Nanocellulose biorefineries – A biomaterial with unparalleled perspectives – 2nd part: Cellulose NanoCrystals (CNC)
Publication date: 22/04/2019.
Last update: 22/04/2019.
Introduction
Introduction
See “Nanocellulose biorefineries – A biomaterial with unparalleled perspectives – 1st part: Introduction”.
Shape and dimensions
Shape: Elongated. In the literature, they are compared with rice grains,
rods, spindles and whiskers.
Dimensions: Typically, 4-15 nm in width and 50-500 nm in length.
Figure 1. CNC produced by Blue Goose Biorefineries (taken from Blue
Goose Biorefineries website). Width: 9–14 nm. Length: 100–150 nm.
Properties
- Abundant, renewable and sustainable.
- Biocompatible.
- Electro-magnetic (charge surface).
- High aspect ratio (length to width).
- High temperature stability.
- High strength (in line with high-performance synthetic material as
Kevlar®).
- High surface area.
- Light weight.
- Self-assembly.
- Shear thinning / Unique rheological properties.
- Versatile surface chemistry.
Production processes
The preparation of CNC was pioneered by Ránby in 1949. He used several
mineral acids (including hydrochloric acid and phosphoric acid), to selectively
hydrolyse the disordered segments in native cellulose. At that time, recent
commercialization of the TEM was instrumental for visualizing the nanocrystals.
Historically, CNC has been produced following this method of acid hydrolysis,
most often with sulfuric acid but also with hydrochloric acid. During the acid
hydrolysis, the amorphous region is removed and the crystalline particles are
released as showed in Figure 2.
Figure 2. Isolation of CNC from cellulose by sulfuric acid hydrolysis
(taken from Reference [6] of the 1st part of this series)
Currently, acid hydrolysis is still the predominant and most efficient route
to produce CNC with minimal energy consumption. However, it is important to
mention that, in the last few years, new processes (like catalytic conversion
and enzymatic hydrolysis) have been developed and scaled.
Applications
Much is being said in the last few years about the potential of the
cellulose nanocrystals. CNC have gained a tremendous level of attention because
of their unsurpassed physical and chemical properties, their abundance and
their inherent renewability and sustainability. These are some of the markets
and applications mentioned on the references:
- Adhesives: Viscosity modifier.
- Automotive: Polymer reinforcement and lightweighting.
- Construction: Concrete enhancer.
- Cosmetics: Texture modifier.
- Electronics: Conductive inks.
- Filtration: Mesoporous films and membranes.
- Food: Non-caloric stabiliser.
- Medical: Drug excipient and drug delivery.
- Paints and coatings: Rheology modifier.
- Paper and packaging: Flexible packaging with improved barrier
properties.
Producers
The table below summarizes the current status of the CNC global market.
The total production capacity is close to 600 tons/year. The criterion chosen
for scale classification is the following: commercial > 10 tons/year, pilot
from 1 ton/year to 10 ton/year and lab < 1 ton/year or unknown. In this way,
there are 4 plants at commercial scale, 5 plants at pilot scale and 5
facilities at lab scale.
Company /
Institution
|
Country
|
Product
[Trade name] |
Scale
|
CelluForce
|
Canada
|
Sulphated CNCs [CelluForce NCC]
|
Commercial
|
American Process
(recently adquired by GranBio) |
USA
|
CNCs [Bioplus]
|
Commercial
|
Sweetwater Energy
|
USA
|
CNCs
|
Commercial
|
Melodea
|
Sweden
|
Sulphated CNCs
|
Commercial
|
Alberta Innovates
|
Canada
|
Sulphated CNCs
|
Pilot
|
Forest Products Laboratory
|
USA
|
Sulphated CNCs
|
Pilot
|
ICAR CIRCOT
|
India
|
CNCs
|
Pilot
|
Blue Goose Biorefineries
|
Canada
|
Carboxylated CNCs [BGB Ultra]
|
Pilot
|
Innotech Materials LLC
|
USA
|
Oxidized CNC [SuCellose]
|
Pilot
|
Caspian
Nanocellulose Polymer Development Co.
|
Iran
|
CNCs
|
Lab
|
Cellulose Lab
|
Canada
|
CNCs
Modifications |
Lab
|
FPInnovations
|
Canada
|
Sulphated CNCs
|
Lab
|
Guilin Qihong Technology
|
China
|
Sulphated CNCs [QHCNC]
|
Lab
|
Tianjin Haojia
Cellulose Co. / Tianjin Woodelf Biotechnology Co., Ltd.
|
China
|
CNCs [SHCNC]
Modifications |
Lab
|
_____________________________________________________________________________________________________________________________
References
All the references of the 1st part of this series.
[S1] Innotech Alberta website: “Cellulose Nanocrystals (CNC) Pilot Plant” (accessed on March 2019).
[S1] Innotech Alberta website: “Cellulose Nanocrystals (CNC) Pilot Plant” (accessed on March 2019).
[S2] Blue Goose Biorefineries website (accessed on March 2019).
[S3] CNPD website (accessed on March 2019).
[S4] CelluForce website (accessed on March 2019).
[S5] Cellulose Lab website (accessed on March 2019).
[S6] FPL website: "Nanocellulose Pilot Plant" (accessed on March 2019).
[S7] FPL website: "Just How Small is
Nanocellulose?" (accessed on March 2019).
[S8] UMaine website: "Order Nanocellulose" (accessed on March 2019).
[S9] FPInnovations website: "CNC Factsheet" (accessed on March 2019).
[S10] Guilin Qihong Technology (accessed on March 2019).
[S11] ICAR-CIRCOT website: "Nanocellulose pilot
plant" (accessed
on March 2019).
[S12] Innotech Materials website (accessed on March 2019).
[S13] Presentation: Cellulose Nano Crystals (CNC), Biobuilding blocks for
tomorrow’s materials. Dr. Shaul Lapidot, Melodea Co-founder and CEO.
[S14] Tianjin Haojia Cellulose Co. / Tianjin Woodelf
Biotechnology Co., Ltd. website (accessed on March 2019).
