NOVELTY - Lignin composition characterized (on a dry matter basis) by at least one characteristic selected from: (i) a glass transition temperature (Tg) above 160 degrees C or below 90 degrees C as determined using differential scanning calorimetry (DSC) according to DIN 53765-1994; (ii) a consistent Tg as determined by multiple differential scanning calorimetry (DSC) runs of the same lignin portion; (iii) a mass average molar mass (Mw) greater than 10000 Da as measured by gel permeation chromatography (GPC); and (iv) a number average molar mass (Mn) greater than 6200 Da as measured by GPC.    USE - The lignin composition is useful for producing conversion product, where the conversion product comprises a commodity chemical comprising at least one item selected from bio-oil, carboxylic and fatty acids, dicarboxylic acids, hydroxyl-carboxylic, hydroxyl di-carboxylic acids and hydroxyl-fatty acids, methylglyoxal, mono-, di- or poly-alcohols, alkanes, alkenes, aromatics, aldehydes, ketones, esters, phenols, benzene, toluenes, and xylenes; or the conversion product is selected from dispersants, emulsifiers, complexants, flocculants, agglomerants, pelletizing additives, resins, carbon fibers, active carbon, antioxidants, liquid fuel, aromatic chemicals, vanillin, adhesives, binders, absorbents, toxin binders, foams, coatings, films, rubbers and elastomers, sequestrants, fuels, and expanders; or the conversion product comprises a fuel or a fuel ingredient (all claimed).    ADVANTAGE - Fractions of high purity lignin which are thermally stable, are provided.    DETAILED DESCRIPTION - Lignin composition characterized (on a dry matter basis) by at least one characteristic selected from: (i) a glass transition temperature (Tg) above 160 degrees C or below 90 degrees C as determined using differential scanning calorimetry (DSC) according to DIN 53765-1994; (ii) a consistent Tg as determined by multiple differential scanning calorimetry (DSC) runs of the same lignin portion; (iii) a mass average molar mass (Mw) greater than 10000 Da as measured by gel permeation chromatography (GPC); (iv) a number average molar mass (Mn) greater than 6200 Da as measured by GPC; (v) a Mw less than 2,500 Da as measured by GPC; (vi) a Mn less than 1000 Da as measured by GPC; (vii) a polydisperisity less than 7.00 as measured by GPC; (viii) a formula of C9HxOy; where x is less than 12 and y is less than 3.5; (ix) degree of condensation less than 0.8 as determined by NMR; (x) methoxyl content (#/aryl group) as determined by NMR is less than 1.4; (xi) aliphatic linkages ( beta -O-4') (#/aryl group) less than 0.6; (xii) ratio of aromatic C-O: aromatic C-C: Aromatic C-H (#/aryl group) is 1.6:2.3:2.1 or 1.6:2.2:2.2; (xiii) amount of aromatic C-O bonds (#/aryl group) is less than 2.1; (xiv) elemental composition of greater than 61% carbon, less than 27% oxygen, and less than 0.5% nitrogen by mass as measured by elemental analysis; (xv) a solid lignin composition comprising a marker molecule at a concentration of at least 100 ppb; (xvi) less than 0.1 times the volatile sulfur compounds found in Kraft lignin; (xvii) an ash content of less than 0.5%; (xviii) an ash content of less than 0.1%; (xix) a sulfur content of less than 700 ppm; (xx) a phosphorus content of less than 100 ppm; (xxi) a soluble carbohydrate content of less than 0.5%; (xxii) substantially insoluble in an organic solvent; and (xxiii) substantially soluble in an organic solvent. INDEPENDENT CLAIMS are included for:    (1) a composition comprising at up to 50% wt/wt of the lignin;    (2) a method for fractionating lignin which involves: (i) contacting a sample comprising solid lignin with an organic solvent to form a resulting biphasic mixture, where the mixture comprises: (a) a remainder solid designated as solvent insoluble (SI) fraction comprising a first fraction of the lignin; and (b) a liquid solution comprising the solvent and a second fraction of the lignin, where the second fraction is designated as solvent soluble (SS) lignin fraction; and (ii) spacially separating the (SI) lignin fraction from the (SS) lignin fraction, where the first fraction of lignin and second fraction of lignin have different Tgs;    (3) a method for producing high purity lignin from a biomass, which involves: (i) removing hemicellulose sugars from the biomass thus obtaining a lignin-containing remainder; where the lignin-containing remainder comprises lignin and cellulose; (ii) contacting the lignin-containing remainder with a lignin extraction solution to produce a lignin extract and a cellulosic remainder; where the lignin extraction solution comprises a limited-solubility solvent, an organic acid, and water, where the limited-solubility solvent and water form an organic phase and an aqueous phase; and (iii) separating the lignin extract from the cellulosic remainder; where the lignin extract comprises lignin dissolved in the limited-solubility solvent; and further comprising one, two, three or four additional step(s): (iv) distilling or flash evaporating the lignin extract thus removing the bulk of the limited-solubility solvent from the lignin extract to obtain a solid lignin; (v) heating the solid lignin thus removing trace limited-solubility solvent or water from the solid lignin; (vi) applying a vacuum to the solid lignin thus removing trace limited-solubility solvent or water from the solid lignin; and (vii) contacting a sample comprising solid lignin with an organic solvent to form a resulting biphasic mixture, where the mixture comprises: (a) a remainder solid designated as SI fraction comprising a first fraction of the lignin; and (b) a liquid solution comprising the solvent and a second fraction of the lignin, where the second fraction is designated as SS lignin fraction; and (ii) spacially separating the (SI) lignin fraction from the (SS) lignin fraction; where the first fraction of lignin and second fraction of lignin have different Tgs; and    (4) a method which involves: (i) providing the lignin composition; and (ii) converting at least a portion of lignin in the composition to a conversion product.