Pore engineering and surface functionalization of biochars from sugar beet pulp

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Kül özelliklerinin zeolit 4A sentezi üzerindeki etkisinin incelenmesi.

There is lack of information about the relation between the candidate raw material fly ash and end product, Zeolite 4A.This study aims to fill the gap in the literature through controlled ash production experiments, characterization studies and Zeolite 4A synthesis. As a result of studies, the nucleation behaviour of the alkali fusion product obtained from fly ash was demonstrated and the most crystalline Zeolite 4A with cubic morphology were obtained from Seyitömer fly ash with alkali fusion product of Si/Al mol ratio 1,17 at the conditions, 47 °C, 12 hour aging and 90°C, 4 hour crystallization with the least sodalite impurity. It was observed that hematite and mullite content of fly ash caused differences in the alkali fusion product and Zeolite 4A. In addition, it has been observed that the hematite, mullite content and crystallinity of ash could be tuned by combustion parameters. From the Tunçbilek ash obtained from the drop tube furnace at 1000 °C, which is the poorest in mullite and hematite because of the conditions (high cooling rate and low combustion temperature), Zeolite 4A with 64,1 % crystallinity and cubic structure and minimum sodalite content was achieved under optimal synthesis conditions. Sodalite phase impurity content increased in parallel with hematite and mullite mineral content. In the synthesis product of Soma ash, katoite was obtained because of high level of calcium impurity. Finally, the ash from combustion experiments of the blend of sodium carbonate-coal-aluminum hydroxide, the synthesis of zeolite 4A was carried out under optimized conditions without the need for a fusion step and zeolite 4A was obtained with low crystallinity.Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Micro and Nanotechnology

UÇUCU KÜLDEN ZEOLİT ELDE EDİLMESİ: SENTEZ VE KARAKTERİZASYONU

Bu projenin temel amaçlarından biri, ülkemizde bol miktarda bulunan ve yerel enerji üretiminin en önemli kaynaklarından biri olan Türk linyitinden, kontrollü yanma deneyleri sonucunda elde edilecek olan uçucu külleri kullanarak, birçok uygulama alanı bulunan sentetik zeolitin üretilmesidir. Bu amaç doğrultusunda üretilmesi planlanan zeolit tipi, şu anda bile ülkemize dış kaynaklardan senede en az 50 bin ton ihraç edilen zeolit 4A üretimidir. Proje kapsamında, yurt dışından ve/veya bilinen kimyasal yollarla elde edilen zeolite 4A numuneleri elde edilecek ve uçucu külden elde edilen zeolitler, kimyasal yollarla elde edilen 4A’larla fiziksel ve kimyasal yapıları açısından kıyaslanacaktır. Bu proje kapsamında yine ilk defa yanma parametreleri (ısıtma hızı, yakma sıcaklığı gibi) kontrollü olarak değiştirilerek uçucu kül örnekleri üretilecek, üretilen uçucu küller karakterize edilecek ve bu yanma parametrelerinin zeolit sentezindeki rolü ve başarısı ilk defa ortaya konacaktır. . Böylece, kül karakteristiğinin zeolit sentezi üzerindeki etkilerinin daha iyi anlaşılabilmesi amacıyla, elde edilecek küller literatürdeki çalışmalardan farklı olarak, kontrollü yanma deneyleri sonucunda elde edilecektir. Maliyetin düşürülmesinin yanında, bahsi geçen uçucu kül ile zeolit sentezlenmesi konusunun başarıya ulaşılması durumunda, ülkemizde endüstriyel boyutta zeolit sentezi ve atik kaynakların anlamlı bir malzemeye dönüşümü ülkemizde ilk defa başarılmış olacaktır

Critical analysis of zeolite 4A synthesis through one-pot fusion hydrothermal treatment approach for class F fly ash

In this study, ‘‘One-pot fusion assisted hydrothermal synthesis’’ approach was employed to understand the nucleation and crystallization behaviour of the fusion product of Class F fly ash for zeolite 4A synthesis. Two sets of experiments were conducted by tailoring the control parameter of H2O/Na2O molar ratio (L/S) to investigate the nucleation and crystallization behaviour of zeolite 4A. The molar ratios of SiO2/Al2O3 and Na2O/SiO2 were tuned before alkali fusion by adding different amounts of Al(OH)3 to the fly ash along with the alkali agent, Na2CO3. Under the conditions of 12h aging at 47 °C and 7h crystallization at 90 °C, the sample with high L/S ratio (3.1 Na2O: 2.2 SiO2: 1.0 Al2O3: 79.2 H2O) yielded pure phase of Zeolite 4A with 94% relative crystallinity, while the sample with low L/S ratio (3.1 Na2O: 2.2 SiO2: 1.0 Al2O3: 42.2 H2O) resulted in the highest sodalite impurity. In general, the alkalinity level was observed to be the most dominant factor among all synthesis parameters. Nevertheless, low L/S ratio led to rapid crystallization in just 2.5h at 75 °C. Because of the dependency on the alkalinity level, the dissolution of low-carnegieite (LC) was determined as the decisive factor in the formation of zeolite 4A from the fusion product. The total time of hydrothermal treatment and aging temperature were the other main factors. The crystal growth of zeolite 4A was more sensitive to changes induced by crystallization time and temperature at high L/S ratio. Relative crystallinity of zeolite 4A varied in an expanded range in terms of crystallization time (36%–86%) and temperature (25%–73%) at high L/S ratio