Transesterification mechanism of soybean oil to biodiesel catalyzed by calcined sodium silicate

Effect of preparation conditions on structural and catalytic properties of lithium zirconate

“…Use of a solid base catalyst offers several process advantages, including the elimination of a quenching step (and associated contaminated water waste) to isolate the products and the opportunity to operate a continuous process [18]. Solid base catalysts including zeolites [19], alkali-metal and alkaline earth metal carbonates and oxides [20], lithium silicates [21], sodium silicates [22], transition metal oxides [23] and layered double hydroxides [24] have been investigated in transesterification reactions. Recently, we synthesized and applied magnesium silicate nanomaterials [25] as catalysts for biodiesel production.…”

Transesterification of Waste Cooking Oil to Biodiesel over Calcined Hydroxy Sodalite (HS) Catalyst: A preliminary investigation

“…The production of biodiesel was successful even though the FFA content exceeded the recommended 1% because of the use of hydroxy sodalite as a catalyst for trans-esterification. Since the structure of HS is made up of Si-O-Si, it could be speculated that it exhibits the same behavior as sodium metasilicate whereby hydrolysis reaction with sodium silicate and water resulted in the formation of NaOH and Si-O-H [4], thereby suppressing the formation of soap because of the decreased water content (less than 4%) [12].The tolerance of HS to water could be attributed partly to its porous structure. Furthermore, the unique structure of the catalyst could enhance sequential hydration to occur in three steps when there are high amounts of water present.…”

“…These raw materials are not entirely suitable, more especially in developing countries, due to the limited supply and high cost associated with their application, as well as competition with the food chain [3]. Therefore, low cost, non-edible oils such as Jatropha oil, animal fat and waste cooking oil have been suggested and tested as alternatives [4][5][6][7]. However, the main disadvantage of these non-edible types of feedstock is the high content of free fatty acid (FFA) within the oils, which poses problems in the production process.…”

“…In recent times, the use of heterogeneous catalysts has been proven to be very effective in converting high FFA feedstock directly to biodiesel, thereby by-passing the esterification stage [4,7,[10][11]. The most commonly used heterogeneous catalysts for the production of biodiesel are ion-exchange resins, inorganic-oxide solid acids and supported noble-metal oxides.…”

“…However, a dramatic decrease in the catalytic activity of these catalysts has been observed due to their absorption of water during biodiesel production [10].Besides the sharp reduction in the catalytic activity, the catalysts can form a slurry with the products by absorbing water and carbon dioxide, thereby increases the viscosity of the product mixture, making product separation very difficult [12]. In recent times, a few research efforts have been expended on the development of heterogeneous catalysts for biodiesel production [4,7,[12][13]. For biodiesel production from WCO, recent concerted research efforts have investigated the use of solid-base catalysts obtained from pyrolyzed rice husk [10] and silica sulfuric acid [14].…”