Method for recovering and using lignin in adhesive resins

Patent · Fri Jan 01 00:00:00 EST 1993

OSTI ID:868624

Schroeder, Herbert A ^[1]

---

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 dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

• Assignee: Colorado State University Research Foundation (Ft. Collins, CO) [*] Notice: portion of term of this patent subsequent to June 25, 2009 has been disclaimed.
• Patent Number(s): US 5177169
• OSTI ID: 868624
• Country of Publication: United States
• Language: English

Related Subjects

method
recovering
lignin
adhesive
resins
derived
material
significantly
demethylated
found
raffinate
produced
by-product
dimethyl
sulfide
production
carried
spent
liquor
wood
pulping
operations
isolated
process
organic
solvent
added
lignin-containing
aqueous
solution
typically
polar
partially
water-immiscible
substance
example
ethyl
acetate
resulting
mixture
acidified
produce
water
layer
discarded
contains
recovery
dissolved
alkaline
aldehyde
source
resol-type
resin
formaldehyde
paraformaldehyde
hexamethylenetetramine
aldehydes
including
acetaldehyde
furfural
derivatives
lignin-containing aqueous
organic solvent
aqueous solution
ethyl acetate
demethylated lignin
solvent mixture
alkaline solution
raffinate produced
pulping operations
significantly demethylated
resulting lignin-containing
water layer
water-immiscible substance
spent liquor
solvent layer
wood pulping
lignin found
lignin derived
partially water-immiscible
adhesive resins
sulfide production
wood pulp
dimethyl sulfide
derived material
immiscible substance
partially water
/527/530/