Selectively Producing Acetic Acid via Boric Acid-Catalyzed Fast Pyrolysis of Woody Biomass

Abstract

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

Boron-Doped Pine-Cone Carbon With 3D Interconnected Porosity for Use as an Anode for Potassium-Ion Batteries With Long Life Cycle

“…Based on these results, the formation mechanism of the ultrathin carbon layer of BZPC has been proposed ( Figure 1B ). After the pine-cone powder was impregnated with boric acid solution, boric acid molecules penetrated the cell walls and cavities of the lignocellulosic biomass or were deposited on the surface of the biomass powder, forming non-covalently bonded complexes with hydroxyl groups of lignocellulose through hydrogen bonding ( Zhang et al, 2020a ; Hou et al, 2021 ; Le et al, 2021 ). The boric acid underwent self-polymerisation at the start of pyrolysis and eventually formed a glassy B 2 O 3 film on the lignocellulose surface ( Hou et al, 2021 ; Le et al, 2021 ).…”

“…After the pine-cone powder was impregnated with boric acid solution, boric acid molecules penetrated the cell walls and cavities of the lignocellulosic biomass or were deposited on the surface of the biomass powder, forming non-covalently bonded complexes with hydroxyl groups of lignocellulose through hydrogen bonding ( Zhang et al, 2020a ; Hou et al, 2021 ; Le et al, 2021 ). The boric acid underwent self-polymerisation at the start of pyrolysis and eventually formed a glassy B 2 O 3 film on the lignocellulose surface ( Hou et al, 2021 ; Le et al, 2021 ). Then, lignocellulose went through a series of pyrolysis reactions during calcination and eventually forming a thin localised carbon layer.…”

“…First, B–OH reacts with hydroxyl groups to produce water ( Zhang et al, 2020a ). Second, during carbonation, boric acid catalyses the dehydration and deoxygenation of lignocellulose, releasing water, CO, CO 2 , and some volatile small molecules ( Zhang et al, 2020a ; Hou et al, 2021 ; Le et al, 2021 ). These lead to the formation of a microporous structure.…”

Improvement of Fire Resistance and Mechanical Properties of Glass Fiber Reinforced Plastic (GFRP) Composite Prepared from Combination of Active Nano Filler of Modified Pumice and Commercial Active Fillers

“…With the addition of BA, the protective layer is also stronger because BA melts at a temperature of 236 °C, and it dehydrates when heated above 300 °C [ 54 ]. If the heating continues, the boron oxide forms a protective film to inhibit the flame.…”

On-Line Thermally Induced Evolved Gas Analysis: An Update—Part 1: EGA-MS

“…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 [ 125 ].…”