i need someone to help me translate this to arabic please

Biodiesel

Biodiesel is the name given to a clean burning mono-alkyl ester based oxygenated fuel made derived from natural, renewable feedstock such as new/used vegetable oils, and animal fats. The resulting biodiesel is quite similar to conventional diesel in its main characteristics and can be blended in any proportion with petroleum diesel to create a stable biodiesel blend [1]. Among the biomass sources, vegetable oils and animal fats have attracted much attention as a potential resource for production of an alternative for petroleum-based diesel fuel. This alternative diesel fuel is termed biodiesel [1]. Vegetable oils occupy a prominent position in the development of alternative fuels although, there have been many problems associated with using it directly in diesel engines especially in direct injection engine [1]. These problems are associated with large triglyceride molecule and its higher molecular mass can be solved, if the vegetable oils are chemically modified to biodiesel, which is similar in characteristics to diesel [3, 4]. The unprocessed vegetable oil can be used in diesel engines, but with required engine adjustments and modifications. Unlike diesel fuel, vegetable oil consists mostly of saturated hydrocarbons and those of vegetable oils are triglycerides, consisting of glycerol and esters of fatty acids. The fatty acids vary in their carbon chain length and in the number of double bonds. To overcome these problems the neat vegetable oils have to be modified to bring their combustion-related properties closer to those of petroleum diesel. Biodiesel production from used cooking oil: During frying, vegetable oil undergoes various physical and chemical changes, and some undesirable and unknown compounds are formed. Some of these compounds are polymers which are cleaved, and during the transesterification reaction, they form monomeric and dimeric fatty acid esters. The oligomeric compounds formed during frying increase the molecular mass and reduce the volatility of the oil. Therefore, the fatty acid esters obtained from frying oils influence the fuel characteristics (such as increasing the viscosity and reducing the burning characteristics), leading to a greater amount of Conradson Carbon Residue. [1] The methods of production of biodiesel from used cooking oil do not differ from the conventional transesterification process using alkaline, acidic, and enzymatic catalysts. the type of transesterification selected is dependent on the FFA and water contents. A typical schematic diagram for the production of biodiesel from used cooking oil is shown in Fig1





Fig. 1. Schematic flow diagram of the bio-diesel production from used cooking oil


Biodiesel quality and properties from used cooking oil: The quality of biodiesel is divided for two groups, One group contains major parameters, which are also used for mineral oil-based fuel such as density, viscosity, flash point, CFPP, pour point, cetane number, and the other group especially describes the chemical composition and purity of fatty acid alkyl esters [5], Density is an important property mainly in airless combustion systems because it influences the efficiency of atomization. For comparison, the density values between 850 and 900 kg/ m3 are adopted by many national standards. The viscosity controls the characteristics of the injection from the diesel injector. High values of viscosity give rise to poor fuel atomization, incomplete combustion, and carbon deposition on the injector. Therefore, the biodiesel viscosity must be low. Flash Point is a parameter to consider in the handling, storage, and safety of fuels and flammable materials. High values of flash point decrease the risk of fire which is safe for transport purpose. Cold filter plugging point (CFPP) reflects the cold weather performance of a fuel. At low operating temperature fuel may thicken and might not flow properly affecting the performance of fuel lines, fuel pumps and injectors. Similar to CFPP is the cloud point and pour point respectively. Both parameters are often used to specify cold temperature usability of fuel oils. Cetane number is an indicator of the quality of fuel. It measures how easily ignition occurs and the smoothness of combustion. The higher the cetane number, the better is the ignition properties. Generally, it has been reported that biodiesel contains approximately 10% less energy when compared to petroleum-based diesel. This indicates that approximately 10 vol% more biodiesel would be required compared to petroleum diesel fuel for the travel of the same distance. The lower value is due to the presence of oxygen in biodiesel [1]. Some properties of biodiesel produced from selected UCO compared with petroleum diesel fuel are shown in the below table.


Typical diesel Biodiesel Property
UVOEEg UCO WCOMe/WCOEf WFPOd WMEb/WEEc WAIST PALM OIL WFOME WFOMEª
845 887.2 - 887/878 877.2- 888.2/854.8 873.7 888 890 Density at 15 °c (kg/m³ )
3.47 6.13 5.18 5.16/4.92 6.32 4.68/4.98 - 4.32 4.23 Kinematic viscosity at 40 °c (mm2 /s)
45 - - 39.26/39.48 39.87 37.27/40.72 39.31 39.55 - Heating value (mj/kg)
50 47.9 48 - 62 - - 52.0 54.5 Cetane number
>52 130 148 - 130 - 109 156 171 Flash point ( °c)
<10 10 -4 - 10 -3/-6 0 -2.5 - Pour point ( °c)
-5 10.7 - - - 1/-2 0 3 - Cloud point (°c)
- - - - - -6/-4 - - 1 CFPP (°c )

a Waste frying oil methyl ester.
b Waste fryer grease methyl ester.
c Waste fryer grease ethyl ester.
d Waste frying palm oil.
e Waste cooking oil methyl ester.
f Waste cooking oil ethyl ester.
g Used vegetable oil ethyl ester.

Performance and combustion and emissions: It was reported that the combustion characteristics of biodiesel are similar as diesel and blends were found shorter ignition delay, higher ignition temperature, higher ignition pressure and peak heat release. The engine power output was found to be equivalent to that of diesel fuel [1]. Since the purpose of transesterification process is to lower the viscosity of the oil. The main drawback of vegetable oil is their high viscosity and low volatility, which causes poor combustion in diesel engines, the transesterification process reduces the viscosity to a value comparable to that of diesel and hence improves combustion. Biodiesel emits fewer pollutants over the whole range of air–fuel ratio; it is biodegradable and non-toxic and has low emission profiles as compared to petroleum diesel. [1, 2], The characteristic properties of biodiesel are same as that produced from virgin oils and are generally similar to those of petroleum diesel fuel. The fuel properties of biodiesel derived from UCO, all met the various national biodiesel standards. Thus, biodiesel produced from UCO can be used in diesel engines without any engine modifications. Cost of Biodiesel: The cost of biodiesel is still higher than petroleum-based diesel and this has been the major hurdle to its commercialization; the high cost is primarily Due to the raw material, mostly neat vegetable oil [2]. By collecting used frying oils and converting them to biodiesel fuel, the cost of biodiesel is significantly lowered and the negative impact of disposing used oil to environment reduced