low-temperature architected cementationagents (laminae
TRANSCRIPT
Low-temperature Architected Cementation Agents
(LAMINAE)
Gaurav N. Sant, UCLARoss Arnold, Mathieu Bauchy, Shiqi Dong, Advait Holkar, Dante Simonetti, Samanvaya
Srivastava, Longwen Tang, Juan Carlos Vega-Vila (UCLA)
Aditya Kumar (Missouri S&T)
Bu Wang (University of Wisconsin, Madison)
Yann Le Pape, Elena Tajuelo Rodriguez (ORNL)
Develop a pathway to low-energy, low-CO2,
microstructure-controlled cementation agentsTotal Project Cost: $1.9M
Length 24 mo.
Project Vision
Ordinary Portland Cement (OPC) production
(Vega-Vila et al. In preparation.)
‣ Large, growing global demand for OPC
‣ High energy intensity, primarily due to high-temperature kiln
‣ High CO2 intensity, from heating and from decomposition of limestone
Alternative technology: LAMINAE process
(Vega-Vila et al. In preparation.)
‣ Low-temperature cement production in two steps:
– Acoustically-stimulated precursor (mineral and rock) dissolution
– Ultrafast hydrothermal synthesis of cementitious silicate hydrates
‣ Estimated 60% reduction in CO2 intensity, 30% reduction in energy
requirement vs. OPC production
LAMINAE Team
3
Aditya Kumar
Experimental kinetics
Yann Le Pape,
Elena Tajuelo Rodriguez
Material characterization
Bu Wang
Adhesion and cohesion
Gaurav N. Sant
Project Lead
Mathieu Bauchy, Longwen Tang
Molecular dynamics simulations
Ross Arnold, Shiqi Dong
Acoustically-stimulated dissolution
Dante Simonetti, Samanvaya Srivastava,
Juan Carlos Vega-Vila, Advait Holkar
Ultrafast hydrothermal synthesis
Project Timeline
4
Batch-scale ultrasonic dissolution Batch silicate hydrate synthesis
Completed: >2× dissolution enhancement
for 6+ minerals/alkaline wastes
Completed: Batch synthesis of 3
cementitious silicate hydrate phases
Flow sonoreactor
construction
Energy intensity
analysisProcess condition
effect on morphology
Flow synthesis
reactor construction
Sonoreactor optimization Hydrothermal reactor optimization
Combined process
Goal (Sept. 2021): >100 g/day production
Current progress
(Oct. 2020)
Acoustic Stimulation Hydrothermal Synthesis
First Markets: Cement
‣Main aim of project is to produce silicate hydrates
(zeolites) with cementitious properties such as
phillipsite, Al-tobermorite
‣ These zeolites form in Roman concrete from
interaction of limestone, volcanic ash, and seawater
over 1000s of years
– Synthesize same zeolites in <1000 s using
targeted T, p, concentrations, pH
‣ Allows for microstructure control, while OPC
hydration is passive
– Higher durability and ductility in Roman concrete
5November 10, 2020
Ancient Roman marine concrete sample
UC Berkeley
First Markets: Zeolites
‣ Zeolites are highly porous aluminosilicate
hydrates that are used in ion exchange and
molecular sieve applications
‣ The synthesized zeolites of the LAMINAE
process could be used as high surface area
catalyst supports
– Requires high purity, high crystallinity
‣ Highly porous zeolites could be used as
adsorbents for wastewater treatment, targeting
different non-aluminosilicate atoms (e.g. Ca,
Na, K) within the structure for different
applications
6November 10, 2020
Phillipsite crystalsIndian Ocean Nodule Field
Enhancing Precursor Dissolution by Acoustic Stimulation
7(Dong et al. In preparation); (Wei et al. J Phys Chem C, 122(50), 28665-28673)
‣ Comparing sonicated and stirred (i.e. unsonicated)
dissolution at the same Reynolds number and
macroscopic temperature shows substantive
increase in the dissolution rate
‣ Extent of dissolution enhancement correlates with
bond energy, suggesting sonication assists in bond
rupture processes along solute surface
‣ Suitable precursors for acoustic stimulation are
those which are not highly soluble (e.g. halite,
gypsum) nor very hard (e.g. quartz)
Steel slag50 °C, s/l = 1:100
Acoustic Stimulation and Activation Energy
8(Dong et al., In preparation); (Wei et al. J Phys Chem C, 122(50), 28665-28673)
‣ Adding mechanical agitation increases the
dissolution rate, but does not affect apparent
activation energy
‣ Sonication reduces the apparent activation
energy as well as the dissolution rate,
