Insights into the reaction network and kinetics of xylose conversion over combined Lewis/Brønsted acid catalysts in a flow microreactor

Guo, Wenze; Bruining, Herman Carolus; Heeres, Hero Jan; Yue, Jun

doi:10.1039/d3gc00153a

Cited by 10 publications

(2 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The large plastic production and usage has led to enormous plastic waste, of which only 8.8% is currently recycled (physically), while the rest is mainly disposed in landfills or directly incinerated, , causing severe economic loss and environmental problem. Considering also the depleting fossil reserves and the popularity of exploiting sustainable alternative resources (e.g., lignocellulosic biomass), − upcycling of waste plastics, e.g., polyolefins (PO), which takes up the largest fraction of the waste plastics, into value-added chemicals and fuels represents a promising direction toward a greener chemical industry and circular economy and thus has received significant research attention. − …”

Section: Introductionmentioning

confidence: 99%

Selective Hydrocracking of Waste Polyolefins toward Gasoline-Range Liquid Fuels via Tandem Catalysis over a Cerium-Promoted Pt/HY Catalyst

Zhao,

Guo,

Gui

et al. 2024

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

Upcycling of waste plastics into value-added chemicals and fuels represents a promising orientation toward a more sustainable chemical industry. We present a selective process for hydrocracking waste polyolefins into a spectrum of branched gasoline-range C 5−12 hydrocarbons, utilizing a cerium-promoted Pt/ HY as a metal−acid bifunctional catalyst. The HY zeolite was engineered with a hierarchical meso/microporosity and moderated acidity to alleviate the overcracking of intermediate hydrocarbons to light C 1−4 gas products. The cerium presented as a surface cerium oxide phase, which mitigated acidity and significantly improved Pt dispersion. Upon a proper metal−acid balance, an optimized yield of C 5−12 up to 85 wt % was achieved from the low-density polyethylene over a cerium-promoted Pt/HY catalyst at 280 °C and 2 MPa H 2 for 2 h. The tandem catalysis was proposed to proceed with an initial dehydrogenation of the polymer chain over Pt sites, with subsequent isomerization and cracking over the Brønsted acid sites and hydrogenation of the olefin intermediates over Pt sites. The strong Pt−O−Ce bridging structure inhibited the migration and agglomeration of Pt atoms, affording good stability and no distinct performance loss over three sequential runs. This process is applicable to the hydrocracking of other polyolefins such as high-density polyethylene, polypropylene, and daily plastic bags to gasoline-range fuels in desirable yields (60−80 wt %).

show abstract

Section: Introductionmentioning

confidence: 99%

Selective Hydrocracking of Waste Polyolefins toward Gasoline-Range Liquid Fuels via Tandem Catalysis over a Cerium-Promoted Pt/HY Catalyst

Zhao,

Guo,

Gui

et al. 2024

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The XOS produced through autohydrolysis mainly contains impurities like monosaccharides, partial degradation of lignin-derived products, derivatives of sugars resulting from dehydration, and condensation of carbohydrates and ash . The mild acidic (H + ) condition in combination with higher temperature leads to the dehydration of the xylose to furfural . The treatment with activated charcoal (AC) is an efficient process that is conventionally used for the removal of lignin and furfural from the hemicellulose and also delignification of prehydrolysate .…”

Section: Introductionmentioning

confidence: 99%

Green Downstream Processing Method for Xylooligosaccharide Purification and Assessment of Its Prebiotic Properties

