Levulinate esters from biomass wastes

Garves reported formation of insoluble humic residue at the higher temperatures (P). In our work, the acid-catalyzed reactions of ethanol with seed hulls and with chaff or straw waste at 200 C produced a charcoal product with modest surface areas (//). A significant part (20%-30%) of the cellulose is carbonized to charcoal, which is easily removed by filtration. Flash distillation of the excess alcohol and solvent extraction of the levulinate ester leaves a resinous product consisting mainly of the lignin component of the biomass. Thus multiple marketable products are available from processing waste biomass with the acidic alcohols. 

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