Register for free to
view the full innovation profile.
Methods of Pretreating Comminuted Cellulosic Material with Carbonate-Containing Solutions
About
Prehydrolysis of wood chips initiated with hot water or dilute acetic acid is an established practice in the pulp and paper industry. Prior processes include acid hydrolysis pretreatment of wood chips and nitric acid pretreatment of wood chips with caustic extraction. Furthermore, the inventor has found that an acid treatment of chips followed by a soda/anthraquinone (SAQ) pulping process provides an improved pulp yield for hardwood chips compared to kraft treatment alone. In the prior art, the hydroxide anion (OH--) is used to neutralize acid pretreated biomass, whereas the present invention employs the carbonate anion (CO32-) for neutralization, which shows superior pulp properties. The present invention provides an enhanced pulp that can be produced by pre-treating the chips with an acid solution and a carbonate solution and recirculating/reusing at least some of the treatment effluents to supplement and/or replace at least some of the acid and/or carbonate treatment solutions. Patents: U.S. 8,303,767 SUNY-ESF-1636
Key Benefits
(1) Recycle rate of both A & N stage effluent favorably affects the overall process chemistry. (2) A-N pretreatment can be placed ahead of any alkaline pulping process including kraft. (3) Improved bleachability.
Applications
Pulp and paper industry.