Sonkar,

Gade,

Mudliar

et al. 2023

ACS Omega

View full text Add to dashboard Cite

Xylooligosaccharides (XOS) obtained from lignocellulosic biomass after autohydrolysis primarily consist of ligninderived impurities and autogenerated inhibitors like furfural, hydroxymethylfurfural, and acetic acid. In this study, graphene oxide-mediated purification (GOMP), a novel and environmentally friendly downstream processing method, was developed for the purification of XOS from hydrolysate obtained after ozone-assisted autohydrolysis of wheat bran. GOMP resulted in appreciable recovery of total XOS from the hydrolysate (73.87 ± 4.25%, DP2− 6) with near complete removal of autogenerated inhibitors (furfural 85.42%, HMF 87.38%, and acetic acid 84.0%). Recovery of XOS by GOMP was higher than the conventional membrane purification technique (44.07 ± 0.92%) and activated charcoal treatment (72.76 ± 0.84%) along with comparatively higher removal of inhibitor compounds. GOMP results in the selective adsorption of inhibitors on the graphene oxide matrix from the XOS-rich hydrolysate, resulting in its purification and concentration. The prebiotic function of the obtained XOS fractions (DP2−4.48%, DP3−39.69%, DP4−36.13%, DP5−8.38%, and DP6−13.10%) was evaluated, indicating the growth stimulation of tested probiotic cultures and differential utilization of XOS oligomers DP3 and DP4 and complete consumption of DP2, DP5, and DP6 along with short-chain fatty acids as a major fermentation product. These findings suggest that GOMP, which employs a common substance (i.e., graphene oxide) used in water treatment, exhibits potential as an efficient and economically viable single-step methodology for XOS purification.

show abstract

Model‐Assisted Optimization of Xylose, Arabinose, Glucose, Mannose, Galactose and Real Hemicellulose Streams Dehydration To (Hydroxymethyl)Furfural and Levulinic Acid

Jakob,

Likozar,

Grilc

2024

ChemSusChem

View full text Add to dashboard Cite

Conversion of hemicellulose streams and the constituent monosaccharides, xylose, arabinose, glucose, mannose, and galactose, was conducted to produce value‐added chemicals, including furfural, hydroxymethylfurfural (HMF), levulinic acid and anhydrosugars. The study aimed at developing a kinetic model relevant for direct post‐Organosolv hemicellulose conversion. Monosaccharides served as a tool to in detail describe the kinetic behavior and segregate contribution of hydrothermal decomposition and acid catalyzed dehydration at the temperature range of 120‐190 °C. Catalyst free aqueous media demonstrated enhanced formation of furanics, while elevated temperatures led to significant saccharide isomerization. The introduction of sulfuric and formic acids maximized furfural yield and significantly reduced HMF concentration by facilitating its rehydration into levulinic acid (46 mol%). Formic acid additionally substantially enhanced formation of anhydrosaccharides. An excellent correlation between modeled and experimental data enabled process optimization to maximize furanic yield in two distinct hemicellulose streams. Sulfuric acid‐containing hemicellulose stream achieved the highest furfural yield after 30 minutes at 238 °C, primarily due to the high Ea for pentose dehydration (150 – 160 kJmol−1). Contrarily, formic acid‐containing hemicellulose stream enabled maximal furfural yield at more moderate temperature and extended reaction time due to its lower Ea for the same reaction step (115 – 125 kJmol−1).

show abstract

Insights into the reaction network and kinetics of xylose conversion over combined Lewis/Brønsted acid catalysts in a flow microreactor

Abstract: The catalytic effect of Lewis acid on xylose conversion to furfural has been widely reported, while the underlying reaction network and kinetics are not fully elucidated. This work presents experimental...

Cited by 10 publications

References 49 publications

Selective Hydrocracking of Waste Polyolefins toward Gasoline-Range Liquid Fuels via Tandem Catalysis over a Cerium-Promoted Pt/HY Catalyst

Selective Hydrocracking of Waste Polyolefins toward Gasoline-Range Liquid Fuels via Tandem Catalysis over a Cerium-Promoted Pt/HY Catalyst

Green Downstream Processing Method for Xylooligosaccharide Purification and Assessment of Its Prebiotic Properties

Model‐Assisted Optimization of Xylose, Arabinose, Glucose, Mannose, Galactose and Real Hemicellulose Streams Dehydration To (Hydroxymethyl)Furfural and Levulinic Acid

Contact Info

Product

Resources

About