We most often hear about environmental issues in the context of production and transportation of crude oil. Its release to the environment can lead to soil degradation, water and atmosphere pollution. Due to great publicity certain steps are taken to address these problems, but the dangers of waste petroleum oil are not always spoken about openly. And this is despite the fact that every day there are thousands of liters of waste oil produced in the world.
What should be considered waste oil?
The general definition states that waste oil is mineral oil derived from crude oil or synthetic oil, which contains impurities and has lost its operational properties. In the course of operation the oil becomes contaminated and loses its characteristics over time. This product is not used for its intended purpose and goes into the category of waste products.
There are many sources of waste oil: transformers, turbines, automobiles, hydraulic drives, etc.
There are certain world standards by which oils to be recycled are classified (only the main points are listed):
- Used motor oil and lubricants of motor vehicles.
- Used industrial oils (turbine oil, electrical insulating oil, compressor oil, bearing oil, cable oil, etc.).
To avoid any confusion, these standards also provide a list of products that should not be considered waste oils. These include:
- Vegetable or animal fats.
- Substances contaminated with waste oil (for example, sorbents and metal scrap).
- Substances formed as a result of cleaning storage tanks for petroleum products.
- Natural fuel oil received from spills.
- Various solvents.
- Waste kerosene and antifreeze.
- Products that cannot be processed using the methods that are normally used for waste oil processing.
Some numbers
About 42 million tons of waste lubricating oil was consumed worldwide in 2010. Experts predict that by 2015 this figure should reach 45 million tons.
Table 1 shows the structure of different types of lubricants use.
Table 1
The structure of different types of lubricants usage.
|
№ |
Type of oil |
Share in total use, % |
| 1 |
Vehicle lubricants |
56 |
| 2 |
Hydraulic oil |
13 |
| 3 |
Process oil |
10 |
| 4 |
Other types of industrial oil |
11 |
| 5 |
Lubricant |
3 |
| 6 |
Industrial transmission oil |
2 |
| 7 |
Other |
5 |
According to preliminary estimates, about 16 million tons of waste oil is subject to uncontrolled draining, burning or other improper method of recycling worldwide annually.
Only about 50% (20 million tons) of waste oil is systematically collected.
What is the danger of waste oil?
Waste oil is most often classified as hazardous waste of 2nd or 3rd class, ie, highly hazardous or moderately hazardous waste.
In general, waste oil is even more dangerous than crude oil, because in addition to petroleum base it is composed of resins, carbenes, additives, polyolefins, mechanical impurities and other contaminants that have been accumulated during operation.
The negative impact of waste oil on the environment is reflected in pollution of water and soil, as well as carcinogenic and mutagenic effect. For example, when discharged to a pond, one liter of waste oil can contaminate up to one million liters of water.
How to recycle waste oil?
For the first time the process of waste lubricating oil processing was mentioned back in 1930. But it became more or less wide-scale only in the 1970s. Historically, the first method of reuse was combustion. Later, waste oil was subjected to special purification, after which it was added to fresh oil.
Burning without preliminary treatment. If waste oil is burnt without being purified, its combustion products can be released into the environment and the human body, which is unacceptable. Such processing is possible only in one case: when both oil and equipment used for its combustion is fully compliant with existing legal acts.
Processing in order to obtain fuel. This type of processing is used to obtain liquid fuels with a low content of sediment and water. This is necessary for the burners and tubes not to be blocked and for sludge not to be accumulated in tanks. This method differs from the previous one by the necessity of filtration to remove coarse solids. Usually, they are separated from oil by settling or passing it through special porous filters. These processes are not enough to remove all chemical contaminants. Therefore, in practice, distillation and bleaching clay treatment are also used.
On site recovery. This approach is typically used by plants or other large enterprises that produce large amounts of waste oil. Filtration system is used to remove harmful impurities directly on site. It is quite possible to extend the service life of oil with timely purification. GlobeCore CFU-type plants are used for this purpose.
Processing at refineries allows the use of waste oil in the process of crude oil refining to produce gasoline.
Regeneration with full recovery of properties. Application of SMM-R-type plants (only transformer oils) and UVR-type plants (transformer, turbine and industrial oils), produced by GlobeCore helps to recover the operating properties of waste oil to their normalized values, allowing their further use for the intended purpose.
Theoretically, service life of oil, in the event of timely application of regenerative processes, is almost unlimited, which makes this approach most preferable from both environmental and economic points of view. Especially considering the fact that energy consumption for regeneration is 70% less compared to obtaining commercial oils from crude oil.