Limited reserve of petroleum and its ever increasing prices necessitated development of alternative energy source which is renewable – and bio-diesel from plant sources appeared to be the most attractive.
Bio-diesel is produced by continuous transesterification of oil/fat with methanol using caustic soda as catalyst. The reaction takes place in two or three stages with subsequent washing, drying and polishing of the product.
The two-step reaction process of Fenix® converts nearly 100 percent of the triglycerides in the oil or fat to bio-diesel (methyl ester). The excess methanol is recovered, and the bio-diesel dried in the same step.
Glycerine generated in the transesterification reaction is recovered and neutralized. The excess methanol is recovered and the glycerine dried in the same step. The glycerine is crude because it contains greater than the maximum 0.01 percent salts allowed in technical grades and is less than 99 percent pure. Some salts are formed during the reaction step. These are removed when the glycerine is distilled or refined to a technical grade or higher quality.
Water recovered from the wash decanter, strippers, and methanol distillation is reused for washing the bio diesel and diluting the acid and caustic. The excess methanol is recovered from the bio-diesel, glycerine, and fatty matter it is dried and reused in the reaction. Fenix uses it own structured packing and columns for effective distillation of methanol.
A small amount of fatty matter, typically mono- and di-glycerides, is generated in the reaction. This fatty matter does not require a separate recovery system because the small quantity generated can be skimmed off or decanted from the glycerine storage tank.
Fenix design minimizes the energy required by using gravity both for separation and flow from vessel to vessel. The design incorporates heat economizers to cool one stream while heating the other.
Removing the phosphorus and fatty acids is critical to producing the highest quality bio- diesel for the lowest cost of production. Phosphorus and fatty acids are inhibitors to the reaction and increases the processing cost. Refined & bleached oil is the most suitable raw material for the process.
