Cooking oil is widely used in homes, bars and restaurants in the preparation (frying) of food; but after a while of use, it loses its properties and goes through a process of rancidity, becoming unfit for use. Many people are still unaware of the risks that the improper disposal of oil causes, these risks range from water, air and soil pollution to the appearance of pests and diseases and the increase in water treatment. But there are ways to add value to used oil through life cycle assessment, recycling and the circular economy, re-inserting it as a raw material for the production of soap, biodiesel and paints, thus preventing its inappropriate disposal. It is in this context that the theme of the present work enters, which aims to add value to a residue, which would be inappropriately discarded, for the production of bar soap on an industrial scale, generating employment and income and avoiding environmental impacts. With this in mind, a recycling unit was proposed, mass and energy balances were calculated and an economic analysis was carried out to arrive at the unit cost of the product. Due to the Covid-19 pandemic, it was not possible to carry out experiments in the laboratory, so the values were taken from articles and explanatory videos and then adapted to the industrial scale; with the adaptations made, it was possible to estimate a daily production of 552 kg of soap, being packaged in 200 gram molds, with this it was possible to estimate a daily production of 2760 bars. Despite being something that already exists, it is very important to implement an oil recycling unit so that people are aware of the negative impacts of improper disposal and that it is possible to add value to a food waste. ; O óleo de cozinha é muito utilizado em residências, bares e restaurantes no preparo (fritura) de alimentos; mas após um tempo de uso, este perde suas propriedades e passa por um processo de rancidez, ficando impróprio para o uso. Muitas pessoas ainda desconhecem os riscos que o descarte inadequado do óleo provoca, ...