Joseph L. McCarthy

Kinetics of Organosolv Delignification in Batch- and Flow-Through Reactors

Etude de la cinetique de delignification du bois de Populus trichocarpa dans une solution aqueuse de methanol

Some Properties of Paucidisperse Gymnosperm Lignin Sulfonates of Different Molecular Weights

ABSTRACT Five purified paucidisperse gymnosperm lignin sulfonate samples (Mw @2,400 to 140,000), prepared by fractionation using ultrafiltration and dialysis, have been characterized in part. The relationship was established between the molecular weights of the fractions and those of the dissolved lignin sulfonates representing nearly all of the total lignin originally present in the woody tissue. The chemical composition, ultraviolet and infrared absorption spectra, intrinsic viscosity, diffusion coefficient, specific volume, hydraulic radius and streaming current properties of the several samples have been determined or estimated as a function of molecular weight.

Condensation of Lignins with Coniferyl Alcohol in Alkaline Aqueous Solutions

Abstract The condensation of coniferyl alcohol with dissolved lignins of low molecular weight (LMWL) has been investigated. In aqueous sodium hydroxide (soda), sodium hydroxide - sodium sulfide (kraft) or sodium hydroxide - anthraquinone (soda-AQ) solutions, lignin preparations were heated and molecular weight distributions of the resultant condensation products were estimated. When coniferyl alcohol dissolved in soda and kraft liquors was heated, self-condensation was observed, mainly to form oligomers with only a small proportion of the reaction products characterized by molecular weights greater than about 1000. When mixtures of LMWL and coniferyl alcohol were heated in sodium hydroxide solutions, condensation reactions occurred and progressed further with increased temperature and concentration of coniferyl alcohol. In contrast to results with sodium hydroxide solutions, heating in kraft liquors gave rise to a higher proportion of the oligomer fraction and a smaller proportion of higher molecular weig...

Utilization of glucoisosaccharinic acid and components of Kraft black liquor as energy sources for growth of anaerobic bacteria

Utilization of Glucoisosaccharinic Acid and Components of Kraft Black Liquor as Energy Sources for Growth of Anaerobic Bacteria By Shu-Han Wang, Joseph L. McCarthy and John F. Ferguson 1 Department of Chemistry and Chemical Engineering of Forest Products, Nanjing Forestry University, Nanjing 210037, China 2 Department of Chemical Engineering and Department of Civil Engineering, University of Washington, Seattle, WA 98195, U.S.A.

Incremental Delignification of Hemlock Wood and Characterization of Lignin Products

Des copeaux de Tsuga heterophylla ont subi une delignification kraft avec traitement incrementiel. Les lignines dissoutes obtenues lors de chaque increment ont ete caracterisees en termes de distribution de masse moleculaire

Some characteristics of the lignins of a fast growing cottonwood hybrid compared with those of black cottonwood.

Because a newly developed cottonwood hybrid (P.trichocarpa x P.deltoides) has been reported to produce significantly more biomass per hectare per year than does black cottonwood (Populus trichocarpa), characteristics of the two lignins were compared. Extractive-free sapwood chips and meal from black cottonwood and the hybrid were delignified by sodium hydroxide solutions. The dissolved lignins were ultrafiltered. The UV absorption spectra, solute lignin concentration, average molecular weight and polydispersity of the lignins present in the initial, permeate and retentate solutions were determined. Results indicate that the dissolved lignins are of relatively low average molecular weight. No significant differences were found between the lignins of the two cottonwoods.

Panel Discussion: Comparison of Traditional and Genetic Strategies

I have heard with enormous interest the earlier presentations of this symposium. I think it is important that we consider the following questions: (1) What is the state of the art? (2) What are the needs with respect to pollution? (3) What are the possibilities of using recombinant DNA procedures or other manipulation of genes to improve our capabilities of coping with pollution problems? (4) What are the prospects for research?