017) 065001. (It was invited)

11. 
P.
Psarras, H. Krutka, M. Fajardy, S. Liguori,
S. Zhang, N. Mac Dowell, J. Wilcox, “Slicing the pie: how big could Carbon
Dioxide removal be?”, WIREs Energy and
Environment, 6 (2017) e253

12. 
S. Liguori, K. Kian, N.
Buggy, B. Anzelmo, J. Wilcox, “Opportunities and challenges
for hydrogen production/separation via metallic membranes”, submitted, Progress in Energy and Combustion Science

13. 
L.
Giugliano, S.
Liguori, K. Kian, J. Wilcox, T Bandhauer,
“Technoeconomic analysis of steam generation with Carbon Dioxide capture via
steam methane reforming in a membrane reactor”, submitted, Environmental
Science & Technology

14. 
J.
Wilcox, P.C. Psarras, H. Pilorge
S. Liguori, J. He, M. Yuan, C
Woodall, K. Kian, L. Pierpoint, J. Jurewicz, M. Lucas, R. Jacobson, N. Deich,
“Strategy for jumpstarting modular DAC using low-temperature heat”, submitted, Proceedings of the National Academy of Sciences.