Review of Recent Developments in Solid Acid, Base, and Enzyme Catalysts (Heterogeneous) for Biodiesel Production via Transesterification

Abstract

Development of new and effective solid catalysts (solid acid base to immobilized enzyme) is necessary for renewable and green energy production. The various choices of heterogeneous solid catalysis were reported recently, and the specific research outcomes of trans-esterification on heterogeneous catalysis are discussed in the present article. The studies on biodiesel production are mainly focused on the following aspects: (i) examining the appropriate oil source, (ii) establishing the adequate alcohol to oil molar ratio, and (iii) evaluating the available solid acid catalysts, solid base catalysts, and lipase immobilized enzyme catalysts. Although homogeneous catalysis are superior in terms of reaction rate compared to heterogeneous catalysis, the focus of research on development of solid catalysts for heterogeneous catalytic transesterification is directed from the point of easy process and possible adoption for large scale production. The scope of this presentation is to examine these aspects in detail and to provide a comprehensive outlook on the aspects mentioned.

Response Surface Methodology for Biodiesel Production Using Calcium Methoxide Catalyst Assisted with Tetrahydrofuran as Cosolvent

“…The errors values between the predicted and the observed results were less than 1% FAME conversion indicating that the regression model was satisfactory. 2 and without THF as Cosolvent. In the authors' previous work (Chumuang and Punsuvon, 2016) [18], the production of WCO biodiesel using Ca(OCH 3 ) 2 without THF as cosolvent was studied and the results of the optimum conditions were compared with THF as a cosolvent as shown in Table 6.…”

“…Although heterogeneous catalysts have many advantages [1], their disadvantages are also many such as a high oil-toalcohol molar ratio, high temperature, and a long reaction time [2]. The addition of a cosolvent such as tetrahydrofuran (THF) to the reaction medium is an alternative way to enhance the reaction rate, as well as increasing the solubility and mass transfer between the oil and methanol [3].…”

First Generation Biodiesel

“…Impregnation method prepared solid acid catalysts showed higher activities. However, leaching of sulfate species restricted the reusability of the catalyst, and on another hand, the use of solid acids still need high temperatures and high methanol-to-oil molar ratio(60:1) for a feasible process (Jothiramalingam & Wang, 2009). Zirconium oxide, titanium oxide and zinc oxide can all be used as solid acid catalyst in biodiesel production.…”

Utilization of Renewable and Waste Materials for Biodiesel Production as Catalyst

“…Enzymatic catalysts are instrumental in restricting soap formation and product refining process is easier to complete. However, the cost and longer reaction time restricts the use of enzymatic catalyst for commercial purposes [1][2][3][4][5][6][7][8][9][10][11][12].…”