Biosilica from Biomass
Construction Material and Energy
ChK Group, Inc.
Plano, Texas
ACS National Meeting & Exposition
Dallas, 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
Biosilica
Renewable Cementitious Material
Rice Field (Upland Cultivation)
Rice Hull
From Rice Mills
Supply of Rice Hulls
Agricultural Waste Generated from Rice Mills
Used 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
Annual Capacities
Area
Rice 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 --
(*) Silica fumes is a byproduct with limited capacity
4
Biosilica
Premium Additive in High Performance Concrete (HPC)
Value Chain for Biosilica
Rice Cultivation
and Processing in
Rice Mills
 Currently Rice
Hull is sent to
landfills at a
cost
 Black ash is
not suited for
HPC due to
high carbon
content
ChK Process
Biosilica Production
and Power
Generation
ChK Process unique
features:
• Biosilica Carbon
content < 0.1%; NO
graphitic carbon
• Zero crystallinity
• Produces process heat
and power based on
site requirements
Biosilica to
HPC and Power to the
Grid
• 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
Atmosphere
O2
CO2
CO2
O2
Steam & Power
Photosynthesis
Rice Fields
Rice
Hulls
Rice Milling Plants
Generates Rice Hulls
Rice Hull
Biosilica Plant
Biosilica
Rice Hull Properties
HHV Dry Basis
16.2 MJ/KG
[6,965 BTU/LB]
Moisture, W%
Volatile, W%
Carbon, W% MF
9.7%
66%
40.2%
Ash, W%
18.2%
Ash Composition (%)
SiO2
Al2O3
Fe2O3
CaO
MgO
K2O
95.00
0.41
0.25
0.75
0.43
2.20
7
Biosilica Properties
•
•
•
•
Silica content:
Type:
Carbon Wt%:
Cristobalite:
> 90 W%
Amorphous silica
< 0.1 W%
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%)
Compressive strength (MPa)
80
70
60
50
40
30
Control
GRHA-7.5%
GRHA-15%
20
10
0
0
20
40
60
80
100
Period of curing (days)
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 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
Biosilica Substantially Reduces
Chloride Permeability
Figure – Comparison of Chloride Permeability Values of Biosilica Concretes after 56-Day Curing
Durability Issues
• Corrosion – Most Prominent Problem
• Alkali-Silica Reactivity (ASR)
• Delayed Ettringite Formation (DEF)
• Sulfate Attack
• Freeze-Thaw Damage
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 3Zone temperature
control
Large (Commercial Scale) Rotary Calciner (Illustrative)
6 FT diameter
tube
> 60 FT long
Heat 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