Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL), enzymatic hydrolysis corn stover lignin (EHL), wheat straw alkali lignin (AL) and wheat straw sulfonate lignin (SL), were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS). Thermogravimetric analysis (TGA) showed that the four lignins exhibited widely different thermolysis behaviors. The four lignins had similar functional groups according to the FTIR analysis. Syringyl, guaiacyl and p-hydroxyphenylpropane structural units were broken down during pyrolysis. Fast pyrolysis product distributions from the four lignins depended strongly on the lignin origin and isolation process. Phenols were the most abundant pyrolysis products from MWL, EHL and AL. However, SL produced a large number of furan compounds and sulfur compounds originating from kraft pulping. The effects of pyrolysis temperature and time on the product distributions from corn stover EHL were also studied. At 350 °C, EHL pyrolysis mainly produced acids and alcohols, while phenols became the main products at higher temperature. No obvious influence of pyrolysis time was observed on EHL pyrolysis product distributions.

Series wood-based MOF composites were fabricated by in situ growth of metal–organic frameworks in nano-wood aerogel, achieving a sustainable and efficient capture and separation of CO ₂ .

Crude bio-oil from pine chip fast pyrolysis was upgraded with olefins (1-octene, cyclohexene, 1,7-octadiene, and 2,4,4-trimethylpentene) plus 1-butanol (iso-butanol, t-butanol and ethanol) at 120 °C using a silica sulfuric acid (SSA) catalyst that possesses a good catalytic activity and stability. Gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H-NMR) analysis showed that upgrading sharply increased ester content and decreased the amounts of levoglucosan, phenols, polyhydric alcohols and carboxylic acids. Upgrading lowered acidity (pH value rose from 2.5 to >3.5), removed the unpleasant odor and increased hydrocarbon solubility. Water content dramatically decreased from 37.2% to about 7.0% and the heating value increased from 12.6 MJ·kg⁻¹ to about 31.9 MJ·kg⁻¹. This work has proved that bio-oil upgrading with a primary olefin plus 1-butanol is a feasible route where all the original heating value of the bio-oil plus the added olefin and alcohol are present in the resulting fuel.

Boric acid is recently proved to be a good substitute for conventional acidic catalytic materials. However, few studies used boric acid as a catalyst in biomass pyrolysis. This study focused on the catalytic effects of boric acid (BA) on pyrolysis behaviors of woody biomass. The birch wood flour (WF) was used as feedstock and treated by impregnation of boric acid solution. Both untreated and boric acid-treated samples (BW) were characterized by FTIR and SEM. Thermogravimetry (TG) and pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) techniques were used for studying mass loss, composition, and distribution of evolved volatiles formed from pyrolysis process. Additionally, a small fixed-bed pyrolyzer with an amplificated loading amount was used to prepare liquid products, and further, GC/MS were used to analyze the composition of these liquid products. Different pyrolysis temperatures and boric acid/wood flour mass ratios were also studied. The main results are as follows. Boric acid infiltrated into both cell cavity and cell wall through impregnation treatment. FTIR analysis showed that boric acid reacted with wood flour to form B-O-C bond during the treatment. After the treatment of boric acid, the initial degradation temperatures and residual carbon contents were increased, while the maximum weight loss rates were decreased. Boric acid significantly altered the composition and distribution of volatile pyrolysis products of wood flour. It significantly increased the contents of small molecule compounds such as acetic acid and furfural but, decreased the contents of phenol derivatives with high molecular weights. And these changes became more pronounced as the temperature increased. When mass ratio of boric acid (BA) to wood flour (WF) was 2, the acetic acid accounted for 91.28% of the total product in the pyrolysis liquid, which was 14 times higher than that of untreated wood flour. Boric acid effectively catalyzed fast pyrolysis of woody biomass to selectively produce acetic acid