TY - JOUR
T1 - Formation, Molecular Structure, and Morphology of Humins in Biomass Conversion
T2 - Influence of Feedstock and Processing Conditions
AU - van Zandvoort, Ilona
AU - Wang, Yuehu
AU - Rasrendra, Carolus B.
AU - van Eck, Ernst R. H.
AU - Bruijnincx, Pieter C. A.
AU - Heeres, Hero J.
AU - Weckhuysen, Bert M.
PY - 2013/9
Y1 - 2013/9
N2 - Neither the routes through which humin byproducts are formed, nor their molecular structure have yet been unequivocally established. A better understanding of the formation and physicochemical properties of humins, however, would aid in making biomass conversion processes more efficient. Here, an extensive multiple-technique-based study of the formation, molecular structure, and morphology of humins is presented as a function of sugar feed, the presence of additives (e.g., 1,2,4-trihydroxybenzene), and the applied processing conditions. Elemental analyses indicate that humins are formed through a dehydration pathway, with humin formation and levulinic acid yields strongly depending on the processing parameters. The addition of implied intermediates to the feedstocks showed that furan and phenol compounds formed during the acid-catalyzed dehydration of sugars are indeed included in the humin structure. IR spectra, sheared sum projections of solid-state 2DPASS (CNMR)-C-13 spectra, and pyrolysis GC-MS data indicate that humins consist of a furan-rich polymer network containing different oxygen functional groups. The structure is furthermore found to strongly depend on the type of feedstock. A model for the molecular structure of humins is proposed based on the data presented.
AB - Neither the routes through which humin byproducts are formed, nor their molecular structure have yet been unequivocally established. A better understanding of the formation and physicochemical properties of humins, however, would aid in making biomass conversion processes more efficient. Here, an extensive multiple-technique-based study of the formation, molecular structure, and morphology of humins is presented as a function of sugar feed, the presence of additives (e.g., 1,2,4-trihydroxybenzene), and the applied processing conditions. Elemental analyses indicate that humins are formed through a dehydration pathway, with humin formation and levulinic acid yields strongly depending on the processing parameters. The addition of implied intermediates to the feedstocks showed that furan and phenol compounds formed during the acid-catalyzed dehydration of sugars are indeed included in the humin structure. IR spectra, sheared sum projections of solid-state 2DPASS (CNMR)-C-13 spectra, and pyrolysis GC-MS data indicate that humins consist of a furan-rich polymer network containing different oxygen functional groups. The structure is furthermore found to strongly depend on the type of feedstock. A model for the molecular structure of humins is proposed based on the data presented.
KW - Biomass
KW - Carbohydrates
KW - Furans
KW - Reaction mechanisms
KW - Structure elucidation
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=d7dz6a2i7wiom976oc9ff2iqvdhv8k5x&SrcAuth=WosAPI&KeyUT=WOS:000325090400024&DestLinkType=FullRecord&DestApp=WOS
U2 - 10.1002/cssc.201300332
DO - 10.1002/cssc.201300332
M3 - Article
C2 - 23836679
SN - 1864-5631
VL - 6
SP - 1745
EP - 1758
JO - ChemSusChem
JF - ChemSusChem
IS - 9
ER -