Hydrothermal synthesis and characterization of kalsilite by using a kaolinitic rock from Sardinia, Italy, and its application in the production of biodiesel

2018 ◽  
Vol 82 (4) ◽  
pp. 961-973 ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Nicola d'Alessandro ◽  
Lucia Tonucci

ABSTRACTThe present work deals with the synthesis of kalsilite using material from a kaolinitic rock outcrop in Romana, Sassary Province, Sardinia, Italy.The hydrothermal synthesis method required the dissolution of kaolin and Al(OH)3 in a KOH solution at a temperature of 190°C and 1.013 bar. Crystallization of kalsilite was confirmed at 12 h in association with kaliophilite H2 as a metastable phase.The products of synthesis were fully characterized by powder X-ray diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, infrared spectroscopy and 29Si nuclear magnetic resonance. The amorphous phase in the synthesis powders was estimated with quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. Cell parameters and density were also calculated for the kalsilite. A potential application of kalsilite was investigated as a heterogeneous catalyst for biodiesel synthesis from sunflower oil used for frying.

2020 ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio

Abstract This work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 ° and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods.The results make the experimental protocol very promising for an industrial transfer.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio

AbstractThis work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The results make the experimental protocol very promising for an industrial transfer.


2020 ◽  
Vol 16 ◽  
Author(s):  
Diogo L. R. Novo ◽  
Priscila T. Scaglioni ◽  
Rodrigo M. Pereira ◽  
Filipe S. Rondan ◽  
Gilberto S. Coelho Junior ◽  
...  

Background: Conventional analytical methods for phosphorus and sulfur determination in several matrices present normally analytical challenges regarding inaccuracy, detectability and waste generation. Objective: The main objective is proposing a green and feasible analytical method for phosphorus and sulfur determination in animal feed. Methods: Synergic effect between microwave and ultraviolet radiations during sample preparation was evaluated for the first time for the animal feed digestion associated with further phosphorus and sulfur determination by ion chromatography with conductivity detection. Dissolved carbon and residual acidity in final digests were used for the proposed method assessment. Phosphorus and sulfur values were compared with those obtained using conventional microwave-assisted wet digestion in closed vessels associated with inductively coupled plasma optical emission spectrometry and with those obtained using Association of Official Analytical Chemists International official method. Recovery tests and certified reference material analysis were performed. Animal feeds were analyzed using the proposed method. Results: Sample masses of 500 mg were efficiently digested using only 2 mol L -1 HNO3. The results obtained by the proposed method was not differing significantly (p > 0.05) from those obtained by the conventional and official methods. Suitable recoveries (from 94 to 99%), agreement with certified values (101 and 104%) and relative standard deviations (< 8%) were achieved. Phosphorus and sulfur content in commercial products varied in a wide range (P: 5,873 to 28,387 mg kg-1 and S: 2,165 to 4,501 mg kg-1 ). Conclusion: The proposed method is a green, safe, accurate, precise and sensitive alternative for animal feed quality control.


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