Coeffect of Na+ and Tetrapropylammonium (TPA+) in Alkali Treatment on the Fabrication of Mesoporous ZSM-5 Catalyst for Methanol-to-Hydrocarbons Reactions

2016 ◽  
Vol 55 (51) ◽  
pp. 13040-13049 ◽  
Author(s):  
Weili Wan ◽  
Tingjun Fu ◽  
Ruiyue Qi ◽  
Juan Shao ◽  
Zhong Li
Keyword(s):  
Alkali Treatment ◽  
Methanol To Hydrocarbons

Kinetic Adsorption of Humic Acids Mixture Obtained from Microalgae on Exfoliated Graphite Nanoplatelets

2018 ◽  
Vol 69 (1) ◽  
pp. 191-195
Author(s):  
Elena Radu ◽  
Elena Emilia Oprescu ◽  
Cristina Emanuela Enascuta ◽  
Catalina Calin ◽  
Rusandica Stoica ◽  
...  
Keyword(s):  
Humic Acid ◽  
Humic Acids ◽  
Alkali Treatment ◽  
Exfoliated Graphite ◽  
Acid Mixture ◽  
Acidic Ph ◽  
Graphite Nanoplatelets ◽  
Mixture Concentration ◽  
Ft Ir ◽  
Exfoliated Graphite Nanoplatelets

The dehydration of polysaccharides fraction in the presence of acid catalysts, is a chemical process in which results as secondary product humic matter. In our work, the humic acid mixture was for the first time based on our knowledge extracted from defatted microalgae biomass rich in polysaccharides by standard alkali treatment, followed by precipitation at acidic pH. The dried humic acid mixture has been characterized using infrared spectroscopic measurements (FT-IR). Exfoliated graphite nanoplatelets (xGnP) were used as new adsorbents for this type of humic acids mixture, their adsorption being investigated. The effect of several parameters such as: contact time, concentration of humic acid mixture, concentration of xGnP, temperature and pH of the solutions were studied. The process of adsorption took place with good results, in the following conditions: at a concentration of humic acid mixture of 18.6 mg L-1, an xGnP amount of 0.01 mg in 25 mL of solution, at a temperature of 25 �� and at acidic pH values, in aqueous solution.

Transformation of methanol to hydrocarbons over Y zeolites with varying Si/Al ratio

1987 ◽  
Vol 52 (7) ◽  
pp. 1701-1707 ◽  
Author(s):  
Miloslav Křivánek ◽  
Nguyen Thiet Dung ◽  
Pavel Jírů
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Coke Formation ◽  
Aliphatic Hydrocarbons ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Methanol To Hydrocarbons

The catalytic activity of Na, H-Y zeolite samples with a varying Si/Al ratio (2·5 to 20) in the transformation of methanol was determined. The amounts of formed individual aliphatic hydrocarbons as function of reaction time were correlated with the amount of Bronsted and Lewis centres on the catalysts. The effect of coke formation on the over-all course of the reaction has been demonstrated.

Influence of alkali treatment on flax fiber for use as reinforcements in polylactide stereocomplex composites

2015 ◽  
Vol 55 (11) ◽  
pp. 2553-2558 ◽  
Author(s):  
Huihui Zhang ◽  
Ruihao Ming ◽  
Gesheng Yang ◽  
Yuzeng Li ◽  
Qiao Li ◽  
...  
Keyword(s):  
Alkali Treatment ◽  
Flax Fiber

Green, efficient extraction of bamboo hemicellulose using freeze-thaw assisted alkali treatment

2021 ◽  
Vol 333 ◽  
pp. 125107
Author(s):  
Jing Li ◽  
Zhaomeng Liu ◽  
Chengqi Feng ◽  
Xiaoying Liu ◽  
Fangyu Qin ◽  
...  
Keyword(s):  
Alkali Treatment ◽  
Freeze Thaw ◽  
Efficient Extraction

Optimization of Alkali Treatment Process Parameters for Kenaf Fiber: Experiments Design

2020 ◽  
pp. 1-10
Author(s):  
R. Sathish Kumar ◽  
Nivedhitha Muralidharan ◽  
Ravishankar Sathyamurthy
Keyword(s):  
Process Parameters ◽  
Treatment Process ◽  
Alkali Treatment ◽  
Kenaf Fiber

scholarly journals Influence of Alkali Treatment on the Microstructure and Mechanical Properties of Coir and Abaca Fibers

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2636
Author(s):  
Petr Valášek ◽  
Miroslav Müller ◽  
Vladimír Šleger ◽  
Viktor Kolář ◽  
Monika Hromasová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Alkali Treatment ◽  
Fiber Surface ◽  
Cellulose Fibers ◽  
Sem Analysis ◽  
Experimental Program ◽  
Time Interval ◽  
The European Union ◽  
Vegetable Fibers

Composite materials with natural fillers have been increasingly used as an alternative to synthetically produced materials. This trend is visible from a representation of polymeric composites with natural cellulose fibers in the automotive industry of the European Union. This trend is entirely logical, owing to a preference for renewable resources. The experimental program itself follows pronounced hypotheses and focuses on a description of the mechanical properties of untreated and alkali-treated natural vegetable fibers, coconut and abaca fibers. These fibers have great potential for use in composite materials. The results and discussion sections contribute to an introduction of an individual methodology for mechanical property assessment of cellulose fibers, and allows for a clear definition of an optimal process of alkalization dependent on the content of hemicellulose and lignin in vegetable fibers. The aim of this research was to investigate the influence of alkali treatment on the surface microstructure and tensile properties of coir and abaca fibers. These fibers were immersed into a 5% solution of NaOH at laboratory temperature for a time interval of 30 min, 1 h, 2 h, 3 h, 6 h, 12 h, 24 h, and 48 h, rinsed and dried. The fiber surface microstructures before and after the alkali treatment were evaluated by SEM (scanning electron microscopy). SEM analysis showed that the alkali treatment in the NaOH solution led to a gradual connective material removal from the fiber surface. The effect of the alkali is evident from the visible changes on the surface of the fibers.

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