Introduction

The invention describes an efficient pre-treatment for the conversion of low quality vegetable oils, waste cooking oils, animal fats and not-edible oils, having a high Free Fatty Acids (FFAs) content, in an oily feedstock convertible into biodiesel through conventional route (basic catalysis). The process does not generate salty-waste with the alcoholic phase that can be recovered and reused.

Technical features

The present invention provides an efficient pre-treatment process for the conversion of oils with high FFAs content (1-90%wt) into biodiesel. This process allows to convert raw materials such as vegetable oils, cooking oils, animal fats and not-edible oils into a new oily feedstock convertible into biodiesel by conventional trans-esterification under basic catalysis (sodium and potassium hydroxide, carbonates and alkoxides). The use of hydrated-salts (soluble in alcohols) as catalysts, allows to carry out the reaction in homogeneous phase (the reaction is fast and complete as in the case of mineral acids), without contaminating the resulting oily phase, which could be trans-esterified without any further pre-treatments. At the end of the process, the catalysts were easily recovered with alcoholic phase and re-used for several further cycles of pre-treatment.

Possible Applications

• Production of biofuels (biodiesel);
• Recovery of oily matrices deriving from industrial and municipal wastewater;
• Recovery of cooking oils, animal fats and not-edible oils intended for disposal;
• Esterification of Volatile Fatty Acids (VFAs) for the production of bio-solvents.

Advantages

• Green methodology (absence of salty-waste);
• Simple and economical process;
• Low environmental impact;
• Easy recover and reuse of the catalysts;
• Lower plant management costs;
• Absence of further treatments of neutralization/purification of pre-treated oils.