Method for recovering and using lignin in adhesive resins by extracting demethylated lignin

Patent · 01 January 1991

OSTI ID:867852

Schroeder, Herbert A ^[1]

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1. Ft. Collins, CO

Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is preferably dried and stored until it is used (along with an alkali, an aldehyde and an adhesive filler) in compounding an adhesive of the type generally used in the manufacture of plywood.

• Assignee: Colorado State University Research Foundation (Ft. Collins, CO)
• Patent Number(s): US 5021531
• OSTI ID: 867852
• Country of Publication: United States
• Language: English

Related Subjects

/527/530/
acetate
acidified
added
adhesive
adhesive resins
aldehyde
alkali
aqueous
aqueous solution
by-product
carried
compounding
contains
demethylated
demethylated lignin
derived
derived material
dimethyl
dimethyl sulfide
discarded
dried
ethyl
ethyl acetate
example
extracting
extracting demethylated
filler
found
immiscible substance
isolated
layer
lignin
lignin derived
lignin found
lignin-containing
lignin-containing aqueous
liquor
manufacture
material
method
mixture
operations
organic
organic solvent
partially
partially water
partially water-immiscible
plywood
polar
preferably
process
produce
produced
production
pulping
pulping operations
raffinate
raffinate produced
recovering
recovery
resins
resulting
resulting lignin-containing
significantly
significantly demethylated
solution
solvent
solvent layer
solvent mixture
spent
spent liquor
stored
substance
sulfide
sulfide production
type
typically
water
water layer
water-immiscible
water-immiscible substance
wood
wood pulp
wood pulping