scholarly journals Effect of Zn/ZSM-5 and FePO4Catalysts on Cellulose Pyrolysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Haian Xia ◽  
Xiaopei Yan ◽  
Siquan Xu ◽  
Li Yang ◽  
Yuejie Ge ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Value Added ◽  
Product Distribution ◽  
Acid Sites ◽  
Gas Chromatography Mass Spectrometry ◽  
Lewis Acid Sites ◽  
Liquid Products ◽  
Temperature Programmed ◽  
Xrd Techniques ◽  
Brønsted And Lewis Acid

A series of Zn/ZSM-5 catalysts with different Zn contents and FePO4were used to pyrolyze cellulose to produce value added chemicals. The nature of these catalysts was characterized by ammonia-temperature programmed desorption (NH3-TPD), IR spectroscopy of pyridine adsorption, and X-ray diffraction (XRD) techniques. Noncatalytic and catalytic pyrolytic behaviors of cellulose were studied by thermogravimetric (TG) technique. The pyrolytic liquid products, that is, the biooils, were analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of the biooils are anhydrosugars such as levoglucosan (LGA), 1,6-anhydro-β-D-glucofuranose (AGF), levoglucosenone (LGO, 1,6-anhydro-3,4-dideoxy-β-D-pyranosen-2-one), and 1,4:3,6-dianhydro-α-D-glucopyranose (DGP), as well as furan derivatives, alcohols, and so forth. Zn/ZSM-5 samples with Brønsted and Lewis acid sites and the FePO4catalyst with Lewis acid sites were found to have a significant effect on the pyrolytic behaviors of cellulose and product distribution. These results show that Brønsted and Lewis acid sites modified remarkably components of the biooil, which could promote the production of furan compounds and LGO. On the basis of the findings, a model was proposed to describe the pyrolysis pathways of cellulose catalyzed by the solid acid catalysts.

scholarly journals Solid Acids for the Reaction of Bioderived Alcohols into Ethers for Fuel Applications

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 172 ◽  
Author(s):  
Federica Zaccheria ◽  
Nicola Scotti ◽  
Nicoletta Ravasio
Keyword(s):  
Physical Properties ◽  
Lignocellulosic Biomass ◽  
Lewis Acid ◽  
Product Distribution ◽  
Acid Sites ◽  
Solid Acids ◽  
Lewis Acid Sites ◽  
Hydroxymethyl Furfural ◽  
Brønsted And Lewis Acid

The use of solids acids in the synthesis of ethers suitable to be used as fuels or fuel additives were reviewed in a critical way. In particular, the role of Brønsted and Lewis acid sites was highlighted to focus on the pivotal role of the acidity nature on the product distribution. Particular emphasis is given to the recently proposed ethers prepared starting from furfural and 5-hydroxymethyl furfural. Thus, they are very promising products that can be derived from lignocellulosic biomass and bioalcohols and possess very interesting chemical and physical properties for their use in the diesel sector.

One-pot transformation of furfural into γ-valerolactone catalyzed by hierarchical Hf-Al-USY zeolite with balanced Lewis and Brønsted acid sites

2021 ◽  
Author(s):  
Bo Tang ◽  
Shuang Li ◽  
Wei-Chao Song ◽  
Yan Li ◽  
En-Cui Yang
Keyword(s):  
Lewis Acid ◽  
Value Added ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Lewis Acid Sites ◽  
One Pot ◽  
Usy Zeolite ◽  
Brønsted Acid Sites ◽  
Brönsted Acid ◽  
Brønsted And Lewis Acid

Upgrading of furfural to high value-added chemicals are currently an attractive and challenging route in biorefineries. Herein, hierarchically structured bifunctional Hf-Al-USY zeolite with balanced Brønsted and Lewis acid sites has...

scholarly journals Glucose Conversion into 5-Hydroxymethylfurfural over Niobium Oxides Supported on Natural Rubber-Derived Carbon/Silica Nanocomposite

