This document discusses the potential for using rice hulls as a source of biosilica. It describes a process called the ChK Process that converts rice hulls into high-purity biosilica and generates process heat and power. Biosilica has various applications as a renewable cementitious material, including as a pozzolan additive in high-performance concrete to improve strength and reduce chloride permeability. The document outlines plans to commercialize the ChK Process through a new company called Biosilica and Energy Corporation.

1. Biosilica
for Manufacturing
and Applications
ChK Group, Inc.
Plano, Texas
Rajan K. Vempati, Ph.D.
Subbaraman Viswanathan, Ph.D.

2. Biosilica a Premium Additive in
High Performance Concrete (HPC)
Value Chain for Biosilica
ChK Process
Rice Biosilica to
Biosilica
Cultivation HPC use
Production
Processing in Power to the
Power
RICE MILLS Grid
Generation
 Currently ChK Process unique • No solid waste as
Rice Hull is features: inorganic matter in
sent to rice hull becomes
• Biosilica Carbon
landfills at a Biosilica
content < 0.1% with
cost
NO graphitic carbon • Simple process easy to
 Black ash is
• Zero crystallinity with operate and control
not suited
for HPC due
no cristobalite • Zero CARBON
to high • Produces process heat emissions and future
carbon and power based on carbon CREDITS
content site requirements

3. Zero Carbon – With Bio-Material Use
(Produces Green Construction Material and Power)
Atmosphere
O2 CO2
CO2
O2
Photosynthesis Steam & Power
Rice
Rice Fields Hulls
Rice Milling Plants Rice Hull
Generates Rice Hulls Biosilica Plant
Biosilica

4. Biosilica
Renewable Cementitious Material
Rice Hull
From Rice Mills
 Rice Field
(Upland Cultivation)

5. Supply of Rice Hulls
Agricultural Waste Generated by the Rice Milling Industry
No Real Value: Most Uses Never Cover the Cost of Transportation
Supply Potential Rice Hull Properties
HHV Dry Basis 16.2
Silica
Rice Bio Silica
Fume MJ/Kg [6,965 BTU/LB]
Actual Potential Actual
Ton/Yr Ton/Yr Ton/Yr
Moisture, W% 9.7%
USA 10,500,000 378,000 60,000*
Volatile, W% 66%
Carbon, W% MF 40.2%
GLOBAL 550,000,000 19,800,000
Ash, W% 18.2%
Most of this silica fume is imported
Ash Composition
SiO2 –W% 89 to 95%; Al2O3 0.41
Fe2O3 0.25; CaO 0.75%; MgO 0.43
K2O 2.2%
5

6. 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

7. Biosilica
High Performance Cement and In Architectural Cement
Unground Ground .

8. 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

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

10. Bridges in Florida
Corrosion 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

11. Biosilica Substantially Reduces
Chloride Permeability

12. The ChK Process
For Biosilica Production
Scrubber and
Thermal
Oxidizer to Stack
2 Energy
1
Stack
Options Steam Boiler/
Turbine-Power
2
Pyrolysis oil 2
Refining to diesel..
Refinery
Partial Upgrading
Oxidation
Drying Dried Pyrolysis and
Rice Hull 150 oC Rice Hull Gasification Biosilica
< 700 oC
Natural gas and
Recycle fuel gas Water/
Steam
Combustion Air

13. Pilot Scale Rotary Calciner for BioSilica
Manufacture
6 in diameter tube
20 FT long 3-Zone
temperature
control

14. Large (Commercial Scale) Rotary Calciner (Illustrative)
6 FT diameter tube
> 60 FT long
Heat input with a string
of natural gas burners

15. 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

16. 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

18. 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