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: