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Klason lignin is the residue remaining when a biomass is treated with strong acid at high temperatures. This lignin is black in color and has a very different structure from natural lignin. Why is that? What reactions happened to lignin during the acid hydrolysis of carbohydrates ?

The three different lignin monomers are present in different concentrations in different biomass types. Please list which lignin monomer is predominant in softwoods, what you would find in hardwoods and what would be present in non-woods (such as grass).

a.) What would the next reaction step be for this molecule (alkaline conditions, no sulfur compounds present). b.) What would likely happen if this molecule would have a free phenolic OH on the aromatic ring. c.) why ? 

The lignin bonds that are split fastes under alkaline condition are :

The reaction below is a condensation reaction. Complete the sentences

What trype of structure is shown below? Why is the ester bond connected to the alpha carbon?

Softwood lignin has more 5-5 bonds than hardwood lignin. Why is that? 

The lignin fragment below is an intermediate state during lignin radical polymerization.  a.) what is the name of the lignin bond that was formed here (THE BOND CONNECTION TWO FORMER MONOMERS) b.) this molecule is not stable, what would the next reaction step be if the only other material involved would be water

a.) What would the next reaction step be for this molecule ( alkaline conditions, no sulfur compounds present). b.) What would likely happen if this molecule would have a free phenolic OH on the aromat. c.) why ? 

Converting HB to MC equivalents yields (ceq, φeq) that are: