Submitted to: BioResources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2011
Publication Date: 6/6/2011
Citation: Klasson, K.T., Uchimiya, M., Lima, I.M., Boihem, Jr., L.L. 2011. Feasibility of removing furfurals from sugar solutions using activated biochars made from agricultural residues. BioResources. 6(3):3242-3251.
Interpretive Summary: Plant feedstocks are often prepared for ethanol fermentation by soaking them in an acid. The acid attacks the wood and breaks it down to sugars that later can be used to make biofuels and natural products. However, the acid also can convert the sugars to compounds that are toxic to yeast that are used to make the biofuels. This work summarizes the use of plant waste as starting material for making activated biochars to capture these toxic degradation products. Results show that two toxins are adsorbed by phosphoric acid-activated and steam-activated biochars prepared from wastes collected from cotton and linen production.
Technical Abstract: Lignocellulosic feedstocks are often prepared for ethanol fermentation by treatment with a dilute mineral acid catalyst that hydrolyzes the hemicellulose and possibly cellulose into soluble carbohydrates. The acid catalyzed reaction scheme is sequential whereby released monosaccharides are further degraded to furans and other chemicals that are inhibitory to the subsequent fermentation step. This work summarizes the use of agricultural residues (e.g., plant waste) as starting materials for making activated biochars to adsorb these degradation products. Results show that both furfural and hydroxymethylfurfural (HMF) are adsorbed by phosphoric acid-activated and steam-activated biochars prepared from residues collected from cotton and linen production. Best results were obtained with steam activated biochars. The activated biochars adsorbed about 14% (by weight) of the furfurals at an equilibrium concentration of 0.5 g/L, and by adding 2.5% of char to a sugar solution, with either furfural or HMF (at 1 g/L), 99% of the furans were removed.