Investigation Of Lauric Acid Conversion With The STA Incorporated Heterogeneous Catalysts In Liquid Phase Reaction

Abstract

In this study, firstly the synthesis of acidic catalysts was carried out by loading the active compound silicotungstic acid(STA) with dry (W/Si:10-50%) and wet (W/Si:10%) impregnation methods into MCM-41 support material. These synthesized catalysts were used in the production of mono-di and tri laurin. The amount of active substance in the synthesized catalysts was determined by the ratios of tungsten in STA and silicon in MCM-41 structure. Moreover, W/Si: 10% by weight of STA was applied to the support material after the calcination process was loaded by dry impregnation method. Brønsted acid (BA) and Lewis acid (LA) regions of synthesized catalysts were determined by DRIFT analysis. The catalytic activities of the catalysts were determined by a glycerollauric acid esterification reaction in a batch reactor. The effect of calcination and active compound ratio with reaction temperature on the lauric acid conversion and mono-di and tri laurin selectivity was investigated. Furthermore, the esterification reaction of glycerol with lauric acid was carried out under the same conditions in the presence of a commercial catalyst Amberlyst-21. The experimental results of the synthesized catalysts and Amberlyst-21catalyst were compared. The synthesized catalysts after comparison were observed that have high catalytic activity. Lauric acid conversion and monolaurin selectivity have been obtained with W/Si: 10% catalyst (dry impregnation method) 3/3/1 molar ratio at383K after 6 hours 95% and 88%, respectively. XRD analysis was conducted on calcineduncalcined MCM-41support material. Moreover, the structural properties of synthesized catalysts after the esterification reaction were determined by SEM-MAPPING analysis methods.

Synthesis and Characterization of Fe/SBA-15 Heterogeneous Catalysts for Methyl Acetate Production

“…Among the SiBSMs, SBA-15 (Hess, 2009;Cavalleri et al, 2009) and M41S family (Brahmkhatri & Patel, 2011;Sawant, et al, 2007;Liu et al, 2004;Kumar et al, 2006) are the most well-known. Impregnation (Brahmkhatri & Patel, 2011;Sawant, et al, 2007;Liu et al, 2004;Kumar et al, 2006), dry-wet impregnation (Şimşek &Mürtezaoğlu, 2019) and sol-gel (Yang, et al, 2005) methods are widely used in the synthesis of supported mesoporous materials and HeCs (solid catalysts). However, recently, direct HM has come to the forefront as an alternative synthesis method in studies where heteropoly acid catalysts (Fulvio et al, 2005) metals (Jimenez et al, 2010;Laugel et al, 2009) are used as active substances.…”

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

“…The major disadvantages of bulk HPAs derivatives are the low specific area (1-10 m 2 g -1 ), low thermal stability and the high solubility in polar media [23]. For this reason and in order to overcome these problems, different supports were employed to immobilize HPAs, for example activated carbon, zeolites, silica, zirconium, titanium, MCM-41, and polymers among others [24,25]. Different HPAs in heterogeneous form have been tested in biodiesel production such as cesium-doped heteropoly tungstate (HPW), HPW/ZrO2, HPW/γ-Al2O3 and HPW/SiO2 for the simultaneous esterification and transesterification of 10% oleic acid-soybean oil mixture [26]; core-shell nanostructured heteropoly acidfunctionalized zeolitic imidazolate frameworks-8 (ZIF-8) for rapeseed oil transesterification [18]; HPW/kaolinite, HPW/bentonite and HPW/montmorillonite for acetic acid esterification [27]; HPW/SiO2 and cesium-doped HPW for rapeseed oil transesterification [28]; H3PMo12O40/bentonite [29] for esterification of a waste from palm oil; H3PW12O40/KIT-6 for neem oil transesterification [30]; 12-tungstophosphoric HPA/ZrO2 [31], and H3PW12O40 and H3PMo12O40 supported on activated carbon fibers [32] for palmitic acid esterification; Ni0.5H3SiW/SiO2 [33], NiHSiW/UiO-66 [34] and Sn1.5PW12O40/Cu-BTC [35] for oleic acid esterification.…”

Reactive RED 120 Boyarmaddesinin Silika Esaslı Gözenekli Malzeme Üzerine Absorpsiyon Koşullarının İncelenmesi

“…XRD analiz sonuçlarına göre, sentezlenen silika bazlı gözenekli malzemelerin sentezinde hidrotermal yönteminin başarıyla uygulandığı gözlenmiştir. Yani literatüre uygun olarak temel Bragg piklerinin elde edildiği belirlenmiştir [2,3]. Çalışma kapsamında gerçekleştirilen karakterizasyon işlemleriyle kalsinasyon işlemi öncesi ve sonrası sentezlenen silika esaslı gözenekli malzemelerin fiziksel özelliklerindeki değişmeler incelenmiştir.…”

“…Bilim insanlarının kullanım amaçlarına yönelik hidrotermal yöntemle malzemelerin sentezi diğer bazı yöntemlerde olduğu gibi yüksek madde kullanımı olmadan gerçekleştirilmektedir. Örneğin: Simsek ve arkadaşları tarafından hidrotermal yöntemle silika esaslı katalizörlerin sentezi gerçekleştirilmiş ve düşük yükleme oranlarına bağlı olarak katalizörlerin yüksek termal kararlılığa ve katalitik aktiviteye sahip oldukları gözlenmiştir [2,3]. Tekstil üretiminin sonucu oluşan atık sular içerisindeki boyalar; alıcı ortamdaki suyu ve su içerisindeki yaşamı olumsuz etkiler.…”

“…Bu kapsamda ilk olarak, yüksek termal kararlılığa, yüksek yüzey alanına ve düzenli gözenek yapısına sahip silika esaslı malzemelerin hidrotermal yöntemle sentezleri gerçekleştirilmiştir. Daha sonra silika esaslı malzemelerin kalsinasyonları literatüre göre belirlenen 500-600°C [2,3] sıcaklıkları arasında yapılmıştır. Sentezlenen ve kalsinasyon işlemleri tamamlanan silika esaslı malzemelerin yüzey yükü, gözenek dağılımı gibi bazı fiziksel özellikleri BET, ZETA, XRD ve SEM vb.…”