Restaurants and households generate significant amounts of waste edible oil every day, which requires its careful disposal. On the other hand, as global energy needs grow and non-renewable resources are used up, the path to renewable energy sources seems like an inevitable option. The burning of fossil fuels also releases harmful gases into the atmosphere and thus contributes to environmental pollution. The alternative to this unsustainable principle of energy production lies precisely in the utilization of waste edible oils. Today, waste edible oils represent a key raw material for the production of environmentally friendly fuel - biodiesel.

Biodiesel offers a promising alternative to fossil fuels, boasting advantages such as renewability, reduced emissions of harmful gasses and waste quantity reduction. Waste edible oil, which is often considered an environmental challenge, is emerging as a valuable resource for biodiesel production at a time of drastic increases of raw oil prices and great needs for a sustainable and environmentally friendly alternative.

Biodiesel has several significant advantages compared to petroleum-derived diesel:

• Use of raw materials for production from recycled sources;
• Energy efficiency;
• Reduction of global warming and emissions of harmful gases;
• Non-toxicity and biodegradability;
• Potential to clean fuel lines and tank deposits due to solvent properties;
• Lower sulphur emissions, which helps reduce acid rain;
• Faster decomposition in the environment, mitigating the consequences of spills compared to raw oil.

However, biodiesel also has a certain smaller number of limitations in its application:

• Approximately 8% lower energy content per gallon compared to conventional diesel;
• Risk of softening, degradation and cracking of certain engine parts. The penetration of biodiesel into the molecular structure of hoses and seals can cause them to leak and dissolve. Accumulations of hard deposits can form on fuel injectors and piston rings. Service intervals for changing the lubricating oil and oil filter are shorter due to the property of biodiesel to dilute the lubricating oil;
• Incompatibility with certain metals and plastics.

The association of citizens Ekosol with its project "Used edible oil - energy resource" stands out as an innovative example of good practice in this domain. This initiative is part of the three-year project "Think about nature" implemented by the Centre for the Promotion of Civil Society, whose main goal is to increase the influence of civil society in environmental protection.

The motivation behind this idea is based on the effort to actualize the collection of used edible oil, its processing into biodiesel, as well as the initiation of a law that will introduce the obligation of companies, restaurants and households to collect used edible oil, but also in highlighting positive examples of socially responsible companies in Tuzla Canton.

The main partner in this project was the company Bingo Ltd Tuzla, and the direct beneficiaries who participated were Majevica JSC Corn Flips Srebrenik and restaurants Barok, Sezam, Sedra and MamaMia from Tuzla. During the implementation of the project, barrels were procured for companies that participated in the project and expressed interest in collecting the used edible oil.

As part of this project, a presentation and survey of the citizens of Tuzla, Srebrenik and Gradačac was also carried out regarding the use and disposal of used edible oils and the consequences of inadequate disposal of the same. Among other things, this survey revealed that 74% of respondents do not know what happens to used edible oils after use in restaurants, but also that even 92% of respondents would take the collected oil to the designated places if it existed in their city. This really showed the great interest of citizens in the application of such ideas.

The main achievements are:

• as much as 17.2 tons of collected used edible oil in just 6 months;
• broadcast of 4 educational and promotional shows on the mentioned topic of biodiesel production from used edible oils;                      
• familiarization of relevant institutions with the problem of inadequate disposal of used edible oil; 
• Processor for the process of biodiesel submitted initiative to introduce the collection of used edible oil into the Federal Waste Management Plan from 2021 – 2027;
• established cooperation with socially responsible companies that collect used edible oil, but also with the producer of processors and presses - independent craft shop (SZR) "IN PAK" from Banatski Karlovac. The owner of SZR "IN PAK", which is engaged in the production of plants for the production of biodiesel from used edible oil, showed great interest in this idea, and cooperation between this company and the company Bingo Ltd tuzla was agreed regarding the procurement and installation of one plant - a processor for the processing of used edible oil into biodiesel.

As a plan for the sustainability of this project, from the association "Ekosol" the following is stated: "It is envisaged that the company Bingo Ltd., with the permission of the Federal Ministry of the Environment, takes over and continues using edible/waste oils from the companies that participated in the project. However, the main challenge in the implementation of this activity is the storage of certain used edible oils, i.e. the characteristic of the high crystallization point of biodiesel from waste oil (from -6 to 12 °C), which can be improved to some extent by adding dedicated additives for biodiesel or by mixing with fossil diesel or by focusing on sunflower waste oil that does not have these obstacles."

However, the Association Ekosol did not find a complete understanding of the environment, considering that plans for the organized collection of used edible oils require certain funds. According to the Association, ideas for the future can go in the direction of cooperation with PC "Vodovod i kanalizacija" Ltd Tuzla. In this way, the problem of huge amounts of used oils that end up in sewer systems and create huge lumps that can lead to clogging and bursting of sewer pipes would be solved. Therefore, it is very important to point out that the constant support of the government is of vital importance for the further progress of such initiatives.