demonstrating that applying ultrasound
creates a lower energy pathway to dissolution
‣Our hypothesis is that sonication stimulates
the reactant material, lowering the energy
barrier required to reach the transition state –
momentum transfer, not an electronic effect
Precursor Dissolution by Acoustic Stimulation
9(Tang et al., In submission)
‣Molecular dynamics simulations used to
quantify properties of minerals and rocks
– Surface energy: resistance to particle
fracture (comminution)
– Stacking fault energy: resistance to
surface defect formation
‣ Dissolution enhancement was found to
increase as both properties decreased
‣ Sonication enhances dissolution by
inducing particulate fracture and by
creating surface dislocations
Synthesis of Cementitious Silicate Hydrates
‣ Hydrothermal (batch) synthesis of three
cementitious zeolitic materials:
– Phillipsite [(Ca,Na2,K2)3Al6Si10O32·12H2O]
– Tobermorite [Ca5Si6O16(OH)·4H2O]
– Mordenite [(Ca,Na2,K2)Al2Si10O24·7H2O]
‣ Precursor gel composition based on
literature studies
‣ At batch scale, 100-150 °C, synthesis
requires approximately 1 week (compared to
millennia at ambient conditions), ~30% yield
10
XRD pattern, tobermorite
Effects of Synthesis Process Conditions
‣ Si concentration, pH tested for their effect on the
morphology of produced zeolites
‣ XRD peaks become broader as Si concentration
decreases (change in FWHM)
– Lower threshold of Si concentration (0.2 M for
phillipsite, 0.012 M for tobermorite) below which
no solid forms
– Si is the limiting reagent
‣ Only amorphous solids produced for pH <12 (will
gain order, in time; and Ostwald ripening)
‣ Sets targets for pH, Si concentration from
sonoreactor
11
Challenge: Si concentration
‣ Effluent solutions from mineral dissolution
often contain <1 mM Si (e.g., cement like)
‣ Zeolite synthesis solutions typically have Si
concentrations > 1 M (laboratory synthesis)
‣Mitigation strategies:
– Adjust sonication conditions (e.g. T, pH,
s/l) to maximize Si concentration and
reduce liquid content
– Minimize divalent cation concentration to
prevent CSH/MSH precipitation (solubility
controls)
[Si] vs. t, various steel slags
phillipsite, XRD patterns, varied [Si]
Challenge: Water demand
‣ Tobermorite (as a case study) can be formed from
Si concentrations as low as 12 mM, possibly lower
at high pressure
‣ At this concentration and 30% yield, ~2.5 L of
water would be required per gram of zeolite
produced
‣Mitigation strategies:
– Reduce water demand through recycle stream
– Use of membrane to decrease water demand;
would add to CapEx, but may reduce OpEx
– Combine with low Si concentration mitigation
(or enrichment) strategies
Challenges
‣ Reactor Development: Dissolution rate expressions necessary to scale up
batch sonoreactors and for translation into continuous flow reactors
– Optimized reactor parameters lead to minimum energy input
‣ Resistance to adoption of new technology: Ordinary Portland Cement
(OPC) production has remained largely unchanged since 19 th century
– Consulting with industry partners to address market limitations
– Industrial collaboration will likely require pilot-scale demonstration
Potential Partnerships
‣ Our team is always interested in potential partnerships. Our strengths include
reactor design, zeolite synthesis, molecular dynamics simulations,
thermodynamic modeling, experimental kinetics, and material characterization
‣We are interested in partnering with others with experience with ultrasonic
reactors, with high-pressure thermal analysis (including differential scanning
calorimetry), and high (p,T) kinetic modeling of dissolution processes
‣We are also always interested in expanding our list of industrial partners,
consultants and pilot (“scale up”) partners
15November 10, 2020
Summary
‣ Estimated 30% energy reduction, 60% CO2 reduction vs. OPC production
‣ Collaborative effort between UCLA, MST, UW-M, ORNL
‣ Project goal: Combine acoustic stimulation and ultrafast hydrothermal synthesis
to develop a low-energy, low-CO2 pathway to produce cementation agents with
controlled microstructure
16Insert Presentation NameNovember 10, 2020
‣ LAMINAE Process: