EXTRACTION OF HIGHVALUE CHEMICALS FROM WHEAT STRAW BY SCO2

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EXTRACTION OF HIGH-VALUE CHEMICALS FROM WHEAT
STRAW BY SCO2

• FABIEN DESWARTE
• Supervisors Prof. James Clark, Dr. Jeff Hardy

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PLAN

• Background of the project
• Wheat straw wax
• High value fractions from wheat straw waxes
• Variation between varieties components

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WHAT IS WHEAT STRAW ?

• Wheat worlds foremost crop plant
• UK 2 million hectares
• 17 million tonnes
• Straw stem from which the seed head has been
  removed.
• - 3 botanical components

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TRADITIONAL USESAVAILABILITY
Burning
Feeding/Bedding
WHEAT STRAW
Incorporation
Mushroom compost
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CHEMICAL COMPOSITION
LIGNIN
(15-20)
MINOR CONSTITUENTS
(5-10)
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MINOR CONSTITUENTS

• Suberin/Cutin
• Waxes
• Phenolic acids
• Proteins
• Pigments
• Polar lipids
• Inorganic

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MINOR CONSTITUENTS

• Waxes
• Proteins

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WAXES DEFINITION
Alkanes
Fatty acids
Fatty alcohols
Sterols/ Steryl esters
Wax esters
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MINOR CONSTITUENTS
COSMETICS, COATINGS, ETC..
Polycosanols/ sterols
INSECT SEMIOCHEMICALS
CHOLESTEROL REDUCING AGENTS
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SOLVENT EXTRACTION
WAXES
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CHEMICAL COMPOSITION
Variety Consort
Sterols
Alkanes
Fatty acids
Wax esters
Fatty alcohols
C29
C12
C18/ C181
C31
C33
C182
C28
unknown
C16
C183
C14
C22
C24
C20
C26
C24
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ALKANES FROM WHEAT STRAW
C31
C29
C27
C33
C30
C25
C28
C26
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POLYCOSANOL FROM WHEAT STRAW
HEXANE/ETHER (85/15, v/v) FRACTION
POLYCOSANOL
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SUPERCRITICAL CO2
SUPERCRITICAL FLUID substance above both its
critical T(TC) and P (PC) CO2 Tc 31
C Pc 73 bars
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PILOT SCALE EXTRACTION
Sabre wheat variety 200g scale 22 factorial
design - Pressure - Temperature
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1st ORDER FACTORIAL DESIGN
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QUALITY OF MODEL FIT
T55C/P200bar (coded value T0/P0)
y0.36-0.36?exp(-t/19)
R20.99537
y0.35-0.15T0.13P-0.07PT
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PILOT SCALE FRACTIONATION
C16
Sitosterol
Stigmasterol
Hentriacontane?
Cholestone?
Sterol derivatives
Cholesterol
C14
C29
C12
C18
C31
C15
C27
C31
C18
C29
C28
Stigmasterol
C16
Sitosterol
C24
Sterol derivatives
C27
C12
C14
C28
C30
C28
C26
C30
C26
C24
Sitosterol
C32
C24
C29
C31
C34
C22
C16
C12
C18
C20
Patent pending GB patent 0502337.9, 4th Feb 2005
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COMMERCIAL SCALE EXTRACTION
4 ? 25 kg extractors
extraction of 250 kg of wheat straw
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VARIATION BETWEEN VARIETIES
Wax yield ( dry matter)

• Grown under field control conditions
• Hexane extracts

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WHEAT STRAW COMPONENTS
Nodes
Leaves
Internodes
Nodes
Botanical components within wheat straw
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WAX YIELD
Wax yield ( dry matter)
? Consort variety ? Hexane extracts
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SURFACE OF COMPONENTS
Nodes
Botanical components within wheat straw
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CONCLUSIONS
Low environmental impact technology
Low value, natural and renewable resource
Development of crops harvesters
BIOREFINERY
Applications to other crops
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Les Moeres, FRANCE Summer 1949
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THANKS TO
THANKS FOR YOUR ATTENTION
feid100_at_york.ac.uk