Natural Phosphate Supported Titania as a Novel Solid Acid Catalyst for Oleic Acid Esterification

Abstract

In the present study, a novel solid acid catalyst based on titanium dioxide (2.5–10 wt %) supported on natural phosphate (TiO2/NP) was prepared by a sol–gel process, and 10 wt % loaded catalyst was characterized by several physicochemical techniques. The performances of the synthesized catalyst were investigated in esterification of oleic acid with methanol. The catalytic performance was screened under different reaction conditions, namely, loading amount of TiO2, calcination temperature, molar ratio of methanol to oleic acid, reaction temperature, and amount of catalyst. Under optimal conditions, the catalyst loaded with 10 wt % TiO2 and calcined at 800 °C showed the highest oleic acid conversion of 87%. The catalyst showed a good stability under high reaction temperature and can be reused without severe loss of activity. As a versatile application, the TiO2(10)/NP catalyst exhibits a good ability for the esterification of free fatty acids in a highly acidic feedstock.

Biodiesel production from rapeseed oil and low free fatty acid waste cooking oil using a cesium modified natural phosphate catalyst

“…2. The XRD pattern of treated NP shows typical diffractions peaks of carbonate-uoroapatite (JCPDS card 01-073-9695) 33 as the main mineralogical phase in combination with two other secondary phases attributed to calcite (JCPDS card 96-900-1298) and quartz (JCPDS card 96-901-5023). We note that no other phases such as tricalcium phosphate (b-Ca 3 (PO 4 ) 2 ) or dolomite are observed in the XRD spectrum of NP.…”

“…Natural phosphate was pretreated using the procedure reported in a previous work. 33 The pretreated natural phosphate was calcined at 700 C for 4 h to eliminate moisture from its surface, and nally grounded (63-125 mm) before being used. The chemical composition of treated NP was determined as: CaO (50.47%), P 2 O 5 (30.74%), CO 2 (6.64%), SiO 2 (5.91%), F (3.6%), Al 2 O 3 (0.43%), SO 3 (1.83%), Fe 2 O 3 (0.2%) and other negligible elements.…”

Biodiesel from batch and continuous oleic acid esterification using zeolite catalysts

“…Examples include the use of a water adsorption apparatus, which increases the reaction yield via water removal to enhance the oleic acid:methanol equilibrium towards the ester [1], and the application of ultrasound during reaction [2]. Heterogeneously catalysed oleic acid:methanol reactions have been reported over the following catalysts; Amberlyst-46 [3]; sulfonated carbon [4]; acid ion-exchange polymer resin [5]; titanium dioxide supported on natural phosphate [6]; 12-tungstophosphoric acid supported on mesoporous silica [7]; and solid acid catalysts prepared from Amazon flint kaolin [8]. Ethyl esters have superior properties to their methyl counterparts, evidenced by higher oil solubility, calorific value, cetane number, cold filtering plugging point, cloud point and pour point.…”

Efficient one-pot, three-component procedure to prepare new α-aminophosphonate and phosphonic acid acyclic nucleosides

“…Among supports reported in the literature, natural phosphate was found [31] to be an efficient Lewis acid to catalyse the synthesis of αaminophosphonates in one-pot due to its ability to tolerate the water generated during the course of the reaction. Moreover, it was used widely as support because of its ionic substitution ability, structural stability, and high adsorption capacity, making it an attractive cost-effective catalyst for several chemical transformations [35][36][37].…”