Regeneration technology of waste rolling oil

December 27, 2023

Regeneration technology of waste rolling oil

For metallurgical industries such as aluminum processing, rolling oil has the function of cooling, annealing decontamination and lubrication. Under the action of high temperature and high pressure, the effect of annealing decontaminating can improve the cleanliness and accuracy of the processed surface, the use of lubrication can effectively reduce the surface friction, improve the stability of rolling, improve the quality of metal products, and cooling can take away a lot of heat generated by rolling, reduce roll wear, so that mechanical equipment can work normally. The main component of rolling oil is Base Oil, which can be mixed with various additives to improve the rolling oil quality.

First, the significance of rolling oil regeneration

In the rolling process, under the condition of high temperature and high pressure, the additives and the base oil may appear aging, pollution and other problems, in these processes, the base oil and the additives because of oxidation, isomerization, polymerization and other reactions and lose their effectiveness at the same time. At the same time, the mechanical equipment is worn, and the metal particles and dust generated by it will enter the rolling oil, which further aggravates the rolling oil pollution. After the pollution and aging of rolling oil, it produces low molecular weight compounds, these compounds are called sludge or colloids, the physical and chemical properties of rolling oil will also have serious changes, and its lubrication performance is greatly reduced and can not continue to be used, otherwise it will cause further damage to mechanical equipment.

This part of the rolling oil that can not be used is called waste rolling oil, but in view of the fact that a large number of oil fields in China have been developed, the cost of oil production is increasing, the oil production has declined, and the oil consumption is increasing, in this case, if these waste rolling oil can be reused in the production of metallurgical industry, it can improve the utilization rate of resources and alleviate the problem of tight oil resources. At the same time, considering that the characteristics of waste rolling oil are different, which contains different chemical additives, if it is discharged without any treatment or inappropriate treatment, it will aggravate the problem of environmental pollution.

At present, the main treatment methods for waste rolling oil include: It is directly discharged into the wastewater system, soil or garbage, but in this way, when the waste oil enters the sewer and the sewage is mixed, it will flow into rivers and lakes together with the sewage, and be discharged into the soil. In addition to the microbial decomposition, a large number of other waste oil is washed into rivers and lakes by rain, causing extremely serious damage to the soil and water resources. Most of the waste oil also contains chlorine, sulfur, phosphoric acid and other organic compounds and polycyclic aromatic hydrocarbons, while containing a large number of heavy metal additives, once absorbed by the human body will cause extremely serious harm.

Other ways are directly burning waste oil as fuel in the combustion furnace, using it as fuel after heavy metal removal treatment, and extracting base oil from waste oil, which will be recycled after recycling. Among them, the extraction of base oil from waste lubricating oil and the use of recycling technology to convert waste oil into usable resources after proper treatment not only improve the utilization rate of resources, but also with the increase of the scale of recycled waste oil, the yield continues to increase, the cost continues to decrease, and modern production technology and equipment are more applicable, which is of great significance for promoting the development of society and the environment.

Ii. Overview of rolling oil regeneration

Due to the lack of petroleum resources in China, waste rolling oil can be recycled into metallurgical production after proper treatment, which not only reduces environmental pollution, but also improves resource utilization rate and reduces cost for enterprises. In recent years, China has been advocating the recycling of waste oil, and has also formulated relevant policies and laws and regulations. However, due to the lack of mandatory and punitive policies, the operability of lubricating oil recycling is low, and the implementation of waste lubricating oil recycling in various regions is different, and the recycling methods are different. At present, most metallurgical enterprises for the application of lubricating oil recycling process, mainly using distillation purification, hydrogenation process technology, but the recovery of waste oil market is not clear, waste oil recycling prospects are uncertain.

Most of the domestic waste oil regeneration is cracked into fuel oil after high temperature, which greatly reduces the quality of lubricating oil, and also causes environmental pollution in the process of recycling because of the non-standard production process and operation. The price of waste oil will also increase due to the irregular market competition, which makes the waste lubricating oil recycling process of some metallurgical production enterprises lack of sufficient raw materials, which is not conducive to normal production and operation. Therefore, the recycling of waste lubricating oil needs to go through long-term construction and exploration, is a systematic, long-term comprehensive project, and also needs the cooperation of various departments of the enterprise.

At present, the main technologies used for waste rolling oil regeneration include conventional unit operation, acid-clay process, distillation - clay process, distillation - hydrogenation process and membrane separation technology. Among them, the physical methods commonly used in conventional unit operations are filtration, sedimentation, centrifugal separation, water washing, adsorption, distillation, and chemical methods include flocculation, hydrogenation, etc. Sedimentation is the easiest way to effectively remove moisture and mechanical impurities from the waste oil and is often used as the first step in the recycling technology route. Centrifugal separation is the use of oil and impurity density difference separation, filtration is through the external force to make the liquid all through the filter medium, so that the solids and large particles in the suspension are trapped in the filter medium to achieve the effect of solid-liquid separation.

Distillation process is based on the different boiling point differences of different compounds to achieve separation, distillation can not only remove the waste oil in the water, light hydrocarbons, asphaltene, gum and additives and other impurities, but also can separate different base oil fractions, waste oil after pretreatment through the distillation process, so that the oil itself becomes clear and transparent, good quality. The hydrogenation process is generally the last step in the waste oil recycling treatment, but the hydrogenation unit is easy to leak or even explode under high temperature and pressure conditions, and there are more safety problems, and the requirements for design, installation, maintenance and maintenance are higher, and it is generally only applied in the waste oil recycling plant with a large scale and enough waste oil sources.

Acid clay process is a more traditional waste oil regeneration process, its biggest disadvantage is that the quality of recycled waste oil is poor and the regeneration rate is low, and the demand for sulfuric acid and clay is large, improper operation will produce a lot of waste gas, not only lead to resource waste but also cause environmental pollution, so this method has been abandoned. Distillation - hydrogenation process, mainly through distillation to remove the light hydrocarbons and water in the waste oil, but also can divide the regenerated base oil into different fractions. Finally, the undesirable part of the waste oil is removed by hydrogenation process, and high quality recycled oil is obtained by hydrorefining, flash evaporation, drying and other processes.

Three, rolling oil regeneration technology principle

The principle of rolling oil regeneration is that according to the properties of each component of rolling oil, the solution in the mixture is separated from the solute by vacuum distillation, and the gum, particles, asphaltene and oxidizing compounds in the waste rolling oil are extracted in time to achieve purification, separation and purification. After separation and purification, the rolling oil is re-used in metallurgical production, which not only improves the utilization rate of resources, but also has very important significance for improving production efficiency and economic benefit of enterprises.

Author:

Mr. James

E-mail:

sales@cn-lubricantadditive.com

Phone/WhatsApp:

+86 13783582233