(6ei) Clathrate Hydrates for Sustainable Development

Clathrate Hydrates for Sustainable development

Ponnivalavan
Babu

Department of Chemical and Biomolecular Engineering,
National University of Singapore, Singapore, Singapore 117 585

Keywords: gas
hydrates; desalination; clathrate process; seawater, cold energy, LNG

*corresponding
author: e-mail: valavan@nus.edu.sg; Tel:
(65) 8693-7709; Fax: (65) 6779-1936.

Research
Interests:

Energy and Water are key resources
for sustainable and smart nation development. Climate change is the most
significant challenge to achieving sustainable development. Water, Energy and
Climate change are intricately interlinked. Therefore there is a need for
developing innovative technologies to address these challenges in a holistic
way. My research focus is on Energy, Water and Climate change pertaining to
clathrate hydrate as a technology enabler.

Clathrate hydrate or gas hydrate
are ice-like crystalline solid compounds, consisting of a small molecule
surrounded by a cage of water molecules. In nature, natural gas hydrate exists
in permafrost regions and marine sediments and it is considered as a huge
potential energy resource for the future. Selective fractionation of gas
components and high storage capacity in gas hydrates have enabled a wide range
of applications including seawater desalination, natural gas storage, and
transport, CO2 capture and sequestration, cold storage and refrigeration. 

My Ph.D. thesis title was
"Hydrate based gas separation (HBGS) technology for pre-combustion capture
of Carbon dioxide”. While most of the research groups employed traditional
stirred tank reactors, I employed an innovative fixed bed reactor with new porous
media and demonstrated improved process efficiency. Further, a major finding
that emanated from my Ph.D. work is that when propane is present as co-guest,
it has the ability to draw dispersed water above the porous media towards the
gas phase to form hydrate. Based on this mechanism, I proposed a clathrate
hydrate based desalination (HyDesal) process utilizing LNG cold energy and
simultaneous HBGS – HyDesal process.

Currently, I am developing an
innovative technology, HyDesal to desalinate seawater utilizing LNG cold
energy. HyDesal process was studied for last 70 years but never commercialized
due to slow kinetics; difficulty in separation of hydrate crystals from brine
solution, higher energy cost involved due to refrigeration. My innovative
approach/reactor design will address all the major challenges that were
associated with the HyDesal process. Based on the innovative design, I have
built a start of the art prototype to demonstrate the HyDesal process which can
strengthen the water-energy nexus. A patent application on the innovative
reactor designs is pending (allocated application number
PCT/SG2018/050083).  This work is of
strategic interest for any country since both energy and water demand can be
met using an environmentally benign process.

I intend to extend this technology
for simultaneous CO2 capture and desalination utilizing LNG cold energy and for
wastewater treatment. My experience and experimental know-how to enhance the
hydrate formation kinetics would enable me to design and make operational an
innovative reactor for simultaneous CO2 capture and desalination and wastewater
treatment.

Another area of my research
interest is the development of next-generation high-efficiency thermal energy
carriers for district cooling. District cooling is an energy efficient, low
carbon and affordable solution for meeting the rising cooling demand. Hydrate
slurry is a promising cooling medium for air conditioning. I intend to evaluate
the techno-economic feasibility of hydrates as thermal energy carriers for next-generation
sustainable district cooling systems.

Teaching Interests:

I
believe that learning needs to be student-centered
and students need to be equal partners in
the learning process. The teacher’s role should be to use his/her expertise on
lesson organization and its clarity, to hand the necessary resources to the
students, promote self-learning, build positive classroom climate and use
different teaching techniques to reach every student in the classroom. The teacher should make an effort to kindle student’s
interest in the subject and stimulate their critical thinking and apply the
concepts to real-world problems. Teacher-student interactions are the key to quality classrooms and should be
bidirectional.  Continuous feedback will
help to improve teaching effectiveness.

My
interest in teaching started during my
undergraduate degree at Crescent
Engineering College, Chennai, India. During those days, I enjoyed sharing my
knowledge and explaining the new topics to my fellow classmates on Chemical reaction Engineering, Fluid Mechanics and
Polymer Chemistry. My confidence in teaching was boosted when my fellow
students often approached me for clarification and explanations regarding
various concepts. During my doctoral degree in National University of Singapore,
Singapore, I worked as teaching assistant in CN2125 Heat and Mass Transfer,
CN3102 Chemical Engineering Laboratory II and CN4123R Final Year Design
Project. This experience as teaching assistant provided me with greater insight
into the challenges of teaching in a multicultural environment. Feedback from
the students helped me strengthen my teaching abilities. My interactions with
the students as a teaching assistant gave me an insight into the student’s interest, motivations and their point of view.

Having
a strong background in Chemical Engineering and Polymer Technology, I would be
interested to teach Chemical Reaction Engineering, Separation Processes, Fluid
Mechanics, Polymer Chemistry and Polymer Engineering. However, I would like to
teach rest of the courses if required by the department. Apart from teaching, I
would also embrace the opportunity to mentor students for their projects. As a
research advisor, I would teach my students the necessary technical skills to
operate safely and effectively in a laboratory and also providing them the
freedom to think, learn from mistakes and develop as an independent researcher.

Selected
Publications:

1.     
Babu, P.; Kumar, R.; Linga, P.
Pre-combustion capture of carbon dioxide in a fixed bed reactor using the clathrate
hydrate process. Energy 2013,
50 (1), 364-373. “Highly cited
paper” by Essential Science Indicators of Thomson Reuters since
September, 2013; Top 25 “Most Cited Paper” in Energy journal (top 1%
among 7000+ publications in the Journal since 2013). Highlighted by Elsevier in
a Virtual Special Issue on Chemistry and
Materials for Energy; "h5 core paper"
Google Scholar Metrics in 2016 & 2017.

2.      Babu,
P.;
Kumar, R.; Linga, P. Medium pressure hydrate based gas separation (HBGS)
process for pre-combustion capture of carbon dioxide employing a novel fixed
bed reactor. International Journal of Greenhouse Gas Control 2013, 17, 206-214. “Highly cited
paper” by Essential Science Indicators of Thomson Reuters since
July, 2014; Top 25 “Most Cited Paper” in
International Journal of Greenhouse Gas Control (top 1% among 1600+
publications in the Journal); "h5 core paper"
Google Scholar Metrics in 2017.
3.      Babu,
P.;
Kumar, R.; Linga, P. Unusual behavior of propane as a co-guest during hydrate
formation in silica sand: Potential application to seawater desalination and
carbon dioxide capture. Chemical
Engineering Science 2014, 117, 342-351.
4.      Babu,
P.;
Linga, P.; Kumar, R.; Englezos, P. A Review of the Hydrate Based Gas Separation
(HBGS) Process for Carbon Dioxide Pre-Combustion Capture. Energy 2015, 85, 261-279. “Highly cited
paper” by Essential Science Indicators of Thomson Reuters; Top
25 “Most Cited Paper” in Energy journal (top
1% among 7000+ publications in the Journal since 2013); "h5 core paper" Google Scholar Metrics
in 2017.
5.      Chong, Z. R.; Yang, S. H. B.; Babu,
P.; Linga, P.; Li, X.-S. Review of natural gas hydrates as an energy resource: Prospects and
Challenges. Applied Energy 2016, 162,
1633-1652. “Highly cited paper” by
Essential Science Indicators of Thomson Reuters; 2016 Applied
Energy Award; Top 25 “Most Cited
Paper” Award (2013-2018); "h5
core paper" Google Scholar Metrics in 2017.