Biosilica for Manufacturing

and Applications

ChK Group, Inc. Plano, Texas

Rajan K. Vempati, Ph.D.

Subbaraman Viswanathan, Ph.D.

Biosilica a Premium Additive in High Performance Concrete (HPC)

Value Chain for Biosilica

Rice CultivationProcessing in RICE MILLS

ChK Process Biosilica ProductionPower Generation

Biosilica to HPC use 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% with NO graphitic carbon

• Zero crystallinity with no cristobalite

• 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 – With Bio-Material Use(Produces Green Construction Material and Power)

Rice Hull Biosilica Plant

O2CO2

Photosynthesis

Rice Fields

Rice Milling PlantsGenerates Rice Hulls

Rice Hulls

Biosilica

CO2

O2

Atmosphere

Steam & Power

BiosilicaRenewable Cementitious Material

Rice Field (Upland Cultivation)

Rice HullFrom Rice Mills

Supply of Rice HullsAgricultural Waste Generated by the Rice Milling Industry

No Real Value: Most Uses Never Cover the Cost of Transportation

Supply Potential

Rice Bio Silica Silica Fume

Actual Ton/Yr

Potential Ton/Yr

Actual Ton/Yr

USA 10,500,000 378,000 60,000*

GLOBAL 550,000,000 19,800,000

5

Rice Hull Properties

HHV Dry Basis MJ/Kg

16.2[6,965 BTU/LB]

Moisture, W% 9.7%

Volatile, W% 66%

Carbon, W% MF 40.2%

Ash, W% 18.2%

Ash CompositionSiO2 –W% 89 to 95%; Al2O3 0.41Fe2O3 0.25; CaO 0.75%; MgO 0.43K2O 2.2%

Most of this silica fume is imported

Biosilica Properties

• Silica content: > 90w%

• Type: Amorphous silica

• Carbon Wt%: < 0.1 W%

• Cristobalite Wt%: Not Detected Crystalline Silica

• 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 and plastics

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%)

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

The ChK ProcessFor Biosilica Production

ThermalOxidizer to Stack

Scr

ub

ber

an

d

Sta

ckSteam Boiler/ Turbine-Power

2 Energy Options 1

2

Partial OxidationPyrolysis and Gasification< 700 oC

Biosilica

Pyrolysis oilRefining to diesel..

Water/ Steam

Refinery Upgrading

Rice HullDrying150 oC

DriedRice Hull

Natural gas andRecycle fuel gas

Combustion Air

2

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 long

Heat input with a string of natural gas burners

Future Plans• Biosilica and Energy Corporation (BsEC) formed to commercialize

the ChK Process

• Seeking investors to construct the first commercial plant

• Plant payback in less than 5 years

• Contacts:

Rajan K. Vempati, Ph.D.

President, ChK Group, Inc.

Phone: (214) 704-4128; e-Mail: chkgroup@att.net

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

Acknowledgements• Dr. Prasad Rangaraju - Clemson University, Clemson, SC

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

• Dr. Antonio Nanni - University of Miami, Coral Gables, FL

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

• Dr. Ramesh Borade

• Dr. Arun Bonapati - Harper International, Inc., Lancaster, NY

• NSF SBIR Phase II Award Number: 0724463