How to Make Diesel Fuel from Used Motor Oil?
Used motor oil is the main waste produced mostly by the automotive and industrial sectors. The annual production of used motor oil is more than 25 billion gallons. However, it is a known fact that only 60% of the total waste generated is handled in a proper way via recycling or disposal methods. The remaining amount is dealt with in an improper way.
One method of problem confrontation is the conversion of used motor oil to diesel oil, which can be achieved through a process called pyrolysis. Pyrolysis is an endothermic process, i.e., thermal decomposition in contrast to the way it usually occurs in the presence of oxygen. Among the different products obtained, diesel oil is one.
The process of converting waste motor oil into diesel fuel is accompanied by various advantages. First, it minimizes the total waste to be disposed of; second, it cuts down on fossil fuel consumption. Third, it yields a fuel that is cleaner and less harmful to nature compared to conventional diesel fuel.
Understanding the Pyrolysis Process
There are different ways to conduct the pyrolysis process. The usage of a batch reactor is one of the most common ways. Used motor oil is heated to a very high temperature, usually between 400 – 600 degrees Celsius, which is the temperature at which the batch reactor operates. Then the oil is kept at that temperature for 1-2 hours. The oil cracks during that time into various products, one of them being diesel fuel.
Once the pyrolysis process has been done, the products are cooled and then condensed. From the condensed products, the diesel fuel can be isolated by employing various methods, such as distillation or centrifugation.
What Kind of Equipment Is Required in the Pyrolysis Process?
To convert waste motor oil into diesel fuel, one must have such equipment:
- Pyrolysis reactor
- Condenser
- Separator
- Safety system
A pyrolysis reactor is the container where waste motor oil is subjected to heat and undergoes decomposition. The product of the pyrolysis process is cooled, and the condenser changes it into liquids. The separator’s role is to obtain the diesel fuel from the remaining products of the pyrolysis process.
The safety system is very important in eliminating accidents. It has to be equipped with temperature and pressure sensors, as well as a gas detection system.
Process Steps of Pyrolysis
The steps below are followed in the process of manufacturing diesel fuel from used motor oil through a batch reactor:
- Prepare the used motor oil. The used motor oil should be filtered to eliminate all impurities that may be present in the material to be pyrolyzed. Water should be removed to prevent foam formation in the oil during the pyrolysis process because it will be difficult to control the pyrolysis process by handling foamy materials.
- The used motor oils must then be transferred to the reactor. The reactor is then filled with the used motor oils, leaving space that consists of about 10% of the volume.
- Close the reactor and begin the heating procedure. Heat the reactor up until the optimum pyrolysis temperature of between 400-600 degrees Celsius.
- Hold the pyrolysis temperature for the specified duration. The duration of the pyrolysis will differ based on the used motor oil type and the needed diesel fuel yield.
- Reactor cooling and product condensation. After the pyrolysis operation, cool the reactor and the products will be condensed by the condenser.
- Isolate the diesel fuel from the other products. Employ the separator to isolate the diesel fuel from the pyrolysis process’ remaining products.
What Safety Precautions Should be Taken?
The course of making diesel fuel out of used motor oil necessitates the implementation of safety measures. The whole pyrolysis scenario is a potential source of danger in case of any mismanagement.
The precautions listed below must be observed:
- Personal protective equipment (PPE) should always be used in the case of handling used motor oil and pyrolysis products. PPE incorporates gloves, goggles, a respirator, and a fireproof apron.
- Product of pyrolysis can be a source of unpleasant odor and even a little bit toxic; therefore, work should always be done in a well-ventilated area.
- Leave the reactor for pyrolysis never unattended. The entire pyrolysis can be unpredictable, and it is very fast to respond to any kind of problem.
In the case of a fire, have a fire extinguisher ready.
How is Product Yield?
The yield of diesel fuel from used motor oil will vary depending on the type of used motor oil and the pyrolysis conditions. However, in general, the yield of diesel fuel is typically in the range of 50-70% of the weight of the used motor oil.
Conclusion
The process of converting used engine oil into diesel fuel is not only a method to cut down the used oil’s negative influence on the environment but also to save the non-renewable resource. There are different methods to perform the pyrolysis process, among which batch reactors are the most frequent ones applied. The production of diesel fuel from used oil necessitates the adoption of safety measures because the pyrolysis process if not properly managed could be quite hazardous.
In case you want to know more about the process details of converting used oil into diesel, Purepath, the professional manufacturer of used oil recycling plants in China, will be able to answer you expertly.
