Recycling of waste cooking oils to produce biofuel

Recycling of waste cooking oils is increasingly being carried out to produce biofuel. Opportunities for businesses and consumers to recycle used cooking oil (“yellow grease”) have increased due to the price of waste cooking oils (WCO), which is 2–3 times cheaper than virgin vegetable oils.

A significant advantage is that, biofuels derived from waste cooking oil typically burn clean, have low carbon content and do not produce carbon monoxide. This helps communities to reduce their carbon footprints (there was on average of a decrease of 14% for CO2, 17.1% for CO and 22.5% for smoke density when using biodiesel from recycling of waste cooking oils.).

The recycling of cooking oil also provides a form of revenue for restaurants, which are sometimes compensated by cooking oil recyclers for their used deep fryer oil. However, the optimum conditions for biodiesel production (methanol/oils ratio and concentration of catalyst) are inconsistent. They strongly depend on the properties of WCO.

The processes of such oils and fats pose a significant challenge because of their disposal problems and possible contamination of the water and other resources.

The chemical properties of waste cooking oil and produced biodiesel are very important factors for using the biodiesel in industrial sector.