Biosilica from BiomassConstruction Material and Energy

ChK Group, Inc. Plano, Texas

ACS National Meeting & ExpositionDallas, TX

March 20, 2014

Rajan K. Vempati, Ph.D.

Prasad Rangaraju, Ph.D.

Antonio Nanni Ph.D.

Sridhar Komernini, Ph.D.

John Imhoff

Subbaraman Viswanathan, Ph.D.

Project Goals

Manufacture Amorphous silica from biomass (Biosilica) with multiple uses Construction material in High Strength Concrete Additive in paints, plastics & tires Zeolite manufacture

Sustainable Product Unlike Other Food Products used in Bio-Fuels. The Rice

Production for Human Consumption Unaffected. Generate Revenues

From Biosilica - a high value product Sell energy as steam and power

Create Jobs

BiosilicaRenewable Cementitious Material

Rice HullFrom Rice Mills

Rice Field (Upland Cultivation)

Supply of Rice HullsAgricultural Waste Generated from Rice MillsUsed as fuel for its caloric value. Ash (black ash) with high carbon content is rejected as waste.Off-white or white Biolica Supply Potential is high

Major competition – from silica fumes in Cement

4

AreaRice Mill Capacity Supply Biosilica

Competition From Silica Fumes (*)

USA 10.5 Million Tons 0.4 Million Tons 60,000 Tons

Worldwide 550 Million Tons 20 Million Tons --

Annual Capacities

(*) Silica fumes is a byproduct with limited capacity

Biosilica Premium Additive in High Performance Concrete (HPC)

Value Chain for Biosilica

Rice Cultivation and Processing in Rice Mills

ChK Process Biosilica Production and Power Generation

Biosilica to HPC and Power to the Grid

Currently Rice Hull is sent to landfills at a cost

Black ash is not suited for HPC due to high carbon content

ChK Process unique features:

• Biosilica Carbon content < 0.1%; NO graphitic carbon

• Zero crystallinity

• Produces process heat and power based on site requirements

• No solid waste as inorganic matter in rice hull becomes Biosilica

• Simple process easy to operate and control

• Zero CARBON emissions and future carbon CREDITS

Zero Carbon - Feed BIOMASS

Rice Hull Biosilica Plant

O2CO2

Photosynthesis

Rice Fields

Rice Milling PlantsGenerates Rice Hulls

Rice Hulls

Biosilica

CO2

O2

Atmosphere

Steam & Power

7

Rice Hull Properties

HHV Dry Basis 16.2 MJ/KG[6,965 BTU/LB]

Moisture, W% 9.7%

Volatile, W% 66%

Carbon, W% MF 40.2%

Ash, W% 18.2%

Ash Composition (%) SiO2 95.00Al2O3 0.41Fe2O3 0.25CaO 0.75MgO 0.43K2O 2.20

Biosilica Properties• Silica content: > 90 W%• Type: Amorphous silica• Carbon Wt%: < 0.1 W%• Cristobalite: No crystalline matter

(verified in XRD and FTIR)• Major Uses:– Pozzolan additive to concrete; replaces 10 to 20% of

cement

– Produces ZSM-5 zeolite by thermochemical methods WITHOUT an organic template

– Filler in paints, plastics and tires

Biosilica High Performance Cement and In Architectural Cement

Unground Ground .

High Performance Concrete (HPC)Use to Mitigate Severe Erosion in Dams

Kinzua Dam in Pennsylvania HPC used to mitigate severe erosion due to abrasion with water flow

DOING WELL AFTER HPC INSTALLATION IN 1983

Addition of Biosilica in HPC Results in Slower Curing and Higher Strengths (Increase by 35%)

0

10

20

30

40

50

60

70

80

0 20 40 60 80 100Period of curing (days)

Com

pres

sive

stre

ngth

(MPa

)

Control

GRHA-7.5%

GRHA-15%

Figure – Rate of Development of Compressive Strength in GBiosilica Concrete

Figure – Comparison of the 28-Day Compressive Strength of UBiosilica and GBiosilica Concrete

Bridges in FloridaCorrosion concerns – State Government Specifies Addition of 8 to 9%

Silica Fume in Concrete that Stands in Salt Water or Gets Splashed

Bridge in Florida in US – 1 Highway

Other applications for Biosilica in HPC• Parking lots in cold climates – subjected to severe chloride corrosion from

salted roadways• High rise buildings that require HPC with high modulus of elasticity

Biosilica Substantially Reduces Chloride Permeability

Figure – Comparison of Chloride Permeability Values of Biosilica Concretes after 56-Day Curing

• Corrosion – Most Prominent Problem

• Alkali-Silica Reactivity (ASR)

• Delayed Ettringite Formation (DEF)

• Sulfate Attack

• Freeze-Thaw Damage

Durability Issues

White Architectural Cement

Biosilica Use in ZSM-5 Production

• ChK Process - patented

– ChK has developed a process to minimize heating requirements without using any organic template

• Synthesis conditions

– Si/Al molar ratio of reaction mixture: 20 to 100

– Temperature 190°C (could use 200 LB steam for heat up)

– Crystallization time 36 hours

– Seeding with up to 1% ZSM 5

– Product is filtered washed and dried at 120°C.

– For special applications, ZSM-5 could be calcined, as needed

• Product ZSM-5 properties

– Si/Al Molar ratios of 80 and above are easily obtained.

– Carbon content of Rice Hull ash affects the type and quality of ZSM-5

Pilot Scale Rotary Calciner for BioSilica Manufacture

6 in diameter tube 20 FT long 3-Zone temperature

control

Large (Commercial Scale) Rotary Calciner (Illustrative)

6 FT diameter tube

> 60 FT longHeat input with a string of natural gas burners

Acknowledgements• Dr. Harish, K.V. - Clemson University, Clemson, SC

• Dr. Ferraro, R. M. - University of Miami, Coral Gables, FL

• Dr. Ramesh Borade

• Dr. Arun Bonapati

• NSF SBIR Phase II Award Number: 0724463