Biodiesel production methods

In this communication a study of the catalytic behavior of the immobilized Rhizomucor miehei lipase in the transesterification reaction to biodiesel production has been reported. The main drawbacks associated to the current biodiesel production by basic homogeneous catalysis could be overcome by using immobilized lipases. Immobilization by adsorption and entrapment have been used as methods to prepare the heterogeneous biocatalyst. Zeolites and related materials have been used as inorganic lipase supports. To promote the enzyme adsorption, the surface of the supports have been functionalized by synthesis procedures or by post-treatments. While, the enzyme entrapping procedure has been carried out by sol-gel method in order to obtain the biocatalyst protected by a mesoporous matrix and to reduce its leaching after several catalytic uses. 

A further example of process quality monitoring and reactor batch profiling using NIRS comes with oleo-chemical and biodiesel production. An established use of FT-NIR analysis (AOCS Method Cd le 01) is the determination of the key vegetable oil processing parameters - iodine value (IV) and percentage trans fat content (%Trans) (Figure 5.38). 

Figure 9 shows a schematic process of biodiesel production by the two-step supercritical methanol method. Several advantages have been attributed to the two-step reaction method. At temperature of 270°C, a common type of 316 stainless steel can fulfill the requirements of good corrosion resistance and cover the reaction condition (5). Energy requirements may be less because mild reaction conditions for hydrolysis and methyl esterification are employed, whereas high-temperature treatment causes operational and equipment problems with, in some cases, the formation of undesirable degradation products. In addition, a reaction temperature of 270°C is commonly used in industries, so such a reaction condition is applicable for commercial applications. 

Dembiras, A., Biodiesel production via non-catalytic SCF method and biodiesel fuel characteristics, Energy Corner. Manag., 47, 271-2282, 2006... 

Scott W., and Furman, N. H. (ed.). 1961. Scott s Standard Methods of Chemical Analysis (5th ed., vol. 1, pg. 604). Princeton, NJ D. Van Nostrand Company Inc. Shibasaki-Kitakawa, N., Honda, H., Kuribayashi, H., Toda, T., Fukumura, T., and Yonemoto, T. 2007. Biodiesel production using anionic ion-exchange resin as heterogeneous catalyst. Bioresour. Technol., 98(2), 416-421. 

TABLE 9.1. Comparison between commercial chemical-catalysis and lipase-catalysis methods for biodiesel production. 

The principles of sonochemistry can also be applied to disrupt different species of oil-bearing microalgae cells. Detailed experimental results are necessary to support the cost-effectiveness and industrial scale applicability of ultrasound for microbial lipid extraction, and subsequent biodiesel production in comparison to conventional methods (Mata et al., 2010). 

In this study, we have attempted to evaluate the efficacy of a technique for the production of the methyl ester of rapeseed oil via enzyme-catalyzed transesterifications using tert-butanol, a moderately polar organic solvent. We conducted experiments involving the alteration of several reaction conditions, including reaction temperature, methanol/oil molar ratio, enzyme amount, water content, and reaction time. The selected conditions for biodiesel production were as follows reaction temperature 40 °C, Novozym 435 5% (w/w), methanol/oil molar ratio 3 1, water content 1% (w/w), and 24h of reaction time. Under these reaction conditions, a conversion of approximately 76.1% was achieved. Further studies are currently underway to determine a method by which the cost of fatty acid methyl ester production might be lowered, via the development of enzyme-catalyzed methanolysis protocols involving a continuous bioprocess. 

Marchetti, J.M. V.U. Miguel A.F. Errazu. Possible methods for biodiesel production. Renew. Sustain. Energy Rev. 2007b, 11, 1300—1311. 

Biodiesel production is a complex process. Simply explaiited, oite method of producing the fuel is to firstly pass seeds or other raw materials through a mill to release fiieir oil (Stage 1). Subsequently, the product is transferred to a centrifuge, w hich removes seeds from the oil bv ... 

The purpose of this chapter is to introduce conventional methods in biodiesel production and their challenges, but the center of attention is on the novel technology used in biodiesel production, membrane reactors, in which both production and separation occur simultaneously. Membrane reactors have the ability to block the passage of unreacted TG to final biodiesel product. This phenomenon has the benefits of providing high-quality biodiesel fuel (Atadashi, Aroua, Abdul Aziz, 201 la). 

A precise, widespread and the best method for biodiesel production, is the reaction of oil or fats with an alcohol to produce glycerol (GLY) and esters. The reaction usually takes place in the presence of a catalyst to increase reaction rate and yield. The... 

In comparison with dilution, microemulsion, and pyrolysis, transesterification has attracted more attention. The reason probably is the fact that pyrolysis and microemulsion are costly methods with low-quality biodiesel production compared to the transesterification method (Taher, Al-Zuhair, Al-Marzouqi, Haik, Farid, 2011), and the quality of biodiesel produced in the transesterification is better (mainly due to its lower viscosity) (Ferella et al., 2010). 

Weak points of conventional methods in biodiesel production... 

Removal of residual TG and catalyst and separation of undesirable products such as free glycerin is another hamper in biodiesel production. Refining methods mostly deal with distillate water. Therefore, alkaline or acidic catalyst removal contributes to water consumption and causes the need for wastewater treatment. As a result, the cost of refining will increase. 

The challenges of conventional methods in biodiesel production and the importance of cost and energy saving have led to the apphcation of novel reactors to improve transesterification reaction and eliminate problems. 

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