Today, the problem of waste oils is quite acute and requires effective ways and approaches to its solution. To understand the whole scale, it is enough to cite only one fact: the amount of waste oil that is discharged into reservoirs and soil substantially exceeds the amount of these substances entering the environment during accidents. Equally important is the financial aspect. The high cost of lubricants makes them at least partial regeneration expedient and justified. Purification and regeneration technologies significantly extend the service life of petroleum oils. For example, transformer oil purification are restored and sold through a distribution network, and then again poured into gearboxes. There is also the use of recycled oil in the form of fuel oil.
The origin of the used oil also has a great influence on the disposal method. For example, emulsions for aluminum rolled products are cleaned directly at metallurgical plants and are reused there for their intended purpose.
In the General case, the methods of disposal of waste oil can be divided into several groups:
- extension of the service life of the waste oil directly at the place of operation;
- partial improvement of lost functions with extended life;
- the use of waste oil as an additive to the feedstock in the preparation of new commercial products at refineries;
- regeneration of waste oil. The advantage of this method of disposal is the possibility of its repetition. Experts point out that it is regeneration that is the ideal option for restoring used oils to their original condition. This allows you to achieve maximum savings of oil resources;
- dehydration. This method of disposal is the removal of water from waste oil and its subsequent use as a coolant. In fact, it is burning dehydrated waste oil for heating industrial and residential premises. Since this type of recycling is one-time in nature, it is not very progressive. But the undoubted advantage of this approach is in obtaining and generating low-cost thermal energy;
- thermal cracking. The use of this process does not allow the recovery of oil. In this case, the waste product is converted into fuel, which is very similar in properties to diesel oil. The scope of such raw materials – mainly domestic needs, including space heating. Cracking is also considered a good option for disposal, as it allows up to 85% of the initial quantity of raw materials to be obtained;
- physical and chemical methods of disposal. This group of methods includes many ways. Consider the most common.
Coagulation is the precipitation of various impurities dissolved in oil. To ensure the binding of garbage particles are used special substances – coagulants. This approach requires strict support for a certain temperature regime, the dosage of the reagent, as well as intensive mixing of the oil. In the general case, half an hour is enough to settle the impurities during coagulation, after which the oil product is purified by settling, separation or filtration.