The document describes a process for producing biogenic silica (BioSilica) from rice hulls as a sustainable additive for concrete applications. The ChK process thermally converts rice hulls into BioSilica and energy through pyrolysis or gasification without producing solid waste. BioSilica offers advantages over other pozzolans as a concrete additive due to its low carbon content, amorphous structure, and cost competitiveness. A pilot plant demonstrates the potential for commercial production of BioSilica and power with attractive financial returns. Future plans involve commercializing the technology through an energy and BioSilica corporation.

1. Biogenic Silica &
Nanophase Mn Oxide
for Manufacturing
& Applications
ChK Group, Plano, Texas
Subbaraman Viswanathan, Ph.D.
Richard Wagner, Ph.D.
Rajan Vempati, Ph.D.

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

3. Biogenic silica
Renewable cementitious material
Rice Hull
From Rice Mills
 Rice Field
(Upland Cultivation)
BioSilica
Unground & Ground

4. ZERO Carbon – with Bio-Material use
Produces Green Construction Material & Power
Atmosphere
O2 CO2
CO2
O2
Photosynthesis Steam & Power
Rice
Rice Fields Hulls
Rice Milling Plants Rice Hull
Generates Rice Hulls BioSilica Plant
BioSilica

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 silicafume 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 W%: < 0.1 W%
• Cristobalite, W%: None (Not detected) No 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. Comparison of Concrete Additives used as
POZZOLANS
Particle
Origin $/Ton Color
Size
Comments
Fe-Si
Ultra
Silica Fumes Byproduct $585 Grey
Fine
USA Supply Decreasing
(limited)
Heated 1.5 Geological constraints on
Metakaoline Kaolinite
$400 White
Micron deposits
Black Rice Hull 3-40% Carbon Content,
Gasifier +10
byproduct
<$50 Black
Micron
Crystalline Silica Present,
Ash Poor Freeze-Thaw
5-10 Non-Toxic, very low Carbon,
BioSilica™ Rice Hulls $300 Off White
Micron Architecturally pleasing
BioSilica™ is better performing
as well as cost competitive
7

8. BioSilica could be used in
High Performance Cement & in Architectural Cement
Unground Ground .

9. HPC (High Performance Concrete)
use to mitigate severe erosion in dams
Kinzua Dam in Pennsylvania
HPC (High Performance Concrete) used to mitigate severe erosion due to abrasion
with water flow
DOING WELL AFTER HPC INSTALLATION IN 1983

10. Addition of BioSilica in HPC results in slower curing
and higher strengths (increase by 35%)

11. Bridges in Florida
Corrosion concerns – State Government specifies addition of 8 to
9% silicafume in concrete that stands in salt water or gets splashed with it
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

12. BioSilica substantially reduces chloride
permeability

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

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

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

16. Attractive return on Investment [IRR > 20%]
Table 1: Process Economics Summary
Plant type Biosilica™ Plant Biosilica™
Only Plant with
power
module
Capacity, TPY of Biosilica™ 18,400 18,400
Power generation 0 6 MW
CAPEX $ 9 Million $ 18 Million
Feed Rice Hull cost $8/T $8/T
Product Biosilica™ price (*) $300/T $300/T
Power sale price -- $60/MWH
IRR, % 24% 19%
NPV $13 million $ 16 Million

17. Future Plans
• BioSilica and Energy Corporation formed to commercialize the ChK
Process
• Seeking investors to construct the first commercial plant
• Plant payback in less than5 years
• Contacts:
Subbaraman Viswanathan (VIS) Ph.D.
President, BsEC
Phone: 832-457-6486; e-Mail: VISWAS@SSTDINC.COM
Rajan Vempati, Ph.D.
Vice President, BsEC
Phone: 832-457-6486; e-Mail: CHKGROUP@ATT.NET

18. 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 ratio of reaction mixture: 20 to infinity
– Temperature 210 Degrees C (could use 200 LB steam for heat up)
– Crystallization time 36 hrs 20 to 72 hours
– Seeding with up to 1% ZSM 5
– Product is filtered washed and dried at 120° degrees 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