[Kurious]

Here is a question. Lignin is extracted from wood-cellulose.
I think it acts as a bonding agent between cell walls. Lignin
can be used as a fuel. My understanding is that with lignin,
a product can be made similar to coal and produce an efficient
means of heating ( homes etc. ) Can lignin be mixed with sawdust,
wood chips etc. and pressed into a solid lump ( briquette ) ? Would
heat and pressure work ? Any thoughts ?

mike

[Arkcon]

Lignin is a major component of wood, the other major component being cellulose, there is less cellulose than lignin in wood..  Lignin is found in other places, for example, it is a major component of the gritty particles you find in pear flesh.  Isolating lignin from wood, and mixing it with wood, makes very little sense.

[Kurious]

Arkcon,

I see you want to be my disciple . You are quick on the draw,
everytime, every topic.
I assume Lignin can be purchased ? Clean burning ?
I used to be an Arkcon, myself, but have reformed..
is this David on Holly St, McGoo,Ar ? I know most of
em.   

mike

[Arkcon]

Lignin is a difficult concept to understand.  It's not a fixed chemical formula, but a generic name for a class of compounds.  Basically, it is a polymer of phenolics, that's aromatic alcohols. They're hard to analyze quantitatively, because the only reactions they undergo is burning or decomposition. Plants deposit them in their tissues that are to provide more support than cellulose.  There is an abundance of lignin in wood, practically none in say, a tomato plant stem, except for tiny amounts, like the the liginified sclerocytes found in pears, as I said above.  It can't be isolated easily, so no, it usually isn't for sale in bulk.

P.S.  Arkcon is just a creative abbreviation of my first initial and surname.  You may be the first person to spell it right, usually people drop the 'k' or 'c'.

[Borek]

You may be the first person to spell it right, usually people drop the 'k' or 'c'.

2^nd at least

http://www.chemicalforums.com/index.php?topic=23185.msg88357#msg88357

[tasmodevil44]

Yes,you can use heat and pressure to put lignin and wood cellulose together.But like ARKON said,what is the point in separating it and putting it back together again?

[tasmodevil44]

From what I have heard about lignin in the past,is that even though it usually only undergoes decomposition,combustion,breakdown,and etc.quite readily,it can still be the starting material for a major chemical industry based upon forestry wastes.They say that all kinds of fuels and plastics,and etc.could be manufactured from it.But I still don't know much about the specifics,as far as all the chemical pathways and processing steps it would entail.

[tasmodevil44]

Or perhaps somthing similar to Fisher-Tropsh where you first break the lignin molecules down into hydrogen and carbon monoxide and then reassemble them into larger molecules again with the right kind of catalysis might be the way to go about it.And of course,micro-organisms can also be used to feed on lignin and convert it to other things more useful.There are companies out there that are already working on these things with lignin I'm pretty sure.

[Gerard]

how much does heating value does lignin contain?