scholarly journals Offretite Zeolite Single Crystals Synthesized by Amphiphile-Templating Approach

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2238
Author(s):  
Eng-Poh Ng ◽  
Nur Hidayahni Ahmad ◽  
Fitri Khoerunnisa ◽  
Svetlana Mintova ◽  
Tau Chuan Ling ◽  
...  

Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates.

Author(s):  
Yan Cui ◽  
Wenqiao Wayne Yuan ◽  
Zhijian Pei

Continuous use of petroleum derived fuels is widely recognized as unsustainable due to depleting supplies and the accumulation of greenhouse gases in the environment. Renewable, carbon neutral transport fuels are needed for environmental and economic sustainabilities. Algae have been demonstrated to be one of the most promising sources for biofuel production. However, large-scale algae production and harvesting for energy manufacturing are too costly using existing methods. The approach of growing algae on solid carriers is innovative and can potentially lead to cost-effective manufacturing of algae biofuels. As cells approach to the solid surface, many factors come in to influence microbial attachment such as the surface wettability, free energy, polarity, roughness and topography. Surface wettability plays an important role in the initial cell attachment. For further contact, surface free energy and polarity are more directly related to cell-substratum attachment strength. Surface roughness and texture are species-specific parameters and have been applied widely in attachment studies.


Author(s):  
Sadananda Muduli ◽  
Subir K. Pati ◽  
Smrutirekha Swain ◽  
Surendra K. Martha

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6025
Author(s):  
Marcin Dębowski ◽  
Magda Dudek ◽  
Marcin Zieliński ◽  
Anna Nowicka ◽  
Joanna Kazimierowicz

Hydrogen is an environmentally friendly biofuel which, if widely used, could reduce atmospheric carbon dioxide emissions. The main barrier to the widespread use of hydrogen for power generation is the lack of technologically feasible and—more importantly—cost-effective methods of production and storage. So far, hydrogen has been produced using thermochemical methods (such as gasification, pyrolysis or water electrolysis) and biological methods (most of which involve anaerobic digestion and photofermentation), with conventional fuels, waste or dedicated crop biomass used as a feedstock. Microalgae possess very high photosynthetic efficiency, can rapidly build biomass, and possess other beneficial properties, which is why they are considered to be one of the strongest contenders among biohydrogen production technologies. This review gives an account of present knowledge on microalgal hydrogen production and compares it with the other available biofuel production technologies.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5300
Author(s):  
Mamata Singhvi ◽  
Beom Soo Kim

The conversion of lignocellulosic biomass (LB) to sugar is an intricate process which is the costliest part of the biomass conversion process. Even though acid/enzyme catalysts are usually being used for LB hydrolysis, enzyme immobilization has been recognized as a potential strategy nowadays. The use of nanobiocatalysts increases hydrolytic efficiency and enzyme stability. Furthermore, biocatalyst/enzyme immobilization on magnetic nanoparticles enables easy recovery and reuse of enzymes. Hence, the exploitation of nanobiocatalysts for LB to biofuel conversion will aid in developing a lucrative and sustainable approach. With this perspective, the effects of nanobiocatalysts on LB to biofuel production were reviewed here. Several traits, such as switching the chemical processes using nanomaterials, enzyme immobilization on nanoparticles for higher reaction rates, recycling ability and toxicity effects on microbial cells, were highlighted in this review. Current developments and viability of nanobiocatalysts as a promising option for enhanced LB conversion into the biofuel process were also emphasized. Mostly, this would help in emerging eco-friendly, proficient, and cost-effective biofuel technology.


2018 ◽  
Vol 6 (26) ◽  
pp. 12244-12249 ◽  
Author(s):  
Weifeng Chu ◽  
Xiujie Li ◽  
Shenglin Liu ◽  
Xiangxue Zhu ◽  
Sujuan Xie ◽  
...  

MCM-49 zeolite with a three-dimensional MWW framework was directly synthesized using low-toxicity and cost-effective cyclohexylamine (CHA) as an organic structure-directing agent under hydrothermal conditions.


GCB Bioenergy ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 914-929 ◽  
Author(s):  
Diego F. Correa ◽  
Hawthorne L. Beyer ◽  
Hugh P. Possingham ◽  
Skye R. Thomas‐Hall ◽  
Peer M. Schenk

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 220 ◽  
Author(s):  
Neha Srivastava ◽  
Rishabh Rathour ◽  
Sonam Jha ◽  
Karan Pandey ◽  
Manish Srivastava ◽  
...  

The biomass to biofuels production process is green, sustainable, and an advanced technique to resolve the current environmental issues generated from fossil fuels. The production of biofuels from biomass is an enzyme mediated process, wherein β-glucosidase (BGL) enzymes play a key role in biomass hydrolysis by producing monomeric sugars from cellulose-based oligosaccharides. However, the production and availability of these enzymes realize their major role to increase the overall production cost of biomass to biofuels production technology. Therefore, the present review is focused on evaluating the production and efficiency of β-glucosidase enzymes in the bioconversion of cellulosic biomass for biofuel production at an industrial scale, providing its mechanism and classification. The application of BGL enzymes in the biomass conversion process has been discussed along with the recent developments and existing issues. Moreover, the production and development of microbial BGL enzymes have been explained in detail, along with the recent advancements made in the field. Finally, current hurdles and future suggestions have been provided for the future developments. This review is likely to set a benchmark in the area of cost effective BGL enzyme production, specifically in the biorefinery area.


2014 ◽  
Vol 918 ◽  
pp. 12-16 ◽  
Author(s):  
Bin Sun ◽  
Xiu Ling Xu ◽  
Guo Wei Zhou

TiO2nanorods were successfully fabricated via hydrothermal method using cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. The synthesized samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). The study showed that as-prepared samples were the mixed crystalline phase of rutile and brookite. The weight fraction of rutile and brookite in the mixed-phase were accurately tuned by changing the concentration of CTAB. The morphology of prepared samples was TiO2nanorods with the diameter of 2530 nm and the length of 80150 nm. The samples for degradation of papermaking wastewater under ultraviolet light irradiation showed better photocatalytic activity than the commercial Degussa P25. HRT-3 prepared from CTAB: TBT molar ratio of 0.48 exhibited the highest photocatalytic activity, achieving 47.2% CODcrremoval rate and 89.5% chroma removal rate under irradiation 12 h.


2017 ◽  
Vol 898 ◽  
pp. 1916-1922
Author(s):  
Tie Ming Zhang ◽  
De Yong Li ◽  
Wen Liu

Fe-SBA-15 materials with different Fe content have been prepared using tetraethyl orthosilicate (TEOS) and iron nitrate (Fe (NO3)3·H2O as precursors and Pluronic P123 as structure directing agent through evaporation-induced self-assembly (EISA) method. The materials were characterized by nitrogen sorption, powder X-ray diffraction and TEM. All the Fe-SBA-15 samples appeared ordered 2D hexagonal mesostructure. The BET surface area and pore diameter were about 500 m2/g and 4 nm respectively. In the reaction of phenol hydroxylation to dihydroxybenzenes, the Fe-SBA-15 materials showed good catalytic activity, giving 20.2% of phenol conversion, 58.2% of selectivity for o-dihydroxy benzene and 41.8% of selectivity for p-dihydroxy benzene. After five cycles, the product yield was 25.2%, while selectivities of o-dihydroxy benzene and p-dihydroxy benzene were 58.2% and 41.8%, respectively. All these findings indicated the potential of Fe-SBA-15-10 could be used as a cost-effective, environment-friendly catalyst.


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