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Microwave Mediated Biodiesel Production
Published in Veera Gnaneswar Gude, Microwave-Mediated Biofuel Production, 2017
Potassium hydroxide (KOH) and sodium hydroxide (NaOH) flakes are the most commonly used alkaline catalysts in the biodiesel industry because they are inexpensive, easy to handle in transportation and storage, and preferred by small producers. Alkyl oxide solutions of sodium methoxide or potassium methoxide in methanol, which are now commercially available, are the preferred catalysts for large continuous-flow production processes. However, both NaOH and KOH catalysts make separation and purification a difficult process due to their high solubility in the both biodiesel and glycerin (Gude et al. 2013). Biodiesel with the best properties was obtained using sodium hydroxide as catalyst in many studies. On the other hand, many other studies achieved best results using potassium hydroxide (Refaat et al. 2008a). Refaat used 500 mL reactor at a reaction temperature of 65°C with a microwave power of 500 W controlled by a microprocessor. A methanol/oil molar ratio of 6:1 was employed, and potassium hydroxide (1%) was used as a catalyst. Barium hydroxide was also used as a homogeneous catalyst. The range of homogeneous catalysts applied was between 0.1 and 5% (Table 5). Slightly higher concentrations of KOH are required compared to NaOH catalyst due to its higher molecular weight. For feedstock containing high free fatty acid content such as animal fats and used vegetable oils, KOH proved to be a better performer (Brunschwig et al. 2012). Transesterification reaction depends on the type of oil and catalyst applied and the effects of catalysts vary with types of oils.
Inorganic, Coordination and Organometallic Compounds
Published in Suresh C. Ameta, Rakshit Ameta, Garima Ameta, Sonochemistry, 2018
Kiran Meghwal, Sharoni Gupta, Chetna Gomber
Activated barium hydroxide is used as a catalyst as it is nontoxic, easy to handle, low cost, and has a high catalytic activity (Pinto et al., 2000). Activated barium hydroxide has been used as a catalyst for the synthesis of 1,5-diarylpenta-2,4-dien-1-ones under ultrasound exposure (Xin et al., 2009). This methodology offers several advantages over other conventional methods with simple procedure such as excellent yields, shorter reaction times, and milder conditions. 1,5-Diarylpenta-2,4-dien-1-ones are important intermediates and raw materials widely used as precursors to different drugs, nonlinear optical materials, and biological activities.
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
Barium hydroxide is available as colorless or white crystals. It is odorless and soluble in water. It is stable under ordinary conditions of use and storage. It is incompatible with acids, oxidizers, and chlorinated rubber. Barium hydroxide is corrosive to metals such as zinc. It is very alkaline and rapidly absorbs carbon dioxide from air and becomes completely insoluble in water. Barium hydroxide is used in analytical chemistry for the titration of weak acids and is used in organic synthesis as a strong base. Barium hydroxide decomposes to barium oxide when heated to 800°C.
Ultrasound supported synthesis of waste mangifera indica linn biodiesel: an optimization using whale algorithm
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
S Arumugam, Chengareddy Peddamangari Venkatesulu Reddy, Tamilarasan Arulvalavan, Sriram Gopalasamy
Dutra et al. (Dutra et al. 2018) and Perea-Moreno et al. (Perea-Moreno et al. 2018) discussed the physicochemical properties of discarded mango seed kernel oil and reported that the feedstock is found suitable for biodiesel production in complying with European-EN14214 standard and prospective for minimizing Carbon-dioxide emissions. Lazzari et al. (Lazzari. et al. 2016) demonstrated the synthesis of mango seed waste biofuel by pyrolysis method and concluded that the maximum yield of only 28% was obtained in a fixed-bed reactor at 450°C. Velmurugan and Sathiyagnanam (Velmurugan and Sathiyagnanam 2015) experimented the effect of Di-ethyl amine, Pyridoxine hydrochloride and Tertbutyl hydroquinone antioxidants on engine efficiency and toxic emissions of compression ignition engine fueled by mango seed methyl ester. They inferred that the mixtures of antioxidants and WMS biodiesel reduced the oxides of nitrogen significantly. Prasanthkumar et al. (Prasanth Kumar et al. 2019) studied the application of WMS biodiesel in a stationary diesel engine. However, in all the studies reported above, the WMS biodiesel formulation was undertaken by using homogeneous base catalyzed traditional transesterification or pyrolysis method. The traditional transesterification and pyrolysis method involve extended reaction time, reaction temperature and excess catalyst consumption with overall reduced yield percentage of WMS biodiesel. Additionally, the use of homogeneous catalyst involves deactivation and estrangement from reaction mixtures. This could be overwhelmed by the use of heterogeneous catalysts (Barrios et al. 1988). In this row, Mazzocchia et al. (Mazzocchia et al. 2004) reported the higher activity of heterogeneous catalyst, Ba(OH)2.8H2O for transesterification process than α and β-Barium hydroxide which was prepared by heating the monohydrate at 300 and 200°C respectively.