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•Zeolites included in the nanofibers increased the adsorption capacity of model VOC.•Silicalite type of zeolite adsorbed 60 % higher amount of model VOC.•Up-scaling of the process ...with a 150 fold increase of formed CA/UHSZ nanofibers.•Diffusion of ammonia vapours is not influenced by the structure of the material.
The optimized preparation of novel electrospun nanofibrous composites from cellulose acetate (CA) and ultra-high silica zeolites (UHSZ) are reported as a promising material for the adsorption of Volatile Organic Compound (VOCs). Two types of UHSZs, i.e. silicalite and USY were prepared by hydrothermal crystallization while the fabrication of composites was performed using single needle and needle-less electrospinning systems, demonstrating the scalability of the composite fibres’ manufactured. Herein, factors such as properties of spinning solutions and electrospinning process parameters were studied, as well as interactions between the CA and UHSZs. In addition, Quartz Crystal Microbalance - Dissipation technique (QCM-D) was employed with an aim to study the adsorption behaviour of newly developed composites using ammonia as a model pollutant. The QCM-D data revealed that the presence of UHSZs in the CA materials increased adsorption capacity, designating CA/UHSZ composites as potential materials suitable for a large-scale removal of VOCs from polluted air.
This work concerns freeze-dry processing of CNF aerogels, including aluminum hydroxide trihidrate (Alolt) particles and Sodium silicate, as active and passive flame retardants, respectively. ...Alkalinity of Sodium silicate promotes stability, dissociation and co-precipitation of Al(OH)
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component onto CNFs. The (auto)fluorescence-enabled confocal microscopy enabled visualization of anisotropic microstructure with open and closed-cell segments, depicting the Alolt as single and aggregated particles. Low thermal conduction (~ 0.045 W/mK) was estimated, irrespective of composition, while Alolt was found to reduce (by 30%) the aerogel moisture content. Sodium silicate promotes char formation as passive action, reducing the evolution of gaseous species, while burning test shows complete flame retardation through active endothermic reaction assigned to Alolt. Additive combinations did not amplify, nor diminish, the flame retardant effect of particular component, yet affected positively the elastic modulus. Considering simple “green” processing, low additive load, and high insulation and flame retardant efficiency, these aerogels hold promise as thermal insulation materials.
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A new environmental friendly technology was developed for the preparation of highly crystalline binder-free zeolite ZSM-5 granules. It comprises a preparation of amorphous aluminosilicate granules by ...using inexpensive industrial reactants like sodium water glass and sodium aluminate without the use of organic structure directing agents. Dried aluminosilicate gel was compacted in granules by using sodium water glass as a “pseudo-binder”. Zeolite ZSM-5 granules were prepared by hydrothermal crystallization at 180 °C after 24 h by using lifted set-up reactor in 0.01 M NaOH comprising 10 wt% of amorphous aluminosilicate granules. The influence of crystallization temperature and time, SiO2/Al2O3 molar ratio of reactants and relationship between the amount of amorphous aluminosilicate granules and NaOH medium during hydrothermal treatment on the crystallization process of granulated ZSM-5 product were monitored and characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscope, and N2 physisorption technique. The presented procedure enabled more than doubled increase of the synthesis product yield, which positively impacts the economy and ecology of the production process.
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•A new technology for the preparation of binder-free ZSM-5 granules was developed.•Low-cost industrial reactants like sodium water glass and sodium aluminate were used.•Sodium water glass acted as a reactant, a wetting agent and a “pseudo-binder”.•Hydrothermal crystallization of amorphous aluminosilicate granules in NaOH medium.•Lifted set-up reactor was developed and the product yield was increased.
The aim of this research was to apply three different types of zeolites and the combination thereof in the form of a very fine powder, together with different chemicals and additives on polyamide ...knitted fabric according to an industrially acceptable exhaustion procedure in order to study changes in the morphology, optical properties and wettability of surfaces. Zeolites were analysed using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and gas physiosorption. Additionally, the morphology of zeolite-coated surfaces was examined closely using SEM, while changes in molecular-chemical level were examined by means of IR spectroscopy. Optical properties were studied using CIE colour measurement and diffuse refl ectance profile determination, while the hydrophilic/hydrophobic character was examined using goniometry. The obtained results show the suitability of the employed exhaustion procedure, depending on the type of zeolite and the composition of the treatment bath. The results also provided evidence of the enhanced wettability of PA fabrics using 4A and 13X zeolites in combination with selected additives.
