sc8b02206_si_001.pdf (1007.63 kB)
From Biomass to Sugar Alcohols: Purification of Wheat Bran Hydrolysates Using Boronic Acid Carriers Followed by Hydrogenation of Sugars over Ru/H-ZSM‑5
journal contribution
posted on 2018-07-16, 00:00 authored by Nuria Sánchez-Bastardo, Irina Delidovich, Esther AlonsoWheat
bran is a lignocellulosic waste of milling industry. It contains
hemicelluloses, which can be valorized into arabitol and xylitol via
a few-step approach. It begins with extraction and hydrolysis of hemicelluloses
to produce a solution of xylose and arabinose, along with proteins
and inorganic salts. This work focuses on the purification of sugars
of this hydrolysate and the subsequent catalytic production of sugar
alcohols. A purification process based on the recovery of sugars by
anionic extraction with a boronic acid, followed by back-extraction
and a further refining step with ion exchange resins is described.
After this process, a high purity sugars solution (∼90%) free
of inorganic elements and proteins was obtained. The feasibility of
the process was also highlighted by a successful recycling of the
organic phase containing the boronic acid. The hydrogenation of purified
sugars was then performed over Ru/H-ZSM-5. A high yield into pentitols
of ∼70% with 100% selectivity was achieved. Importantly, the
catalytic hydrogenation of sugars in the hydrolysate prior to purification
did not occur. We determined that proteins caused the deactivation
of the catalyst, and consequently, the inhibition of the production
of sugar alcohols.