Novel Drying and Impregnation Technology for Water-Soluble Biopolymers Bernhard Seifried, Ph.D.

Bio World Congress May 14, 2014 Philadelphia

Contents 1

Background on Ceapro

2

Biopolymer Drying Challenges

3

PGX Drying Technology

4

Applications and Scale-up

5

Summary & Outlook

Ceapro Inc  Edmonton based Canadian Innovator  Publically traded on TSX-Venture (CZO)  Manufacture commercial botanical extracts & formulations  Oat Avenanthramides (AV)  anti-inflammatory Polyphenols

 Oat beta-glucan (BG)  linear unbranched hemicellulosic Polysaccharide  Mixed linkage poly-b-(1-3),(1-4)-D-glucan  MW: 500-1500 kDa

 Collagen synthesis, anti-ageing  Skin moisturizing  Dietary fiber – FDA/EFSA health claims  3 g/d BG decrease LDL-cholesterol

Cellulose Nanocrystals (CNC) Cellulose: poly-β-(1→4)-D-glucose; DP: 200 to 30000, MW: 20 to >5000 kDa

CNC crystallite

Microfibrils

L D Aqueous Dispersion of CNC: 0.5-1%wt

Amorphous Regions

Crystalline Regions

Cellulose Source

L (nm)

D (nm)

Bacterial

100-1000

10-50

Soft wood

100-200

3-4

Cotton linter

100-200

10-20

Biopolymer Drying Challenges

VISCOSITY

High Molecular Weight: 500-1500kDa Viscosity: honey like 1%wt BG 200-500cP

 Why drying? - To avoid use of preservatives - To increase shelf life - To decrease storage and shipping costs - To facilitate dispersion/solubilization of dried biopolymer - To improve dry application performance

%wt

 Conventional technologies: - Spray drying - high temperature, thermal degradation - high viscosity, atomization, droplet size - nozzle clogging

- Freeze drying - expensive (40tons/yr !)

- Drum / oven drying - Poor product quality - powder does not re-dissolve easily

Conventional Drying Technologies for CNC  Oven or Drum Drying - Poor product quality – dense pebbles or sheets - Dried material does not re-dissolve easily

 Spray drying - high air temperatures needed - nozzle clogging, atomization issues

Capillary Forces agglomeration of CNC

 Freeze drying - 10x more expensive than spray drying - time and energy consuming - Scale-up issues

 “Supercritical Drying” - Ethanol used to replace water in multiple washing steps - then lengthy drying process using supercritical CO2

Little or no capillary forces minimized agglomeration of CNC

Source: Drying cellulose nanofibrils: in search of a suitable method, Peng et al. 2011 Cellulose.

The Challenge of CNC Drying  Spray Drying of CNC

Spray Dried CNC

- Generates aggregates, - donuts shaped spherical particles - 10-20 microns - Limited dispersibility and functionality Wood & Fiber Science, 44(4), pp.1-14

CNC crystallites

 Needed drying technology to: - Avoid aggregates, - generate open porous structure

http://www.acceler8or.com/2012/09/4403/

PGX Spray Drying – a novel drying technology “Pressurized Gas eXpanded Liquid (PGX) – Spray Drying “ Advantages:  Spray drying of •Rapid precipitation and drying -

aqueous biopolymer solution/suspension

-

supercritical carbon dioxide

•Process intensification – small footprint drying system  •Ultra using low/vanishing interfacial tension •Minimal capillary forces - SC-CO2 by means of a coaxial •Nanoscale featuresnozzle preserved ! -

modifier - ethanol

•turbulent fast mixing •No - agglomeration cosolvent •atomization •Moderate drying temperature -  water solubility •precipitation - antisolvent •Thermosensitive bioactives/drugs biopolymer •drying- ofprecipitate biopolymers

CO2 + Ethanol

P=100 bars T=40°C

Aqueous biopolymer solution/ suspension

PGX spray dried BG = PGX-BG Oat -Glucan High Molecular Weight, 500-1500 kDa

Viscous , honey-like solution

Cobweb structure, fibrils

1% BG

Instead of donuts we make cotton candy !

Morphology – PGX-BG microfibers

100 µm

10 µm

10 µm

10 µm

1 µm

1 µm

2 µm

2 µm

10 µm

Morphologies of PGX-BG

Micro-fibrils 0.02 g/mL 200 nm thick

Fine powder 0.10 g/mL 2 mm

PGX-BG impregnated with Nutraceutical CoQ10  The PGX process allows - Formation of highly porous biopolymer matrix - Impregnation of the biopolymer matrix - with thermosensitive bioactives (drugs, API)

 by means of supercritical CO2  in the same processing equipment  at moderate temperatures of 40 °C.

