No abstract

No abstract

Biodiesel synthesis reaction routes from palm oil using plasma electro-catalysis process over Dielectric-Barrier Discharge (DBD) plasma reactor were studied. The study was focused on finding possible reaction mechanism route during plasma electro-catalysis process. The prediction was performed based on the changes of Gas Chromatography Mass Spectrometer (GC-MS) and Fourier Transform Infra Red (FT-IR) analyses to the biodiesel products with respect to time length of plasma treatment. It was found that main reaction mechanism occurred in the plasma electro-catalysis system was non-thermal pyrolysis rather than transesterification. The main reactions within the plasma treatment were due to collision between high energetic electrons (supplied from high voltage power supply through high voltage electrode) and the reaction mixtures. The high energetic electrons affected the electrons pair of covalent bonding to be excited or dissociated even ionized at higher energy. Therefore, this plasma electro-catalysis system was promising for biodiesel synthesis from vegetable oils due to only very short time reaction was needed, even no need a catalyst, no soap formation, and no glycerol by-product. This system could produce fatty acid methyl ester yield of 75.65% at 120 seconds and other possible chemicals, such as alkynes, alkanes, esters, carboxylic acid, and aldehydes. However, during the plasma process, the reaction mechanisms were still difficult to be controlled due the action of available high energetic electrons. The advanced studies on how to control the reaction mechanism selectively in the plasma electro-catalysis will be published elsewhere.

Catalyst waste from the residue fluid catalytic cracking (RFCC) plant process can still be utilized to catalyze the catalytic cracking of palm oil to fuels. However, we should regenerate the active sites of the catalyst waste. This paper focuses on enhancement of Brønsted and Lewis acid sites on the spent RFCC catalyst waste through various acid treatments in order to regenerate its catalyst active sites. In order to regenerate the Brønsted and the Lewis acid sites as active sites in the palm oil catalytic cracking, the spent RFCC catalyst was treated by citric acid, sulfuric acid, and mixture of both acids. The catalysts were characterized by X-ray fluorescence, X-ray diffraction, Brunauer–Emmett–Teller-Barrett–Joyner–Halenda, and pyridine-FTIR analysis. The modified catalyst performance was tested over a fixed bed reactor for the catalytic cracking process of palm oil to liquid fuels. It was found that the acid treatment on the spent RFCC catalyst can increase surface area, pore volume, and Brønsted to Lewis acid site ratio of catalysts. The Brønsted acid sites of the spent RFCC catalyst strongly increase by the treatment using sulfuric acid, which is because of the proton transfer from acid to catalyst and because of the formation of sulfate groups (HOSO3−) in the catalysts. It was found that the Brønsted acid site leads to the formation of long-chain hydrocarbon, while the Lewis acid site pronounces the formation of short-chain hydrocarbon and coke. Moreover, the total acidity and the Lewis acid site amount on the catalyst have roles in the formation of hydrocarbon fraction in the liquid product.

Biodiesel is an alternative biofuel that can replace diesel oil without requiring modifications to the engine and advantageously produces cleaner emissions. Biodiesel can be produced through transesterification process between oil or fat and alcohol to form esters and glycerol. The transesterification can be carried out with or without a catalyst. The catalyzed production of biodiesel can be performed by using homogeneous, heterogeneous and enzyme. Meanwhile, non-catalytic transesterification with supercritical alcohol provides a new way of producing biodiesel. Microwave and ultrasound assisted transesterification significantly can reduce reaction time as well as improve product yields. Another process, a plasma technology is promising for biodiesel synthesis from vegetable oils due to very short reaction time, no soap formation and no glycerol as a by-product. This paper reviews briefly the technologies on transesterification reaction for biodiesel production using homogeneous, heterogeneous, and enzyme catalysts, as well as advanced methods (supercritical, microwave, ultrasonic, and plasma technology). Advantages and disadvantages of each method were described comprehensively. Copyright © 2016 BCREC GROUP. All rights reserved <br /> <em>Received: 17th May 2016; Revised: 20th September 2016; Accepted: 20th September 2016</em> <br /> <strong>How to Cite:</strong> Buchori, L., Istadi, I., Purwanto, P. (2016). Advanced Chemical Reactor Technologies for Biodiesel Production from Vegetable Oils - A Review. <em>Bulletin of Chemical Reaction Engineering & Catalysis</em>, 11 (3): 406-430 (doi:10.9767/bcrec.11.3.490.406-430) <br /> <strong>Permalink/DOI:</strong> <a href="http://doi.org/10.9767/bcrec.11.3.490.406-430" /> http://doi.org/10.9767/bcrec.11.3.490.406-430</a>