Organosolv hardwood lignin

This study describes the application of differential vis-cometry as a GPC detector to the problem of determining molecular weight distributions of acetylated hardwood lignins in tetrahydrofuran. Molecular weight distributions of ball-milled, organosolv, alkali-extracted/mild acid hydrolyzed, and alkali-extracted/steam exploded aspen lignins were estimated using universal calibration. 

This study reports the first application of universal calibration via HPSEC-DV to four acetylated hardwood lignins obtained from aspen (Pop-ulus tremuloides) wood meal by ball milling and solvent extraction steam explosion followed by alkaline extraction organosolv pulping followed by water extraction of the associated sugars and dilute sulfuric acid hydrolysis followed by sodium hydroxide extraction. 

At 80°C, the reaction is 90% complete after 1-2 hours with hardwood organosolv lignin, but it takes longer with other lignin types. Treatment with H2O2 introduces carboxylic acid functionality. 

Figure 4. Rate of color loss for HPL derivatives from red oak organo-solv lignin (A), aspen organosolv lignin (B), pine kraft lignin (C), hardwood kraft lignin (D), and spruce organosolv lignin (E). (ON stands for overnight.)...

Goyal, G. C., Lora, J. H., and Pye, E. K., Autocatalyzed organosolv pulping of hardwoods - Effect of pulping conditions on pulp properties and characteristics of soluble and residual lignin. Tappi J1992, 75 (2), 110-116. 

Techniques such as Py-MS or Py-GC/MS are not always suitable for the identification of less volatile or highly polar compounds. HPLC analysis with MS detection provides a better tool in such cases, and it was successfully applied for lignin pyrolysate analysis (see Section 5.7). Pyrolysis products from a lignin sample from mixed hardwood, obtained using the organosolv procedure with ethanol/water and generated at 510° C in an on-line Curie point pyrolyser and analyzed by HPLC [8], indicated the presence of a series of compounds shown in Table 9.1.7. 

Out in Six Different Laboratories. Tbe Total Yield in Vanillin Syringaldebyde S is Expressed in pmoles/g of Lignin Milled Wood Lignin Steam Explosion Organosolv Lignin from from Cotton Wood Lignin from Aspen Mixed Hardwood V and Kraft Lignin from Mixed Softwood... 

Kraft pine lignin A Kraft pine lignin O Organosolv lignin of oat hull Hardwood residue Switchgrass residue... 

Lignins and biomass residues were treated at 374 °C and 22 MPa for 10 min. The yields of various lignins and biomass residues are listed in Table 3. The liquid yields of Kraft pine lignin A, Kraft pine lignin B, organosolv lignin of oat hull, hardwood residue, and switchgrass residue were 57.8, 71.5, 79.1, 56.3, and 32.6%, respectively. 

Fig. 8.12 Effect of pH on Zeta (( ) potential for samples 1 hardwood Kraft lignin 2 hardwood hydrolysis lignin 3 hardwood steam explosion lignin 4 softwood Kraft lignin 5 softwood organosolv lignin and 6 soda wheat straw lignin...

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