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Rujeeluk Khumho ◽  
Satit Yousatit ◽  
Chawalit Ngamcharussrivichai
Keyword(s):  
Natural Rubber ◽  
Lewis Acid ◽  
Value Added ◽  
Acid Sites ◽  
Superior Performance ◽  
Lewis Acidity ◽  
Lewis Acid Sites ◽  
Niobium Oxides ◽  
Silica Nanocomposite ◽  
Loading Amount

5-Hydroxymethylfurfural (HMF) is one of the most important lignocellulosic biomass-derived platform molecules for production of renewable fuel additives, liquid hydrocarbon fuels, and value-added chemicals. The present work developed niobium oxides (Nb2O5) supported on mesoporous carbon/silica nanocomposite (MCS), as novel solid base catalyst for synthesis of HMF via one-pot glucose conversion in a biphasic solvent. The MCS material was prepared via carbonization using natural rubber dispersed in hexagonal mesoporous silica (HMS) as a precursor. The Nb2O5 supported on MCS (Nb/MCS) catalyst with an niobium (Nb) loading amount of 10 wt.% (10-Nb/MCS) was characterized by high dispersion, and so tiny crystallites of Nb2O5, on the MCS surface, good textural properties, and the presence of Bronsted and Lewis acid sites with weak-to-medium strength. By varying the Nb loading amount, the crystallite size of Nb2O5 and molar ratio of Bronsted/Lewis acidity could be tuned. When compared to the pure silica HMS-supported Nb catalyst, the Nb/MCS material showed a superior glucose conversion and HMF yield. The highest HMF yield of 57.5% was achieved at 93.2% glucose conversion when using 10-Nb/MCS as catalyst (5 wt.% loading with respect to the mass of glucose) at 190 °C for 1 h. Furthermore, 10-Nb/MCS had excellent catalytic stability, being reused in the reaction for five consecutive cycles during which both the glucose conversion and HMF yield were insignificantly changed. Its superior performance was ascribed to the suitable ratio of Brønsted/Lewis acid sites, and the hydrophobic properties generated from the carbon moieties dispersed in the MCS nanocomposite.

On the nature of framework Brønsted and Lewis acid sites in ZSM-5

Zeolites ◽  
1997 ◽  
Vol 19 (4) ◽  
pp. 288-296 ◽  
Author(s):  
G.L. Woolery ◽  
G.H. Kuehl ◽  
H.C. Timken ◽  
A.W. Chester ◽  
J.C. Vartuli
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid

scholarly journals Liquid Phase Benzylation of Toluene over Modified Titania Catalysts

2012 ◽  
Vol 11 (2) ◽  
pp. 31-44
Author(s):  
Sunaja Devi K R ◽  
Sugunan S
Keyword(s):  
Liquid Phase ◽  
Lewis Acid ◽  
Benzyl Chloride ◽  
Sol Gel ◽  
Active Phase ◽  
Temperature Programmed Desorption ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Sulfated Titania ◽  
Temperature Programmed

Titania, sulfated titania and a series of iron loaded sulfated titania catalyst with different iron loadings (39 %) are prepared by sol-gel method and calcined at 500°C. Anatase is found to be the active phase with crystallite size in the nano range. All the prepared catalysts are found to be stable up to 700°C. Acidity is measured using spectrophotometric monitoring of adsorption of perylene, thermogravimetric desorption of 2,6-dimethylpyridine and temperature programmed desorption of ammonia. The activities of the catalysts were tested for liquid phase Friedel-Crafts benzylation of toluene with benzyl chloride. It has been concluded that Lewis acid sites are responsible for the reaction.

Enhancing Brønsted and Lewis Acid Sites of the Utilized Spent RFCC Catalyst Waste for the Continuous Cracking Process of Palm Oil to Biofuels

2020 ◽  
Vol 59 (20) ◽  
pp. 9459-9468 ◽  
Author(s):  
I. Istadi ◽  
Teguh Riyanto ◽  
Luqman Buchori ◽  
Didi Dwi Anggoro ◽  
G. Gilbert ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Palm Oil ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Cracking Process ◽  
Brønsted And Lewis Acid
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