Biodiesel methyl ester

Fig. 10.1 Transesterification of vegetable oils to produce biodiesel (methyl esters).

The standard analytical methods for biodiesel methyl ester are time-consuming and often require multiple physical analyzes per sample. NIRS allows for the simple set up of calibrations for multiple important biodiesel qualities such as mono-, di- and triglycerides, residual methanol, glycerol and moisture as well as... 

Biodiesel methyl esters blend quite easily into petroleum based conventional diesel fuel. Biodiesel esters typically have better lubricity properties and higher cetane number ratings than conventional diesel fuel, but have poorer water demulsibility and color stability properties. At sub-zero temperatures, the handling characteristics of biodiesel becomes more difficult to control than conventional diesel fuel. 

Index Entries Supercritical methanol biodiesel methyl esters transesterification methyl esterification. 

Scheme 7.1. Base-catalyzed transesterification of triacylglycerols (TAGs) to produce fatty acid esters (biodiesel). Methyl esters (shown) are the most common but others, such as ethyl esters, can be produced depending on the alcohol used in the reaction. Ri, R2 and R3 represent unique fatty acids attached to the glycerol backbone of the TAG.

Li et al. (2007) reported the use of dry biomass, Rhizopus oryzae (R. oryzae) IF04697, whole cell-catalyzed methanolysis of soybean oil for biodiesel (methyl ester) in rm-butanol system. Changing one separate factor at a time (COST), live-level-four-factor Central Composite Design (CCD) were used to evaluate the effects of synthesis conditions, such as tert-butanol to oil volume ratio, methanol to oil molar ratio, water content, and dry biomass amount. Biodiesel yields of 72% were obtained under the optimal conditions using the proposed model for prediction. 

Southern Europe and France use relatively little canola oil. Instead, olive, sunflower and peanut oils predominate. In the case of France, this is somewhat surprising, since this country is a large producer of canola seeds. France uses large amounts of canola oil for biodiesel methyl ester production. 

Ahmad, S. P. Siwayanan ZA.. Murad H.A. Aziz H.S. Soi. Beyond biodiesel, methyl esters as the route for the production of surfactants feedstock. INFORM 2Wf7, 18, 216—220. 

Figure 8.15 Thermogravimetric and derivative curves for biodiesel (methyl esters from soy oil).

Table I-E-4 shows physical and chemical properties for No. 1 diesel fuel. No. 2 diesel fuel, and a typical biodiesel made from soy oil (Canakci, 2005). The fatty acid composition (%) for the soybean oil used was C16 0, 10.5 C17 0, 0.11 C18 0, 4.76 C18 l, 22.52 C18 2, 52.34 C18 3, 8.19, C20 0, 0.36 unknown components, 0.48 % saturation, 16.3. The composition of the biodiesel methyl esters prepared from the soybean oil is similar C16 0, 10.56 C17 0, 0.11, C18 0, 4.74 C18 l, 22.51 C18 2, 52.39 C18 3, 8.22 C20 0, 0.44 unknown components, 0.44 % saturation, 16.3. As seen from table I-E-4, the biodiesel has similar properties to fossil diesel. Biodiesel has a greater viscosity and tendency to gel than conventional diesel fuel, which restricts its use at low ambient temperature unless sufficient heating of the fuel and engine components is provided.

The concentration of biodiesel (fetty acid methyl esters) and glycerides were analyzed by liquid chromatography (Shimadzu-lOA HPLC). An ODS-2 column (250x4.6mm) was used for the separation. The flow rate of the mobile phase (acetone acetonitrile=l l) was set to 1 ml/min. Peaks were identified by comparison with reference standards. Standards of methyl esters, monoglycerides, digjycerides and triglycerides were bought from Fluka. 

Experiments showed that high methyl ester yields can be achieved with solid bases and super acids under moderate reaction conditions. The solid bases were more effective catalysts than the solid super acids. High stability can be achieved by an ordinary inexpensive preparation process, and the catalyst can be separated easily from the reaction products in the heterogeneous catalysis process. The costly catalyst removal process can be avoided compared with the homogeneous process. Therefore, the heterogeneous process using a solid catalyst should be more economical for biodiesel production. 

In our first experiment we decided to test the conversion of sunflower oil into biodiesel (16). Treatment of sunflower oil (1) with NaOMe in MeOH results in formation of a mixtme of fatty acid methyl esters (FAME), also known as biodiesel, and glycerol (2) (Figme 4.3). The reaction was performed with a six-fold molar excess of methanol with respect to sunflower oil at elevated temperatures (60°C) using a basic catalyst (NaOMe, 1% w/w with respect to sunflower oil). The CCS was equipped with a heating jacket to ensure isothermal conditions. The sunflower oil was preheated to 60°C and was pumped at 12.6 ml/min into one entrance of the CCS. Subsequently, a solution of NaOMe in MeOH was introduced through the other entrance at a flow rate of 3.1 ml per minute. After about 40 minutes, the system reaches steady state and the FAME containing some residual sunflower oil is coming... 

