Sub-contract with State University of New York

Project Summary:

            In an earlier investigation, black locust (Robinia pseudoacacia) appeared to be delignified to a greater extent than silver maple (Acer saccharinum).  This project is a one-year investigation to see if the o-dihydroxyphenyl groups in the black locust polyphenols (flavonoids) were acting as redox catalysts in a manner similar to anthrahydroquinone.  The hypothesis is that during alkaline pulping of black locust o-dihydroxyphenyl groups reductively cleave ether bonds in lignin and are oxidize to o-quinones.  The o-quinones then oxidize polysaccharides and are reduced back to o-dihydroxyphenyl group.

     Two commercial flavonoids (quercetin and rutin) as well as the polyphenols extracted from black locust will be added to soda pulping (NaOH only) of aspen (Populus tremuloides).  Soda pulping characteristics of extracted and unextracted black locust will also be investigated.  If any evidence of redox catalysis were to be found then a more comprehensive study would be likely.  Such an investigation would involve chemical modifications of the black locust polyphenols to improve their efficacy.

Key Words:

Polyphenols, Alkaline pulping, Redox catalysts, Anthraquinone    

Current Project:

Soda Pulping of black locust:

        The objectives of this study are to:

1)         Determine if the o-dihydroxyphenyl groups in the black locust (Robinia pseudoacacia) polyphenols are acting as catalysts during alkaline pulping. 

2)         Determine if a low-lignin, chemical pulp can be produced by soda pulping (NaOH only) of black locust.  The traditional kraft process uses NaOH and Na2S.  By-products recovery would be much more feasible if Na2S is eliminated.