301 / 2018-07-29 17:55:10

Effect of lignin removal by γ-valerolactone treatment for improving enzyme hydrolysis of acetic acid treated poplar

全体主题 > 生物质多联产

Cellulosic biomass represents a renewable and low-cost resource that can be converted into biofuels and chemicals by biorefinery process. However, the high costs associated with sequential biomass deconstruction and product refining continues to limit opportunities for profitable implementation of biorefinery processes. Poplar is considered as a benign feedstock for biorefinery because of its growth characteristics, such as fast growing, wide distribution and short rotation period. Especially, poplar sawdust, which belongs to poplar wood processing residues, is rich in total volume of poplar plantation leftovers in China, generating a series of questions including resource waste, low utilization, environmental pollution and high costs of manual processing. For this reason, it’s crucial to realize the biotransformation of these woody feedstocks to value-added products for re-utilization, cleaning and high-value applications. Here we proposed a novel biorefinery process for XOS and fermentable sugars production from poplar by a two-step process using acetic acid and γ-valerolactone. XOS was obtained directly from the liquid fraction after first step acetic acid treatment, and the solid residue was pretreated by γ-valerolactone. After pretreatment, the solid was transformed into fermentable sugars by cellulase. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), hydrophobicity and Scanning electron microscopy (SEM) were employed to assess the structural changes induced by the two-step treatments. Meanwhile, the optimal enzymatic hydrolysis conditions were investigated. This process is environment-friendly because no sulfur and chlorine were introduced.