Biodiesel may be represented chemically as a mixture of fatty acid methyl esters. It is a naturally derived liquid fuel, produced from renewable somces which, in compliance with appropriate prescriptions, may be used in place of diesel fuel for both internal combustion engines and for producing heat in boilers. The advantages, especially environmental, which can potentially result from the widespread use of biodiesel, are manifold ... 

The traditional catalyst used for esterification of acids to methyl esters is sulfuric acid. Homogeneous sulfuric acid catalysis has many downsides. When using sulfuric acid, much capital expense is required for Hastalloy and/or other specialty metals of construction. Homogeneous catalysis results in the contamination of the product by sulfur containing species. Therefore, neutralization and removal of acid is required to meet biodiesel specifications and to protect the downstream transesterification reactor. Inevitably, when using sulfuric acid, organic sulfur compounds will be produced. These products will cause the resultant biodiesel to fail specification tests. 

Fatty acid methyl esters (FAME) are currently manufactured mainly by trans-esterification with an alcohol, using a homogeneous base catalyst (NaOH/KOH). Methanol is more suitable for biodiesel manufacturing, but other alcohols can in principle also be used, depending on the feedstock available. The... 

Biodiesel (fatty acid methyl ester (FAME)) production is based on transesterification of vegetable oils and fats through the addition of methanol (or other alcohols) and a catalyst, giving glycerol as a by-product (which can be used for cosmetics, medicines and food). Oil-seed crops include rapeseeds, sunflower seeds, soy beans and palm oil seeds, from which the oil is extracted chemically or mechanically. Biodiesel can be used in 5%-20% blends with conventional diesel, or even in pure form, which requires slight modifications in the vehicle. 

In Europe, vegetable-oil-based fuels are mainly produced from rapeseed. In the USA, vegetable-oil-based fuels are mainly derived from soybeans. Another feedstock used in Europe and North America is sunflower seed. Most of the vegetable oil that is used as energy source for the generation of transportation fuel is converted to fatty acid methyl ester (FAME), often called biodiesel . 

Vegetable all methyl esters (biodiesel) Kinematic viscosity Cetane no. Lender heeling value (MJJkg) Cloud point l°C Pour point <"C) Flesh point fC) Denelly (kgfl)... 

The role of biocomponents in traffic fuel is increasing. The European Union Directive [1] on the promotion of the use of biofuels for transport purposes states that by the end 2005 traffic fuels should have contained 2% of components produced from renewables. The figure rises to 5.75% by the end of 2010 and up to 20% by the end of 2020. This directive defines biofuel as a liquid or gaseous fuel for transport produced from biomass, biodiesel as a methyl ester produced from vegetable or animal oil, of diesel quality, to be used as biofuel and synthetic biofuel as synthetic hydrocarbons or mixtures of synthetic hydrocarbons, which have been produced from biomass. The European Commission also encourages member states to lower tax rates on pure and/or blended biofuels, to the offset cost premium over petroleum-based fuels [1, 2]. 

Biodiesel is a mixture of methyl esters of fatty acids and is produced from vegetable oils by transesterification with methanol (Fig. 10.1). For every three moles of methyl esters one mole of glycerol is produced as a by-product, which is roughly 10 wt.% of the total product. Transesterification is usually catalyzed with base catalysts but there are also processes with acid catalysts. The base catalysts are the hydroxides and alkoxides of alkaline and alkaline earth metals. The acid catalysts are hydrochloride, sulfuric or sulfonic acid. Some metal-based catalysts can also be exploited, such as titanium alcoholates or oxides of tin, magnesium and zinc. All these catalyst acts as homogeneous catalysts and need to be removed from the product [16, 17]. The advantages of biodiesel as fuel are transportability, heat content (80% of diesel fuel), ready availability and renewability. The... 

Biodiesel can be produced from various oilseed-yielding plants like castor, cotton, jatropha, palm, rape, soy, etc. The straight vegetable oils (SVO), which can be derived by physical and chemical treatment (milling/refining), are then converted into fatty acid methyl esters (FAME), also known as biodiesel. Similar to ethanol, these routes are established and proven, and their costs depend heavily on two factors ... 

Fig. 13.3 Electronic absorption spectra of C60 fullerene dissolved in (A) brassica oilseeds methyl ester (biodiesel) (B) olive oil (C) sunflower oil (D) soybean oil (E) linseed oil (F) linseed oil and C60 fullerene after heating at 150°C for 15 minutes...

Crude oil Soybean oil Soybean oil methyl ester (biodiesel) Pyrolysis oil... 

Fig. 7 Gas chromatography of the fatty acid methyl esters in biodiesel. Reproduced from [46] by permission of Elsevier Press Table 2 Fatty acid methyl esters in biodiesel ...

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