Biodiesel is a long-chain fatty acid ester made from renewed and biological raw materials such as used cooking, animal fat, vegetable oil, and algae. Biodiesel is a renewable and clean fuel as it reduces carbon monoxide, carbon dioxide, hydrocarbons, and particulate matter emissions compared with petroleum-based diesel fuel. Production of biodiesel from renewable resources is done through the transesterification reaction at which the organic group (alkyl) of alcohol is substituted with the organic group of a triglyceride-the main component of the feedstock-producing fatty acid alkyl ester (biodiesel) and crude glycerol. Biodiesel can be used in pure form (B100) or may be blended with petroleum diesel at any concentration if its specifications is identical to the international standard specifications provided by American standard for testing materials (ASTM) or EN14214 in the European Union for alternative fuels. In this paper, the different types of biodiesel feedstocks, feedstocks treatment methods, and biodiesel production technologies are reviewed and discussed.

Silica and montmorillonite-supported silica nanoparticles were prepared via an acid one step sol-gel process. The synthesized solids were characterized using XRD, FTIR, TEM and N 2 adsorption. The effect of preparing temperatures on the structure and properties of the silica nanoparticles were studied. The results show that the increase of annealing temperature from 25˚C to 200˚C, don't change amorphous state of silica. While for montmorillonite-supported silica the clay platelets are delaminated during the sol-gel process. TEM results showed that the average particle size of silica is increased by increasing temperature due to the particle sintering and the clay-silica nanoparticles possessed core-shell morphology with diameter of 29 nm. The surface area measurements showed that by increasing annealing temperature the surface area was decreased due to aggregation of particle. The clay-silica sample showed lower average pore width than that of the silica prepared at 200˚C indicating that it has a macropores structure. The adsorption efficiency of the prepared samples was tested by adsorption of protoporphyrin IX. The highest adsorption efficiency was found for SiO 2 prepared at 200˚C. Temkin model describe the equilibrium of adsorption of protoporphyrin IX on caly-silica nanoparticles under different conditions.

No abstract

No abstract

No abstract