CoQ10 on BG not visible using SEM

10 μm

Pure BG

10 μm

Impregnated BG

10 μm

Pure CoQ10

Porous Structure of BG Allows CoQ10 Entry Pure BG

Impregnated BG

200 μm

200 μm

20 μm

20 μm

Nano-Agglomerates of Gum Arabic (GA) Gum Arabic, complex mixture of glycoproteins and polysaccharides. MW: >600kDa

PGX-GA Nano-Agglomerates impregnated with b-Carotene

PGX Dried CNC  aerogel like structure  highly porous  translucent  CNC needles not agglomerated  Under light microscope - individual particles not discernible - 200nm particles = wavelength of light

CNC before and after PGX drying 0.5 g CNC Spray Dried

0.5 g CNC PGX Dried

CNC AEROGEL Density : 0.006 g/cm3

Scale-up from lab to processing plant EtOH

Phase Equilibrium



- CO2-EtOH-Water - Process conditions P,T, flowrates

Nozzle design



- Prototype single orifice nozzles - Multi-orifice coaxial nozzle - Computational Fluid Dynamics



Mass and Energy Balances



Pilot Plant Modifications - Ethanol Sampling System - Ethanol dehydration



Pilot Plant Tests



Process Plant -

Design Skid

 Economic Feasibility

H2O

CO2

Scale-up – Processing Capacities 2L lab scale 15 mL/min aq.solution

12L pilot scale 300mL/min aq.solution

Scale-up 20L pilot scale 120 kg/hr aq.solution

2x50L pilot/production scale 300 kg/hr aq.solution

Scale-up: many applications possible

Summary - Outlook  Novel PGX drying technology offers many opportunities  The PGX technology can be used to  Dry aqueous biopolymer solutions and dispersions  at moderate drying temperatures  Generate

(BG, GA)

and preserve(CNC) nano-scale-features

 Unique morphologies are possible by tuning process parameters  Fibrils, spherical, porous granular powders  Process thermosensitive components/ bioactives with biopolymers  Impregnation of biopolymers with bioactives, drugs, APIs  Generation of value-added biopolymers  Highly soluble fibers and powders  Co-precipitate and make bio-composites

Summary - Outlook  Applications of PGX-CNC  Composite-Plastics  Paints  Cosmetics  Wound healing, scaffolds  Drug delivery  Absorbants

 PGX processing allows processing of high value biopolymers:  Beta Glucan  Chitosan  Gum Arabic  CNC  etc..

Acknowledgements  Feral Temelli, University of Alberta  BioFoodTech Center PEI  John Moses, CF-Technologies, Boston  Massachusetts Institute of Technology (MIT) and Whitehead Institute - Chadd Kiggins - Alexander Kendrick - Sarah Mayner

 Tech Support: - Nicki Watson

 Funding Agencies

Thank you! Questions? Contact: Bernhard Seifried www.ceapro.com

[email protected]

Theoretical background – Gas eXpanded Liquids

 “A gas expanded liquid (GXL) is - a mixed solvent composed of…

a compressible (dense) gas dissolved in an organic solvent”1. P. G. Jessop, B. Subramaniam, Chemical Reviews 107, 2666-2694 (2007).

Theoretical Background – GXLs

 CO2 - expanded (CX) Ethanol

- tuneable solvent properties - f (pCO2,T) = f(xCO2)

relative volume change dV/V0 []

30 Acetonitrile 313.15 K

25

Acetonitrile 298.15 K 20

Ethyl Acetate 313.15 K Ethyl Acetate 298.15 K

15

Ethanol 298.15 K

10 5 0

-  xCO2 (mole fraction CO2)

0

- Volumetric expansion  - Viscosity  - Polarity  - Interfacial tension (IFT) 

10 15 pressure [MPa]

20

25

30 Acetonitrile 313.15 K relative volume change dV/V []

- Density  

5

25

Acetonitrile 298.15 K Ethyl Acetate 313.15 K

20

Ethyl Acetate 298.15 K Ethanol 298.15 K

15 10 5 0 0

0.2 0.4 0.6 0.8 mol fraction xCO2 [mol CO2 / (mol CO2 + mol solvent)]

1

Theoretical Background – ternary system



H2O – CO2 – EtOH : ternary system

EtOH MASS FRACTION 40°C      10MPa

CXL region mixture critical point (MCP) SCF region

H2O Fluid Phase Equilibria 252 (2007) 103–113

CO2