NMR methods can be used to delineate detailed structural and regiochemical information on the plant cell wall and elucidate biochemical incorporation pathways. Maize lignin isolated in high yield from rind tissue of stem internodes contained high amounts of esterified p-coumaric acid. Available literature indicated that acylation of the lignin by p-coumaric acid was at the αor γ-position of the...

I. The technique for the quantitative estimation of lignin by digestion with 72 % H,S04 has been investigated. Two methods of pretreatment designed to eliminate interference products of carbohydrates and proteins were compared, namely (a) acid and pepsin and (6) acid detergent. The latter technique gave low lignin yields owing to the colloidal dispersion of lignin in the acid detergent treatmen...

Enzymatic hydrolysis (EH) lignin was modified with formaldehyde. TGDSC and PY-GC-MS analysis methods were adopted to characterize the differences between EH lignin and the modified lignin. The modified lignin was then mixed with wood sawdust and made into a lignin-based composite under the following conditions: pressure of 2 to 5 MPa, temperature of 175 to 190 C, and the modified lignin dosage ...

Asphalt pavements undergo long-term aging due to oxidation of the asphalt binder. As a pavement oxidizes, it stiffens and eventually cracks. The use of an antioxidant in an asphalt binder could retard aging, thus increasing the pavement’s service life. Lignin is a known antioxidant and is highly available from timber and many agricultural products. A wet-mill ethanol process produces several co...

Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H2 pressure of 100 bar, 4 h). The best results were obtained at 450 °C resulting in 34 wt % of liquefied kraft lignin (lignin oil) on lignin intake. The composition of the lignin oil was determined in detail (elemental composition...

We have recently described a hitherto unsuspected catechyl lignin polymer (C-lignin) in the seed coats of Vanilla orchid and in cacti of one genus, Melocactus (Chen et al., Proc. Natl. Acad. Sci. USA. 2012, 109, 1772-1777.). We have now determined the lignin types in the seed coats of 130 different cactus species. Lignin in the vegetative tissues of cacti is of the normal guaiacyl/syringyl (G/S...

The deconstruction of cellulose is an essential step in the production of ethanol from lignocellulosic biomass. However, the presence of lignin hinders this process. Recently, a novel cosolvent based biomass pretreatment method called CELF (Cosolvent Enhanced Lignocellulosic Fractionation) which employs tetrahydrofuran (THF) in a single phase mixture with water, was found to be highly effective...

The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlO x ) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO2, Ni2P/SiO2, and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin de...

The effect of lignin as an inhibitory biopolymer for the enzymatic hydrolysis of lignocellulosic biomass was studied; specially addressing the role of lignin in non-productive enzyme adsorption. Botanical origin and biomass pre-treatment give rise to differences in lignin structure and the effect of these differences on enzyme binding and inhibition were elucidated. Lignin was isolated from ste...

Decreasing lignin content of plant biomass by genetic engineering is believed to mitigate biomass recalcitrance and improve saccharification efficiency of plant biomass. In this study, we compared two different pretreatment methods (i.e., dilute acid and cellulose solvent) on transgenic plant biomass samples having different lignin contents and investigated biomass saccharification efficiency. ...