Ex situ catalytic biomass pyrolysis was investigated at both laboratory and bench scale by using a zeolite ZSM‐5‐based catalyst for selectively upgrading the bio‐oil vapors. The catalyst consisted of ...nanocrystalline ZSM‐5, modified by incorporation of ZrO2 and agglomerated with attapulgite (ZrO2/n‐ZSM‐5‐ATP). Characterization of this material by means of different techniques, including CO2 and NH3 temperature‐programmed desorption (TPD), NMR spectroscopy, UV/Vis microspectroscopy, and fluorescence microscopy, showed that it possessed the right combination of accessibility and acid–base properties for promoting the conversion of the bulky molecules formed by lignocellulose pyrolysis and their subsequent deoxygenation to upgraded liquid organic fractions (bio‐oil). The results obtained at the laboratory scale by varying the catalyst‐to‐biomass ratio (C/B) indicated that the ZrO2/n‐ZSM‐5‐ATP catalyst was more efficient for bio‐oil deoxygenation than the parent zeolite n‐ZSM‐5, producing upgraded bio‐oils with better combinations of mass and energy yields with respect to the oxygen content. The excellent performance of the ZrO2/n‐ZSM‐5‐ATP system was confirmed by working with a continuous bench‐scale plant. The scale‐up of the process, even with different raw biomasses as the feedstock, reaction conditions, and operation modes, was in line with the laboratory‐scale results, leading to deoxygenation degrees of approximately 60 % with energy yields of approximately 70 % with respect to those of the thermal bio‐oil.
Upgrading bio‐oil: The performance of a nanocrystalline ZSM‐5‐based technical catalyst, modified by the incorporation of ZrO2 and agglomerated with attapulgite, is investigated for ex situ catalytic biomass pyrolysis. This catalyst possesses the right combination of accessibility and acid–base properties, leading to superior and more selective deoxygenation degrees in the bio‐oil product than the parent zeolite in a laboratory setup.
The emerging industrialization of cellulosic bioethanol will create large amounts of lignin-rich residues, so called hydrolysis-lignin, which may be used as a raw material for further fuel ...production. In this study, fermentable sugars were removed from hardwood and softwood substrates by combining steam explosion and enzymatic saccharification with a cellulose hydrolysis yield of 90.1% and 41.5%, respectively. The remaining lignin-residues were further processed using intermediate pyrolysis to produce bio-oils, gas and char. The pyrolysis of hydrolysis-residues was compared with the pyrolysis of the original hardwood and softwood substrates. Overall, the lignin-enriched residues yielded up to 30 wt% of bio-oils. By applying low cost ZSM-5 vapour cracking catalysts, produced by template-free methods, the content of monophenolics in this fraction could be increased to more than 80 wt%. Thus, this study shows that by using enzyme technology, lignin and carbohydrates can be separated and a liquid sugar stream generated. This wood-based sugar stream can then be converted by fermentation or chemical methods to fuels and chemicals. The remaining lignin-rich residue is a valuable source for bio-based aromatics. This process of separate conversion of sugars and lignin further results in an improved overall product yield compared to the direct pyrolysis of the original wood biomass. Additionally, the pyrolysis of lignin-residues produces a simpler oil of higher quality than the pyrolysis of wood. The process of thermochemically converting lignin-rich hydrolysis residues is a simple and viable option for existing bioethanol plants to improve their process economics and diversify the product portfolio.
This study shows, by a combination of enzymatic saccharification and pyrolysis, how integrated biochemical and thermochemical processes can be used to valorize woody biomass.
Ex situ catalytic biomass pyrolysis was investigated at both laboratory and bench scale by using a zeolite ZSM-5-based catalyst for selectively upgrading the bio-oil vapors. The catalyst consisted of ...nanocrystalline ZSM-5, modified by incorporation of ZrO
and agglomerated with attapulgite (ZrO
/n-ZSM-5-ATP). Characterization of this material by means of different techniques, including CO
and NH
temperature-programmed desorption (TPD), NMR spectroscopy, UV/Vis microspectroscopy, and fluorescence microscopy, showed that it possessed the right combination of accessibility and acid-base properties for promoting the conversion of the bulky molecules formed by lignocellulose pyrolysis and their subsequent deoxygenation to upgraded liquid organic fractions (bio-oil). The results obtained at the laboratory scale by varying the catalyst-to-biomass ratio (C/B) indicated that the ZrO
/n-ZSM-5-ATP catalyst was more efficient for bio-oil deoxygenation than the parent zeolite n-ZSM-5, producing upgraded bio-oils with better combinations of mass and energy yields with respect to the oxygen content. The excellent performance of the ZrO
/n-ZSM-5-ATP system was confirmed by working with a continuous bench-scale plant. The scale-up of the process, even with different raw biomasses as the feedstock, reaction conditions, and operation modes, was in line with the laboratory-scale results, leading to deoxygenation degrees of approximately 60 % with energy yields of approximately 70 % with respect to those of the thermal bio-oil.
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